Archaeological micromorphology in Latin America: an overview

Micromorphology helps to reveal fundamental aspects of archaeological sites and landscapes that are invisible to the naked eye. Apart from discerning human contributions from patterns of natural sediment/soil formation, deposition, and alteration, this technique, coupled with others, has been able to showcase specific human activities hidden in the archaeological record. Over the last couple of decades, micromorphology has slowly entered the realm of archaeological techniques in Latin America and neighboring regions. From a late start in the mid-1990s, micromorphological studies have begun to occupy a central role in geoarchaeological research in the region. In this paper, we review 166 scientific papers published until July 2026. Our goal is to summarize the archaeological contexts and problems that led to the introduction of micromorphology in the geoarchaeology of Latin America and related regions (e.g., the Caribbean), from human-environment interactions, through others such as caves and rockshelters and coastal shell-matrix sites, to activity areas, offering an overview of the state of the art and future directions.

Archaeological micromorphology has become a critical analytical tool in global archaeological research, enabling the high-resolution study of site formation processes, activity areas, and environmental contexts through the microscopic examination of soils and sediments. It plays a central role in current geoarchaeological research, offering insights into domestic behaviors, combustion features, paleoenvironments, and stratigraphic integrity. Regions with extensive micromorphological application include the Near East, Europe, and Africa, especially in cave and rockshelter contexts linked to Paleolithic occupations, where pioneering work took place, initiating a growing wave of micromorphological research in archaeology worldwide. In Latin America, the earliest application of archaeological micromorphology can be traced to the 1990s, with Taulé's study of the shell middens in Tierra del Fuego, Argentina (1996) and Hansen’s (1996) observation of Mayan plasters, both conducted seven years after the publication of the seminal work by Courty et al. (1989). Subsequently, the technique was applied both in Guatemala and Mexico by Houston et al. (2003) and McLung de Tapia (2003), respectively, initiating a long tradition of micromorphological analyses for the study of earthen architecture and paleosols. In South America, Goodman-Elgar’s (1999) study in the Bolivian Andes, and Ruivo et al.'s (2004) early encouragement to use micromorphology in the research of Amazonian Dark Earth were followed by several others, further expanding the application of this technique to a wide array of archaeological contexts. In the following decades, micromorphology gradually gained traction in geoarchaeological research across a broader range of archaeological contexts in Latin America, including paleosol analysis, earthen architecture, shell middens, caves and rockshelters, among others.

In this review, we focus on geoarchaeological research that uses soil and sediment micromorphology to address landscape-scale dynamics and site formation processes, setting aside other aspects of the field, such as raw material procurement analysis. Only studies published in scientific journals, books, and book chapters were included; grey literature—such as academic or commercial reports, theses, and dissertations—was deliberately excluded. The geographical scope of this review encompasses Latin American countries, but it also includes non-Latin American territories that are archaeologically or culturally integrated within the region from Mexico to Tierra del Fuego, such as French Guiana and the Antilles.

Throughout the paper, we have adopted a consistent terminology following Stoops (2003, 2021), despite differences in nomenclature found among the sources (e.g., Brewer, 1964; Bullock et al., 1985; Stoops 2003),. Review or introductory papers and chapters relevant to the themes and regions considered here were cited when available. However, only literature employing micromorphological analysis was examined in detail, with other geoarchaeological contributions beyond this methodological focus left outside the scope of this synthesis.

In the following sections, the reviewed literature, published until July 2026, is organized according to the main type of context, deposit, or human impact analyzed. In grouping the references under sections (e.g., shell-matrix sites, past agriculture, etc.), the author(s)’ objectives were the primary criteria considered. For instance, in sites where site formation processes were tackled alongside paleoenvironmental issues, the site type was used as a grouping factor. This worked as a guiding strategy to navigate the frequently overlapping themes. A north-to-south order for the presentation of the study cases is followed. A specific section is destined to other geoarchaeological works.

Apart from the literature review, we performed basic quantitative descriptions of the resulting compilation. While time series were plotted for the whole period under analysis, a lollipop plot was made to showcase frequency of studies per country where they were executed. This also took into account works dealing with more than one country or region, in which case they were counted for every one of them. To address the importance of the specific themes under which the review is arranged, bar charts were performed. These charts were also used to depict the local or non-local character of the researcher and institution who carried out the studies. All graphics were executed using RStudio (Posit team, 2025).

Finally, a brief discussion is made, and perspectives for future micromorphological work in the region are introduced in the last section.

Human-environment interactions: paleoenvironments and human occupation

The interpretation of the insertion of archaeological sites and materials in the wider landscape through time has been the main focus of geoarchaeological research worldwide since its beginnings. Micromorphology has been used in tandem with paleoenvironmental/paleoecological proxies to decipher the natural conditions and processes shaping contexts occupied by people at different scales (French, 2003).

Micromorphology has been a fundamental tool for unraveling the paleoenvironmental setting of the first human occupations of Mexico, the northernmost region of Latin America. In the Sonoran Desert, Northwest Mexico, red and gray paleosols covering the Late Pleistocene/Early Holocene transition register Clovis-age (∼13,000 cal BP) artifactual and megafaunal assemblages (Cruz-y-Cruz et al., 2015). Micromorphology revealed clay accumulation and illuviation in the paleosols, indicating humid stable phases at the onset of the human occupation. The presence of carbonate spar and micrite-rich matrixes and coatings/hypocoatings suggests increasing aridity towards the Middle Holocene (Cruz-y-Cruz et al., 2015; Ibarra et al., 2018). Mexico's volcanic central highlands, at more than 2000 masl, where the country's capital city and former Lake Texcoco sit, present evidence of early occupation. Hunter-gatherers arriving in the Valley of Teotihuacan, in the northeastern sector of the Basin of Mexico, would have witnessed Late Pleistocene humid unstable conditions with fluvial sedimentation of volcanogenic materials (as revealed by micromorphology), with swampy areas in low topographic settings, according to sedimentary and paleosol sequences (Sedov et al., 2010; Solleiro-Rebolledo et al., 2006, 2011). In Tlaxcala, to the southeast, the analysis of toposequences has revealed a transition from late glacial unstable cold conditions to more humid, well-drained, fluvially dynamic landscapes in the early Holocene, as seen, among others, in pedofeatures (Solís-Castillo et al., 2012).

The initial peopling of the Andes has been the target of recent micromorphological research. In Colombia, paleosol/sedimentary sequences in the highland plateaus (∼2600 masl) register human occupations dating back to ∼11,745 cal BP, amidst overall dry/cold conditions with the deposition of vulcanogenic colluvial sediments (Triana et al., 2025; Triana-Vega et al., 2020). Illuviation and redoximorphic features have been interpreted as the result of more humid and warmer conditions towards the early Holocene, when human occupation was more intense (Triana-Vega et al., 2019). Moreover, in archaeological sites of this region, micromorphology proved fundamental not only to making paleoenvironmental inferences, but to showcase the presence of microcharcoal and bone fragments in Late Pleistocene layers previously interpreted as sterile (Triana-Vega et al., 2019).

In the tropical sector of central and eastern Brazil, the detection of open-air primary assemblages linked to early hunter-gatherer occupations has been considered challenging due to thick soils and intense post-depositional processes. In a study conducted by Araujo et al. (2013) in the karstic region of Lagoa Santa, which combined micromorphology with artifactual/charcoal data, grain-size and dating methods, this long-held view was put to test. The analysis of a catena on a slope next to a lake revealed the presence of viscous porphyric and vesicle-rich lateral colluvial flows succeeded by pedogenetic processes, the latter coinciding with archaeological occupation surfaces, the first of which dates back to the Early Holocene. Following a similar methodological approach, alongside a slope leading to a lake in southeastern Brazil, Araujo et al. (2017) documented sequences (bounded by unconformities) of microlaminated soil aggregates transported by low energy sheetwash and further slightly altered by pedogenetic processes. This dynamic helped preserve the horizontal surfaces in which the archaeological materials were deposited since ∼10,500 cal BP. In an alluvial setting in the same region of Brazil, Cheliz and Giannini (2020) and Cheliz et al. (2021) also found sediment/paleosol successions linked to possible human-occupied surfaces since, at least, an Early Holocene humid phase, by analyzing thin sections and other parameters in excavations and soil profiles. In another fluvial context in southeastern Brazil, an extensive stratigraphic and chronological analysis of a previously purported Late Pleistocene site allowed for its repositioning as a younger one (Araujo et al., 2022). Here, micromorphology showed the presence of microdebitage and charcoal as well as the different intensities of bioturbation-related processes in these sandy tropical soils.

In southern South America, micromorphology was applied to study two stratigraphic sequences at the Monte Verde site, southern Chile, one of the earliest known human settlements in the Americas (Dillehay et al., 2015). At the Monte Verde I and Chinchihuapi sites, the method was instrumental in verifying the stratigraphic integrity of the deposits and in confirming the reliability of the ages obtained by optically stimulated luminescence for archaeological layers with ephemeral human activity (∼18,500 and 14,500 cal BP). At the Pleistocene-Holocene transition, Ozán et al. (2019) apply micromorphology to understand the fine-scale sedimentary and biological dynamics within two volcanic cave sites in Southern Chile (Baño Nuevo 1 and Cueva de la Vieja) occupied by hunter-gatherers. The authors identified microstratigraphic features linked to biological activity, organic matter content, and cave weathering patterns—factors that reflect temperature and humidity shifts over a 19,000-year sequence. The method enabled the differentiation between anthropogenic and natural inputs, distinguishing human activity from broader climatic processes (e.g., deglaciation, the Pleistocene-Holocene transition, and Holocene environmental shifts).

