A group of alluvial fans formed in the early Paleogene represent marginal sedimentary facies at the foot of the South Tianshan Mountain, Kuqa Depression, Tarim Basin, Xinjiang province. Two types of fans occurred in t...A group of alluvial fans formed in the early Paleogene represent marginal sedimentary facies at the foot of the South Tianshan Mountain, Kuqa Depression, Tarim Basin, Xinjiang province. Two types of fans occurred in the middle-late Paleogene Kumugeliemu and Suweiyi formations： one alluvial, and the other fan delta deposited in a lacustrine setting. Within the early Neogene Jidike Formation, coastal subaqueous fans developed, probably in a deeper water lacustrine setting. The three types of fans are stacked vertically in outcrop with the sequence in ascending order： bottom alluvial, middle fan-delta, and top suhaqueous. The subaqueous is a typical coarse-fan deposit occurring in the glutinite member of the Jidike Formation in some wells. Laterally, from the foreland to the lacustrine settings, the distribution pattern of sedimentary facies represents the same three fan types sequentially. The spatial distribution of these fans was controlled by the Paleogene-Neogene Basin transformation, and evolution with different types of fans developed in the Kuqa Depression in response. In the Paleogene, the Kuqa Depression was a rift basin where an alluvial fan was deposited in the foreland setting, which, by early Neogene, became a foreland basin when the lake level changed. With any rise in lake level, fan-deltas migrated from lacustrine to foreland settings, whereas when the lake level fell, fan migration was reversed. In the early Neogene, with increasing slope and rising lake level, fans progressed and covered the previous fan-delta and lacustrine mudstone. Eventually, subaqueous fans developed, forming the present spatial configuration of these three fan types.展开更多
Based on the data of 1:250000 geological mapping completed by CGS and the previous literature of the Cenozoic strata, 98 remnant basins and 5 stratigraphic realms with 13 stratigraphic subrealms have been recognized o...Based on the data of 1:250000 geological mapping completed by CGS and the previous literature of the Cenozoic strata, 98 remnant basins and 5 stratigraphic realms with 13 stratigraphic subrealms have been recognized on the Qinghai-Tibet Plateau and its adjacent area. Through the research of the types of remnant basins, tectonic setting, stratigraphic sequence and sedimentary characteristics, contact relationship between the strata, the formation time and evolution history of sediments, we divided the uplift process and sedimentary response of the Qinghai-Tibet Plateau into 3 stages and 8 sub-stages, namely, subduction-collision uplift stage (65-34 Ma) with three sub-stages, intercontinental convergence and compressive uplift stage (34-13 Ma) with three sub-stages, and intercontinental isostatic adjustment uplift stage (since 13 Ma) with two sub-stages.展开更多
The Cenozoic uplift of Qilian Mountains is critical to comprehend the uplift and extension of the Tibet Plateau as well as the formation of the first and second steps in China's topography. This study summarized d...The Cenozoic uplift of Qilian Mountains is critical to comprehend the uplift and extension of the Tibet Plateau as well as the formation of the first and second steps in China's topography. This study summarized dynamic stratigraphic realm comprehensively on the basis of stratigraphic correlation of different Cenozoic sedimentary basin regions of the Qilian Mountains and adjacent mountains. This facilitated the re-creation of the tectonic-sedimentary evolutionary process of the Qilian Mountains and their surrounding areas. The results indicate that during the Early Paleogene(Paleocene-Eocene), the Qilian Mountains were part of an uplift realm. During the Oligocene, Guide-Xining-Lanzhou-Linxia sag basin at the northern margin of the West Qinling Mountains came into being and was subjected to sedimentation. The Suli Basin located between the North and South Qilian paleo-uplifts began to form and undergo sedimentation. Intracontinental orogenic extrusion and basin detachment occurred at the Qilian Mountains during the Miocene, which caused successive uplifts of various mountains, including the Laji, South Qinghai,Jishi, Liupan, and South Shule Mountains. Until Pliocene, Qilian Mountains uplifted continuously and resulted in the shrink,extinction and being eroded of the basins, and aeolian red clay started to accumulate.展开更多
基金supported by the National scientific special:Tectonic and sedimentary and reservoir features of foreland basin in west-central China(2008zx05000-003-01).
