Geochemistry of basalts from IODP site U1365: Implications for magmatism and mantle source signatures of the mid-Cretaceous Osbourn Trough

doi:10.1016/j.lithos.2012.04.014

	Geochemistry of basalts from IODP site U1365: Implications for magmatism and mantle source signatures of the mid-Cretaceous Osbourn Trough
	Zhang, Guoliang 1; Smith-Duque, Christopher 2; Tang, Suohan 3; Li, He 4; Zarikian, Carlos ; D'Hondt, Steven ; Inagaki, Fumio ; IODP Expedition 329 Scientists
刊名	LITHOS
	2012-07-01
卷号	144 页码:73-87
关键词	Mid-ocean ridge basalt Cretaceous Mantle source U1365 Osbourn Trough
ISSN号	0024-4937
DOI	10.1016/j.lithos.2012.04.014
文献子类	Article
英文摘要	The Integrated Ocean Drilling Program site U1365 drilled into the basement of the southwest Pacific crust formed from the mid-Cretaceous Osbourn Trough that rifted apart the Manihiki and Hikurangi Plateaus (the Greater Manihiki). The basalt geochemistry at this site is crucial for understanding the magmatic processes and mantle source of the mid-Cretaceous Osbourn Trough. The recovered fresh basalts were low-K tholeiitic normal (N) and depleted (D) mid-ocean ridge basalt (MORB). Their trace element and Sr-Nd isotope compositions indicate a Pacific-type mantle source rather than any significant influences from the nearby Louisville Seamount Chain or from the Greater Manihiki Plateau. Despite the presence of a plume head underneath the Osbourn Trough at its initial stage, the insignificance of a plume head could be explained by the long-distance (>1000 km) southward migration of the Osbourn Trough. Lavas at site U1365 vary from low-MgO (<6.9 wt.%) N-MORB at the bottom to high-MgO (8 wt.% to 9.5 wt.%) D-MORB and, then, to medium-MgO (7.3 wt.% to 8.2 wt.%) N-MORB according to their eruption sequences, which was accompanied by magma mixing in the magma reservoir. The D-MORB group lavas have higher melting degrees than those of N-MORB group based on their concentrations of TiO2, Na2O and CaO corrected for crystallization relative to MgO = 7.8 wt.%. The major element compositions of the high-MgO D-MORB lavas were consistent with partial melting in the spinel-peridotite zone over a pressure interval from similar to 3.1 GPa to 2 GPa in the mantle. The significant overlap of N-MORB and D-MORB in Sr-Nd isotopes suggests that chemical differences between the two groups were derived from the mantle melting processes. Based on comparison with lavas from the East Pacific Rise where a positive correlation of mantle melting degree vs. spreading rate is shown, we suggest that the Osbourn Trough might have a full spreading rate of similar to 140 mm/yr. Thus, the slow ridge-like axial morphology of the Osbourn Trough should be a character of an extinct fast ridge. (C) 2012 Elsevier B.V. All rights reserved.
WOS关键词	EAST PACIFIC RISE ; ONTONG JAVA PLATEAU ; LARGE IGNEOUS PROVINCES ; MARBLE-CAKE MANTLE ; FLOOD BASALTS ; RIDGE BASALT ; GLOBAL CORRELATIONS ; TECTONIC EVOLUTION ; ISOTOPIC EVIDENCE ; OCEANIC PLATEAUS
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000306155100006
资助机构	Chinese Academy of Sciences(KZCX2-EW-QN205) ; Chinese Academy of Sciences(KZCX2-EW-QN205) ; National Natural Science Foundation of China(41176043) ; National Natural Science Foundation of China(41176043) ; Chinese Academy of Sciences(KZCX2-EW-QN205) ; Chinese Academy of Sciences(KZCX2-EW-QN205) ; National Natural Science Foundation of China(41176043) ; National Natural Science Foundation of China(41176043) ; Chinese Academy of Sciences(KZCX2-EW-QN205) ; Chinese Academy of Sciences(KZCX2-EW-QN205) ; National Natural Science Foundation of China(41176043) ; National Natural Science Foundation of China(41176043) ; Chinese Academy of Sciences(KZCX2-EW-QN205) ; Chinese Academy of Sciences(KZCX2-EW-QN205) ; National Natural Science Foundation of China(41176043) ; National Natural Science Foundation of China(41176043)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/84590]
专题	中国科学院地质与地球物理研究所
通讯作者	Zhang, Guoliang
作者单位	1.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 2.Univ Southampton European, Natl Oceanog Ctr, Way Southampton S014 3ZH, England 3.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Guoliang,Smith-Duque, Christopher,Tang, Suohan,et al. Geochemistry of basalts from IODP site U1365: Implications for magmatism and mantle source signatures of the mid-Cretaceous Osbourn Trough[J]. LITHOS,2012,144:73-87.
APA	Zhang, Guoliang.,Smith-Duque, Christopher.,Tang, Suohan.,Li, He.,Zarikian, Carlos.,...&IODP Expedition 329 Scientists.(2012).Geochemistry of basalts from IODP site U1365: Implications for magmatism and mantle source signatures of the mid-Cretaceous Osbourn Trough.LITHOS,144,73-87.
MLA	Zhang, Guoliang,et al."Geochemistry of basalts from IODP site U1365: Implications for magmatism and mantle source signatures of the mid-Cretaceous Osbourn Trough".LITHOS 144(2012):73-87.