Although there are important landscapes developed on underlying quartzite in Brazil, there is still very little known about the processes and mechanisms involved in their formation. Some recent research has drawn attention to the presence of karstic features associated with silica dissolution in this lithology. However, there are other relief forms and materials commonly encountered in the domain of quartzite in the Espinhaço Mountain Range in the southeast region of Brazil. The main objective of this research is to analyze the geomorphic processes associated with the material overlying relatively flat surfaces of low inclination that always occur near quartzite outcrops in the study area. This is relevant in order to attempt to understand the development of landforms in quartzite domains in tropical humid areas. A Geomorphic approach for the analysis of the material was used, in which geomorphic sites were identified and two soil profiles were described and sampled for laboratory analysis. This was complemented with laboratory analysis of phytoliths found in the soil, ¹³C analysis and ¹⁴C-AMS dating. The relatively shallow profiles show a sequence of similar horizons, in which the material varies from sandy organic material at the top to stony immediately below. The superficial horizons have predominantly finer sand and also clay, which is expected in humid tropical environments. Both profiles present a stony layer formed of angular to subangular quartz pebbles lying just on the top of the weathered quartzite in the C horizons where the oldest SOM ¹⁴C dating values were found. Considering the mean residence time (MRT), it is possible to assume that the first depositions in P2 are more than 10.000 yrs old (10,506-10,230 yr cal BP) and that the first profile in P1, located on the upper slope, presents younger SOM (5,919-5,664 yr cal BP). This suggests that the erosive processes were either more intense or more recent on this portion of the slope and that these deeper horizons may have previously been on the surface, when the material was deposited. Also, the high amount of phytoliths which are unclassified due to their destruction, along with the presence of the most robust types, can be interpreted as evidence of intense erosion and transportation of the material by surface runoff, enabling the assumption that the material is colluvium and that its source is a nearby quartzite outcrop. After deposition along the gently inclined slope, identified as a “colluvial ramp”, the material was relatively undisturbed, which allowed pedogenic processes to take place, forming Quartz-sand Neosols. The ramp itself seems to be the result of very slow rates of weathering and removal of the material, together with strong control from relatively flat Mesoproterozoic depositional macro-structures of the underlying rock. This study is one of the first attempts to use phytoliths combined with carbon isotope analysis for geomorphologic purposes, with very interesting results. Their relevance points to their potential for geomorphic studies.

A Serra do Espinhaço Meridional (SdEM) tem sido intensamente pesquisada por arqueólogos, produzindo um conhecimento significativo sobre a história indígena regional. Entretanto, também é necessário conhecer as condições paleoclimáticas e o contexto ambiental em que essas ocupações ocorreram. Este trabalho pretende contribuir com pesquisas já desenvolvidas pelo Laboratório de Arqueologia e Estudo da Paisagem da UFVJM na Área Arqueológica de Serra Negra, na face leste da SdEM, entre as bacias dos rios Jequitinhonha e Doce. O objetivo deste trabalho é a reconstituição paleoambiental desta região utilizando como indicadores os fitólitos, partículas de sílica que se depositam no interior das células das plantas e que permitem inferir a vegetação de onde se originaram. Em Felício dos Santos, foram coletados sedimentos do Sítio Arqueológico Cabeças 4, que foi ocupado em uma faixa cronológica entre 7225 anos AP e 480 anos cal AP. Além disso, coletou-se uma amostra em cada horizonte de um perfil de Organossolo próximo ao Sítio Arqueológico. Nas amostras do Sítio Arqueológico Cabeças 4 predominam fitólitos de gramíneas e palmeiras. Estes resultados foram corroborados com os do perfil de solo, que se apresentam preservados e distribuídos de forma homogênea. As análises de fitólitos se mostraram promissoras para inferências de variações climáticas e um maior conhecimento do ambiente em que se processou a ocupação arqueológica regional. A B S T R A C TThe Southern Espinhaço Mountain Range (SdEM) has been intensively studied by archaeologists, producing significant knowledge on the regional indigenous history. However, it is also necessary to know the paleoclimatic conditions and environmental context in which such occupations occurred. This work intends to contribute to research developed by the Archeology and Landscape Studies Laboratory of UFVJM in the Archaeological Area of Serra Negra, located on the eastern side of the SdEM, between the Jequitinhonha and Doce river basins. The objective of this work is paleoenvironmental reconstruction of this region using phytoliths, silica particles deposited inside plant cells, enabling inference of the vegetation from which they originated. Sediments were collected from the Cabeças 4 Archaeological Site, in Felício dos Santos, which was occupied during a chronological period between 7225 and 480 years cal BP. In addition, a sample was collected from each horizon of an organosol profile near the Archaeological Site. Phytoliths from grasses and palm trees predominate in the samples from the Cabeças 4 Archaeological Site. These results were corroborated with the types found in the soil profile, which are preserved and homogeneously distributed in the profile. Therefore, the phytolith analyses were promising for inferences of climatic variations and for improving knowledge on the environment in which the regional archaeological occupation occurred.Keywords: archaeological site; organosol; climatic variations.