Based on the integrated interpretation to the area located between 32°N and 35°N latitude,88°E and 89°E longitudes, the authors analysis the shallow and deep crust deformation of the Qiangtang Mass...Based on the integrated interpretation to the area located between 32°N and 35°N latitude,88°E and 89°E longitudes, the authors analysis the shallow and deep crust deformation of the Qiangtang Massif.Gravity,aeromagnetic,magnetotelluric and seismic surveys show that the Qiangtang Massif could be divided from north to south in the horizontal surface into three parts: the northern and the southern Qiangtang sag, the medial Armugang dome. The aeromagnetic anomaly contour line (AACL) of the medial dome is linear anomaly belts, whose amount varies between -50 nT and 260nT; the AACL of the northern sag is gently negative,whose value varies between 0 and -10nT, and its maximum aeromagnetic basement top depth is 11km;the AACL of the southern sag is gently low,positive alternating with negative, whose amount varies between -30nT and 30nT,and its maximum basement top depth is 9km.展开更多
Qiangtang Massif is located in the hinterland of Qinghai—Tibet plateau, which belong to the mid\|east section of Tethys Tectonic Domain.1 Features of the whole texture and structure of Qiangtang massif By synthetic a...Qiangtang Massif is located in the hinterland of Qinghai—Tibet plateau, which belong to the mid\|east section of Tethys Tectonic Domain.1 Features of the whole texture and structure of Qiangtang massif By synthetic analysis of gravity,magnetic field,MT,seismic surveying,etc. Geophysical data, the massif, lied in the tectonic setting and geodynamic setting mingled by the south,north tectonic belts, have the features of massif,basin and tectonic belt three forming an organic whole,multi\|degree coupling in plane and section with division of region in south\|north trend,division of block\|fault in east\|west trend,division of sphere\|layer in vertical direction. (1) Belting in south\|north trend: Qiangtang massif could be divided into four units from north to south, that is north edge doming zone, west part doming area,Qiangtang Basin and south edge doming zone. Qiangtang Basin also can be divided into four tectonic units—north Qiangtang down\|warping region, middle downing zone, south Qiangtang down\|warping and east part slope region. The near east\|west trend tectonic zones are well developed. There is aero\|magnetic anomaly distributed in belting with east\|west trend but also concentrated in section. Gravity anomaly is high in the south\|west part and low in the northeast part. Inter\|crust low resistance layer alternately distributed with high and low belting of sou th\|north trend in plane.展开更多
The northern Tibet plateau is the core of generalized Qinghai—Tibet plateau. The main part of Qiangtang—Changdu massif, which is 45×10 4km 2 and more than 5000m in altitude, conforms to the northern Tibet plate...The northern Tibet plateau is the core of generalized Qinghai—Tibet plateau. The main part of Qiangtang—Changdu massif, which is 45×10 4km 2 and more than 5000m in altitude, conforms to the northern Tibet plateau in area.1 The shape features and boundary conditions of Qiangtang—Changdu massif\;(1) Qiangtang—Changdu massif shows huge flat\|lying “S” area In MSS7 mosaic image, Qiangtang—Changdu massif extends in west and east, and appears a long\|elliptic huge block composed of feathered and dendritic textures.. Noticeably, there are two similar texture “tails" in the west and east ends of the massif. The western tail turns and constringes to the north, and eastern tail to the south. Thereby, the massif shows huge “S" area. According to the regional analysis, the eastern tail locates between Shaluli Mt.\|Taniantaweng Mt. and Mujiang River, and western part through Bangong\|Co connects with Pamirs along Karakoram Mt. In regional tectonics, the massif locates between Lazhulong\|Xijinwulan\|Co\|Jinshajiang River and Bangong\|Co\|Dongqiao\|Nujiang River fault belts.展开更多
Basic features Bangonghu—Dingqing Suture is the medial and western segment of the Bangonghu—Nujiang Suture which many researchers called as ,and it is often regarded as the Qiangtang Massif boundary line in the nort...Basic features Bangonghu—Dingqing Suture is the medial and western segment of the Bangonghu—Nujiang Suture which many researchers called as ,and it is often regarded as the Qiangtang Massif boundary line in the northern side and the Lasa (Gangdisi) Massif in the souther. The era of the ophiolites spreading along the Bangonghu\|Dingqing suture include every period of the whole Jurassic, and the spreading of the ophiolites has distinct segmentation. From west to east there are Ritu segment,Gaize segment,Dongqiao segment and Dingqing segment.Between the Gaize segment and Dongqiao one ,that is ,between the E89°and E86°40′,no ophiolites are discovered in the surface.Aeromagnetic data shows that the magnetic field of this segment is quite gentle,there are no difference from its adjacent northern and southern sides. When its east adjacent segment extends into this segment, the high areomagnetic anomaly belt corresponding to of the Dongqiao ophiolite disappear abruptly. Apparently,it is impossible for the ophiolites to develop in such a deep crust of the same segment.展开更多
文摘Based on the integrated interpretation to the area located between 32°N and 35°N latitude,88°E and 89°E longitudes, the authors analysis the shallow and deep crust deformation of the Qiangtang Massif.Gravity,aeromagnetic,magnetotelluric and seismic surveys show that the Qiangtang Massif could be divided from north to south in the horizontal surface into three parts: the northern and the southern Qiangtang sag, the medial Armugang dome. The aeromagnetic anomaly contour line (AACL) of the medial dome is linear anomaly belts, whose amount varies between -50 nT and 260nT; the AACL of the northern sag is gently negative,whose value varies between 0 and -10nT, and its maximum aeromagnetic basement top depth is 11km;the AACL of the southern sag is gently low,positive alternating with negative, whose amount varies between -30nT and 30nT,and its maximum basement top depth is 9km.