Paleoenvironments of the early to middle/late Holocene transition, a period that encompasses hunter-gatherer settlements and pre-agricultural sites, have also been an important topic of geoarchaeological inquiry. In the mountainous central-eastern Mexico, Ferrand et al. (2014) reported phases of landscape stability potentially beginning in the early Holocene and interrupted by volcanism ca. 4000 cal BP, were inferred through illuviation features and other proxies in paleosols.

In the Colombian highlands, arid phases have been identified in thin sections (e.g., in pedogenic carbonates) from the Middle and early Late Holocene layers of two archaeological sites (Triana-Vega et al., 2019). While some sites from this region and period exhibit gaps in sedimentation, other sites show, at the macro- and- microscopic level, plant and animal management related to changes in subsistence practices.

A particular focus of geoarchaeological research concerns the interaction of Middle/Late Holocene environmental changes and the emergence/decline of urban centers in Mesoamerica (García et al., 2019). This vast cultural area encompasses central and southern Mexico and the Pacific coast of Central America until Costa Rica.

The development of the first Maya polities (which occupied southern Mexico and parts of Central America) took place under changing climatic conditions during the Preclassic or Formative period (around 5,500 cal BP), as indicated by micromorphology and other proxies (Solís-Castillo et al., 2013, 2015). In the Yucatán Peninsula, a large carbonate platform with karst depressions, lakes and hilly areas, swampy but less flooded-than-today Preclassic conditions were revealed in thin section, with clayey groundmasses, redoximorphic features, and neoformed minerals (Leonard et al., 2019). This would have allowed the development of widespread agricultural practices by the early Maya centers (see Section 3.2). Micromorphology also records the formation of biogenic micritic muds linked to the flooding of wetlands during the Late Holocene, which would have stimulated other economic practices during the Postclassic period (Leonard et al., 2019; Wollwage et al., 2012).

Volcanic activity has also been linked to settlement abandonment and other impacts on Mesoamerican societies. In Central Mexico, colluvial events triggered by earthquakes and volcanic eruptions, which led to dark sediment deposition and the collapse of buildings, were macro- and microstratigraphically documented in archaeological sites (Solleiro-Rebolledo et al., 2021). Here, micromorphology has been a fundamental tool to showcase the presence of the highly unstable volcanic ashes within sediments, including fills in buildings (García-Zeferino et al., 2024; Solleiro-Rebolledo et al., 2021).

A major topic of human-environmental research in the coastal Pacific areas of South America concerns the impact of El Niño Southern Oscillation (ENSO). A geoarchaeological survey (which included micromorphology) by Beresford-Jones et al. (2009), alongside an abandoned river terrace in the today-depopulated southern Peruvian desert, revealed a buried soil surface and archaeological features and artifacts dating back to at least the Early Intermediate period (1 BCE to 500 CE). An ENSO flooding event seen in fluvial deposits at the end of this period, although devastating, did not involve the immediate abandonment of the area and was not the only cause of landscape change, as human-induced forest removal for agriculture would have also triggered the exposure of surfaces to eolian deflation. Further micromorphological studies in this region (Quispe et al., 2022) indicated the presence of ashes, charcoal and other materials in short-lived surfaces in a context of increasing aridization ∼1000 CE. An extensive study conducted by Villa et al. (2023) at the Huaca Grande mound, in the desertic coast of northern Peru, combined micromorphology with faunal, macrobotanical and Bayesian chronological modelling to tackle the interaction of the populations with climatic events such as El Niño. The analyses revealed an intricate microstratigraphic sequence of human occupation deposits, clay floors and combustion features, indicating changing site uses beginning around 500 cal CE, interbedded with aeolian sand deposition pointing to abandonment episodes, the longest taking place between 750 and 1250 cal CE. Wetter, ENSO-related phases before and after that episode concentrated the main occupation deposits.

A specific, microstratigraphically well-documented case for the impact of lightning strikes and its relationship with human populations has been made for the northern Peruvian coast during the Late Holocene. Working in the Moche valley, Courty (2022) combined micromorphology with scanning electron microscope (SEM) and wet-sieved sediment analysis to characterize finely laminated alluvial deposits affected by wildfires and fine eolian inputs ∼3000 and ∼2100 cal BP. The presence of vesicular slag, metal coatings of a specific nanostructure and composition on angular quartz grains and plant remains, polymer filaments and films, among others, all pointed to plasma-jet droplet splashing, aerosol transformation, and vaporization induced by electrification of the air and posterior lightning strike on the surface. Phytolith- and ash-rich laminated stratigraphic sequences from an initial Mochica funerary context (∼2100 cal BP) yielded similar materials, which would indicate that they were specifically sourced for ritual purposes.

In southern South America, several studies have utilized micromorphology to understand site formation processes and extract environmental information from Late Holocene contexts associated with hunter-gatherer occupations

Alvarez (2025), used micromorphology as a core analytical tool to distinguish between natural and anthropogenic processes at the open-air site of El Cangrejo (Argentina), located at the margins of the Uruguay River. By integrating thin-section analysis with complementary methods such as x-ray diffractometry (XRD), sediment texture profiling, and pedological surveys, the study reconstructed past environmental conditions and identified subtle signatures of human activity. The soil formation model developed at the site traced climatic and cultural dynamics over time.

In lacustrine and wetland settings belonging to the humid Argentinean Pampean region, Fernández et al. (2022) tackled the pedogenetic processes affecting the preservation of archaeological materials deposited during the Late Holocene. Micromorphology revealed features related to hydromorphic, soil fauna-derived and other processes that are impacting bones and other materials, as a consequence of environmental and recent anthropic impacts.

A complex scenario of Middle and Late Holocene occupations in the dynamic dunefield-lake systems of the Argentinian Pampean region was tackled through geoarchaeological and taphonomic analyses by Scheifler et al. (2024). Together with other techniques, micromorphology helped to maximize, in this challenging setting, the information about human inputs (charcoal, microbones) and changing environmental conditions in specific periods.

Ozán (2012) offers an insightful review of geoarchaeological and microstratigraphic approaches to understanding the intensity of human occupation in hunter-gatherer contexts in southern Patagonia, Argentina, with emphasis on the potential of micromorphology to understand site formation processes and pedogenesis. Later Ozán and Orgiera (2015) and Ozán et al. (2017) applied micromorphology in combination with environmental magnetism to study the pedogenesis of the Marazzi 2 archaeological site, an open-air location on the northwestern coast of Isla Grande de Tierra del Fuego (Argentina). The site was occupied from 3000 cal BP until the European arrival. Analysis of two stratigraphic profiles allowed the identification of thermally altered minerals, such as magnetite and red ochre residues embedded in volcanic ash, supporting the interpretation of magnetic susceptibility peaks as the result of short-term human activities—particularly combustion practices and the use of pigment (red ochre). The study demonstrates how micromorphology complements geophysical data, confirming anthropogenic impacts on sediment composition, even in ephemeral hunter–gatherer contexts.

Past agriculture and soils: formation, impacts, enhancements

As the historical result of the cultivation and domestication of plants, agriculture has involved a complex set of activities, from the management of soils and other environmental components to extensive landscape modifications (Harris and Fuller, 2014). Micromorphological research has focused on identifying traits derived from vegetation clearance, soil exposure (e.g., textural coatings), and the use of implements such as ploughs and spades (see Deák et al., 2017).

The desertic Mexican northwest was an important early agricultural center involving the cultivation of corn and other crops (see Pearsall, 2015). The analysis of paleosols has revealed the impact of the irrigation infrastructure used by agriculturalists since∼4500 cal BP. The formation and further reworking of indurated thin surface crusts, the presence of poorly sorted coarse materials and randomly-distributed anthropic constituents like bone micro-fragments, all seen in thin sections, have been linked to irrigation and the construction/destruction of earthen canals in this arid setting (Cruz-y-Cruz et al., 2019; Ibarra-Arzave et al., 2019, 2024). Additionally, erosion/sedimentation processes as well as incipient pedogenesis, e.g., humus pigmentation and leaching of carbonates, have been related to phases of intensive occupation in this region (Cruz-y-Cruz et al., 2019).

Extensive alteration of natural soil material during pre-Hispanic times has been widely recorded through micromorphology and linked to agricultural practices in several areas of Mesoamerica. Occupation dynamics since the Formative in the Valley of Teotihuacan has involved settlement around 2000 BP under stable, soil-forming, conditions, with fertile soils such as the Black San Pablo Paleosol, which were succeeded by the intensification of erosion events triggered by deforestation, sediment deposition at the valley bottom, clay illuviation (seen e.g., in impure coatings), pedoturbation and water saturation (seen in redoximorphic features as well as paleobotanical and other indicators) possibly due to irrigation (González-Arqueros et al., 2017; McLung de Tapia et al., 2003; Rivera-Uria et al., 2007; Sánchez-Pérez et al., 2013; Sedov et al. 2009; Stahlschmidt et al., 2019). In paleosoils under volcanic deposits in the central Mexican highlands, possible links between redoximorphic features, humus depigmentation, etc. and irrigation practices have been made (Solleiro-Rebolledo et al., 2016). The construction of terraces, a landmark of agricultural impact in mountainous regions (see below for the Andean region), has also been documented in Mesoamerica using micromorphology, highlighting, since 5300 cal yr BP in southwest Mexico, the presence of finely laminated silty and dusty clays and nodules due to water retention within terraces (Solís and Bocco, 2018). In the Gulf of Mexico, paleopedological studies have shown that, despite unfavorable structure and nutrient holding capacity of the local soils, several settlements thrived there over time (Hinojosa et al., 2016).