文摘A group of alluvial fans formed in the early Paleogene represent marginal sedimentary facies at the foot of the South Tianshan Mountain, Kuqa Depression, Tarim Basin, Xinjiang province. Two types of fans occurred in the middle-late Paleogene Kumugeliemu and Suweiyi formations： one alluvial, and the other fan delta deposited in a lacustrine setting. Within the early Neogene Jidike Formation, coastal subaqueous fans developed, probably in a deeper water lacustrine setting. The three types of fans are stacked vertically in outcrop with the sequence in ascending order： bottom alluvial, middle fan-delta, and top suhaqueous. The subaqueous is a typical coarse-fan deposit occurring in the glutinite member of the Jidike Formation in some wells. Laterally, from the foreland to the lacustrine settings, the distribution pattern of sedimentary facies represents the same three fan types sequentially. The spatial distribution of these fans was controlled by the Paleogene-Neogene Basin transformation, and evolution with different types of fans developed in the Kuqa Depression in response. In the Paleogene, the Kuqa Depression was a rift basin where an alluvial fan was deposited in the foreland setting, which, by early Neogene, became a foreland basin when the lake level changed. With any rise in lake level, fan-deltas migrated from lacustrine to foreland settings, whereas when the lake level fell, fan migration was reversed. In the early Neogene, with increasing slope and rising lake level, fans progressed and covered the previous fan-delta and lacustrine mudstone. Eventually, subaqueous fans developed, forming the present spatial configuration of these three fan types.
基金supported by Geological Survey of China (Grant Nos.1212010610103 and 1212010733802)National Natural Science Founda-tion of China (Grant Nos.40921062 and 400830212)MOST Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences
文摘Based on the data of 1:250000 geological mapping completed by CGS and the previous literature of the Cenozoic strata, 98 remnant basins and 5 stratigraphic realms with 13 stratigraphic subrealms have been recognized on the Qinghai-Tibet Plateau and its adjacent area. Through the research of the types of remnant basins, tectonic setting, stratigraphic sequence and sedimentary characteristics, contact relationship between the strata, the formation time and evolution history of sediments, we divided the uplift process and sedimentary response of the Qinghai-Tibet Plateau into 3 stages and 8 sub-stages, namely, subduction-collision uplift stage (65-34 Ma) with three sub-stages, intercontinental convergence and compressive uplift stage (34-13 Ma) with three sub-stages, and intercontinental isostatic adjustment uplift stage (since 13 Ma) with two sub-stages.
基金supported by the China Geological Survey (Grant No. DD20160345-16)the National Natural Science Foundation of China (Grant Nos. 40382039, 41372020, 41372036, 41472035)
文摘The Cenozoic uplift of Qilian Mountains is critical to comprehend the uplift and extension of the Tibet Plateau as well as the formation of the first and second steps in China's topography. This study summarized dynamic stratigraphic realm comprehensively on the basis of stratigraphic correlation of different Cenozoic sedimentary basin regions of the Qilian Mountains and adjacent mountains. This facilitated the re-creation of the tectonic-sedimentary evolutionary process of the Qilian Mountains and their surrounding areas. The results indicate that during the Early Paleogene(Paleocene-Eocene), the Qilian Mountains were part of an uplift realm. During the Oligocene, Guide-Xining-Lanzhou-Linxia sag basin at the northern margin of the West Qinling Mountains came into being and was subjected to sedimentation. The Suli Basin located between the North and South Qilian paleo-uplifts began to form and undergo sedimentation. Intracontinental orogenic extrusion and basin detachment occurred at the Qilian Mountains during the Miocene, which caused successive uplifts of various mountains, including the Laji, South Qinghai,Jishi, Liupan, and South Shule Mountains. Until Pliocene, Qilian Mountains uplifted continuously and resulted in the shrink,extinction and being eroded of the basins, and aeolian red clay started to accumulate.
