Origin of spongy textures in clinopyroxene and spinel from mantle xenoliths, Hessian Depression, Germany

被引:67
作者
Carpenter, RL [1 ]
Edgar, AD [1 ]
Thibault, Y [1 ]
机构
[1] Univ Western Ontario, Dept Earth Sci, London, ON, Canada
关键词
D O I
10.1007/s007100200002
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
Spongy textures are observed in anhydrous Group 1 mantle xenoliths (harzburgite, lherzolite and wehrlite) hosted in Tertiary alkali basaltic lavas from the Hessian Depression, Germany. These textures are developed only on clinopyroxene, and spinel, and occur as rims or cross-cutting veinlets and patches showing optical continuity with the host grain. They are often associated with pools of amorphous glassy material. There is no preferential development of spongy domains against the xenolith-lava contact suggesting that the host magma did not play any significant role in their formation. Spongy clinopyroxene and spinel occur in all rock types, but, are more pervasive in wehrlite. Chemically, spongy domains of clinopyroxene and spinel are more refractory than unaffected areas, which is consistent with their formation through a partial melting event. The associated glassy material shows chemical characteristics which suggest that the melt pools are genetically related to the development of the spongy textures. The partial melting event was probably triggered by the infiltration of a low-density fluid. The fluid may have evolved from a silicate melt responsible for the metasomatic Fe-enrichment recorded in wehrlite. In this context, the more pervasive development of spongy clinopyroxene in wehrlite may be explained by a higher concentration of the evolved fluid phase at proximity to its silicate melt source.
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页码:149 / 162
页数:14
相关论文
共 35 条
[1]  
ARAI S, 1995, AM MINERAL, V80, P1041
[2]  
BELL PM, 1969, AM J SCI, V267, P17
[3]   THE PETROLOGY OF ULTRAMAFIC XENOLITHS FROM SUMMIT LAKE, NEAR PRINCE GEORGE, BRITISH-COLUMBIA [J].
BREARLEY, M ;
SCARFE, CM ;
FUJII, T .
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 1984, 88 (1-2) :53-63
[4]   GEOTHERMOBAROMETRY IN 4-PHASE LHERZOLITES .2. NEW THERMOBAROMETERS, AND PRACTICAL ASSESSMENT OF EXISTING THERMOBAROMETERS [J].
BREY, GP ;
KOHLER, T .
JOURNAL OF PETROLOGY, 1990, 31 (06) :1353-1378
[5]   ORIGIN OF PHLOGOPITE IN MANTLE XENOLITHS FROM KOSTAL LAKE, WELLS-GRAY PARK, BRITISH-COLUMBIA [J].
CANIL, D ;
SCARFE, CM .
JOURNAL OF PETROLOGY, 1989, 30 (05) :1159-1179
[6]  
Carpenter RL, 1996, THESIS U W ONTARIO
[7]   P-T phase relations of silicic, alkaline, aluminous liquids:: new results and applications to mantle melting and metasomatism [J].
Draper, DS ;
Green, TH .
EARTH AND PLANETARY SCIENCE LETTERS, 1999, 170 (03) :255-268
[8]  
EHRENBERG SN, 1982, J PETROL, V23, P507, DOI 10.1093/petrology/23.4.507
[9]   Thin intergranular melt films and melt pockets in spinel peridotite xenoliths from the Rhone area (Germany): early stage of melt generation by grain boundary melting [J].
Franz, L ;
Wirth, R .
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 1997, 129 (04) :268-283
[10]   ULTRAMAFIC INCLUSIONS FROM SAN-CARLOS, ARIZONA - PETROLOGIC AND GEOCHEMICAL DATA BEARING ON THEIR PETROGENESIS [J].
FREY, FA ;
PRINZ, M .
EARTH AND PLANETARY SCIENCE LETTERS, 1978, 38 (01) :129-176