太行神仙山髫髻山组火山岩锆石SHRIMP U-Pb年龄及其地质意义

SHRIMP U-Pb Dating and Its Geological Implications for Zircon in the Tiaojishan Group Volcanic Rocks of the Shenxian Mountain in the Taihang Aera

太行山中北段发育大量燕山期中-酸性火山岩,其中位于太行山北段的涞源县神仙山地区的断陷盆地正是其中一期构造-岩浆活动形成的逆冲推覆残片。本文报道了研究区内广泛出露的髫髻山组安山质角砾凝灰岩的锆石SHRIMP U-Pb年龄为131±2Ma。该年龄对太行山地区的髫髻山组火山岩进行了时限上的厘定并限定了太行山北段北西向拉张断裂构造系统的发育时间。本研究为太行山中生代岩浆活动研究提供了新的依据。

The Yanshanian neutral-acidic volcanic rocks are widely spread in the north-middle section of the Taihang Mr. The faulted basin in the Laiyuan county, Shenxianshan region, north section of the Taihang Mt is geologically considered as the thrust nappe of one stage tectono-magmatic event. This paper reported that the zircon SHRIMP U-Pb dating result for the andesitic breccia tuff in the Tiaojishan group is 131±2Ma, which constrains the forming age of the Tiaojishan group and the timing of NW extensional structure in the north section of the Taihang Mr. This study provided new information for the Mesozoic magmatic events in the Taihang Mt.