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The beachrock Jaconé, Maricá and Saquarema - RJ: importance to the history of science and to the geological knowledge

Abstract:

The Caminhos de Darwin Project aims to redeem the episodes experienced by Charles Darwin in the state of Rio de Janeiro and that they have had part in his scientific training aboard the Beagle. In the geological approach of this project, the outcrops described by Darwin in the State of Rio de Janeiro are being described with purposes of geoconservation. The beachrock of Jaconé was identified by the naturalist, at then 23 years old, on April 9, 1832. Over the years, archaeological researches conducted in the region discovered pebbles of beachrock in the middens of Beirada and Moa. This fact demonstrates that thisrock was already known by prehistoric men for over 4000 years BP. The present study aimed to assess these outcrops as geological heritage and, at the same time, update the knowledge about its geology. Three lithofacies were identified and two of them were analyzed petrographically. The age of the shells was calculated at 8198-7827 cal BP by the radiocarbon method. The occurrence is constituted as a geological heritage of the following typologies: geomorphological, sedimentary, paleoenvironmental, petrological, and archaeological and, also, contextualized in the science history. It has international significance and scientific, cultural, educational and ecological value.

Keywords:
Geological Heritage; Science History; Beachrock; Darwin

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