Rhodope: From Mesozoic convergence to Cenozoic extension
Rhodope: From Mesozoic convergence to Cenozoic extension
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罗多彼：从中生代汇聚到新生代伸展
DOI：
10.3809/jvirtex.2011.00270
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
J. Burg
中科院分区：
文献类型：
--
作者：
J. Burg
保加利亚和希腊罗多彼的糜棱质片麻岩是在中压型变质角闪岩相条件下变形的。这些片麻岩的应变状态和历史所包含的运动学信息表明，在推覆复合体的发育过程中发生了韧性剪切变形。推覆复合体具有南向西南（前陆方向）堆积、同期伸展和后期伸展的特点。不同的岩性、变形和变质史区分了下（下盘）和上（上盘）大陆地体，定义了地壳尺度的双相。超高压变质岩、榴辉岩、蛇绿岩和岩浆弧原岩分布在地壳尺度复式构造的不同单元中。这些岩石圈定了上盘和下盘大陆单元之间的缝合带。同变质缝合和逆冲作用暗示了白垩纪时期地壳增厚，表明罗多彼地块是在特提斯活动边缘环境下叠加的同变质推覆体复合体。参与碰撞的两个地块是北部的欧洲大陆的莫西亚部分，以及南部的下罗多比地板块，后者是在这个超大陆分裂时期从盘古大陆分离出来的一个迁移地块。同变质切变意义的区域反转表明，挖掘构造始于白垩纪，可能与低密度弧和陆相岩石向上向前排出有关。晚始新世海侵将早期、晚造山伸展/掘出阶段与另一个伸展事件分开，该伸展事件伴随着一个主要的热岩浆事件，随后是中新世爱琴海伸展，导致罗多彼地块上的晚地堑。
Mylonitic gneisses of the Bulgarian and Greek Rhodope were deformed under amphibolite-facies conditions of medium pressure type metamorphism. The kinematic information contained on the strain regime and histories of these gneisses shows that ductile, shear-deformation occurred during development of a nappe complex. The nappe complex is characterised by south to southwestward (forelandward) piling-up and both coeval and subsequent extension. Different lithologies, deformation and metamorphic histories discriminate lower (footwall) and upper (hangingwall) continental terranes that define a crustal-scale duplex. Ultrahigh-Pressure metamorphic rocks, eclogites, ophiolitic and magmatic arc protoliths are found in various units of the crustal-scale duplex structure. These rocks delineate a suture zone between the hanging wall and footwall continental units. Synmetamorphic suturing and thrusting imply crustal thickening during the Cretaceous, which implies that the Rhodope massif is a complex of synmetamorphic nappes stacked in a Tethyan active margin environment. The two blocks involved in the collision are the Moesian part of the European continent to the north, and the Lower-Rhodope Terrane to the south, which was a migrating block detached from Pangea during breakup times of this supercontinent. Regional inversions of synmetamorphic sense-of-shear indicate that exhumation tectonics began in Cretaceous times, possibly linked to upward-forward expulsion of low density arc and continental rocks. A Late Eocene marine transgression separates the early, late-orogenic extension/exhumation phase from another extension event accompanied by a major thermal and magmatic event and followed by the Miocene Aegean extension responsible for late grabens over the Rhodope Massif.