학술논문
Caractérisation sédimentologique, minéralogique, géochimique et palynologique des cortèges sédimentaires du Domérien du Quercy septentrional (nord-est du bassin d'Aquitaine)
Document Type
Academic Journal
Author
Source
Bulletin de la Société Géologique de France. 170(4):475-486
Subject
Language
English
ISSN
0037-9409
Abstract
The middle and upper parts of the northern Quercy Domerian comprise 7 successive lithological levels which are distinct with respect to sedimentology, palaeontology and facies. Mineralogical and geochemical analysis of the Lapoujade reference section revealed, firstly, a lowering in sea level accompanied by a decrease in kaolinite and an increase in illite contents, and, secondly, a regressive tendency of the environmental deposits marked by the strontium--the most significant geochemical element. The output of this work allowed to improve and refine our understanding of this section in terms of sequence stratigraphy, primarily based on sedimentary data and on the geometric organization of the deposits. Three depositional sequences and seven systems tracts were identified and characterized; this includes the discontinuities separating them. Mineralogical and palynological data allowed to recognize a major climatic change at a sequence boundary, suggesting a relationship between eustatic variations and climatic phenomena.