唐山凸起PZK15孔浅表第四系沉积物色度特征及沉积环境演化

Chroma Characteristics and Quaternary Sedimentary Environment Evolution Analysis of Borehole PZK15 on the Tangshan Bump

为了详细研究唐山凸起浅表第四系地层色度特征、气候冷暖变迁及沉积物沉积环境演化等问题,依据色度样品、自然电位、自然伽马等测井曲线,并结合沉积物岩性、沉积构造等特征,对唐山西部老庄子镇附近PZK15钻孔地层进行详细研究。结果表明:(1)色度参数L^(*)(亮度)平均值在古土壤层呈最低值,a^(*)(红度)与b^(*)(黄度)平均值在古土壤层呈最高值,L^(*)与a^(*)呈显著的负相关关系,与b^(*)呈一般负相关关系,a^(*)与b^(*)呈高度正相关;(2)中更新统中后期气候由暖转冷,上更新统早期对应深海氧同位素MIS5阶段气温变化为暖-冷-暖,末次盛冰期气候由冷转暖;(3)钻孔中更新统地层主要以洪积扇及扇上河道为主,进入上更新统,地层均以河流相为主。

In order to systematically study Tangshan bump superficial quaternary strata chromaticity characteristic, climate changes in temperature change, and the problem of sediment deposition environment evolution, in this paper, the formation of PZK15 borehole near Laozhuangzi town in the west of Tangshan was studied in detail according to the logging curves of chromaticity samples, spontaneous potential and natural gamma ray, combined with the characteristics of sedimentary lithology and sedimentary structure. The results show that:(1) The average value of L^(*)(brightness) is the lowest in the paleosoil layer, and the average value of a^(*)(reddness) and b^(*)(yellowness) is the highest in the paleosoil layer. L^(*) has a significant negative correlation with a^(*),a^(*) has a general negative correlation with b^(*), and a^(*) is highly positive correlation with b^(*).(2) The climate changed from warm to cold in the middle and late period of the Middle Pleistocene, and in the early stage of the Upper Pleistocene, the temperature variation of MIS5 stage was warm-cold-warm, and from cold to warm in the last glacial maximum.(3) The Pleistocene strata in the borehole are mainly dominated by diluvial fans and the channel above the fan, and the strata in the Upper Pleistocene are mainly fluvial facies.