Skip to Main content Skip to Navigation
Journal articles

Stable isotope characterization of pedogenic and lacustrine carbonates from the Chinese Tian Shan: constraints on the Mesozoic - Lower Cenozoic palaeo-environmental evolution

Abstract : In the Mesozoic–Cenozoic continental deposits of the Tian Shan area, two main levels containing pedogenic carbonates have been identified on both the southern and northern foothills of the range: one in the Upper Jurassic series and one in the Upper Cretaceous–Lower Palaeocene series. In order to reconstruct the palaeoenvironmental and palaeotopographic characteristics of the Tian Shan area during these two periods, we measured the oxygen and carbon isotope composition of these pedogenic carbonates (calcrete and nodules). The stable isotope compositions are homogeneous: most δ18O values are between 21 and 25‰ and most δ13C values are between −4 and −6‰. No distinction can be made between the calcrete and nodule isotopic compositions. The constancy of isotopic values across the Tian Shan is evidence of a development of these calcification features in similar palaeoenvironmental conditions. The main inference is that no significant relief existed in that area at the Cretaceous−Palaeogene boundary, implying that most of the present relief developed later, during the Cenozoic. In addition to the pedogenic carbonates, few beds of limestones interstratified in the Jurassic series of the southern foothills display oxygen and carbon isotope compositions typical of lacustrine carbonates, ruling out brackish water incursion at that period in the region
Document type :
Journal articles
Complete list of metadatas

Cited literature [44 references]  Display  Hide  Download

https://hal-insu.archives-ouvertes.fr/insu-01116934
Contributor : Isabelle Dubigeon <>
Submitted on : Monday, June 22, 2015 - 9:50:28 AM
Last modification on : Friday, March 27, 2020 - 2:13:25 AM
Long-term archiving on: : Tuesday, April 25, 2017 - 5:51:35 PM

File

Heilbronn-2015.pdf
Files produced by the author(s)

Identifiers

Citation

Gloria Heilbronn, Philippe Boulvais, E Marchand, Cécile Robin, Sylvie Bourquin, et al.. Stable isotope characterization of pedogenic and lacustrine carbonates from the Chinese Tian Shan: constraints on the Mesozoic - Lower Cenozoic palaeo-environmental evolution. Chemie der Erde / Geochemistry, Elsevier, 2015, 75 (1), pp.133-141. ⟨10.1016/j.chemer.2014.11.004⟩. ⟨insu-01116934⟩

Share

Metrics

Record views

375

Files downloads

718