کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8953055 1645895 2018 40 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A basin-wide record of the Late Cambrian Steptoean positive carbon isotope excursion (SPICE) in the Amadeus Basin, Australia
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
A basin-wide record of the Late Cambrian Steptoean positive carbon isotope excursion (SPICE) in the Amadeus Basin, Australia
چکیده انگلیسی
The Cambrian Paibian sedimentary succession of the central Australian Amadeus Basin contains a sequence of supratidal to subtidal shallow marine siliciclastic and oolitic, stromatolitic limestones and dolostones. Basin-wide sequence stratigraphy in combination with biostratigraphy revealed the G. stolidotus Zone within a 3rd-order transgressive systems tract (TST). The westward transgression caused changes from a fluvial-dominated depositional environment towards a shallow-marine oolitic carbonate shoal environment. The eastern succession is dominated by stromatolitic, oolitic carbonate rocks with 2- to 5-m 5th-order shoaling upward cycles with several 4th-order cycles. The change from TST to HST (highstand systems tract) is marked by a maximum flooding surface within the Goyder Formation, which coincides with the peak of the Steptoean Positive Carbon Isotope Excursion (SPICE). The SPICE shows a facies-independent, synchronous positive δ13C excursion of 5‰ in a 130 m interval in 8 sections across a ~460 km transect. The SPICE peak is lowest in the nearshore successions (+0.4‰ δ13C), and highest in the platform succession (+4.9‰ δ13C) and is interpreted to be related to the chemical gradient of seawater and mixing of the DIC with atmospheric CO2-derived (i.e. terrestrial) bicarbonate. The recovery from SPICE is recorded by 4th-order shoaling upward cycles that compose the 3rd-order HST. This is the first time that sequence stratigraphy and biostratigraphy has been combined with carbon isotope chemostratigraphy across the nearshore to subtidal Cambrian basin succession in Australia.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Palaeogeography, Palaeoclimatology, Palaeoecology - Volume 508, 1 November 2018, Pages 116-128
نویسندگان
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