CO2, organic carbon burial, and global climate change in the Wenlock (Silurian):waired 13 Ccarb and 13 Corg analyses of marine carbonates

这项调查的提出是为了研究全球碳循环显生界历史上最不稳定的系列，以及二氧化碳在全球气候变化中的作用。温洛克系列包括两个主要的(+4%)正碳同位素漂移(早期温洛克Ireviken漂移和晚期文洛克穆德漂移)，这两个漂移在文献中都与冰川和全球气候变化有关。长期以来，碳循环和二氧化碳在全球气候变化中的作用一直是一个相当有争议的话题。然而，二氧化碳的变化通常被认为是显生宙气候变化的主要驱动因素。最近有关这场辩论的出版物通过比较不同的显生目规模替代记录，对长期气候变化进行了有力的分析。对古生代二氧化碳变化进行高分辨率(子系统尺度)记录的反演工作才刚刚开始。在下古生界，最广泛接受的测定古二氧化碳的方法是对碳酸盐和有机碳中的碳同位素进行配对分析。来自北美的最新数据表明，之前未知的13Corg的负漂移与文洛克早期的13Corg的正漂移相吻合。数据表明，在艾雷维肯正碳同位素漂移过程中，二氧化碳浓度呈上升趋势。这种关系对志留纪气候/海洋模型有很大的影响，但目前全球只有一个部分知道这种关系。~(13)Ccarb和~(13)Corg在文洛克晚期岩石中的配对同位素分析迄今仅对一个钻孔的14个样品进行。本文提出的研究将提供下古生界任何系列中最全面的(时间和空间上)二氧化碳和有机碳埋藏记录。这将通过两个步骤完成：1)高分辨率(每个样本10万年)碳酸盐碳(13Ccarb)同位素地层学；2)全球文洛克系列剖面的碳酸盐和有机碳(13Ccarb和Corg)同位素地层学。由于文洛克期的同位素漂移与其他早古生代的同位素漂移有许多明显的相似之处(地球化学、沉积学和古生物学)，我们期待对文洛克乃至整个早古生代的气候系统有新的认识。

The propose of this investigation is to examine the most volatile Series in the Phanerozoic history of the global carbon cycle and the role of CO2 in globale climate change. The Wenlock Series contains two major (+4%) positive carbon isotope excursions (early Wenlock Ireviken Excursion; late Wenlock Mulde Excursion) and both have been associated in the literature with glaciation and global climate change. The role of the carbon cycle and CO2 in global climate change has long been a topic of considerable debate. However, changes in CO2 are most often considered to be the primary driver of Phanerozoic climate change. Recent publications framing this debate have forcused on long-term climate change by comparing various Phanerozoic scale proxy records. Inversitgations to produce high-resolution (sub System scale) records of CO2 change in the Palaeozoic are only just beginning. In the lower Palaeozoic, the most widely accepted method for determining palaeo-¿ CO2 is paired analysis of carbon isotopes in both carbonate and organic carbon. Recent data from North America indicate that a previously unknown negative excursion in ¿ 13Corg coincided with the positive excursion in ¿ 13Corg during the early Wenlock. The data indicate the ¿ CO2 was increasing during the Ireviken positive carbon isotope excursion. This relationship has great implications for Silurian climate/ocean models, but at present is known from only one section globally. Paired isotopic analyses of ¿ 13Ccarb and ¿ 13Corg on the late Wenlock excusion have been carried out so far only on 14 samples on one bore hole. The investigation proposed herein will provide the most comprehensive (both temporally and spatially) record of ¿ CO2 and organic carbon burial of any Series in the lower Palaeozoic. This will be accomplished in two steps: 1) high-resolution (100,000 years per sample) carbonate carbon (¿ 13Ccarb) isotope stratigraphy 2) paired carbonate and organic carbon (¿ 13Ccarb and ¿ Corg) isotope stratigraphy of the Wenlock Series from sections globally. As the Wenlockian isotope excursions have many conspicuous similarities (geochemial, sedimentological, and palaeontological) with other Early Palaeozoic isotope excursions we expect new insights into the climate systems not only for the Wenlock but for the whole Early Palaeozoic.