A topic of extensive geoarchaeological and paleopedological research concerns the impacts of Maya land-use practices (e.g., reviews in Dunning et al., 2023, Sedov et al., 2023). The diversity of soils developed in the karstic landscape of southern Mexico and bordering countries, triggered different agricultural strategies (Solleiro-Rebolledo et al., 2015). In the southern Maya area, garden agroforestry took advantage of present-day shallow Rendzinas around main urban centers located on the hills, while more extensive agriculture, with canal construction for drainage, developed on fluvial terraces and karst depressions (Sedov et al., 2023). As a consequence, erosion of Rendzinas in upland settings, colluviation and redeposition of soil, clay aggregates and charcoal in lowland depressions, are observed in the micromorphology and geochemistry (XRD) of this area (García-Ramírez et al., 2024; Sedov et al., 2008, 2023). In the northeastern area of Yucatan, in the limestone plateau, a scenario of upland vs. lowland erosion/deposition has also been inferred, but here the focus of agricultural use would have been in the former rather than in the latter. The exposure of upland Rendzina and Terra Rosa soils by slash-and-burn agriculture resulted here in the short-distance transport and deposition of reworked soil material (pedosediments) in caves and karstic pockets, leaving behind heavily mixed materials from different sources, burnt caliche, charcoal, etc., (Cabadas-Báez et al., 2010; Sedov et al., 2007, 2023; Solleiro-Rebolledo et al., 2015). Comparative analyses of some pedosediment fills from Yucatán Peninsula with soils exposed to fire by recent slash-and-burn, has shown similar heated coarse components and a reddened micro-charcoal-rich clayey groundmass, alongside other parameters (Moreno-Roso et al., 2024).

In South America, raised fields with elongated platforms, mounds, ditches and other associated earthworks are a striking characteristic of the indigenous agricultural wetland landscapes (Rostain, 2017). In the tropical wetlands around the Gulf of Urabá, in northwestern Colombia, micromorphology, geochemical and paleobotanic parameters allowed Posada-Restrepo et al. (2023) to interpret the construction of raised fields, after ∼800 cal CE, as the outcome of the management of episodic, low-energy flood pulses during a dry period. Another archaeological site in the same region and cultural affiliation, inhabited ∼500 cal CE, would have been a center for domestic activities not involving hydraulic interventions, as evidenced by pottery and combustion, faunal, botanical remains seen in thin sections (González-Avendaño et al., 2025).

Further to the south, in Ecuador, a pioneering micromorphological study by Wilson et al. (2002) compared two pre-Hispanic and one Hispanic agricultural field management systems. While frequent thick compound silty clay and limpid clay coatings around voids in pre-Hispanic raised fields (camellones) pointed to the intense combined effects of tillage and animal manuring, the more localized and mutually exclusive occurrence of these features in the smaller ridge field systems (wachukuna) indicated a more punctual use for the development of these activities. The fewer abundance and thickness of the same pedofeatures in Hispanic arable fields indicated an even less intensive use.

A study conducted by Rodrigues et al. (2015) in the Llanos de Moxos lowlands of southwestern Amazonia, Bolivia, provided fresh geoarchaeological insights into the formation and use of the characteristic raised fields of this region. Although the presence of dusty clay coatings around voids and infillings in the upper sequence of the sampled platforms pointed to some human disturbance, the absence of laminated deposits which would indicate the gradual accumulation of sediment and green manure from the adjacent canals was not observed, suggesting a different use of the field from the intensive agricultural one proposed by the predominant model. Together with stratigraphy, radiocarbon ages and the lack of geochemical enrichments and variations in other parameters away from the natural profile, the authors postulated that the fields were built in discrete episodes since ∼570–770 CE and used in short periods mainly to drain the excess water during flooding events.

The variability in terms of management and degradation of the well-known pre-Hispanic highland Andean terrace systems has been studied in thin sections and, at times, combined with bulk sample analyses. In the hilly inter-Andean valley of central Colombia, Godoy-Toro et al. (2022) reported the agricultural alteration of the natural acidic soils linked to a settlement dated to ∼1950 cal BP, through micromorphology and other indicators such as physico-chemical parameters and paleobotanic analysis. The presence of low porosity, vesicle- and plane-rich, sharp angular aggregates in bioturbated soils with mixed horizons was interpreted as evidence of ploughing and tillage which, alongside artifacts, terracing and irrigation features, pointed to the improvement of the original soil fertility conditions. In present-day soils and paleosols from abandoned terraces at the Chichas-Soras Valley of southern Peru (at ∼3350–3400 masl), Kemp et al. (2006) reported abundant thick impure clay coatings among limpid ones, suggesting the possible impact of both natural climate-induced weathering and irrigation practices. A comparison of soil catenas cross-cutting active terraces in the Paca Valley (at ∼3670–3400 masl), central Peru, undertaken by Goodman-Elgar (2008a), showed that, despite overall improving the depth and fertility of the locally poor soils, the overuse in the last thousand years and the moving away from traditional farming practices have led to degraded fields with high downslope translocation of clays and silts, among others. Working in two terrace systems at ∼3550–3630 masl in the upper Ica Valley of south Peru, Nanavati et al. (2016) also found signs of erosion, but did not observe the illuviation pedofeatures and other indicators associated with long-term agriculture, with local ethnographic information indicating long fallow periods as a strategy to cope with these impoverished soils.

Alongside surface clearance, tillage, and the building of terraces and raised fields, micromorphology has been used in the Andes to search for evidence of pastoralism. By analyzing sediment blocks from one building and one potential plaza area at the Viejo Sangayaico site, at 3700 masl, in southern Peru, Whitlock and Lane (2023) found faecal spherulite-rich deposits, known to be derived from herbivorous dung (see Canti and Brochier, 2017; for the Andean region, see also Goodman-Elgar, 1999). While the close association of these materials with ash pseudomorphs and trampled surfaces was suggestive of animal (camelid) enclosures in one area, their occurrence in the building could be more linked to ceremonial activities, as interpreted from the presence of amorphous organic matter, plant remains and field evidence (e.g., offerings).

A close relationship between ritual activities and agricultural practices was evidenced in Easter Island/Rapa Nui (Chile) by Sherwood et al. (2019). The excavation of the quarry where most of the moai statues were produced, in the inner region of Rano Raraku, allowed for a systematic characterization of manufacture methods and land-use over time. A thorough analysis combining micromorphology with geochemical and macro/microbotanical data showed the episodic influx of colluvial aggregates rich in the locally-exploited lapilli tuff fragments, as a result of ritual moai production, with high soil nutrient values which were widely taken advantage of for garden agriculture - even in moments of island-wide soil fertility loss.

Earthen architecture and other construction materials (plasters, stucco, mortar, etc.)

Earthen architecture refers to the use of sediments and soils as building materials (Karkanas and Goldberg, 2019). Micromorphological studies have proved essential for characterizing not only the composition but also the construction techniques and subsequent postdepositional alterations (e.g., Friesem et al., 2017). “Plaster” designates any material applied, in a plastic state, as a coating on the surface of building elements such as walls (Karkanas and Goldberg, 2019, p. 136). In general terms, lime plasters are a specific case of calcareous mortar, which is prepared after calcination of limestone in a kiln, slaking with water, and mixing of the resulting lime binder with temper (Stoops et al., 2017).

In the Mesoamerican region, micromorphological analyses of earthen materials date back to the beginning of the 21st century (e.g., Goldberg, 2009; Houston et al., 2003) but have received more regular applications since the 2010s. In an early reference, Houston et al. (2003) studied the building history of the acropolis of Kaminaljuyú, an important earthen-built Mayan urban center in Guatemala City. By doing micromorphology on floors and other features, the authors managed to differentiate the sedimentary matrixes and tempers that were employed in the construction phases from Pre-Classic times onwards.

In further works, the emphasis was placed on characterizing both the technical properties of the materials and the soil/sediment sources of specific archaeological sites/structures. This is the case of mud-bricks from Zethé and Sabina Grande sites in central-eastern Mexico, in which Gama-Castro et al. (2012) identified, in thin section and several other parameters (e.g., grain-size and XRD), coarse fraction constituents and alteration patterns similar to the ones observed in the volcanic soils surrounding the sites. In a study of some Formative-period habitation units in Xochitécatl-Cacaxtla, central Mexico, Pogosyan et al. (2019a) determined that the material employed in the foundations was not tepetate (hardened soil horizon typical of volcanic areas), due to the lack of clay coatings observed in thin sections of these horizons in the surrounding areas. Micromorphological and micro-computed tomography (micro-CT) studies of tepetates have shown less frequent and more regular-shaped voids than those seen in archaeological mud-bricks (Pogosyan et al., 2019b).

The site of La Joya, a monumental earthen urban compound located in the coastal plain of the Gulf of Mexico and inhabited from the Pre-Classic to the Classic period, has received special attention from a micromorphological point of view (Daneels et al., 2022; García-Zeferino et al., 2018, 2022; Liberotti and Daneels, 2012; Piña Guido et al., 2019; Piña-Guido and Cabádas-Báez, 2018; Pogosyan et al., 2019b). Regarding the soil/sediment sources, local/regional sandy sediments and different soil horizons found both underneath (i.e., pre-construction paleosols) and outside of the structures would have been used as fills and for mud-bricks, as suggested by the similar textural parameters, microstructure and pedofeatures (Daneels et al., 2022; García-Zeferino et al., 2018, 2022; Liberotti and Daneels, 2012; Piña-Guido and Cabádas-Báez, 2018).

La Joya and other earthen architectural sites have been the scope of recent comparative micromorphological studies, both within (Daneels et al., 2022; Mateu et al., 2022; Mateu and Daneels, 2020) and outside (Liberotti and Daneels, 2012; Mateu, 2019; Mateu and Daneels, 2020; Sedov and Alexandrovskiy, 2018) the Mesoamerican area. By comparing the manufacturing processes of mud-bricks, cobs, and floor and wall facings of seven Mesoamerican sites, Mateu et al. (2022) found similar patterns, e.g., in matrix grain-size (mud-bricks) and low porosity with vesicles indicating a well-mixed hydric plastic state (mud-bricks and facings). These and other micromorphological traits have been shown to be useful for differentiating fills from constructed elements (Daneels et al., 2022).

