广东1:5万厚街圩、小榄镇、容奇镇、太平镇幅区域地质调查项目进展及主要成果

    Main Progress and Achievements in 1:50 000 Regional Geological Survey of Houjiexu, Xiaolanzhen, Rongqizhen, Taipingzhen Regions,Guangdong Province

    • 摘要: “广东1:5万厚街圩、小榄镇、容奇镇、太平镇幅区域地质调查”项目区内,第四系浅覆盖区面积占71%。在充分利用前人地质调查研究成果的基础上,综合采用地表路线调查、物探、遥感、钻探和钻孔第四系精细研究等方法开展工作。通过3 a的调查与研究,建立了珠江三角洲晚更新世(始自128 ka)5阶段(MIS5)海洋氧同位素海侵层序及地层格架;  根据钻孔沉积物样品磁化率变化进行了地层对比及沉积旋回划分,为珠江三角洲第四纪研究奠定了基础;  查明了测区NE、NW向隐伏主干断裂的空间展布及其活动性,为工程建设及防震减灾提供了基础资料;  通过花岗岩类锆石SHRIMP U-Pb精确定年,提出了二长花岗岩存在于印支期花岗岩带并形成于晚侏罗世陆壳伸展构造环境的新认识。

       

      Abstract: The proportion of shallow overburden area by Quaternary sediments in regional geological survey projects of 1:50 000 Houjiexu, Xiaolanzhen, Rongqizhen, Taipingzhen sheets has risen to 71%. Basing on previous achievements on regional geological survey, and combing with integrated method of route geological survey,geophysical prospecting, remote sensing,  geological drilling and detailed study of Quaternary sediments, the transgressive sequence and stratigraphic framework of the Pearl River delta have been established since Late Pleistocene 128 ka (MIS 5) in past three years. The susceptibility change law of sediment core provides evidences for stratigraphic correlation and sedimentary cycle division as well as basic data in Quaternary research of the Pearl River delta. The spatial extensions and activities of buried NE and NW trending main faults were found out which provided basic data for civil engineering construction, earthquake preparedness and disaster reduction. The SHRIMP dating technique is applied to determine U-Pb ages of zircons from monzogranites, the result suggests that Late Jurassic granitic magmatism formed in post-collisional extensional environment, Late Jurassic and Indosinian granitic magmatism coexisted in the study area.

       

    /

    返回文章
    返回