CaltechAUTHORS
  A Caltech Library Service

Paleoelevations in the Jianchuan Basin of the southeastern Tibetan Plateau based on stable isotope and pollen grain analyses

Wu, Jing and Zhang, Kexin and Xu, Yadong and Wang, Guocan and Garzione, Carmala N. and Eiler, John and Leloup, Philippe Hervé and Sorrel, Philippe and Mahéo, Gweltaz (2018) Paleoelevations in the Jianchuan Basin of the southeastern Tibetan Plateau based on stable isotope and pollen grain analyses. Palaeogeography, Palaeoclimatology, Palaeoecology, 510 . pp. 93-108. ISSN 0031-0182. http://resolver.caltech.edu/CaltechAUTHORS:20180403-085035622

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20180403-085035622

Abstract

The southeastern margin of the Tibetan Plateau (TP) is a key region for understanding the region's surface uplift mechanisms. This study focused on the Jiuziyan and Shuanghe Formations (Fms) in the Jianchuan Basin, both of which include lacustrine calcareous mudstones and marls. Ostracods of the genus Austrocypris found within the Jiuziyan and Shuanghe Fms constrain the age of strata to the Late Eocene. This study used two different proxies, i.e. fossil pollen coexistence and the δ^(18)O (VPDB) values of carbonate (δ^(18)O_c), to reconstruct paleoelevation and the extant paleoenvironment from lacustrine calcareous mudstones and marls preserved in the Eocene stratigraphy of the Jianchuan Basin. The coexistence approach (CA) using pollen data from the Shuanghe Fm indicates a paleoelevation of 1.3–2.6 km above sea level (asl), which would most probably have been associated with a vegetation cover consisting of tropical-subtropical, deciduous, coniferous, broadleaf forests. The reconstructed mean annual air temperature (MAAT) had a value of 16.8–21.7 °C, warmer than today's MAAT (~6 °C). Oxygen isotope results from the Jiuziyan Fm, with/without modification between Eocene and modern Myanmar sea level, suggested that the surface of the Jianchuan Basin was at a paleoelevation between 0.5^(+0.8)_(–0.5) km asl and 2.5 ± 0.7 km asl (δ^(18)Omw: −8.9 ± 1.3‰, 2σ). During the Shuanghe Fm sedimentation the paleoelevation was between 0.9^(+0.7)_(–0.7) km asl and 2.9 ± 0.6 km asl (δ^(18)O_(mw): −9.5 ± 1.1‰, 2σ). Our results suggest that a stepwise uplift of Jianchuan Basin and crustal thickening initiated during the Eocene was the cause of passive surface uplift of the southeastern Tibetan Plateau (TP) rather than Miocene lower crustal flow.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1016/j.palaeo.2018.03.030DOIArticle
https://www.sciencedirect.com/science/article/pii/S0031018217309379PublisherArticle
Additional Information:© 2018 Elsevier B.V. Received 12 September 2017, Revised 23 March 2018, Accepted 24 March 2018, Available online 3 April 2018.
Subject Keywords:Yunnan; Clumped isotopes; Paleoaltimetry; Palynomorphs
Record Number:CaltechAUTHORS:20180403-085035622
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20180403-085035622
Official Citation:Jing Wu, Kexin Zhang, Yadong Xu, Guocan Wang, Carmala N. Garzione, John Eiler, Philippe Hervé Leloup, Philippe Sorrel, Gweltaz Mahéo, Paleoelevations in the Jianchuan Basin of the southeastern Tibetan Plateau based on stable isotope and pollen grain analyses, Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 510, 2018, Pages 93-108, ISSN 0031-0182, https://doi.org/10.1016/j.palaeo.2018.03.030. (http://www.sciencedirect.com/science/article/pii/S0031018217309379)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:85576
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:03 Apr 2018 17:13
Last Modified:06 Nov 2018 22:14

Repository Staff Only: item control page