Plasters, mortar and stucco have attracted a particular research interest in the Mesoamerican area from a microscopic point of view. Lime plaster was extensively used since Pre-Classic times to coat walls (including walls with paintings), floors and roofs. In optical terms, most analyses have followed a more petrographic orientation and terminology, rather than a micromorphological one, usually in combination with scanning electron microscopy (SEM) and chemical techniques (e.g., Ahern, 2021; Barba et al., 2009; Miriello et al., 2013; Miriello et al., 2021; Murakami, 2016; Pecci et al., 2018; Straulino et al., 2013; Villaseñor, 2010; Villaseñor and Graham, 2010). In Teotihuacan, thin section analysis was crucial to revealing a specific plaster-making recipe that lasted for four centuries, with a basal layer of beaten earth and crushed volcanic material being overlaid by a thin layer of lime mixed with glass fragments (Barba et al., 2009; Blancas et al., 2019; Miriello et al., 2021; Pecci et al., 2018). Variations of this recipe and several replastering events were observed under the microscope in the Aztec capital, Tenochtitlán (Miriello et al., 2013).

In the Maya area, micromorphological/petrographic studies have documented the diversity of plaster recipes and their changes over time and across sites and specific intra-site areas (Macphail et al., 2017; Spensley-Moriarty, 2012; Straulino et al., 2016; Villaseñor, 2010). For instance, in some sites, well-sorted fine-grained aggregates (e.g., calcite crystals and soil aggregates) have been observed as tempers in wall plasters and sculpture stucco, in contrast to the coarser ones added to floor plasters, indicating a more refined and costly production process in the former (Hansen et al., 1996; Spensley-Moriarty, 2012). Differences like these have also been attributed to both periods of political stability/decline and social status, as only the wealthy elites could have had access to the resources and a more specialized craftsmanship to produce better plasters (Spensley, 2005; Spensley-Moriarty, 2012; Spensley-Moriarty and Moriarty, 2015; Villaseñor, 2010).

Studies of post-depositional alteration of Mayan plasters have relied on micromorphology and SEM to document several pathways by which calcite was recrystallized and neoformed after dissolution by meteoric/percolating water (Straulino et al., 2013; Villaseñor and Price, 2008). These works offer important insights for conservation research and practices.

The Andean region of South America has been an important hub for the development of earthen construction techniques in the past. In a series of studies, Goodman-Elgar (1999, 2004, 2008b) and Goodman-Elgar et al. (2015, 2024) characterized in micromorphology thin sections several aspects linked to earthen architecture and construction materials from the Taraco Peninsula area, in the southern Titicaca Lake (∼3800 masl), Bolivia, where initial human occupation dates back to the Formative Period (1500 BCE - 400 CE). A pioneer work (Goodman-Elgar, 1999) offered a comparative analysis of mud-bricks, plaster floors and fills from two sites, revealing major coarse inclusions, recipes and void patterns (e.g., linked to trampling of floors), as well as post-depositional alteration. Years later, other ancient and contemporary sites in the region were sampled (Goodman-Elgar, 2004). This set the basis for an ethno-geoarchaeological approach focused on elucidating the processes of formation and transformation of archaeological deposits, in which Gooldman-Elgar (2008b) examined recently abandoned (∼50 years) domestic adobe structures in the Taraco peninsula. Based on the micromorphological analysis of intact and weathered adobe, plasters, floors, and thermal features, it was possible to indicate that, even after a short period of decay under semi-arid conditions, the anthropogenic signature of mud-bricks was relatively subtle, particularly when these have not been exposed to heat. Weathering processes and bioturbation acted as major agents of deposit disruption, promoting the mixing of architectural sediments with the topsoil, a process intensified by the decay of organic matter derived from roof collapse. In a further study (Goodman-Elgar et al., 2015), thin section-based groupings of construction elements such as mud-bricks were compared with geochemical elemental data, showing the intricacies of sediment sourcing and the different recipes employed in the mixing. Finally, building on these previous works, extensive research combining micromorphology from archaeological, contemporary, experimental open-air and controlled firing contexts, with faunal and paleoethnobotanical analysis, was conducted by Goodman-Elgar et al. (2024) to inquire about a fire event at a ceremonial structure in the Chiripa mound site. The results showed the systematic, laterally contained and sustained fire event at specific temperature ranges hard to achieve under the low oxygen conditions of the high Andes, pointing to the planned ritual burning and closure of the structure.

Earthworks and earthen mounds

Mounds and other human-made positive earthen accumulations are generally considered types of earthworks, landforms derived from the landscape-scale removal and/or deposition of soil/sediment material (Saunaluoma et al., 2018). Micromorphology plays a crucial role in the characterization of these sites as anthropogenic features and the disentangling of activities behind its construction (Kidder and Sherwood, 2017).

In the Upper Paraná delta (Argentina), Castiñeira et al. (2013) conducted a multi-proxy investigation of the Los Tres Cerros mounds (Late Holocene) to determine whether they are natural floodplain forms or anthropogenic earthworks. The authors combined stratigraphy, sedimentology, phytolith analysis, radiocarbon dating, and archaeological micromorphology. Micromorphology was key to distinguishing a sharp transition from natural alluvial deposits to anthropogenic layers in one of the mounds, and to tracing constructional episodes within the mound. It also revealed differences in microfacies and biosilica (phytolith) assemblages between mound sediments and surrounding plain deposits, including plant taxa associated with human use—that corroborate deliberate earthmoving and occupation activities rather than purely fluvial formation.

In the lowlands of central-eastern Uruguay, Villagrán and Gianotti (2013) demonstrated how micromorphology was fundamental in deciphering the intricate formation processes of indigenous earthen mounds (locally known as cerritos), at the Pago Lindo archaeological complex (Late Holocene). Micromorphological analysis provided a high-resolution lens to detect subtle construction techniques in sediments that closely resemble natural soils and exhibit extensive bioturbation. Micromorphology corroborated field identification of anthropogenic layers and revealed activity areas that were invisible in the macrostratigraphy. Thin-section analyses showed the repeated use of surface soil horizons for mound construction and helped identify two significant activity areas: a domestic hut (∼1600 BP) and a plant residue accumulation zone (∼800 years later). Additionally, the complete absence of microscopic bioarchaeological residues was interpreted as intentional surface cleaning. Micromorphology also enabled the researchers to validate the proposed spatial–temporal discontinuous model of earthen mound use and reoccupation, showcasing its critical role in interpreting ambiguous archaeological stratigraphies.

In the eastern Uruguayan lowlands, Cancela et al. (2024) combine thorough stratigraphic descriptions with grain-size analyses and micromorphology as a tool to unravel the formation processes of the Isla de los Talitas earthen mound (Late Holocene). Micromorphological analyses allowed identification of anthropogenic components—such as reworked termite mounds (heated and non-heated), burned soils, and daily residues (e.g., heated bone fragments and microcharcoal)—that were intentionally incorporated into the construction sequence of mound TALQ28. The microscopic perspective helped to characterize each episode of mound building, together with phases of use. The study reveals that mound construction practices reflect a long-standing architectural tradition spanning three millennia, underscoring community-based ecological knowledge and cultural continuity in how space was modified, inhabited, and remembered.

Anthropogenic dark earths

Under the expression “dark earths” have been included dark-colored soil horizons or layers rich in artifacts and/or human-made features encountered throughout the world. They are considered types of Anthrosols, a group of soil within the World Reference Base for Soil Resources (IUSS Working Group WRB, 2022) that include diagnostic horizons (e.g., pretic horizons) resulting from extensive anthropic modification (e.g., irrigation, manuring, cultivation, etc.) of at least 50 cm in thickness.

Micromorphology and bulk sample geochemical indicators have been crucial to understanding the formation of dark soil horizons in the Maya area. A series of studies conducted by Graham et al. (2017) and Macphail et al. (2017) analyzed the site formation history of three mound-shaped occupation deposits with dark layers dated to between the Preclassic and the Late Classic in the island of Ambergris Caye, off the coast of Belize. A complex microstratigraphic sequence consisting of reworked and intact anthropogenic deposits was revealed, including lime plaster floors, trampled surfaces, combustion features, and randomly mixed midden remains. Moreover, the study identified Late Classic deposits derived from salt production, as seen in burnt clay aggregates from highly saline tidal mud flats, rich in sponge spicules, mixed with ashes, charcoal and pottery shards, indicating extraction of salt from sediment heated within vessels. A Maya Dark Earth was interpreted from a microcharcoal- and carbonate-rich excremental soil formed on previous occupation surfaces, rich in reworked lime plaster floors and other anthropogenic debris.

The resemblance of dark profiles to Amazonian Dark Earths (see below), developed in modern-day cultivated soils affected by past human activities in a tropical karstic area of Mexico, was reported by Solleiro-Rebolledo et al. (2023). Alongside geomorphological location, the authors pointed at micromorphological similarities, e.g., strong humus pigmentation, charcoal-rich micromass and coarse fraction, weakly separated blocky microstructures, and some pedofeatures.

In the Caribbean region, a specific case for anthrosol formation was made by Brancier et al. (2018). Working in the French island of Martinique, Lesser Antilles, the authors characterized a ca. 340–530 cal CE dark soil horizon found at the foothills of a volcano. Charcoal, burnt clay aggregates, lithic debitage, and pottery shards are all embedded in between finely grained microcharcoal-rich episodes of colluvial accretion, affected by further pedogenesis. This cumulic anthrosol was formed on top of and sealed by volcanic pumice deposits.

