Circum-Pacific arc flare-ups and global cooling near the Eocene-Oligocene boundary
Circum-Pacific arc flare-ups and global cooling near the Eocene-Oligocene boundary
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DOI：
10.1130/g25392a.1
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发表时间：
2009-04
期刊：
影响因子：
5.8
通讯作者：
B. Jicha;D. Scholl;D. Rea
中科院分区：
文献类型：
--
作者：
B. Jicha;D. Scholl;D. Rea
陆上弧火山的爆发会对环境造成重大影响，因为火山灰和挥发物会直接排入大气层和海洋。由于缺乏支持性证据，气候变冷和大量火山爆发之间的联系仍然是推测性的。对四个环太平洋弧的2814 K-Ar和40 Ar/ 39 Ar年龄测定结果的汇编表明，火山高产出期（即，突发事件）是偶发性的，在某些情况下是同时发生的。过去5000万年弧岩浆活动的高峰期和随后的平静期。与全球气候的重大波动是同时代发生的，包括始新世-渐新世过渡，这是新生代最突出的全球气候重组之一。在始新世晚期开始的环太平洋火山活动极其活跃的时期，发生了数百次中等至中等喷发，这可能导致平流层中硫气溶胶的产生和太平洋表面沃茨的施肥。我们提供了一种机制，可能是部分负责的气候预处理，必须有之前，并最终促进南极冰盖的增长~34百万年。前
Explosive eruptions from subaerial arc volcanoes can have significant environmental impact because of the discharge of ash and volatiles directly into the atmosphere and oceans. The link between climate cooling and voluminous volcanic eruptions has remained speculative due to a lack of supporting evidence. A compilation of 2814 K-Ar and 40 Ar/ 39 Ar age determinations from four circum-Pacific arcs indicates that periods of high volcanic output (i.e., flare-ups) have been episodic and, in some cases, synchronous. Peak periods and subsequent lulls in arc magmatism over the past 50 m.y. have occurred coeval with major fluctuations in global climate, including the Eocene-Oligocene transition, one of the most prominent global climate reorganizations in the Cenozoic. Hundreds of intermediate to silicic eruptions occurred during an extremely vigorous period of circum-Pacific volcanism beginning in the late Eocene, which likely led to the production of sulfur aerosols in the stratosphere and fertilization of surface waters of the Pacific Ocean. We provide a mechanism that may have been partly responsible for the climatic preconditioning that must have preceded and ultimately promoted Antarctic ice sheet growth ~34 m.y. ago.