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对泥河湾盆地郝家台、后沟、红崖和虎头梁4个地点湖相及其上覆沉积物样品进行了光释光年代学研究。由于中粒石英的单片再生剂量法所测光释光信号已经达到了饱和,故采用中粒混合矿物的红外激发后高温红外激发方法,并对其异常衰退进行校正,这种方法利用长石的释光信号,饱和剂量较高,且异常衰退较小,为测量老样品提供了可能性。根据红外激发后高温红外激发光释光测年结果,郝家台、后沟和红崖地区现存泥河湾湖相顶部沉积物年龄为360~420ka,虎头梁湖相顶层沉积物年龄为约270ka,而郝家台和后沟湖相沉积物上覆黄土-古土壤年龄分别为约130ka和180ka。这些测年结果表明在泥河湾地区湖相沉积物顶层及其上覆沉积物之间广泛存在一个沉积间断,且不同地点湖相沉积物侵蚀的程度不同。因此,推测现在泥河湾地区出露的湖相沉积物顶层并不是当时古湖泊消失时的沉积,即至少部分古湖泊沉积的顶部已被侵蚀。
The photoluminescence chronology of the lacustrine and its overlying sediments in Haojiatai, Hougou, Hongya, and Hutotiang areas in the Nihewan Basin was studied. Due to the monolithic regenerative dose method of meso-quartz, the photoluminescence signal has reached saturation, so the method of infrared excitation after the high-temperature infrared excitation of the medium-sized mixed mineral is adopted and the anomalous recession is corrected. This method uses the feldspar Of the light-emitting signal, the higher saturation dose, and the smaller the anomalous recession, provides the possibility of measuring old samples. According to the results of infrared light-induced luminescence dating after infrared excitation, the sediments of the top Niuhewan lacustrine sediments from 360 to 420 ka in Haojiatai, Hougou and Hongya areas are about 270 ka, The overlying loess-paleosol ages of Haojiatai and Hougouhu sediments are about 130ka and 180ka. These dating results show that there is a widespread depositional discontinuity between the top of lacustrine sediments and its overlying sediments in the Nihewan area and the erosion of lacustrine sediments in different locations is different. Therefore, it is speculated that the top of the lacustrine sediments now exposed in the Nihewan area are not the sediments of the ancient lakes that disappeared at that time, that is, the top of at least part of the ancient lakes has been eroded.