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、下阿尔卑斯推覆体被“拉古中新世的伸展被认为是由希腊俯冲带的回滚所控制的。主张伸展运动沿着“拉张拆离带”的一个理由是，上盘假定的非变质岩（特里波利察单元）位于下盘变质岩（千枚岩石英岩或板状岩单元）之上。第一个微组构，应变和伊利石结晶度数据从克里特岛东部，但是，建议逆变质时，交叉的“Alberan momentum”，这意味着非常低级变质的Tripolitza石灰岩是几乎nonmetamorphic岩石的PhylliteQuartzite单位休息。因此，在克里特岛东部，“拉法拉拆离”可能形成一个逆冲断层，其运动应该导致地壳增厚。目前的项目将集中在这一假设，因为（1）“伊特鲁里亚拆离体”是非常重要的东地中海地区的阿尔卑斯山的地球动力学，（2）“伊特鲁里亚拆离体”可以穿透的ICDP钻井在梅萨拉地堑。