Micromorphological research dealing with Amazonian Dark Earths has been carried out by both archaeologists and pedologists, seeking to understand their genesis and transformation over time. While pedological studies have emphasized the chemical enrichment and pedogenetic evolution of pretic horizons, archaeological approaches focus on reconstructing human activities and the spatial organization of settlements (Arroyo-Kalin, 2012; Brancier et al., 2014; Macedo et al., 2013, 2017). A pioneer study by Schaefer et al. (2004), which combined micromorphology with SEM-EDS (SEM with Energy Dispersive x-ray Spectroscopy), revealed that fish bones and their further alteration by soil fauna are behind the high calcium and phosphorus concentrations exhibited by these anthropogenic soils.

Studies conducted by Arroyo-Kalin in Central Amazonia (Arroyo-Kalin, 2009, 2010, 2012, 2017, 2021; Arroyo-Kalin et al., 2009) have shown that these soils were formed by long-term cumulative processes associated with human occupation and land management. Observations made in thin sections revealed an abundance of finely dispersed charcoal, ceramic and bone fragments, phytoliths, and trampling and reworking features, combined with intense bioturbation responsible for vertical mixing and thickening of the horizons. Micromorphology also made it possible to differentiate between residential and agricultural areas, distinguishing Amazonian Dark Earth from the adjacent brown earth, characterized by a predominance of microcharcoal and low density of cultural materials. These data indicate that controlled burning, domestic disposal, and successive reoccupations produced stable and highly fertile anthropogenic horizons.

Research conducted by Brancier in French Guiana (Bel, 2015; Brancier, 2014; Brancier et al., 2018; Brancier and Cammas, 2021), particularly at the Chemin Saint-Louis site, identified comparable cumulic anthrosols, but with more detailed microstratigraphic resolution of the activity areas. The analyses revealed finely stratified anthropogenic deposits composed of microcharcoal, combustion residues, ceramics, burnt bones, and organic matter, interspersed with natural sedimentary inputs and subsequently modified by pedogenesis. These characteristics allowed the recognition of distinct occupational surfaces, disposal areas, and combustion zones, demonstrating that the dark horizons resulted from successive anthropogenic inputs interacting with natural soil formation processes, and not from a single depositional event.

Taken together, these studies corroborate the interpretation of ADEs as complex anthrosols resulting from long-term occupations. They can be considered palimpsests formed by the continuous interaction between anthropogenic deposition and natural pedogenesis.

Shell-matrix sites

A widespread archaeological phenomenon, shell-matrix sites, such as shell-middens and shell-mounds, comprise - at times extensive - deposits resulting from the recurrent accumulation of mollusk shells (Rick, 2024; Villagran, 2019). Pioneer micromorphological research on these sites has been undertaken in South America since 2009 (see below).

Working in the southern Peruvian coast Beresford-Jones et al. (2022) reported micromorphological and geochemical data from the La Yerba II, a shell-midden built since around 7000 cal BP. The analyses revealed a complex occupational sequence comprising several microstratigraphic fabric types, some of them found in shell-matrix sites elsewhere (Villagran, 2019, see below), some of them unique to this midden.

In the extensive savannah wetlands of southwestern Amazonia, in Bolivia, micromorphology was used by Lombardo et al. (2013) in tandem with elemental, mineralogical and organic chemistry techniques to tackle the possible anthropogenic origin of three of the so-called “forest islands”, mound-shaped features that can be regularly seen in this landscape. The analyses revealed that these sites are, in fact, human-made stratified shell-middens, with mixed burnt and unburnt freshwater gastropod shells and other coarse fraction constituents such as charcoal.

In Brazil, particularly along the South Atlantic coast, micromorphology has played a central role in demonstrating that shell mounds are not simple refuse heaps, but complex anthropogenic constructions formed through structured depositional practices.

Since the first applications of micromorphology to Brazilian shell mounds (Villagran, 2009; Villagran et al., 2009a,b), coupled with complementary techniques such as x-Ray Fluorescence (XRF), SEM-EDS, and stable isotopes in the organic matter (δ 13 C, δ 15 N) studies have consistently shown that their sediments are composed of transported and reorganized materials rather than primary domestic discard. Thin-section analyses revealed microaggregated matrices containing quartz grains, bone fragments, charcoal, phytoliths, and diatoms randomly distributed within the shell matrix, together with burned bones, ash pseudomorphs, and silica aggregates produced at high temperatures. The frequent absence of in situ hearths and the presence of thermally altered materials indicate that residues were often burned elsewhere and later redeposited (e.g., tertiary deposits). Alternations between carbon-rich dark micromass and phosphatic micromass derived from bone dissolution demonstrate successive depositional events and post-depositional chemical transformation (Estevez et al., 2014; Villagran et al., 2009b, 2010, 2015; Villagran et al., 2019). All of these observations helped to define microfacies types that are typically encountered in shell-matrix sites (Villagran, 2019), serving as a base for other similar contexts elsewhere.

Micromorphology also allows the identification of archaeofacies related to specific practices. In sites such as Jabuticabeira II and Sernambetiba, superimposed microfacies of whole shells, trampled fragments, and bone-rich combustion layers indicate cycles of deposition, covering, and mound construction associated with funerary architecture. Rather than domestic accumulation, these deposits correspond to the deliberate transformation of food refuse into building material. Similar patterns were observed in several southern Brazilian sambaquis, where deposits record repeated transport of midden material from habitation areas to monumental mounds (Villagran, 2010, 2014a; Villagran et al., 2009b, 2010; Villagran et al., 2015, 2019).

In addition to revealing cultural practices, micromorphology has demonstrated that sambaquis incorporate environmental information. Microcomponents such as diatoms, echinoid spines, lagoonal gastropods, and terrigenous particles preserve the provenance of collected resources and reflect coastal environmental changes. Consequently, shell mounds function simultaneously as cultural constructions and paleoenvironmental archives (Colonese et al., 2025; Villagran and Giannini, 2014). Studying shell mounds as anthropogenic soils, Corrêa et al. (2013) examine how phosphate is distributed and transformed, helping in the preservation of archaeological materials. Using micromorphology and SEM/EDS analysis, the authors found that phosphorus moved downward through the soil profile and reprecipitated as secondary calcium phosphates in deeper layers.

After Taulé’s (1996) initial proposal for the use of micromorphology in shell-midden research, Balbo et al. (2010) conducted the first fully micromorphological study of shell-midden in Tierra del Fuego (Argentina). The authors demonstrate how micromorphology significantly enhances the understanding of formation processes in complex shell-midden stratigraphies. At the Tunel VII site—an ethnohistorical fisher-hunter-gatherer site occupied by Yamana peoples— thin-section analysis of one monolith column extracted from the passageway into a domestic shell-midden revealed microstratigraphic features that were not discernible during field excavation. Micromorphology revealed discrete shell deposition events, floor preparation phases, burning residues, and evidence of trampling, providing a nuanced reconstruction of activity areas and occupational intensity. These observations helped validate and refine stratigraphic interpretations based on macroscopic excavation, underscoring micromorphology's role in tracing short-term human actions, post-depositional alterations, and occupational rhythms that would otherwise be lost in shell-rich archaeological matrices.

Also, at the Túnel VII site, Villagran et al. (2011a) analyzed a second monolith from the shell-midden deposit, a set of micromorphology samples from the central hearths inside the domestic hut and combined these with experimental archaeology and ethnohistorical accounts. The study advanced the use of micromorphology to uncover the spatial organization and occupation dynamics of domestic shell middens. Micromorphology allowed researchers to distinguish between functional areas based on differences in the relative frequency, pre-depositional alteration, arrangement, and preservation of shell-midden components. Shell dumping zones, occupation surfaces, trampling, and periods of site abandonment versus intensive use were described within a small-scale shell-midden of less than a meter high. Micromorphological observations offered a nuanced interpretation of seasonal habitation patterns, distinguishing combustion residues from summer vs. winter hearths. This fine-resolution approach served as a methodological model for identifying functional zones in shell middens, even in the absence of ethnographic records (see also Villagran, 2019).

On the hyperarid coast of the Atacama Desert (Chile), Villagran et al. (2021a) combined micromorphology with faunal data to investigate site formation at the Zapatero shell-midden (Middle to Late Holocene). Micromorphology, Fourier Transform Infrared Spectroscopy (FTIR), and micro-FTIR on the micromorphology thin sections, revealed three occupation phases: initial continuous shell accumulation (∼7000 cal BP), intermittent fish and shell deposits (6600–6400 cal BP), and a later reworked phase likely caused by a tsunami (∼4000 years ago). Micromorphological evidence indicated shifting paleoclimatic conditions, offered insights into taphonomic processes and supported the tsunami reworking hypothesis. Such a hypothesis had been brought up by geologists working at the site and was later investigated in Salazar et al. (2022), gathering geological and archaeological evidence of a Mx ∼9.5 earthquake that affected the northern coast of Chile and caused severe social disruption 3800 years ago. In this work, micromorphology played a key role in identifying the microscopic evidence of a tsunami event that affected the Zapatero site. Microstratigraphic features, such as redeposited shell fragments, disrupted layering, high-energy sediment inputs, and a sudden increase in marine fossils (e.g., red algae and echinoid spines) are consistent with tsunami-induced reworking of the top segment of the site.

Also, at the Zapatero shell-midden, Power et al. (2022) investigated an intriguing and uncommon feature in shell-matrix sites: a stone architectural construction built during the Late Archaic period (∼5700–4000 cal BP), before the strike of the 3800 BP earthquake. The authors employed micromorphology, combined with faunal and lithic analyses and revealed anthropogenic modifications to the midden substrate, including deposition of a pit grave, compacted surfaces, ash residues, and reworked shell layers, indicating deliberate preparation for architectural stability. Furthermore, the identification of localized burning features and sediment compaction patterns provided insight into activity areas and maintenance practices within the structure. These microscopic observations offered crucial evidence for understanding ritual behavior and construction techniques among hunter-gatherer-fisher societies of the Atacama coast.

