Artículos de revistas
Evidence for euphotic zone anoxia during the deposition of Aptian source rocks based on aryl isoprenoids in petroleum, Sergipe-Alagoas Basin, northeastern Brazil
Registro en:
Organic Geochemistry. Pergamon-elsevier Science Ltd, v. 63, n. 94, n. 104, 2013.
0146-6380
WOS:000325470100011
10.1016/j.orggeochem.2013.07.009
Autor
Sousa, GR
Santos, ALS
de Lima, SG
Lopes, JAD
Reis, FAM
Neto, EVS
Chang, HK
Institución
Resumen
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Four crude oil samples from the Sergipe-Alagoas Basin, northeastern Brazil, were analyzed using full scan gas chromatography-quadrupole mass spectrometry (GC-qMS) for biomarkers, in order to correlate them using aromatic carotenoids thereby enhancing knowledge about the depositional environment of their source rocks. The geochemical parameters derived from saturated fractions of the oils show evidence of little or no biodegradation and similar thermal maturation (Ts/(Ts + Tm) for terpanes, C-29 alpha beta beta/(alpha beta beta + alpha alpha alpha), C-27, and C-29 20S/(20S + 20R) for steranes). Low pristane/phytane ratios and the abundance of gammacerane and beta-carotane are indicative of an anoxic and saline depositional environment for the source rocks. Moreover, we identified a large range of diagenetic and catagenetic products of the aromatic carotenoid isorenieratene, including C-40, C-33, and C-32 diaryl isoprenoids and aryl isoprenoid derivatives with short side chains and/or additional rings. These results indicate anoxia in the photic zone during the deposition of the source rocks. (c) 2013 Published by Elsevier Ltd. 63 94 104 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) PETROBRAS UFPI Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)