کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4698511 1637569 2015 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Novel 1H-Pyrrole-2,5-dione (maleimide) proxies for the assessment of photic zone euxinia
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Novel 1H-Pyrrole-2,5-dione (maleimide) proxies for the assessment of photic zone euxinia
چکیده انگلیسی


• Pristane/phytane ratios and aryl isoprenoid ratios used as indicators of ancient redox conditions and photic zone euxinia.
• Maleimide ratios have been proposed as new, robust indicators of photic zone euxinia.
• All three mass extinction events were affected by persistent photic zone euxinic depositional conditions.

1H-Pyrrole-2,5-diones (maleimides) and 1-alkyl-2,3,6-trimethylbenzenes (aryl isoprenoids), degradation products of tetrapyrrole pigments and carotenoids respectively, were analysed and compared with pristane/phytane (Pr/Ph) ratios to reconstruct past redox conditions in three geologic sections. One section comes from the Middle–Late Devonian and was deposited before the Frasnian–Famennian boundary mass extinction. The two other sections span the Late Permian to the Early Triassic as well as the Late Triassic to the Early Jurassic, and recorded the Permian–Triassic (P/T) and Triassic–Jurassic (T/J) extinction events respectively. The 2-methyl-3-iso-butyl-maleimide (Me,i-Bu maleimide) to 2-methyl-3-ethyl-maleimide (Me,Et maleimide) and 2-methyl-3-n-propyl-maleimide (Me,n-Pr maleimide) to Me,Et maleimide ratios (Me,i-Bu/Me,Et and Me,n-Pr/Me,Et ratios) in the studied sections revealed a moderate to strong negative correlation to the aryl isoprenoid ratio (AIR), defined as (C13–C17 1-alkyl-2,3,6-trimethylbenzenes)/(C18–C22 1-alkyl-2,3,6-trimethylbenzenes), indicating that these maleimide ratios can be used as robust, specific indicators of photic zone euxinia (PZE). These results agreed with Pr/Ph ratios, which were used as diagnostic indicators to differentiate between oxic and anoxic conditions. In agreement with previous studies, the novel maleimide proxies suggest that all three mass extinctions were largely characterised by PZE depositional conditions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Geology - Volume 404, 26 May 2015, Pages 100–109
نویسندگان
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