Age and compositional data of zircon from sepiolite drilling mud to identify contamination of ocean drilling samples

被引:14
作者
Andrews, Graham D. M. [1 ,2 ]
Schmitt, Axel K. [3 ]
Busby, Cathy J. [4 ]
Brown, Sarah R. [2 ]
Blum, Peter [5 ]
Harvey, Janet C. [3 ]
机构
[1] West Virginia Univ, Dept Geol & Geog, Morgantown, WV 26506 USA
[2] Calif State Univ Bakersfield, Dept Geol Sci, Bakersfield, CA 93311 USA
[3] Heidelberg Univ, Inst Geowissensch, Heidelberg, Germany
[4] Univ Calif Davis, Dept Earth & Planetary Sci, Davis, CA 95616 USA
[5] Texas A&M Univ, Int Ocean Discovery Program, College Stn, TX USA
基金
美国国家科学基金会;
关键词
zircon; drilling mud; sepiolite; VALLEY CALDERA COMPLEX; TI-IN-ZIRCON; RAPID GENERATION; PB; GEOCHRONOLOGY; MAGMAS; CRUST;
D O I
10.1002/2016GC006397
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Zircon extracted from drilled oceanic rocks is increasingly used to answer geologic questions related to igneous and sedimentary sequences. Recent zircon studies using samples obtained from marine drill cores revealed that drilling muds used in the coring process may contaminate the samples. The JOIDES Resolution Science Operator of the International Ocean Discovery Program has been using two types of clays, sepiolite and attapulgite, which both have salt water viscosifier properties able to create a gel-like slurry that carries drill cuttings out of the holes several hundred meters deep. The dominantly used drilling mud is sepiolite originating from southwestern Nevada, USA. This sepiolite contains abundant zircon crystals with U-Pb ages ranging from 1.89 to 2889 Ma and continental trace element, O-18, and epsilon Hf isotopic compositions. A dominant population of 11-16 Ma zircons in sepiolite drilling mud makes identification of contamination in drilled Neogene successions particularly challenging. Interpretation of zircon analyses related to ocean drilling should be cautious of zircon ages in violation of independently constrained age models and that have age populations overlapping those in the sepiolite. Because individual geochronologic and geochemical characteristics lack absolute discriminatory power, it is recommended to comprehensively analyze all dated zircon crystals from cores exposed to drill mud for trace element, O-18, and epsilon Hf isotopic compositions. Zircon analyzed in situ (i.e., in petrographic sections) are assumed to be trustworthy.
引用
收藏
页码:3512 / 3526
页数:15
相关论文
共 44 条
[1]  
Andrews G. D. M., 2015, AGU FALL M
[2]  
[Anonymous], 2003, Proceedings of the Ocean Drilling Program, Initial Reports, V201, P1, DOI [DOI 10.2973/ODP.PROC.IR.201.102.2003, DOI 10.2973/0DP.PR0C.IR.201.102.2003]
[3]  
Bindeman I.N., 2006, CONTRIB MINERAL PETR, V152, P649, DOI DOI 10.1007/S00410-006-0124-1
[4]  
Bindeman IN, 2003, GEOL SOC AM BULL, V115, P581, DOI 10.1130/0016-7606(2003)115<0581:RGOBHA>2.0.CO
[5]  
2
[6]  
Byers F.M., 1976, U.S. Geological Survey Professional Paper 919, P1
[7]  
Carr M. D., 1996, US GEOL SURV OPEN FI, P96
[8]   Zircon and apatite thermochronology of the Nankai Trough accretionary prism and trench, Japan: Sediment transport in an active and collisional margin setting [J].
Clift, Peter D. ;
Carter, Andrew ;
Nicholson, Uisdean ;
Masago, Hideki .
TECTONICS, 2013, 32 (03) :377-395
[9]   New thermodynamic models and revised calibrations for the Ti-in-zircon and Zr-in-rutile thermometers [J].
Ferry, J. M. ;
Watson, E. B. .
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 2007, 154 (04) :429-437
[10]   Ti-in-zircon thermometry: applications and limitations [J].
Fu, Bin ;
Page, F. Zeb ;
Cavosie, Aaron J. ;
Fournelle, John ;
Kita, Noriko T. ;
Lackey, Jade Star ;
Wilde, Simon A. ;
Valley, John W. .
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 2008, 156 (02) :197-215