DOI: 10.1016/j.earscirev.2018.07.012
论文题名: Unusual shallow marine matground-adapted benthic biofacies from the Lower Triassic of the northern Paleotethys: Implications for biotic recovery following the end-Permian mass extinction
作者: Feng X. ; Chen Z.-Q. ; Bottjer D.J. ; Wu S. ; Zhao L. ; Xu Y. ; Shi G.R. ; Huang Y. ; Fang Y. ; Tu C.
刊名: Earth Science Reviews
ISSN: 00128252
出版年: 2019
卷: 189 起始页码: 194
结束页码: 219
语种: 英语
中文关键词: Deep-tiering infauna
; Early Triassic
; Ichnodiversity
; Microbial mats
; Northwestern China
; Phase shifts
; Unusual biofacies
英文关键词: benthic infauna
; biodiversity
; biofacies
; ichnology
; mass extinction
; microbial activity
; Triassic
; China
; Qinghai
; Bivalvia
; Diplocraterion
; Metazoa
英文摘要: We report two shallow marine, ichnofauna-bivalve-microbial mat biofacies from the Lower Triassic Xiahuancang Formation of the southern Qilian area, Qinghai Province, northwestern China, which was located at moderate-high paleolatitudes on the northern margin of the Paleotethys Ocean. Paleoenvironmental analyses show that Members I and II of the Xiahuancang Formation represent a shoreface and a lower shoreface to offshore transition setting, respectively. Biofacies 1, recognized from Member I, is characterized by a diverse ichnofauna (including deep-tiers of Rosselia and Diplocraterion), Claraia-dominated bivalves, and microbially induced sedimentary structures (MISSs). Biofacies 2, in succeeding Member II, is dominated by a diverse ichnofauna, epifaunal and shallow infaunal bivalves, and wrinkle structures. Primary co-occurrences, preservational features, and palimpsest or crosscutting relationships of all components within the biofacies indicate that microbial mats, bivalves, and trace-makers actively interacted with one another during deposition. They largely represent contemporaneous biotic associations. Microbial mats are interpreted to have grown under well-oxygenated conditions after storm deposition due to the association of deep-tiering infauna and diverse epifauna as well as well-developed cross-stratification, and the top layer of microbial mats could serve as an oasis for metazoans. Microbial mats not only proliferated in harsh environments, but also coexist with epifauna and deep-tiering infauna in well-oxygenated settings following the end-Permian crisis. Their occurrences in the Early Triassic are unrelated to environmental stresses, which are coincident with their sedimentologic record from other geological time intervals. Apparently, the southern Qilian ichnofauna-bivalve-microbial mat biofacies with juxtaposed epifauna, infauna and MISS- or wrinkle-related microbial mats represents a matground-adapted benthic metazoan ecosystem in the earliest Triassic, which provided sufficient oxygen, food, and other hydrodynamic conditions hospitable for metazoans and ecosystems to recover and reached a fairly high level (recovery stage 3) in a tough time when most biotas suffered biotic depletion and environmental stress. The biotic components in unique biofacies may represent a phase shift community in siliciclastic settings during the Early Triassic. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165800
Appears in Collections: 气候变化与战略
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作者单位: State Key Laboratory of Biogeology and Environmental Geology, School of Earth Science, China University of Geosciences (Wuhan), Wuhan, 430074, China; Department of Earth Sciences, University of Southern California, Los Angeles, California, 90089, United States; State Key Laboratory of Geological Process and Mineral Resources, China University of Geosciences (Wuhan), Wuhan, 430074, China; Deakin University, School of Life and Environmental Sciences, Burwood Campus, Melbourne, Victoria 3125, Australia
Recommended Citation:
Feng X.,Chen Z.-Q.,Bottjer D.J.,et al. Unusual shallow marine matground-adapted benthic biofacies from the Lower Triassic of the northern Paleotethys: Implications for biotic recovery following the end-Permian mass extinction[J]. Earth Science Reviews,2019-01-01,189