Coupled sedimentary and δ13C records of late Mississippian platform-to-slope successions from South China: Insight into δ13C chemostratigraphy
Coupled sedimentary and δ13C records of late Mississippian platform-to-slope successions from South China: Insight into δ13C chemostratigraphy
复制标题
中国南方密西西比晚期台地-斜坡序列的沉积和三角洲 C-13 耦合记录：深入了解三角洲 C-13 化学地层学
DOI：
10.1016/j.palaeo.2015.10.051
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发表时间：
2016-04-15
影响因子：
3
通讯作者：
Lin, Wei
中科院分区：
文献类型：
--
作者：
Chen, Jitao;Montanez, Isabel P.;Lin, Wei
Variability in stratigraphic accumulation rates and distribution of stratal hiatuses along with strong endemism of index fossils hinder regional to global stratigraphic correlation of the Visean-Serpukhovian (V-S) boundary interval (late Mississippian) and thus geological inferences regarding the onset of the late Paleozoic ice age. Here we integrate high-resolution delta C-13 time series with detailed sedimentary fades analysis of late Visean-early Serpukhovian (V-S) carbonate platform-to-slope successions from South China to evaluate the influences of local depositional and diagenetic processes on delta C-13(carb) and to address the correlation issue.Analysis of 11 sedimentary fades from 5 outcrop sections indicates a restricted platform setting (Yashui section) dominated by bioclastic wacke-packstone to lime mudstone in which paleokarst developed, and contemporaneous carbonate slope settings dominated by thin-bedded lime mudstones intercalated with slumps and calciturbidites. Based on vertical fades assemblages, three depositional units are recognized, recording a significant sea-level drawdown across the V-S boundary. Multiple negative delta C-13 excursions (>1 parts per thousand) can be correlated across the V-S boundary interval in several slope sections (Naqing, Luokun, and Narao sections). Variability in the V-S boundary delta C-13 record in some sections is interpreted to record truncation physically by submarine erosion by slumps or chemically during karstification. A long-term decrease in delta C-13 values through the Serpukhovian of the Yashui section likely records local influences on carbon cycling in the restricted platform setting. This negative delta C-13 trend and associated depositional facies at the Yashui section can be correlated to the Arrow Canyon section, USA, which, together with other coeval global sedimentary and geochemical records, indicate a widespread eustatic drawdown in the late Visean with initial buildup of Gondwanan ice sheets. We conclude that integrated sedimentary facies analysis and delta C-13 chemostratigraphy can be used for stratigraphic correlation when interpreted within a well-constrained sedimentary and carbon-isotope regional framework. (C) 2015 Elsevier B.V. All rights reserved.
