龙虎山丹霞地貌区河流阶地地貌面的热释光测年研究

采用热释光(TL)测年方法对龙虎山丹霞地貌区泸溪河的阶地进行了年代学研究,获得了低阶地沉积物的堆积年代及其阶地面的形成时代,该区河流主要发育两级阶地,T1阶地堆积于3 400~6 000 a B.P.,其地貌面形成于3 400~4 000 a,T2阶地堆积于7 600~11 200 a B.P.,该级地貌面形成于7 600~8 000 a B.P.。利用低阶地地貌面的年代学成果,推算出龙虎山丹霞地貌区地壳隆升速率为0.33~0.63 m/ka,根据这一速率推算得出,第一夷平面形成于6×104a左右,第二夷平面形成于28×104a左右。分布于这些夷平面上的丹霞地貌景观的年龄与此相当。

TL Dating Research of Geomorphic Surface on Lower Terraces of Rives in Longhushang Danxia Landform Areas

Based on the research of TL dating for the river sediment on the lower terrace along the Luxi River in the Longhushang danxia landform areas,the deposited age of sediments and the formation times of the geomorphic surfaces of these lower terraces have been obtained along this river.There are tow lower terraces along the river in the research area.The sediments on the first terraces deposited in 3 400~6 000 a B.P.and their terrace surfaces formed during 3 400~4 000 a B.P.The second is in 7 600~11 200 a B.P.and the terrace surfaces formed in 7 600~8 000 a B.P.At the same time,the rates of the crust uplift have been presumed of 0.33~0.63 m/ka based on the chronological research of these lower terrace,and the formation times of the sights of the danxia landform is 60 000 to 280 000 years,the same ages as the old terraces or called the plane surfaces of the rive.