The `Cretan detachment` and adjacent units in eastern Crete: Structure, kinematics, deformation mechanisms, and metamorphic evolution

克里特岛东部的“克里特支队”和邻近单位：结构、运动学、变形机制和变质演化

• 批准号: 5363787
• 负责人: Professor Dr. Gernold Zulauf
• 金额: --
• 依托单位: Arbeitsgruppe Strukturgeologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5363787?language=en
• 关键词: Cretan; detachment; adjacent; units; eastern

The upper and lower Alpine nappes of Crete are separated by the 'Cretan detachment', which is commonly interpreted to represent a large-displacement extensional shear zone that contributed to exhume subducted rocks of the foot wall. Miocene extension is supposed to have been controlled by roll back of the Hellenic subduction zone. One reason to argue for extensional movements along the 'Cretan detachment' is the fact that supposed nonmetamorphic rocks of the hanging wall (Tripolitza unit) are resting on top of metamorphic rocks of the foot wall (PhylliteQuartzite or Plattenkalk unit). First microfabric, strain and illite-crystallinity data from eastern Crete, however, suggest inverse metamorphism when crossing the 'Cretan detachment', meaning that very-low grade metamorphic Tripolitza limestone is resting on almost nonmetamorphic rocks of the PhylliteQuartzite unit. Thus, in eastern Crete the 'Cretan detachment' might form a thrust, the movements of which should have led to crustal thickening. The present project will focus on this hypothesis because (1) the 'Cretan detachment' is of major importance for the Alpine geodynamics of the eastern Mediterranean area, and (2) the 'Cretan detachment' could be penetrated by ICDP drillings in the Mesara graben.

克里特岛的上和下高山尿布由“ Cretan脱离”分开，Cretan脱离通常被解释为代表一个大置位的伸展剪切带，该剪切带有助于发掘脚壁的俯冲岩石。中新世的扩展应该是由希腊俯冲带的后背控制的。沿着“克里特岛脱离”的伸展运动的原因之一是，悬挂墙的假定非型岩石（Tripolitza单位）搁在脚壁的变质岩石（Phyllitequartquartzite或Plattenkalk单位）的顶部。然而，来自东部克里特岛的第一个微型实物，应变和伊利特 - 结晶数据表明，跨越“克里特群岛脱离”时的变质逆，这意味着非常低的级变质的tripolitza limestone息息相关，几乎息息在phyllitequartzite单元的几乎非metamorphic岩石上。因此，在东部克里特岛，“克里特群岛脱离”可能会形成推力，其运动应该导致地壳增厚。本项目将重点放在这一假设上，因为（1）“ CRETAN脱离”对于东地中海地区的高山地球动力学至关重要，并且（2）米萨拉·格拉登（Mesara Graben）的ICDP钻探可以通过ICDP钻探来渗透“ CRETAN脱离”。