A ductile extensional shear zone at the contact area between HP-LT metamorphic units in the Talea Ori, central Crete, Greece: deformation during early stages of exhumation from peak metamorphic conditions
A ductile extensional shear zone at the contact area between HP-LT metamorphic units in the Talea Ori, central Crete, Greece: deformation during early stages of exhumation from peak metamorphic conditions
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希腊克里特岛中部 Talea Ori 的 HP-LT 变质单元之间接触区的延性拉伸剪切带：从峰值变质条件折返的早期阶段的变形
DOI：
10.1007/s00531-018-1650-6
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发表时间：
2019
影响因子：
2.3
通讯作者：
Janots
中科院分区：
文献类型：
--
作者：
Seybold;Trepmann;Janots
本文报道了克里特岛中部高压低温(HP-LT)变质千枚岩-石英岩单元Sensu strato(Pq s.str)接触部位的伸展韧性剪切带。和Talea Ori群(Pltenkalk单位)。沿20公里长的接触线填图和显微分析显示，两个单元中都有伸展剪切带、剪切带解理(C‘型)和伴生的石英脉，分布在宽达一公里的地方。沿剪切带的剪切偏移量系统地垂直于与悬块的接触(Pq s.str.)失灵了。丰富的不协调石英脉与剪切带边界、不对称环状和面理环状伴生，形成m-宽的脉网。这些介观变形结构与应变阴影、钠长斑岩生长缘、花柱石等微观结构相结合，表明溶解-沉淀蠕变是主要的变形机制，并伴随着矿脉的形成。变形时的温度接近峰值变质温度(≥ 30 0~35 0℃)，与剪切带解理中的钠长石原生斑岩和云母的生长边缘相一致，与表现亚颗粒和缝合的高角度晶界的石英脉显微结构一致。由含碳物质石墨化程度推断的峰温在剪切带的上盘和下盘相似，与快速、近绝热折返一致。我们的研究表明，HP-LT变质岩中具有高应变率溶解-沉淀蠕变和脉状形成的韧性剪切带对早期折返历史具有重要意义。
We report on an extensional ductile shear zone in central Crete at the contact area between the high-pressure low-temperature (HP-LT) metamorphic Phyllite-Quartzite unit sensu stricto (PQ s.str.) and the Talea Ori group (Plattenkalk unit). Mapping and microscopic analysis along the 20 km long contact reveal extensional shear bands, shear band cleavages (C′-type) and associated quartz veins in both units, occurring over a width of up to a kilometer. The shear offset along the shear bands is systematically perpendicular to the contact with the hanging block (PQ s.str.) being downfaulted. Abundant discordant quartz veins are associated to shear band boundaries, asymmetric boudinage and foliation boudinage, forming m-wide vein networks. These mesoscopic deformation structures together with related microstructures such as strain shadows, growth rims of albite porphyroblasts and stylolites indicate dissolution–precipitation creep as main deformation mechanism accompanied by vein formation. Temperatures during deformation are indicated to be close to peak metamorphic temperatures (≥ 300–350 °C) by the growth rims of albite porphyroblasts and micas present in the shear band cleavages, which are consistent with quartz vein microstructures showing subgrains and sutured high angle grain boundaries. Peak metamorphic temperatures inferred by the degree of graphitization of carbonaceous material are similar in the hanging wall and the footwall of the shear zone, which is consistent with fast and nearly adiabatic exhumation. Our study demonstrates the importance of ductile shear zones with high strain rate dissolution–precipitation creep and vein formation in HP-LT metamorphic rocks for the early exhumation history.
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影响因子：
2.9
作者：
L. Jolivet;C. Faccenna;B. Huet;L. Labrousse;L. Pourhiet;O. Lacombe;E. Lecomte;E. Burov;Y. Denèle
通讯作者：
L. Jolivet;C. Faccenna;B. Huet;L. Labrousse;L. Pourhiet;O. Lacombe;E. Lecomte;E. Burov;Y. Denèle
DOI：
10.1127/1860-1804/2008/0159-0375
发表时间：
2008-09
影响因子：
1.1
作者：
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通讯作者：
T. Klein;Henning Reichhardt;L. Klinger;S. Grigull;Georg Wostal;G. Kowalczyk;G. Zulauf
影响因子：
2.1
作者：
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通讯作者：
T. Theye;E. Seidel
影响因子：
3.1
作者：
Whitney, Donna L.;Evans, Bernard W.
通讯作者：
Evans, Bernard W.
密歇根州 Negaunee 铁矿层中的赤铁矿 Framboid；
DOI：
--
发表时间：
1973
期刊：
影响因子：
--
作者：
M. Lougheed;J. J. Mancuso
通讯作者：
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