Deep solid-state equilibration and deep melting of plagioclase-free spinel peridotite from the slow-spreading Mid-Atlantic Ridge, ODP Leg 153
Deep solid-state equilibration and deep melting of plagioclase-free spinel peridotite from the slow-spreading Mid-Atlantic Ridge, ODP Leg 153
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来自缓慢扩张的大西洋中脊的无斜长石尖晶石橄榄岩的深层固态平衡和深层熔融，ODP Leg 153
DOI：
10.1007/s00710-010-0125-7
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发表时间：
2010
影响因子：
1.8
通讯作者：
Frimmel HE
中科院分区：
文献类型：
--
作者：
Will TM;Schmädicke E;Frimmel HE
大洋钻探153航次期间在北大西洋钻探的深海无斜长石尖晶石橄榄岩的岩石学研究表明，橄榄岩代表耐火的部分残留地幔物质，在上地幔熔融期间经历了不相容微量元素的耗尽。从尖晶石组成估算的部分熔融程度为c。百分之十二分馏的中、重稀土元素暗示了多压熔融，c。石榴石橄榄岩稳定区的初始熔融为1-4%，尖晶石橄榄岩稳定区的部分熔融为7-10%。地质温压研究表明，尖晶石橄榄岩的固态平衡发生在1,100-1,150°C和c. 20-23 kbar，对应于平衡深度c。70 ± 5 km，温度梯度异常低，约为11-17°C/km。橄榄岩的热再平衡发生在约850- 1，000 °C的相似深度。自然地，石榴子石橄榄岩稳定场中的初始地幔熔融必须在大于70 ± 5 km的深度开始。残余橄榄岩可能通过岩石圈盖层向洋脊轴快速上升。深海橄榄岩的折返至少部分是通过伸展拆离断层作用发生的。鉴于断层表面的浅至中等倾角，橄榄岩从其平衡深度的折返将意味着总的山脊法向水平位移c。如果构造伸展和拆离断层是唯一的折返机制，则为50-160 km。
A petrological investigation of abyssal, plagioclase-free spinel peridotite drilled during ODP cruise 153 in the North Atlantic revealed that the peridotite represent refractory, partial residual mantle material that experienced depletion of incompatible trace elements during upper mantle melting. The degree of partial melting as estimated from spinel compositions was c. 12%. Fractionated middle and heavy rare earth elements imply polybaric melting, with c. 1–4% initial melting in the garnet peridotite stability field and subsequent partial melting of ~7–10% in the spinel peridotite stability field. Geothermobarometric investigations revealed that the solid-state equilibration of the spinel peridotite occurred at some 1,100–1,150°C and c. 20–23 kbar, corresponding to an equilibration depth of c. 70 ± 5 km and an unusually low thermal gradient of some 11–17°C/km. A thermal re-equilibration of the peridotite occurred at ~850–1,000°C at similar depths. Naturally, the initial mantle melting in the garnet-peridotite stability field must have commenced at depths greater than 70 ± 5 km. It is likely that the residual peridotite rose rapidly through the lithospheric cap towards the ridge axis. The exhumation of the abyssal peridotite occurred, at least in parts, via extensional detachment faulting. Given the shallow to moderate dip angles of the fault surfaces, the exhumation of the peridotite from its equilibration depth would imply an overall ridge-normal horizontal displacement of c. 50–160 km if tectonic stretching and detachment faulting were the sole exhumation mechanism.
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影响因子：
3.4
作者：
E. Schmädicke;J. Gose;T. Will
通讯作者：
E. Schmädicke;J. Gose;T. Will
Site 920 附近 MARK 地区西中谷壁蛇纹岩暴露的构造环境
影响因子：
3.9
作者：
J. Karson;R. M. Lawrence
通讯作者：
R. M. Lawrence
来自 Sea Beam 和 Sea MARC I 观测的 Mark 区域的形态和构造（大西洋中脊 23° N）
DOI：
10.1007/bf02424661
发表时间：
1988
期刊：
Marine Geophysical Researches
影响因子：
--
作者：
L. Kong;R. Detrick;P. J. Fox;L. Mayer;W. Ryan
通讯作者：
W. Ryan
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影响因子：
3.5
作者：
K. Kimball;F. Spear;H. Dick
通讯作者：
H. Dick
天然矿物组合中斜方辉石和钙质辉石中镁和铁的分布
DOI：
10.1086/626953
发表时间：
1963
期刊：
The Journal of Geology
影响因子：
--
作者：
R. Kretz
通讯作者：
R. Kretz