Origin of high-Mg arc volcanism and fate of subducted sedimentary carbonates in the western Pacific: Evidence from partial melting experiments on mixed sediment and peridotite

doi:10.1002/gj.4306

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	Origin of high-Mg arc volcanism and fate of subducted sedimentary carbonates in the western Pacific: Evidence from partial melting experiments on mixed sediment and peridotite
	Zhan, Mingjun 3,4; Zhang, Guoliang 1,2,4
刊名	GEOLOGICAL JOURNAL
	2021-10-28
页码	15
关键词	arc volcanism garnet effect sediment diapir sedimentary carbonate subduction zone
ISSN号	0072-1050
DOI	10.1002/gj.4306
通讯作者	Zhang, Guoliang(zhangguoliang@qdio.ac.cn)
英文摘要	Andesitic to rhyolitic arc volcanism commonly occurs in the cold subduction system in the modern western Pacific, however, their genesis remains debated. The high-Mg andesitic arc rocks with enrichments of Th and K are suggested to be derived from a contribution of the subducted sediments and the depleted mantle wedge. The partial melts of pure sediments have MgO too low to explain the origin of such high-Mg arc rocks. For a cold subduction system, melting of subducted slab can unlikely occur, while sediment diapirism serves as a possible mechanism to contribute to the origin of arc volcanism. Here, we conducted high-pressure experiments on the mixed sediment (+/- CaCO3) and peridotite with proportions of 7:3 and 5:5 at 3.5 GPa and 1000-1300 degrees C. The experiment resulted in andesitic to rhyolitic melts with elevated MgO and enriched K2O. All melts reduce in K2O with increasing temperatures as no K-rich minerals were produced. The interactions between carbonate-bearing sediments and peridotites during the diapirism promote decarbonation and produce melts with elevated MgO. The results of the experiments can explain the origin of high-Mg and K-rich andesite-rhyolite series of the Izu-Bonin-Mariana arc system. A higher sediment proportion used in the experiment is coupled with a stronger effect of garnet, which explains the volcanic rocks with higher K2O and La/Yb. We propose that sediment diapirism in the mantle wedge can produce high-Mg and K-rich andesitic-rhyolitic arc lavas and facilitate decarbonation of subducted sedimentary carbonates in the typical cold Izu-Bonin-Mariana subduction zone.
资助项目	National Natural Science Foundation of China[91858206] ; Science & Technology Basic Resources Investigation Program of China[2017FY100801] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA22050101] ; Taishan Scholars Program of Shandong Province[tsqn201909157]
WOS研究方向	Geology
语种	英语
出版者	WILEY
WOS记录号	WOS:000712023500001
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/177137]
专题	海洋研究所_深海极端环境与生命过程研究中心
通讯作者	Zhang, Guoliang
作者单位	1.Chinese Acad Sci, Ctr Ocean Megasci, Qingdao, Peoples R China 2.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao, Peoples R China 3.Univ Chinese Acad Sci, Beijing, Peoples R China 4.Chinese Acad Sci, Ctr Deep Sea Res, Inst Oceanol, Qingdao 266071, Peoples R China
推荐引用方式 GB/T 7714	Zhan, Mingjun,Zhang, Guoliang. Origin of high-Mg arc volcanism and fate of subducted sedimentary carbonates in the western Pacific: Evidence from partial melting experiments on mixed sediment and peridotite[J]. GEOLOGICAL JOURNAL,2021:15.
APA	Zhan, Mingjun,&Zhang, Guoliang.(2021).Origin of high-Mg arc volcanism and fate of subducted sedimentary carbonates in the western Pacific: Evidence from partial melting experiments on mixed sediment and peridotite.GEOLOGICAL JOURNAL,15.
MLA	Zhan, Mingjun,et al."Origin of high-Mg arc volcanism and fate of subducted sedimentary carbonates in the western Pacific: Evidence from partial melting experiments on mixed sediment and peridotite".GEOLOGICAL JOURNAL (2021):15.