ABSTRACT

Apatite fission-track and (U-Th)/He ages from Carboniferous to Eocene siliciclastic rocks of the Istanbul Zone (NW Turkey) range from 220 to 46 Ma, and from 46 to 18 Ma, respectively. Apatite grains from the upper Cretaceous and Eocene volcaniclastic and siliciclastic formations yielded unreset fission-track ages (85 to 65 Ma), whereas the Lower Cretaceous siliciclastic rocks yielded both reset and unreset apatite fission-track ages. This suggests the absence of substantial burial after the Early Cretaceous. The thermochronological dataset presented here in conjunction with published data defines three major deformation and uplift/exhumation phases: (i) 220–179 Ma (Late Triassic-Early Jurassic), (ii) 101–107 Ma (mid-Cretaceous), and (iii) 66–16 Ma (Palaeocene-early Miocene). The Late Triassic-Early Jurassic uplift/exhumation phase can be attributed to the Cimmeride orogeny and the uplift of the Pontides. The mid-Cretaceous uplift/deformation is also reflected in the stratigraphic record as a major unconformity, which was probably caused by the accretion of an oceanic plateau or a seamount. The Palaeocene-early Eocene uplift/deformations resulted from the closure of the Izmir-Ankara-Erzincan oceanic domain. The late Oligocene-early Miocene uplift/deformation is probably caused by extension in the Aegean region due to the suction along the Hellenic trench.

摘要

伊斯坦布尔地区（土耳其西北部）石炭纪至始新世硅质碎屑岩的磷灰石裂变径迹和 (U-Th)/He 年龄分别为 220 至 46 Ma 和 46 至 18 Ma。来自上白垩统和始新世火山碎屑和硅质碎屑地层的磷灰石颗粒产生了未重置的裂变径迹年龄（85 至 65 Ma），而下白垩统硅质碎屑岩产生了重置和未重置的磷灰石裂变径迹年龄。这表明早白垩纪之后没有大量埋葬。这里提供的热年代数据集与已发表的数据一起定义了三个主要的变形和隆起/折返阶段：（i）220-179 Ma（晚三叠世-早侏罗世），（ii）101-107 Ma（白垩纪中期）和（ iii）66-16 Ma（古新世-早中新世）。晚三叠世-早侏罗世隆升/折返阶段可归因于 Cimmeride 造山运动和 Pontides 隆升。白垩纪中期的隆起/变形也反映在地层记录中作为主要的不整合面，这可能是由海洋高原或海山的增生引起的。古新世-始新世早期的隆起/变形是由伊兹密尔-安卡拉-埃尔津詹洋域的闭合造成的。晚渐新世-早中新世隆起/变形可能是由于沿希腊海沟的吸力作用在爱琴海地区的伸展引起的。古新世-始新世早期的隆起/变形是由伊兹密尔-安卡拉-埃尔津詹洋域的闭合造成的。晚渐新世-早中新世隆起/变形可能是由于沿希腊海沟的吸力作用在爱琴海地区的伸展引起的。古新世-始新世早期的隆起/变形是由伊兹密尔-安卡拉-埃尔津詹洋域的闭合造成的。晚渐新世-早中新世隆起/变形可能是由于沿希腊海沟的吸力作用在爱琴海地区的伸展引起的。