A complex magmatic system beneath the middle and northern Okinawa Trough: evidence from pyroxene characteristics

doi:10.1002/gj.2873

	A complex magmatic system beneath the middle and northern Okinawa Trough: evidence from pyroxene characteristics
	Liao, Renqiang 1,3; Huang, Peng 1,2; Hu, Ningjing 4
刊名	GEOLOGICAL JOURNAL
	2017-11-01
卷号	52 期号:6 页码:1059-1068
关键词	Okinawa Trough pumice pyroxene magma system magma chamber physical process
ISSN号	0072-1050
DOI	10.1002/gj.2873
英文摘要	The Okinawa Trough is an initial marginal back-arc basin. In this paper, we present a comparative study of pyroxenes in white and black pumice from the Okinawa Trough to explore the magmatic evolution of the region and the characteristics of the magmatic system. The results show two species of pyroxenes in the white pumice (clinopyroxene and orthopyroxene) but only one species in the black pumice (orthopyroxene). Many isomorphic replacements among the cations occurred during clinopyroxene crystallization. Clinopyroxene-melt thermobarometry yielded a temperature of 847-988 degrees C and a pressure of 2.73-7.42kbar, which vary considerably and correspond to a maximum depth of approximately 24km. All of the orthopyroxenes in both the white and black pumice crystallized at similar pressures ranging from 0.67 to 4.59kbar, which correspond to a maximum depth of approximately 15km. The clinopyroxenes crystallized mainly in the lower crust, whereas the orthopyroxenes formed at the boundary depth between the upper crust and the lower crust. The similarities in the pyroxene chemical compositions and the whole-rock characteristics between the two types of pumice indicate that both types of pumice are linked to the same magmatic system at depth. The pyroxenes crystallized from genetically related melts within a magmatic system that had undergone various degrees of differentiation. The physicochemical characteristics of the pyroxenes show that the magma chamber module changed during the crystallization process from clinopyroxenes to orthopyroxenes. This change most likely resulted from local characteristics of the near-surface structure. These observations support the model of a two-layered magma chamber' in the northern Okinawa Trough. Copyright (c) 2016 John Wiley & Sons, Ltd.
资助项目	National Natural Science Foundation of China[41576055] ; National Natural Science Foundation of China[40606021]
WOS关键词	VOLCANIC-ROCKS ; COMPOSITIONAL VARIATIONS ; ARC ; CLINOPYROXENES ; EVOLUTION ; ALUMINUM
WOS研究方向	Geology
语种	英语
出版者	WILEY
WOS记录号	WOS:000414915500012
内容类型	期刊论文
源URL	[http://ir.fio.com.cn:8080/handle/2SI8HI0U/25623]
专题	自然资源部第一海洋研究所
通讯作者	Huang, Peng
作者单位	1.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, 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.State Ocean Adm, Inst Oceanog 1, Key Lab Marine Sedimentary & Environm Geol, Qingdao, Peoples R China
推荐引用方式 GB/T 7714	Liao, Renqiang,Huang, Peng,Hu, Ningjing. A complex magmatic system beneath the middle and northern Okinawa Trough: evidence from pyroxene characteristics[J]. GEOLOGICAL JOURNAL,2017,52(6):1059-1068.
APA	Liao, Renqiang,Huang, Peng,&Hu, Ningjing.(2017).A complex magmatic system beneath the middle and northern Okinawa Trough: evidence from pyroxene characteristics.GEOLOGICAL JOURNAL,52(6),1059-1068.
MLA	Liao, Renqiang,et al."A complex magmatic system beneath the middle and northern Okinawa Trough: evidence from pyroxene characteristics".GEOLOGICAL JOURNAL 52.6(2017):1059-1068.