Late Mesozoic(?)-Mid Cenozoic Hinterland Extension: Black Pine Mountains, Idaho and Raft River Mountains, Utah

在一个薄皮的腹地的水平延伸 逆冲带被认为是地壳运动的自然结果， 缩短和增厚，导致地形隆起。 最 现代造山带和古代造山带的例子是众所周知的， 几乎没有证据。本研究将探讨一个建议， 在神秘的、古老的、自上而下的、向西延伸的 爱达荷州南部的断层似乎与 晚白垩世Laramide挤压。 断层运动与时序 将通过39 Ar/40 Ar测年和重建 伊利石结晶度和牙形石CAI的热状况。 结果 预计将确定伸展的时间和运动学 在这个地区的构造，并将承担之间的关系， 地壳缩短、增厚、地形抬升、侵蚀和 在冲断带腹地的延伸。

Horizontal extension in the Hinterland of a thin-skinned thrust belt has been proposed as a natural consequence of crustal shortening and thickening and resulting topographic uplift. Most examples are known from modern orogens and ancient belts have yielded little evidence. This study will explore a suggestion of extension in the enigmatic, younger-over-older, top-to-the-west faults in southern Idaho that appear to be contemporaneous with Late-Cretaceous Laramide compression. The fault motion and timing will be addressed by 39Ar/40Ar dating and by reconstructing the thermal regime by illite crystallinity and conodont CAI. Results are expected to define the timing and kinematics of extensional tectonics in this region, and will bear on the relations among crustal shortening, thickening, topographic uplift, erosion and extension in the hinterland of thrust belts.