Southern East Asia,including Guangxi and Fujian provinces in China,is home to diverse ethnic groups,languages,and cultures.Previous studies suggest a high complexity regarding population dynamics and the history of so...Southern East Asia,including Guangxi and Fujian provinces in China,is home to diverse ethnic groups,languages,and cultures.Previous studies suggest a high complexity regarding population dynamics and the history of southern East Asians.However,large-scale genetic studies on ancient populations in this region are hindered by limited sample preservation.Here,using highly efficient DNA capture techniques,we obtain 48 complete mitochondrial genomes of individuals from Guangxi and Fujian in China and reconstruct their maternal genetic history over the past 12,000 years.We find a strong connection between southern East Asians dating to~12,000-6000 years ago and present-day Southeast Asians.In addition,stronger genetic affinities to northern East Asians are observed in historical southern East Asians than Neolithic southern East Asians,suggesting increased interactions between northern and southern East Asians over time.Overall,we reveal dynamic connections between ancient southern East Asians and populations located in surrounding regions,as well as a shift in maternal genetic structure within the populations over time.展开更多
Diagenesis exerts an important control on porosity evolution,and research of diagenesis and diagenetic minerals provides insights into reservoir quality evaluation and CO_(2) storage.Thin section,XRD(X-ray diffraction...Diagenesis exerts an important control on porosity evolution,and research of diagenesis and diagenetic minerals provides insights into reservoir quality evaluation and CO_(2) storage.Thin section,XRD(X-ray diffraction),CT(Computed Tomography),scanning electron microscopy(SEM),and NMR(Nuclear Magnetic Resonance)tests were used to investigate composition,texture,pore spaces,and diagenesis of sandstones in Paleogene Dongying Formation in Bohai Bay Basin,China,with special aims to unravel diagentic dissolution along bedding planes.The oversized pores,remnants in feldspar-hosted pores,and kaolinite within feldspar grains indicate a high degree of dissolution the framework grains experienced during burial.The CO_(2)-rich or organic acids are responsible for the feldspar dissolution.Grain size plays the primary role in enhancing bedding dissolution process,and bedding planes in fine-medium grained sandstones with high content of feldspars are frequently enlarged by dissolution.The CT scanning image confirms dissolution pores are distributed discontinuously along the bedding planes.The dissolution pores along bedding planes have large pore size,and correspond to the right peak of the bi-modal T_(2)(transverse relaxation time)spectrum.The laminated sandstones and siltstones,or sandstones with cross beddings help improve framework grain dissolution.These new findings help improve the understanding of diagenetic models,and have implications in reservoir quality prediction and resource assessments in sandstones.展开更多
基金This work was supported by the Chinese Academy of Sciences(CAS,XDB26000000,YSBR-019,XDA1905010,QYZDB-SSW-DQC003)National Natural Science Foundation of China(41925009,41630102,41672021)+2 种基金“Research on the roots of Chinese civilization”of Zhengzhou University(XKZDJC202006)Tencent Foundation through the XPLORER PRIZEthe Howard Hughes Medical Institute(55008731).
文摘Southern East Asia,including Guangxi and Fujian provinces in China,is home to diverse ethnic groups,languages,and cultures.Previous studies suggest a high complexity regarding population dynamics and the history of southern East Asians.However,large-scale genetic studies on ancient populations in this region are hindered by limited sample preservation.Here,using highly efficient DNA capture techniques,we obtain 48 complete mitochondrial genomes of individuals from Guangxi and Fujian in China and reconstruct their maternal genetic history over the past 12,000 years.We find a strong connection between southern East Asians dating to~12,000-6000 years ago and present-day Southeast Asians.In addition,stronger genetic affinities to northern East Asians are observed in historical southern East Asians than Neolithic southern East Asians,suggesting increased interactions between northern and southern East Asians over time.Overall,we reveal dynamic connections between ancient southern East Asians and populations located in surrounding regions,as well as a shift in maternal genetic structure within the populations over time.
基金supported by Natural Science Foundation of Beijing(No.8204069)Science Foundation of China University of Petroleum,Beijing(No.2462021YXZZ003).
文摘Diagenesis exerts an important control on porosity evolution,and research of diagenesis and diagenetic minerals provides insights into reservoir quality evaluation and CO_(2) storage.Thin section,XRD(X-ray diffraction),CT(Computed Tomography),scanning electron microscopy(SEM),and NMR(Nuclear Magnetic Resonance)tests were used to investigate composition,texture,pore spaces,and diagenesis of sandstones in Paleogene Dongying Formation in Bohai Bay Basin,China,with special aims to unravel diagentic dissolution along bedding planes.The oversized pores,remnants in feldspar-hosted pores,and kaolinite within feldspar grains indicate a high degree of dissolution the framework grains experienced during burial.The CO_(2)-rich or organic acids are responsible for the feldspar dissolution.Grain size plays the primary role in enhancing bedding dissolution process,and bedding planes in fine-medium grained sandstones with high content of feldspars are frequently enlarged by dissolution.The CT scanning image confirms dissolution pores are distributed discontinuously along the bedding planes.The dissolution pores along bedding planes have large pore size,and correspond to the right peak of the bi-modal T_(2)(transverse relaxation time)spectrum.The laminated sandstones and siltstones,or sandstones with cross beddings help improve framework grain dissolution.These new findings help improve the understanding of diagenetic models,and have implications in reservoir quality prediction and resource assessments in sandstones.