文摘Qiangtang Massif is located in the hinterland of Qinghai—Tibet plateau, which belong to the mid\|east section of Tethys Tectonic Domain.1 Features of the whole texture and structure of Qiangtang massif By synthetic analysis of gravity,magnetic field,MT,seismic surveying,etc. Geophysical data, the massif, lied in the tectonic setting and geodynamic setting mingled by the south,north tectonic belts, have the features of massif,basin and tectonic belt three forming an organic whole,multi\|degree coupling in plane and section with division of region in south\|north trend,division of block\|fault in east\|west trend,division of sphere\|layer in vertical direction. (1) Belting in south\|north trend: Qiangtang massif could be divided into four units from north to south, that is north edge doming zone, west part doming area,Qiangtang Basin and south edge doming zone. Qiangtang Basin also can be divided into four tectonic units—north Qiangtang down\|warping region, middle downing zone, south Qiangtang down\|warping and east part slope region. The near east\|west trend tectonic zones are well developed. There is aero\|magnetic anomaly distributed in belting with east\|west trend but also concentrated in section. Gravity anomaly is high in the south\|west part and low in the northeast part. Inter\|crust low resistance layer alternately distributed with high and low belting of sou th\|north trend in plane.
文摘The northern Tibet plateau is the core of generalized Qinghai—Tibet plateau. The main part of Qiangtang—Changdu massif, which is 45×10 4km 2 and more than 5000m in altitude, conforms to the northern Tibet plateau in area.1 The shape features and boundary conditions of Qiangtang—Changdu massif\;(1) Qiangtang—Changdu massif shows huge flat\|lying “S” area In MSS7 mosaic image, Qiangtang—Changdu massif extends in west and east, and appears a long\|elliptic huge block composed of feathered and dendritic textures.. Noticeably, there are two similar texture “tails" in the west and east ends of the massif. The western tail turns and constringes to the north, and eastern tail to the south. Thereby, the massif shows huge “S" area. According to the regional analysis, the eastern tail locates between Shaluli Mt.\|Taniantaweng Mt. and Mujiang River, and western part through Bangong\|Co connects with Pamirs along Karakoram Mt. In regional tectonics, the massif locates between Lazhulong\|Xijinwulan\|Co\|Jinshajiang River and Bangong\|Co\|Dongqiao\|Nujiang River fault belts.
文摘Basic features Bangonghu—Dingqing Suture is the medial and western segment of the Bangonghu—Nujiang Suture which many researchers called as ,and it is often regarded as the Qiangtang Massif boundary line in the northern side and the Lasa (Gangdisi) Massif in the souther. The era of the ophiolites spreading along the Bangonghu\|Dingqing suture include every period of the whole Jurassic, and the spreading of the ophiolites has distinct segmentation. From west to east there are Ritu segment,Gaize segment,Dongqiao segment and Dingqing segment.Between the Gaize segment and Dongqiao one ,that is ,between the E89°and E86°40′,no ophiolites are discovered in the surface.Aeromagnetic data shows that the magnetic field of this segment is quite gentle,there are no difference from its adjacent northern and southern sides. When its east adjacent segment extends into this segment, the high areomagnetic anomaly belt corresponding to of the Dongqiao ophiolite disappear abruptly. Apparently,it is impossible for the ophiolites to develop in such a deep crust of the same segment.
