Petrology and mineralogy of pumice from the Iheya North Knoll, Okinawa Trough: Implications for the differentiation of crystal-poor and volatile-rich melts in the magma chamber

doi:10.1002/gj.3106

CORC > 海洋研究所 > 中国科学院海洋研究所 > 海洋地质与环境重点实验室

	Petrology and mineralogy of pumice from the Iheya North Knoll, Okinawa Trough: Implications for the differentiation of crystal-poor and volatile-rich melts in the magma chamber
	Zhang, Yuxiang 1,3; Zeng, Zhigang 1,2,3; Yin, Xuebo 1; Qi, Haiyan 1; Chen, Shuai 1; Wang, Xiaoyuan 1,2; Shu, Yunchao 1,3; Chen, Zuxing 1,3
刊名	GEOLOGICAL JOURNAL
	2018-11-01
卷号	53 期号:6 页码:2732-2745
关键词	decompression Iheya North Knoll magma chamber Okinawa Trough physical differentiation pumice
ISSN号	0072-1050
DOI	10.1002/gj.3106
通讯作者	Zeng, Zhigang(zgzeng@qdio.ac.cn)
英文摘要	The Iheya North Knoll is a submarine hill that is covered with pumice in the Okinawa Trough. The petrology and mineralogy of the crystal-poor rhyolitic pumice collected from two sampling sites (T3 and T6) on the knoll were analysed in this article. The T6 pumice, which contains some mafic minerals (e.g., clinopyroxene, orthopyroxene), is slightly more crystal-rich (<5 vol.%) than the T3 pumice (<2 vol.%). However, both types of pumice are high-potassium rhyolites with similar Nd isotopic ratios and rare earth element patterns, as well as similar glass compositions, which indicates that they may fall along a line of descent of comagmatic evolution. The T6 pumice contains some xenomorphic clinopyroxenes that are not in equilibrium with their whole-rock composition, which suggests that the crystal-poor melt was extracted from a more mafic source. The T3 pumice features a flow structure, and its matrix glass records higher Cl concentrations and a lower total mass than the T6 pumice, which implies that the T3 melt has a higher volatile content and lower viscosity. The distinct petrographic characteristics but similar matrix glass compositions of the T3 and T6 pumice suggest that the extracted melt was physically differentiated during ascent, with the more crystal-poor and volatile-rich T3 melt reaching a higher lever in the magma chamber. Meanwhile, simulation calculations indicate that the melt experienced near-adiabatic decompression-driven chemical differentiation, which led to the growth of sodium-rich plagioclase but not quartz in the pumice.
资助项目	Qingdao Collaborative Innovation Center of Marine Science and Technology ; CAS/SAFEA International Partnership Program for Creative Research Teams ; National High Level Talent Special Support Program ; Scientific and Technological Innovation Project[2015ASKJ03] ; Scientific and Technological Innovation Project[2016ASKJ13] ; Science and Technology Development Program of Shandong Province[2013GRC31502] ; Innovative Talent Promotion Program[2012RA2191] ; AoShan Talents Program[2015ASTP-0S17] ; Special Fund for the Taishan Scholar Program of Shandong Province[ts201511061] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA11030302] ; National Programme on Global Change and Air-Sea Interaction[GASI-GEOGE-02] ; National Natural Science Foundation of China[41325021] ; National Basic Research Program of China[2013CB429700]
WOS研究方向	Geology
语种	英语
出版者	WILEY
WOS记录号	WOS:000450653800019
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/156166]
专题	海洋研究所_海洋地质与环境重点实验室
通讯作者	Zeng, Zhigang
作者单位	1.Chinese Acad Sci, Inst Oceanol, Seafloor Hydrothermal Act Lab, Key Lab Marine Geol & Environm, Qingdao, Peoples R China 2.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao, Peoples R China 3.Univ Chinese Acad Sci, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Yuxiang,Zeng, Zhigang,Yin, Xuebo,et al. Petrology and mineralogy of pumice from the Iheya North Knoll, Okinawa Trough: Implications for the differentiation of crystal-poor and volatile-rich melts in the magma chamber[J]. GEOLOGICAL JOURNAL,2018,53(6):2732-2745.
APA	Zhang, Yuxiang.,Zeng, Zhigang.,Yin, Xuebo.,Qi, Haiyan.,Chen, Shuai.,...&Chen, Zuxing.(2018).Petrology and mineralogy of pumice from the Iheya North Knoll, Okinawa Trough: Implications for the differentiation of crystal-poor and volatile-rich melts in the magma chamber.GEOLOGICAL JOURNAL,53(6),2732-2745.
MLA	Zhang, Yuxiang,et al."Petrology and mineralogy of pumice from the Iheya North Knoll, Okinawa Trough: Implications for the differentiation of crystal-poor and volatile-rich melts in the magma chamber".GEOLOGICAL JOURNAL 53.6(2018):2732-2745.