The geological record of the lowermost tectonic unit of the Cretan nappe pile in the Talea Ori, Crete, Greece - the deformation history during burial and exhumation

这项研究建议破译Talea Ori单元底部的HP-LT变质沉积的地质记录，即克雷坦推覆体桩最古老和最低的已知构造水平。目的是获得有关埋葬和挖掘过程中长期变形和应力历史的信息。在巴厘村周围和Fodele村以西的选定研究区域，低应变变泥岩和砾岩不断进入高应变带。低应变砾岩中片麻岩和片岩成分的矿物组合和显微结构将被用来获得关于未知的前阿尔卑斯山基底的信息。高应变带提供了至少两个不同变形阶段的信息：鳞片面理、线理和厘米级褶皱被剪切带和相关的石英脉以高角度横切。推断的变形构造(面理、线理、褶皱、剪切带、脉)的空间排列将与塔雷奥里大型褶皱结构和北部接壤构造接触进行调查和解释。分析与各种介观结构相关的微结构的结构、化学和结晶学特征，以推断变形机制和变形条件(温度、应力、应变率)。高应变区的初步观察表明，与剪切带和剪切石英脉有关的显微组构指示了石英的高应力晶体塑性变形。现场观测与显微组构分析的相关性将有助于表征和区分不同的变形阶段。利用同一构造地层单元内低应力/低应变和高应变、局部高应力的对比岩石记录，提取俯冲历史中的岩石流变性。最后，将推断的塔里奥里单元底部的地质记录与构造位置有争议的北部接触单元的中观变形结构和显微组构进行对比，将用于阐明塔里奥里单元的区域地质。

The study proposes to decipher the geological record of HP-LT metasediments at the base of the Talea Ori unit, i.e., the oldest and lowermost known structural level of the Cretan nappe pile. The aim is to obtain information on the long-time deformation and stress history during burial and exhumation. In the chosen study areas around the village Bali and west to the village Fodele, low-strain metapelites and conglomerates grade continuously into high-strain zones. The mineral association and microstructure of gneiss and schist components in low-strain conglomerates will be used to obtain information on the unknown pre-Alpine basement. The high-strain zones provide information on at least two different deformation stages: a scaly foliation, lineation and cm-scale folds are crosscut by shear bands and related quartz veins at a high angle. The spatial arrangement of the inferred deformation structures (foliation, lineation, folds, shear band, veins) will be investigated and interpreted in relation to the large-scale fold structure in the Talea Ori and to the northern bordering tectonic contact. The structural, chemical and crystallographic characteristics of the microfabrics related to the various mesoscopic structures will be analyzed to infer the deformation mechanisms and deformation conditions (temperature, stress, strain rate). Preliminary observations on high-strain zones reveal that the microfabrics related to shear bands and sheared quartz veins indicate high-stress crystal plastic deformation of quartz. The correlation of the field observations with the microfabric analyses will allow characterizing and separating the different deformation stages. Reconciling the contrasting rock records of low-stress/low-strain on the one hand and high-strain and locally high-stress on the other within one tectono-stratigraphic unit will be used to extract the rheological properties during the subduction history. Finally, the comparison of the inferred geological record of the base of the Talea Ori unit to the mesoscopic deformation structures and microfabrics of the unit in northern contact, where the structural position is debated controversially, will be used to elucidate the regional geology of the Talea Ori.