globalchange  > 过去全球变化的重建
DOI: 10.1016/j.palaeo.2016.08.020
论文题名:
The Pliensbachian-Toarcian paleoclimate transition: New insights from organic geochemistry and C, H, N isotopes in a continental section from Central Asia
作者: Tramoy R.; Schnyder J.; Nguyen Tu T.T.; Yans J.; Jacob J.; Sebilo M.; Derenne S.; Philippe M.; Huguet A.; Pons D.; Baudin F.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 461
起始页码: 310
结束页码: 327
语种: 英语
英文关键词: brGDGT ; n-Alkanes ; Xenoxylon ; δ15Norg ; δ2H
英文摘要: The Taskomirsay section (South Kazakhstan) is a unique Pliensbachian-Toarcian sequence of lignites, clayey layers and silty-sandstones deposited in a fluvial/lacustrine environment with nearby swampy areas. This period, characterized by a drastic climate change, has been particularly studied in Western Tethyan marine environments, whereas very few studies focused on continental settings. Paleoflora analyses, associated with a multi-isotope approach, based on well-preserved Type-III bulk organic nitrogen isotopes (δ15Norg) and hydrogen isotopic composition (δ2H) of n-alkanes, were developed to document paleoclimatic changes in the area. Sporomorph associations and fossil woods revealed a globally warm- to cool-temperate climate – characterized by Xenoxylon, a conifer morphogenus biogeographically related to cool/humid settings – apart from slightly less humid and warmer conditions in the early Toarcian. Warmer conditions are supported by reconstructed Mean Annual Air Temperatures (MAATs), based on the first branched glycerol dialkyl glycerol tetraethers (brGDGTs) ever recorded in the Early Jurassic. Nevertheless, no drastic changes were recorded in the δ15Norg values; its signal being attributed to tenuous equilibrium between water- and nutrient-availability via intense N-recycling. Based on n-alkane distributions, sources of organic matter were separated in two pools: (i) a purely terrestrial (n-C27) and (ii) an “aquatic” pool (n-C23) constituted of vegetation that thrived under almost permanent water supply. The n-alkane δ2H values (− 248 to − 151‰) as well as their amounts and average chain lengths (ACL) are in agreement with cool-temperate conditions in the Pliensbachian and less humid/warmer conditions in the early Toarcian. The isotopic difference between δ2H values of n-C27 and n-C23 (Δ2Hter-aq) suggests enhanced seasonality during the Pliensbachian-Toarcian transition and low seasonality in the early Toarcian, in agreement with temperate climate-regime. Finally, contrasted response to paleoclimate changes between markers suggests different spatial integration of those proxies. The role of sea-level variations for δ2H values might also resolve this contrasted response. © 2016 Elsevier B.V.
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68249
Appears in Collections:过去全球变化的重建

Files in This Item:

There are no files associated with this item.


作者单位: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut des Sciences de la Terre de Paris (iSTeP), 4 place Jussieu, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, CNRS, EPHE, UMR7619, Milieux Environnementaux, Transferts et Interactions dans les Hydrosystèmes et les Sols (METIS), 4 place Jussieu, Paris, France; Université de Namur, Department of Geology, NaGRIDD, 61 rue de Bruxelles, Namur, Belgium; Institut des Sciences de la Terre d'Orléans, UMR 7327 CNRS—Université d'Orléans—BRGM, 1A rue de la Férollerie, Orléans, France; Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institute of Ecology and Environmental Sciences (iEES), 4 place Jussieu, Paris, France; Université Lyon 1, UMR 5023, CNRS, Campus de la Doua, Darwin A, Villeurbanne cedex, France; Sorbonne Universités, UPMC Univ Paris 06, CNRS, MNHN, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements (CR2P), 4 place Jussieu, Paris, France

Recommended Citation:
Tramoy R.,Schnyder J.,Nguyen Tu T.T.,et al. The Pliensbachian-Toarcian paleoclimate transition: New insights from organic geochemistry and C, H, N isotopes in a continental section from Central Asia[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,461
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[Tramoy R.]'s Articles
[Schnyder J.]'s Articles
[Nguyen Tu T.T.]'s Articles
百度学术
Similar articles in Baidu Scholar
[Tramoy R.]'s Articles
[Schnyder J.]'s Articles
[Nguyen Tu T.T.]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[Tramoy R.]‘s Articles
[Schnyder J.]‘s Articles
[Nguyen Tu T.T.]‘s Articles
Related Copyright Policies
Null
收藏/分享
所有评论 (0)
暂无评论
 

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.