In a setting also belonging to the Pacific hyperarid coast of South America, but in southern Peru, Meinekat et al. (2026) recently shed a high-resolution light on the Quebrada Jaguay 280 site. Dated to the Terminal Pleistocene/Early Holocene, the open-air shell-matrix site had raised some concerns regarding paleoenvironmental conditions, human activities of these early inhabitants and post-depositional alterations. The combination of micromorphology with elemental micro-XRF mapping and micro-FTIR revealed different short-term functional areas, with shells and bones affected by precipitated marine-aerosol-derived halite and gypsum crystals. The detailed study highlighted the extent of these post-depositional changes and their potential use to infer past dryer/wetter phases in this arid setting.

Caves and rockshelters

Due to the protection they offer from the rain, wind, and other natural agents, caves and rockshelters have been both long-preferred spaces for hominin activities, as well as well-targeted sites of archaeological inquiry (Karkanas and Goldberg, 2019; Mentzer, 2017). This has also held true for micromorphology, which has been extensively developed in these settings since the 1970s, offering a highly detailed picture of the processes and human activities behind their sedimentary matrixes (see Courty et al., 1989; Mallol and Goldberg, 2017).

The Central Andes constituted one of the high-altitude environments occupied by hunter-gatherer populations during the initial peopling of the Americas (see Meinekat et al., 2023). Evidence from the Cuncaicha rockshelter indicates human occupation during the Late Pleistocene, between ∼12,300 and 11,100 cal BP. Regional paleoenvironmental records and local geological data suggest that high-elevation settings were environmentally viable for human settlement by at least 12,500 cal BP. In their study of the Cuncaicha site (4480 masl, in the ecoregion known as puna), located in the Pucuncho Basin of the Peruvian Andes, Meinekat et al. (2022) proposed a formation model for rockshelter deposits integrating archaeological, chronological, and paleoenvironmental datasets. Through a multi-proxy approach, the authors analyzed the stratigraphic sequence to identify depositional and post-depositional processes, assess the extent of bioturbation, and correlate site-formation dynamics with regional paleoenvironmental trends.

In Brazil, micromorphology has been used in archaeological caves and rock shelters in different regions of the country and has shown that the deposits in these environments generally also result from the interaction between anthropogenic inputs and natural sedimentation.

An early study by Benabdelhadi (2005) offered some preliminary examples of the use of the technique in the Santa Elina rockshelter, a crucial site in central Brazil with evidence of human-megafauna interactions and purported ages of more than 20,000 cal BP (Vialou, 2017). For the upper layers, combustion features and the scattering of their constituents (ashes, plant tissues, some of them shown in one photomicrograph) are described, together with artifacts, shells, “brown earth fragments” possibly adhered to shoes and other human-activity-derived constituents. For the lower layers only the poorly sorted character of the sandy matrix and the presence of textural pedofeatures are mentioned.

Several sites have well-preserved occupation surfaces formed mainly by in situ accumulation of cultural residues. Working in a limestone shelter in the northeast, Bitencourt (2008) reported the predominant impact of biogenic (e.g., gastropods), geogenic (e.g., mass wasting), and anthropogenic (e.g., burnt sediments, charcoal) inputs on three different stratigraphic units from Late Pleistocene to Late Holocene times. At the Lapa das Boleiras shelter, thin sections revealed lenses of ash and brownish charcoal-rich layers, microcharcoals, and bone fragments, with episodic occupations with trampled surfaces being interdigitated by colluvial inputs (more intense in some periods), low post-depositional reworking and good contextual integrity (Araujo et al., 2008). Similar results were observed in the Bibocas II and Santana do Riacho shelters, where the recurrent use of fire generated carbonaceous lenses, magnetic ferruginous nodules, phosphate enrichment, and mineralogical transformations related to heating, while episodic colluvial inputs contributed to the burial and sealing of successive occupation surfaces (Sousa et al., 2015, 2017, 2018, 2020). In the Itapeva shelter, the overlapping of combustion layers, trampling features, and mixing with natural sediments indicated repeated use of the shelter in an open depositional system (Souza and Porto, 2021). Recent pedological studies conducted in sites inhabited since ca. 12,000 BP in Central Brazil have also shown the mixed origin of some coarse fraction components, e.g., highlighting the different chemical post-depositional pathways and dissolution degrees of bones, as seen in thin sections coupled with SEM/EDS analyses (Vasconcelos et al., 2026).

Other contexts in Brazil reveal highly structured anthropogenic deposits dominated by plant ash accumulation. The geoarchaeological study of Lapa do Santo (Villagran, 2022; Villagran et al., 2017b) shows that its 5 m deposit was formed mainly by repeated human activity rather than passive natural sedimentation. A micro-contextual approach, combining micromorphology, micro-FTIR, organic petrography, and experimental archaeology revealed sediments rich in ash crystals, charcoal, heated bone and shell fragments, plant residues, and quartz grains, demonstrating that continual fire use was the main depositional process. Many layers represent hearth rake-outs or dumped ash, while intact hearths preserved between graves indicate fires were repeatedly lit among burials, likely linked to funerary rituals. Natural inputs were also important: 20%–40% of the sediment consists of clay aggregates eroded from nearby tropical oxisols above the limestone shelter. Many of these aggregates were later heated above 500 °C, showing that soil entered the shelter and were incorporated into fires or ash beds. Researchers also identified fragments of termite mounds, probably collected and used in earth ovens or heating structures. Something similar was observed in other sites in the same region (Silva, 2022). Based on the combination of micromorphology with micro-CT, researchers demonstrate how to identify termite mound fragments embedded within archaeological sediments from Lapa do Santo (Villagran et al., 2019). Traditional thin-section micromorphology had suggested the presence of these materials, but micro-CT allowed non-destructive three-dimensional visualization of their characteristic porous and spongy internal structure created by termite construction. By comparing archaeological samples with modern reference termite mounds, the study confirmed that prehistoric inhabitants intentionally collected and used termite mound material, probably in earth ovens or other heating features (Villagran et al., 2019).

More recently, Batalla et al. (2025) employed a facies/microfacies micromorphologically- and geochemically based approach to characterize the deposits of a shallow metacarbonatic rockshelter occupied since at least the Early Holocene and embedded in the tropical Atlantic rainforest of southeastern Brazil, which was previously excavated in the 1970s. The analyses revealed that the more striking material making up the site's layers, i.e., land snail shells, were deposited by different human activities including the dumping of remains and the preparation of subhorizontal surfaces (see section 7). Alongside these, primary and secondary combustion features and materials were found. Moreover, thin sections showed that even when the site has been exposed to severe post-depositional processes in this tropical environment including formation of soil peds, humification and bioturbation, the depositional signal of past human activities has been preserved.

In contrast, some rockshelters in Brazil exhibit predominantly natural deposition. At Toca da Janela da Barra do Antonião, in northeast of Brazil, micromorphology, FTIR, micro-FTIR and magnetic analyses revealed evidence of changing climatic conditions from the late Pleistocene to the early Holocene (Villagran et al., 2021b). The study showed that artifacts and megafaunal remains are embedded in colluvial sediments controlled by climatic variations, with scarce evidence of anthropogenic fire, suggesting a brief human presence and minimal sediment transformation.

In the western Chilean Patagonia, the already mentioned study by Ozán et al. (2019), which explored two volcanic caves with a maximum human occupation signal of around 12,000 cal yr BP, revealed, apart from regional paleoenvironmental changes the impact of biogenic and human activity on sediment mixing.

Living floors and activity areas

The identification of discrete activity areas within archaeological sites comprises one of the main aims of every archaeological endeavor. Alongside the detection of concentrations of specific artifactual classes and features like intact hearths, geoarchaeological research is essential to unlocking the sedimentary matrix of occupation deposits in “living floors” and characteristic processes affecting them, such as trampling (Karkanas and Goldberg, 2019, 124–127).

In the Mesoamerican area, an early work by Spensley (2005), used micromorphology to analyze midden deposits from an urban site in the Petén Maya Lowlands (Guatemala). Despite microstructural similarities between middens from different areas of the site, anthropogenic inclusions allowed the author to distinguish possible activity-related areas, e.g., the ones richer in lithic microdebitage as linked to lithic workshops.

An extensive micromorphological study conducted in the Teotihuacan district of Tlajinga by Stahlschmidt et al. (2019), documented cuts into the natural tepetate to build part of the Street of the Dead, and an area with natural slacking crusts rich in obsidian microdebitage, evidencing its use as an obsidian workshop, possibly affected by trampling (as seen e.g., in granular microstructures). The typical three-layered microstratigraphy of hearths (Mentzer, 2014) was also recorded by the authors in features within a building compound.

In Guadeloupe, Lesser Antilles (Caribbean region), Brancier and Cammas (2022) explored the fill of a circular pit in thin sections to understand the function of this type of feature, found in the vicinity of houses at an archaeological site dated around 1000–1200 CE. The analysis showed anthropogenic combustion materials, probably discarded within the pit and derived from maintenance activities carried out in nearby fireplaces.

Archaeological micromorphology proved fundamental for characterizing activity areas within occupation floors at the urban complex of Maranga-Lima (ca. 350–780 CE), in Lima, Peru. The analyses revealed evidence of combustion events, including the presence of carbonized material. Non-carbonized grass phytoliths were also identified and interpreted as possible remains of mats covering the floors (Vega-Centeno and Lang, 2021). In addition, bone fragments and malacological remains were recorded, indicating areas associated with food processing activities. Overall, micromorphological analysis enabled the reconstruction of spatial organization, domestic practices, and the presence of perishable elements that would otherwise remain archaeologically invisible.

In the tropical savannah landscapes of central Brazil, Batista Barbosa et al. (2020) analyzed a couple of settlement sites linked to the expansion of the Uru tradition ceramic-makers and ring-village settlers (∼800–1700 CE). Micromorphology showed the more intense discard of charcoal, bone and pottery fragments in a darker, charcoal-rich micromass, in one of the sites, which, together with other lines of evidence, allowed for its consideration as a more permanent village.

