ULTRADEEP (GREATER THAN 300 KILOMETERS), ULTRAMAFIC UPPER MANTLE XENOLITHS

被引：205

作者：

HAGGERTY, SE ^{[1
]}

SAUTTER, V ^{[1
]}

机构：

[1] UNIV PARIS 11,GEOPHYS & GEODYNAM INTERNE LAB,F-91405 ORSAY,FRANCE

来源：

SCIENCE | 1990年 / 248卷 / 4958期

关键词：

D O I：

10.1126/science.248.4958.993

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Geophysical discontinuities in Earth's upper mantle and experimental data predict the structural transformation of pyroxene to garnet and the solid-state dissolution of pyroxene into garnet with increasing depth. These predictions are indirectly verified by omphacitic pyroxene exsolution in pyropic garnet-bearing xenoliths from a diamondiferous kimberlite. Conditions for silicon in octahedral sites in the original garnets are met at pressures greater than 130 kilobars, placing the origin of these xenoliths at depths of 300 to 400 kilometers. These ultradeep xenoliths support the theory that the 400-km seismic discontinuity is marked by a transition from peridotite to eclogite.

引用

页码：993 / 996

页数：4

共 44 条

[1] PYROXENE-GARNET SOLID-SOLUTION EQUILIBRIA IN SYSTEMS MG4S14012-MG3AL2S13O12 AND FE4S14O12-FE3AL2S13O12 AT HIGH-PRESSURES AND TEMPERATURES [J].

AKAOGI, M ;

AKIMOTO, S .

PHYSICS OF THE EARTH AND PLANETARY INTERIORS, 1977, 15 (01) :90-106

[2] HIGH-PRESSURE PHASE-EQUILIBRIA IN A GARNET LHERZOLITE, WITH SPECIAL REFERENCE TO MG2+-FE2+ PARTITIONING AMONG CONSTITUENT MINERALS [J].

AKAOGI, M ;

AKIMOTO, S .

PHYSICS OF THE EARTH AND PLANETARY INTERIORS, 1979, 19 (01) :31-51

[3] MINERALOGY AND COMPOSITION OF THE UPPER MANTLE [J].

ANDERSON, DL ;

BASS, JD .

GEOPHYSICAL RESEARCH LETTERS, 1984, 11 (07) :637-640

[4] TRANSITION REGION OF THE EARTHS UPPER MANTLE [J].

ANDERSON, DL ;

BASS, JD .

NATURE, 1986, 320 (6060) :321-328

[5] THE EARTH AS A PLANET - PARADIGMS AND PARADOXES [J].

ANDERSON, DL .

SCIENCE, 1984, 223 (4634) :347-355

[6] BODY-CENTRED CUBIC CYLINDER PACKING AND GARNET STRUCTURE [J].

ANDERSSON, S ;

OKEEFFE, M .

NATURE, 1977, 267 (5612) :605-606

[7]

[Anonymous], 1987, MANTLE XENOLITHS

[8]

[Anonymous], 1969, CONTRIB MINERAL PETR, DOI [10.1007/BF00377479, DOI 10.1007/BF00377479]

[9] THE ECLOGITE TO GARNETITE TRANSITION - EXPERIMENTAL AND THERMODYNAMIC CONSTRAINTS [J].

BINA, CR ;

WOOD, BJ .

GEOPHYSICAL RESEARCH LETTERS, 1984, 11 (10) :955-958

[10] DIAMONDS AND THE AFRICAN LITHOSPHERE [J].

BOYD, FR ;

GURNEY, JJ .

SCIENCE, 1986, 232 (4749) :472-477

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