Geochemical characterization of fossil turtles from Tartaruguito outcrop (Upper Cretaceous, Bauru Basin, Presidente Prudente Formation), Sao Paulo state, southeastern Brazil

被引：2

作者：

Pinto, Camila Batista ^{[1
]}

da Silva Lacerda, Mauro Bruno ^{[2
,3
]}

Rodrigues, Bernardo Lages ^{[1
]}

Mussel, Wagner da Nova ^{[1
]}

Romano, Pedro Seyferth R. ^{[3
]}

机构：

[1] Univ Fed Minas Gerais, Dept Quim, Belo Horizonte, MG, Brazil

[2] Univ Fed Minas Gerais, Dept Zool, Inst Ciencias Biol, Ave Antonio Carlos 6627,Campus UFMG, BR-31270901 Belo Horizonte, MG, Brazil

[3] Univ Fed Vicosa, Dept Biol Anim, Vicosa, MG, Brazil

来源：

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES | 2020年 / 104卷

关键词：

Bauru group; Bauruemys elegans; Fossil diagenesis; Powder X-ray diffraction; Pirapozinho locality; ADAMANTINA FORMATION; TAPHONOMY; CARCHARODONTOSAURIDAE; COPROLITES; DINOSAURS; THEROPODA; PATTERNS; APATITES; TRACES; EGG;

D O I：

10.1016/j.jsames.2020.102843

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

The Tartaruguito outcrop (Pirapozinho municipality, Presidente Prudente Formation, Bauru Basin) has been considered a Fossil-Lagerstadtte due to its exceptional fossil quality and large number of fossils recovered. Despite its historical and paleontological importance, a geochemical composition study of the fossils from this site and their sedimentary matrixes has never been performed. Here, we have analyzed fossil turtle shell fragments and their respective sedimentary matrixes collected at Tartaruguito through Powder X-Ray Diffraction and Infrared Spectroscopy techniques, to determine their geochemical composition and obtain clues regarding the fossil diagenesis processes. The analyses showed that the fossil remains of the side-necked turtle Bauruemys elegans from the Tartaruguito locality are mainly composed of calcite (CaCO3) and hydroxyapatite partially substituted by fluorine (Ca-10(PO4)(6)(OH)(2-x)F-x). The sedimentary matrixes are mostly composed of quartz (SiO2) and calcite, with secondary amounts of feldspar. The presence of calcite on both, fossil and rocky matrix, might indicate that the fossil diagenesis process that occurred at the Tartaruguito locality was permineralization by calcite, especially considering the absence of quartz on the bones of the fossil specimens. Furthermore, the presence of a fluor-hydroxyapatite solid-solution might be a plausible explanation for the quality of fossils recovered in Tartaruguito, due to the better stability of fluorapatite when compared to hydroxyapatite.

引用

页数：10