In the first geoarchaeological work in Antarctica, Villagran et al. (2013) utilize micromorphology to reconstruct human activity and site formation processes at two 19th-century sealing shelters (Sealer 3 and Sealer 4, on Byers Peninsula, Livingston Island). Micromorphological analysis revealed microstratigraphic indicators of anthropogenic activity—such as pyrotechnic residues, organic inputs, and fuel combustion by-products—that distinguished areas of prolonged habitation from short-term functional spaces. Despite dominant influences from cryogenic processes and lithological inputs, micromorphology enabled the detection of subtle signatures like ash layers, bone fragments, and microcharcoal embedded in the sediments. These microfeatures were essential to differentiate between shelters used for living and those dedicated to fat rendering or other sealing-related tasks. In a landscape where artifact preservation is limited, micromorphology provided high-resolution insight into how early Antarctic occupants used space and local resources under extreme environmental conditions.

Other geoarchaeological problems

Recent research initiatives have expanded the scope of micromorphology into the field of forensic geology. Necrosols are soils associated with burials whose properties derive from the specific environmental conditions generated by funerary contexts (Vélez et al., 2020). In order to identify microstratigraphic signatures related to interments and to assess their potential for forensic geoscience applications, Vélez et al. (2020) integrated archaeological micromorphology and geochemical analyses to detect evidence of clandestine cemeteries in Colombia. From a micromorphological perspective, Necrosols exhibited diagnostic features such as microfragments of coffin wood and bone, minerals displaying parallel orientation, high concentrations of fine roots within the burial zone, and the incorporation of pedogenic aggregates within a non-pedogenic matrix. These features reflect processes triggered by grave excavation, body deposition, organic decomposition, and subsequent structural reorganization of the soil. The study demonstrated that micromorphology, when combined with geochemical approaches, provides a robust methodological framework for confirming the presence of Necrosols and distinguishing burial-affected soils from their natural counterparts.

In a study of Inca stone stepped-platforms (ushnus) in the central Peruvian Andes, Branch et al. (2014) used micromorphology in tandem with other geoarchaeological and archaeobotanical analyses to tackle, among others, the origin of the construction fills used to build these structures. Results indicated the use of surface and sub-surface soil horizons with characteristic colors and other properties, mostly of local provenance with some cases of possible non-local origin, pointing to the transport of soils and other materials in the complex Inca administrative and ritual landscape

Brandão et al. (2025) characterized traditional Amazonian indigenous food technology, the indigenous bread, by combining micromorphology/petrography with micro-CT and FTIR infrared spectroscopy. From these multidimensional techniques, the study identifies two distinct microstructures in the material that reflect differences in processing and ingredients, connecting it to oral tradition and the historical consumption of clay in the region.

A micromorphological experiment conducted by Villagran (2014b) with Anomalocardia flexuosa (reclassified from Anomalocardia brasiliana) shells heated between 200 °C and 800 °C demonstrated that thermal changes can be accurately recognized in thin sections and used to estimate the temperatures of archaeological fires. From ∼400–500 °C, carbonization and disappearance of the periostracum occur, along with darkening of the shell and the beginning of fissures; above 500–600 °C, longitudinal and transverse fractures appear, linked to the loss of the organic matrix and the release of CO₂, while higher temperatures produce high deformation, pseudovacuoles, and mineral transformation to calcium oxide. The experimental comparison allowed for the differentiation of in situ combustion features from reworked deposits, where there is a planned mixture of shells burned at different temperatures and unburned shells.

Villagran et al. (2017a) demonstrated that micromorphology allows the identification of skeletal tissues even when bones are not macroscopically preserved, through microscopic fragments and products of their chemical alteration without sedimentation. In thin section, it was possible to reflect internal bone structures, degrees of burning, dissolution, microbial bioerosion, and options of secondary phosphates, distinguishing between primary deposition, reworking, trampling, and in situ liquidation. The study showed that burned bones tend to fragment intensely, becoming invisible in the excavation, while alkaline environments can completely dissolve the original material, leaving only phosphate halos.

Focusing on understanding bone taphonomy from a geoarchaeological perspective, Villagran et al. (2022) applied FTIR, micromorphology and x-ray powder diffraction (XRPD) to investigate whether the absence of faunal remains in archaeological sites from eastern Uruguay was due to post-depositional soil conditions or intentional cultural practices. By analyzing sediments and thin sections from three contemporaneous sites—one earthen mound rich in bones (CH2D01), one earthen mound with scarce bone remains (Las Palmas), and a cairn with no bones (Mario Chafalote)—micromorphology revealed that micro-bone fragments, though nearly invisible macroscopically and undetectable via FTIR or XRPD, were present in very low frequencies in the Las Palmas mound. Their virtual absence in the cairn sediments, however, could not be explained by taphonomic factors alone, as all sites shared similar acidic soil conditions. These findings led to the conclusion that the lack of bones was more likely due to differences in site function, use, and construction techniques rather than environmental degradation, demonstrating micromorphology's unique value in uncovering behavioral signatures otherwise masked in the sedimentary record.

Villagran et al. (2011b) developed a comparative framework to interpret shell midden formation processes through experimental micromorphology. The study consists of a reference collection of 25 thin sections from experimentally heated shell materials (Mytilus edulis), anthropic features—such as hearths and trampling surfaces—and natural contexts under cold climate conditions (e.g., forest litter, beach, forest pathways etc.). The reference set allowed to distinguish between natural and cultural formation processes in shell middens, providing a controlled baseline for interpreting midden stratigraphy. The study emphasizes that without such experimental reference models, archaeological micromorphology remains limited in interpretive depth, especially in cold coastal environments where preservation and transformation processes differ markedly from temperate settings, where most micromorphological work has been done.

Villagran and Poch (2014) highlighted the critical role of micromorphology in identifying and characterizing a previously undocumented form of needle-fiber calcite formed through mechanical, rather than biogenic or chemical, processes. Using soil thin sections from an ethnohistoric shell midden on the Beagle Channel (Túnel VII), micromorphological analysis revealed monocrystalline, prismatic needle-fiber calcite derived from the disintegration of Mytilus edulis shells under freeze–thaw conditions. Micromorphology, coupled with scanning electron microscopy, allowed the authors to trace the crystals’ origin to the physical breakdown of the shell's outer layer, distinguishing them from other forms typically attributed to pedogenic or microbial origins. Micromorphology thus not only enabled the discovery of this calcite form but also offered a methodological pathway to link crystal morphology with site-specific weathering processes, providing a novel proxy for reconstructing past cold-climate conditions in anthropogenic coastal soils.

Working in northern Tierra del Fuego, Chile, Ozán and Borrero (2018) used micromorphology and other parameters to tackle the genesis of circular depressions which are typically found on the footslope of archaeologically relevant hills and were previously thought to be remnants of historical indigenous huts. By comparing excavated areas inside and outside the depressions, the authors did not encounter major artifactual, microstructural and other differences that would be expected from domestic habitations.

Khamnueva et al. (2018). employed micromorphology, XRD, magnetic susceptibility, total C and phytolith analyses to investigate the enigmatic reddish silty fills of hundreds of prehistoric pits discovered on fluvial terraces near Maunga Terevaka, Easter Island/Rapa Nui. Through thin-section analysis, the study identified microstructural features—such as heat-altered mineral grains, hematite nodules, and fine lamination—that suggested anthropogenic alteration of iron-rich soils, likely through controlled heating with grass as fuel. Micromorphology enabled the researchers to differentiate these altered sediments from natural surrounding deposits and interpret the pits as specialized installations for pigment production, likely tied to ritual or symbolic practices of the Rapa Nui culture.

Archaeological micromorphology in Latin America has evolved from a relatively specialized and underused technique into an increasingly central component of contemporary geoarchaeological research. This review synthesized the results of 166 publications (see full data in Supplementary Table S1) produced over the last two decades that applied micromorphology to archaeological contexts across Latin America and related regions (see map in Figure 1; see also Figure 2A). Since the beginning of the twenty-first century, annual publication output has risen from only a few papers per year to a sustained increase of more than five papers annually, reaching peaks of 15 publications in both 2019 and 2022, with an average annual growth rate of 20.9% (and a compound annual growth rate of 2.9%) since 2002. Although growth has not been linear (Figure 2A), the long-term trend clearly demonstrates the expanding adoption and consolidation of archaeological micromorphology within Latin American geoarchaeology.

Country-level patterns (Figures 1, 2B) reveal the pioneering and sustained leadership of Mexico in archaeological micromorphology, which accounts for 34.12% of the surveyed literature, followed by the rapid expansion of Brazil with 25.29%, despite its later adoption of the technique. The data indicate that Mexico and Brazil emerge as major hubs for methodological development, training, and the formation of new specialists. Specific institutions and research groups, such as the Institute of Geology of the National Autonomous University of Mexico (UNAM) and the Museum of Archaeology and Ethnology at the University of São Paulo (USP), are playing a key role in sustaining future generations of archaeological soil micromorphologists. Research conducted in Peruvian sites contributes to 7.65% of publications, followed by sites in Argentina (7.06%), Chile (5.88%), Bolivia (4.12%), Colombia (4.12%), Guatemala (3.53%), and French Guiana (2.35%). Research conducted at sites in Uruguay and Belize each account for less than 2% of the total, while Ecuador, El Salvador, Martinique, Guadeloupe, Antarctica, and related territories each represent approximately 0.6%. Whole sub-regions still remain unrepresented, such as Central America south of Guatemala (Honduras, Nicaragua, Costa Rica, Panama), the Greater Antilles, Venezuela, Paraguay, and the Amazonian territories of Ecuador, Peru and Colombia. Looking ahead, future priorities should include the establishment of additional regional centers equipped for the full production and analysis of thin sections, greater training opportunities for young researchers, and the development of regionally specific reference collections.

