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运用锆石和磷灰石裂变径迹(FT)分析方法,探讨分析了鄂尔多斯盆地西南缘中生代构造事件的FT年龄分布与峰值年龄事件.结果表明:(ⅰ)早期构造事件主要发生在213～194Ma±,峰值年龄为205Ma,并以晚三叠世构造隆升及其前缘粗碎屑沉积为其地质响应.(ⅱ)中期构造事件至少包含两个幕次,一次发生在165～141Ma±,峰值年龄为150Ma;二次发生在115～113Ma±,峰值年龄为114Ma;其地质响应主要表现为晚侏罗世—早白垩世的逆冲推覆及其前缘粗碎屑沉积.(ⅲ)晚期构造事件主要表现为至少两个幕次的区域隆升作用,一次发生在100～81Ma±,峰值年龄为90Ma;二次发生在66～59Ma±,峰值年龄接近63Ma.结合成矿年代学资料分析认为,峰值年龄事件的极端环境效应和构造转换相对平稳期的适度活动,有可能是鄂尔多斯盆地多种矿产耦合成矿、共存富集的关键因素.
The FT age distribution and peak age events of Mesozoic tectonic events in the southwestern margin of the Ordos Basin were discussed by means of zircon and apatite fission track analysis (FT). The results show that: (i) Early tectonic events mainly occurred in the range of 213-194 Ma ± With a peak age of 205 Ma and its geological response to Late Triassic uplift and its frontal coarse clastic sediments. (Ii) The metaphase tectonic event consists of at least two episodes, occurring once at 165-141 Ma ±, with a peak The age is 150Ma, the secondary occurs at 115 ~ 113Ma ±, the peak age is 114Ma, and its geological response is mainly from the Late Jurassic to the Early Cretaceous thrust nappe and its frontal coarse clastic sediments. (Iii) The tectonic events mainly manifested as at least two episodes of regional uplift, once occurred at 100 ~ 81Ma ±, the peak age was 90Ma, the second occurred at 66 ~ 59Ma ±, and the peak age was close to 63Ma. It is considered that the extreme environmental effects of peak age events and the moderate activities of relatively stable tectonic transformation may be the key factors for mineralization and mineralization and coexistence and enrichment of various minerals in the Ordos Basin.