Oxygen and carbon isotope composition of Callovian–Lower Oxfordian (Middle–Upper Jurassic) belemnite rostra from central Poland: A record of a Late Callovian global sea-level rise?
Oxygen and carbon isotope composition of Callovian–Lower Oxfordian (Middle–Upper Jurassic) belemnite rostra from central Poland: A record of a Late Callovian global sea-level rise?
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波兰中部卡洛世-下牛津阶（中-上侏罗统）箭石喙的氧和碳同位素组成：晚卡洛世全球海平面上升的记录？
DOI：
10.1016/j.palaeo.2009.09.020
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
T. Praszkier
中科院分区：
文献类型：
--
作者：
H. Wierzbowski;K. Dembicz;T. Praszkier
本文介绍了波兰侏罗链（波兰中南部）加里洛世—下牛津世演替中沉积于深陆架环境的钙辉石柱状岩的氧碳同位素数据，这些钙辉石柱状岩保存完好，地层年代确定。根据蛭石δ18O值（9 ~ 14°C）计算的古地温表明，在研究的Callovian和Early Oxfordian区间，气候条件相对稳定。上Callovian铍辉石δ13C时间变化趋势记录了溶解无机碳储层同位素组成的初步变化，显示出明显的正碳同位素偏移（高达1.7‰VPDB左右）。在这一偏移之前和之后，蛭石柱的平均δ13C值下降了约1‰。晚Callovian碳酸盐碳同位素偏移可能与全球海平面上升期间陆架沉积物中有机碳储存的增强有关。所提出的资料不符合中晚侏罗世过渡时期全球冰期延长的理论。
Oxygen and carbon isotope data of well-preserved and stratigraphically well-dated belemnite rostra are presented from a Callovian–Lower Oxfordian succession of the Polish Jura Chain (south-central Poland) that was deposited in a deep shelf environment. Palaeotemperatures calculated from belemnite δ18O values (9 to 14°C) indicate relatively constant climatic conditions during studied Callovian and Early Oxfordian intervals. Belemnite δ13C temporal trends, which are interpreted to record primary variation in the isotope composition of dissolved inorganic carbon reservoir, display a prominent positive carbon isotope shift (up to around 1.7‰ VPDB) in the Upper Callovian. This excursion is preceded and followed by a drop in average δ13C values of belemnite rostra of around 1‰. The Late Callovian carbonate carbon isotope excursion is likely linked to the enhanced storage of organic carbon in shelf sediments during a global sea-level rise. The presented data are not compatible with the theory of prolonged global glaciation at the Middle–Late Jurassic transition.