The data on country distribution reflect the location of archaeological case studies rather than the institutional origin of the researchers. In this review, we also gathered information on the nationality of researchers and the institutions they are affiliated with (Figure 3B). The data demonstrates the increasing autonomy of Latin American scholars. More than 60% of the surveyed studies were conducted by Latin American analysts working in Latin American institutions, while ∼28% were produced by non-local researchers based in foreign institutions, and ∼10% by Latin American researchers working abroad. These data indicate that the region has become an independent and productive center for high-resolution geoarchaeological research, not entirely dependent on external laboratories or institutions. At the same time, more than 70% of publications were written in English, ensuring international visibility, whereas nearly 30% published in Spanish or Portuguese support effective communication with local and regional audiences (see Supplementary Table S1).

We grouped the literature into nine major research themes (Figure 3A) encompassing a wide range of landscapes and archaeological questions: (1) human–environment interactions (20.48%); (2) past agriculture (16.87%); (3) earthen architecture and construction materials (21.69%); (4) earthworks and earthen mounds (1.81%); (5) anthropogenic dark earths in Amazonia, Mesoamerica, and the Caribbean (9.04%); (6) shell-matrix sites (12.06%); (7) caves and rockshelters (9.64%); (8) living floors and activity areas (3.01%); and (9) other geoarchaeological applications, including experimental archaeology, food technologies, and bone taphonomy (5.42%). Three themes account for nearly 60% of all publications: earthen architecture and construction materials, human–environment interactions, and past agriculture.

The distribution of themes is similar to the history and use of micromorphology in archaeological contexts worldwide (see Mentzer, 2023 for review of African sites). It highlights the maturity of certain research areas while also emphasizing the need to expand micromorphological applications to a broader diversity of archaeological contexts. For instance, experimental micromorphology deserves greater investment to develop local reference collections that characterize materials intrinsic to regional geographical and cultural contexts, thereby increasing the interpretative resolution of micromorphological analyses. Likewise, locally specific materials that are not documented elsewhere require further study, such as those related to food technologies, so that they may follow the path inaugurated by the in-depth investigation of Latin American earthen architecture and construction materials.

Earthworks and earthen mounds account for only 1.81% of the corpus, an extraordinarily low figure for a continent whose pre-Columbian landscapes are defined by monumental earthmoving — from the geometric enclosures of southwestern Amazonia and the earthen mounds of the La Plata basin, to the raised-field and causeway systems of the Llanos de Moxos and the Orinoco basin. We acknowledge that a higher figure could have been obtained by including studies that deal with these features but were classified under Past agriculture and Soils (e.g., Posada-Restrepo et al., 2023 and Rodrigues et al., 2015). Notwithstanding this, the recent expansion of LiDAR and remote-sensing survey (Pärssinen et al., 2026; Prümers et al., 2022) has multiplied the number of known earthen structures far faster than our understanding of how they were actually built, and micromorphology is the only technique capable of resolving individual construction episodes, borrow-material selection, and the presence or absence of prepared surfaces within apparently homogeneous fills. Living floors and activity areas represent just 3.07% (a number that could increase with the inclusion of e.g., Villa et al., 2023, who studied floor deposits in coastal Peru and Macphail et al., 2017, who reported Mayan occupation surfaces affected by pedogenesis), despite being the context in which micromorphology has its greatest comparative advantage over other analytical approaches. Finally, the historical and contemporary periods are almost entirely absent: colonial urban deposits, reductions and missions, plantations, “quilombo” and other African-diaspora settlements, mining landscapes, and industrial contexts have received virtually no micromorphological attention in the region. Latin American historical archaeology deals with the kinds of rapidly accumulating, finely stratified anthropogenic sequences for which the method was designed, and its integration here should be considered a priority.

Considering that nearly 70% of Latin America lies within the tropical belt, and given the need to better distinguish the intrinsic characteristics of tropical geosystems and their associated taphonomic pathways, regional case studies can provide valuable reference frameworks for tropical settings worldwide. The descriptive vocabulary, interpretive criteria and reference imagery on which archaeological micromorphology rests were overwhelmingly developed in temperate, Mediterranean and arid settings, and in the karstic caves of Eurasia. Applying them unmodified to deeply weathered, acidic, intensely bioturbated tropical soils risks systematically underreading the anthropogenic signal — a risk already made explicit by several of the studies reviewed here. We would argue that the single most valuable contribution Latin American micromorphology can make to the global discipline over the next decade is a systematic, experimental and actualistic characterisation of tropical and southern taphonomic pathways. Priority targets are clear: the microfabric signatures of neotropical bioturbating agents (termites, leaf-cutter and other ants, earthworms, deep root systems), whose products can closely mimic — and whose activity progressively destroys — anthropogenic microstructures, and which are already known to have been deliberately collected and used as raw material; the differential dissolution, recrystallisation and disappearance of ash pseudomorphs, faecal spherulites, phytoliths, bone and shell across the pH and moisture gradients of tropical and subtropical soils; and the behaviour of clay aggregates, ferruginous nodules and pedorelicts inherited from oxisols and ultisols within occupation deposits.

Such a programme requires reference collections built locally. A standardised regional network of experimental datasets, physical reference slides and openly accessible digital thin-section images would convert isolated efforts into a shared interpretive infrastructure. A reference framework built in Latin America would be directly transferable to tropical Africa, South and Southeast Asia and Oceania, positioning the region as a producer of interpretive standards rather than an importer of them.

This review has shown that archaeological micromorphology in Latin America has passed from a specialized and sporadically applied technique to a consolidated component of regional geoarchaeological research. The 166 publications surveyed here document sustained growth since the early 2000s, a thematic range spanning nine major research areas, and case studies distributed from northern Mexico to Tierra del Fuego, and with more than 70% of the studies carried out by Latin American analysts. Yet the same data expose where the field has not gone. Three themes concentrate nearly 60% of the corpus, while earthworks and earthen mounds, living floors and activity areas, and the historical and contemporary periods remain marginal, and entire sub-regions are still absent from the map. Addressing these silences requires more than a wider application of existing protocols: it calls for reference and experimental materials built locally, for interpretive criteria calibrated to deeply weathered, intensely bioturbated tropical geosystems. This also highlights the substantial potential for the expansion of geo-ethnoarchaeological research in the region. Latin America's exceptional environmental and cultural diversity, together with opportunities for collaborative work with native peoples and local communities, offers a rich framework for advancing globally relevant micromorphological research in the years to come.

Although micromorphology has already been applied to a wide variety of archaeological settings, it is still frequently employed as a stand-alone method. Future research would benefit from broader integration with complementary analytical approaches such as XRD, XRF, FTIR, micro-CT, Raman spectroscopy, organic petrography, lipid and other biomarker analysis, thereby enhancing interpretative resolution and multiproxy potential. Several works reviewed here already demonstrate the interpretive gain of this approach, but it remains the exception rather than the norm. Another issue concerns quantification and reproducibility: image analysis of thin-section scans, together with the emergence of machine-learning approaches to microfabric classification, offers a route out of the descriptive subjectivity that has long limited inter-site and inter-analyst comparison. Realising this depends on a commitment to open data — the routine deposition of high-resolution plane- and cross-polarised scans, full descriptive tables and sample coordinates in public repositories, so that published interpretations become independently testable.

Another issue concerns publication and language practice. Our decision to exclude grey literature was methodologically necessary, but it almost certainly conceals a substantial body of micromorphological work embedded in theses, dissertations and contract-archaeology reports, particularly in countries with strong preventive-archaeology legislation. Converting this work into citable literature, and extending the consistent use of the Stoops (2003, 2021) terminology — including its Spanish and Portuguese equivalents — would materially improve both the visibility and the comparability of regional research. The roughly 30% of publications appearing in Spanish and Portuguese should be understood not as a limitation on international reach but as an asset for regional training and community engagement, and we would encourage bilingual publication of abstracts, figure captions and descriptive tables wherever editorial policy permits.

Thus, on the basis of this synthesis, we propose four concrete priorities for the coming decade. (i) Infrastructure and training: the establishment of additional regional centres capable of full thin-section production and analysis, complemented by a formal mobility and short-course scheme that allows researchers from countries currently absent from Figures 1, 2B to access existing facilities in Mexico, Brazil and elsewhere. (ii) Shared reference infrastructure: coordinated, openly accessible physical and digital reference collections for tropical, Andean and southern-cone materials, built through experimental and ethno-geoarchaeological work. (iii) Sampling by design: the incorporation of micromorphological sampling into excavation planning, including within preventive and rescue archaeology, rather than as a retrospective addition to already-open profiles — a shift that would also address the thematic gaps identified above, since activity-area and construction-sequence questions cannot be answered by opportunistic sampling. (iv) Multiproxy and quantitative integration, with open deposition of primary image and descriptive data.

In summary, archaeological micromorphology in Latin America has become a mature, and rapidly expanding field within global geoarchaeological research. The sustained growth in publications, the diversity of themes investigated, and the broad geographic distribution of case studies demonstrate not only the successful consolidation of the technique across the region, but also its capacity to generate original scientific contributions of worldwide relevance. Particularly significant is the emergence of strong local research centers—especially in countries such as Mexico and Brazil—that possess autonomous facilities for thin-section production and laboratory analysis. These institutions function not merely as regional laboratories, but as centers of methodological development, and the training of human resources, attracting both Latin American and international scholars. Their existence confirms that Latin America is not a peripheral consumer of imported knowledge, but an active producer of cutting-edge science and a leading actor in the global development of archaeological micromorphology. With its exceptional environmental diversity, extensive tropical landscapes, rich archaeological record, and growing scientific infrastructure, Latin America is uniquely positioned to shape future developments in micromorphology, multiproxy archaeology, and the understanding of human–environment interactions on a global scale.