Uplift\|related geological and geophysical data available from regional geological mapping , detailed structural, tectonic, granitic, volcanic, metamorphic , geochronological studies, deep seismic reflection, wide\|an...Uplift\|related geological and geophysical data available from regional geological mapping , detailed structural, tectonic, granitic, volcanic, metamorphic , geochronological studies, deep seismic reflection, wide\|angle seismic experiment, seismic tomography, broadband seismic network, and magnetotelluric sounding of key areas of the Qinghai—Tibet plateau are radically different from models of plate subduction or collision. Key geological features include: (1) obvio us time difference between plate collision and uplift of the plateau; (2) developments of intracrustal low\|velocity layers , low resistivity layers and discontinuous subhorizontal reflectors; (3) similar results between the rate and time of uplift of the Qinghai\|Tibet plateau and the time and rate of subsidence of its surrounding basins; (4) subhorizontal detachments and metamorphic core complexes occurred in Himalayan and Longmenshan; (5) weak deformation of late Cenozoic sediments and development of major steeply to gently dipping normal faults in the central part of the plateau; (6) discovery of high pressure and ultrahigh pressure metamorphic rocks in Nanbajiawa; (7) young volcanic rocks distributed from the northern plateau to the southern plateau; (8) nearly concordant processes among thrusting , mountain building, horizontal extension and intrusion of leucogranite in Himalayans.展开更多
Glacially driven chemical weathering could make concentration of CO\-2 in the atmosphere decrease, and the process might play a significant role in climate change and the carbon cycle. So the study of chemical compone...Glacially driven chemical weathering could make concentration of CO\-2 in the atmosphere decrease, and the process might play a significant role in climate change and the carbon cycle. So the study of chemical components and their contents of glacial meltwater in an alpine glacier\|covered catchment has important geochemical and climatological significance.展开更多
Luonan Basin, formed during Neo\|tectonic movements, is one of the small block basins in East Qinling Mountain. Three faults, Tieluzi Fault, Dajing\|Guojiayuan Fault and Beisi Fault bound it. The west part of the basi...Luonan Basin, formed during Neo\|tectonic movements, is one of the small block basins in East Qinling Mountain. Three faults, Tieluzi Fault, Dajing\|Guojiayuan Fault and Beisi Fault bound it. The west part of the basin is higher than the east part. The elevation, usually more than 1100meters in the west, decreases gradually to less than 800meters in the east. The Cenozoic deposit in Luonan Basin is thin in the west part and becomes increasingly thick towards the east part. The total thickness of both the Eogene and the Neogene is only more than 100meters at Dajing. At Duishan, a place close to Luonan county town, it is about 400meters, and at Gucheng, it becomes nearly 1750meters. The strata crop out in the west part of the basin, usually the Eogene and the Neogene, are older than those in the east part which are usually the Quaternary deposits. The pattern of the Cenozoic deposits in Luonan Basin is similar to that in Shangzhou Basin (Li Kaoshe, personal communication), a basin locating just to the south of Luonan Basin.展开更多
文摘Uplift\|related geological and geophysical data available from regional geological mapping , detailed structural, tectonic, granitic, volcanic, metamorphic , geochronological studies, deep seismic reflection, wide\|angle seismic experiment, seismic tomography, broadband seismic network, and magnetotelluric sounding of key areas of the Qinghai—Tibet plateau are radically different from models of plate subduction or collision. Key geological features include: (1) obvio us time difference between plate collision and uplift of the plateau; (2) developments of intracrustal low\|velocity layers , low resistivity layers and discontinuous subhorizontal reflectors; (3) similar results between the rate and time of uplift of the Qinghai\|Tibet plateau and the time and rate of subsidence of its surrounding basins; (4) subhorizontal detachments and metamorphic core complexes occurred in Himalayan and Longmenshan; (5) weak deformation of late Cenozoic sediments and development of major steeply to gently dipping normal faults in the central part of the plateau; (6) discovery of high pressure and ultrahigh pressure metamorphic rocks in Nanbajiawa; (7) young volcanic rocks distributed from the northern plateau to the southern plateau; (8) nearly concordant processes among thrusting , mountain building, horizontal extension and intrusion of leucogranite in Himalayans.
文摘Glacially driven chemical weathering could make concentration of CO\-2 in the atmosphere decrease, and the process might play a significant role in climate change and the carbon cycle. So the study of chemical components and their contents of glacial meltwater in an alpine glacier\|covered catchment has important geochemical and climatological significance.
文摘Luonan Basin, formed during Neo\|tectonic movements, is one of the small block basins in East Qinling Mountain. Three faults, Tieluzi Fault, Dajing\|Guojiayuan Fault and Beisi Fault bound it. The west part of the basin is higher than the east part. The elevation, usually more than 1100meters in the west, decreases gradually to less than 800meters in the east. The Cenozoic deposit in Luonan Basin is thin in the west part and becomes increasingly thick towards the east part. The total thickness of both the Eogene and the Neogene is only more than 100meters at Dajing. At Duishan, a place close to Luonan county town, it is about 400meters, and at Gucheng, it becomes nearly 1750meters. The strata crop out in the west part of the basin, usually the Eogene and the Neogene, are older than those in the east part which are usually the Quaternary deposits. The pattern of the Cenozoic deposits in Luonan Basin is similar to that in Shangzhou Basin (Li Kaoshe, personal communication), a basin locating just to the south of Luonan Basin.
