Local geological sections and regional stratigraphy based on physical geology and chemical stratigraphy of the Serra Geral Group from Araraquara to Avaré, SP

<div><p>ABSTRACT: From Araraquara to Avaré, in the Serra Geral Group outcropping area, 22 detailed geological sections were elaborated. The stratigraphic relationships and the chemical analysis allowed the identification of seven [P2O5] basalt classes, all of them pertaining to the Pitanga type, showing a consistent stacking order across the studied region. Thus, each class is considered to correspond to a specific lava flow, allowing a general stratigraphic column to be proposed. Besides the stacking order, the validation of P2O5 as a tool for lava correlation at great distances was also based on the values obtained from samples collected at different positions in a single flow, and on the remarkable [P2O5] contrast between adjacent flows. Minimum lateral extensions range from 75 to 185 km, and thickness from 20 to 80 m. Vertical tectonic displacements, which took place in different periods, were inferred from the altitude of specific flows, and also from the Botucatu and Piramboia formations. They are noticeable in a region bounded by EW drainage lineaments, which contains a large area where Piramboia and Botucatu formations crop out, probably due to the tectonic activity causing this region to be a generalized structural high.</p></div

Local geological sections and regional stratigraphy based on physical geology and chemical stratigraphy of the Serra Geral Group from Araraquara to Avaré, SP

<div><p>ABSTRACT: From Araraquara to Avaré, in the Serra Geral Group outcropping area, 22 detailed geological sections were elaborated. The stratigraphic relationships and the chemical analysis allowed the identification of seven [P2O5] basalt classes, all of them pertaining to the Pitanga type, showing a consistent stacking order across the studied region. Thus, each class is considered to correspond to a specific lava flow, allowing a general stratigraphic column to be proposed. Besides the stacking order, the validation of P2O5 as a tool for lava correlation at great distances was also based on the values obtained from samples collected at different positions in a single flow, and on the remarkable [P2O5] contrast between adjacent flows. Minimum lateral extensions range from 75 to 185 km, and thickness from 20 to 80 m. Vertical tectonic displacements, which took place in different periods, were inferred from the altitude of specific flows, and also from the Botucatu and Piramboia formations. They are noticeable in a region bounded by EW drainage lineaments, which contains a large area where Piramboia and Botucatu formations crop out, probably due to the tectonic activity causing this region to be a generalized structural high.</p></div

Integrated geological map of the São Roque Domain, North of São Paulo City – Brazil

<div><p>The São Roque Domain has an extensive geological cartographic base that began in the nineteenth century with the works performed by the <i>Geographic and Geological Commission of São Paulo Province</i>. The first more detailed geological maps of geological substrate of the São Paulo city and neighboring areas were executed in the decades of 1940–1950, and culminated in the integrated maps by <i>José Moacyr Vianna Coutinho</i> published in the 1970s. As part of a systematic geological mapping campaign led by PRÓ-MINÉRIO, most of the São Roque Domain was mapped at 1:50,000 scales; these maps, and others at the same or more detailed scale published mostly in the 1980s, are only available in unpublished academic theses and reports. This article presents an integrated map of most of the São Roque Domain based on all the available maps and some new stratigraphic and geochronological data that appeared in recent local literature.</p></div