Maceral composition and aromatic compounds were determined on columnsamples to study the peat-forming environments of Permian coal seam 2 and Carboniferouscoal seam 9^(-2) from the Xingtai coalfield,China.The macerals...Maceral composition and aromatic compounds were determined on columnsamples to study the peat-forming environments of Permian coal seam 2 and Carboniferouscoal seam 9^(-2) from the Xingtai coalfield,China.The macerals were dominated by inertinitein seam 2 and by vitrinite in seam 9^(-2).Three maceral groups were selected as indicatorsof peat-forming environments.Two triangle diagrams were drawn based on the indicatorsto explicate the peat-forming environments of permian seam 2 and Carboniferousseam 9^(-2).The results indicate that the peat of carboniferous seam 9^(-2) formed dominantlyin wet swamps,whereas the peat of Permian seam 2 formed dominantly in dry swampsand open moor environments.展开更多
Nappe structure, as was first discovered by the authors during the regional geological survey at the scale of 1:50,000 in The Jinggang Mountain, is mainly comprised of a series of NNE-NE-striking thrust fault zones an...Nappe structure, as was first discovered by the authors during the regional geological survey at the scale of 1:50,000 in The Jinggang Mountain, is mainly comprised of a series of NNE-NE-striking thrust fault zones and thrust sheets among them. Sinian, Cambrian, Ordovician, Devonian, Carboniferous,Triassic, Jurassic and Cretaceous strata are involved in the thrust nappe system. The nappe structure is of the type of duplex structures formed as a result of the earlier stage migration from SE to NW and late stage migration from E to W of sedimentary cover or basement strata. Formation of the nappe structure in the studied area involves two main epochs: Early Yanshanian and Late Yanshanian to Early Himalayan. The mineral deposits and the buried coalfields in the area, especially the latter, are extensively controlled by the nappe structure.展开更多
There are many thrust-related structures occurring in the Paleozoic strata of the Niushou Mountain in the central part of Ningxia Hui Autonomous Region. The fault-related folds are the typical structures in this area....There are many thrust-related structures occurring in the Paleozoic strata of the Niushou Mountain in the central part of Ningxia Hui Autonomous Region. The fault-related folds are the typical structures in this area. Based on the analysis about these structures and their relationships, the processes by which these structures of the Miboshan Formation were formed are reconstructed, and the strata underwent about three stages of deformation: (1) horizontal shortening, (2) folding, and (3) thrusting. And the fact that the Niushou Mountain is the leading edge of an old thrust sheet was proved, the Niushou Mountain,the Daluo Mountain and the Xiaoluo Mountain together constitute the front part of this old thrust zone,so the Niushou Mountain and the Ordovician strata in the central and southern parts of Ningxia now are likely allochthons. In the period from middle Ordovician to Devonian, the areas of the central and southern Ningxia belonged to the back-arc foreland basin of North Qilianshan orogen, which was adjacent to the continent in the north. In the later part of the early Paleozoic period, the Niushou Mountain was formed after the closure of the back-arc foreland basin.展开更多
基金Supported by the National Natural Science Foundation of China(40773040)the National Basic Research Program of China (2003CB214607)
文摘Maceral composition and aromatic compounds were determined on columnsamples to study the peat-forming environments of Permian coal seam 2 and Carboniferouscoal seam 9^(-2) from the Xingtai coalfield,China.The macerals were dominated by inertinitein seam 2 and by vitrinite in seam 9^(-2).Three maceral groups were selected as indicatorsof peat-forming environments.Two triangle diagrams were drawn based on the indicatorsto explicate the peat-forming environments of permian seam 2 and Carboniferousseam 9^(-2).The results indicate that the peat of carboniferous seam 9^(-2) formed dominantlyin wet swamps,whereas the peat of Permian seam 2 formed dominantly in dry swampsand open moor environments.
基金supported by a grant from the Ministry of Land and Resources(Project No:19961300002011)for the regional geological survey of the Jinggangshan City section,Yaqian section,Tianhe section,Nashan section of the 1:50,000 geologic mapa key orientation grant(No.KZCXZ-SW-117)of CAS Knowledge Innovation Project for the constitution,structure and evolution of the geotectonic systems of South China Sea and its adjacent regions.
文摘Nappe structure, as was first discovered by the authors during the regional geological survey at the scale of 1:50,000 in The Jinggang Mountain, is mainly comprised of a series of NNE-NE-striking thrust fault zones and thrust sheets among them. Sinian, Cambrian, Ordovician, Devonian, Carboniferous,Triassic, Jurassic and Cretaceous strata are involved in the thrust nappe system. The nappe structure is of the type of duplex structures formed as a result of the earlier stage migration from SE to NW and late stage migration from E to W of sedimentary cover or basement strata. Formation of the nappe structure in the studied area involves two main epochs: Early Yanshanian and Late Yanshanian to Early Himalayan. The mineral deposits and the buried coalfields in the area, especially the latter, are extensively controlled by the nappe structure.
基金supported by National Science Foundation(Grant No.4983402).
文摘There are many thrust-related structures occurring in the Paleozoic strata of the Niushou Mountain in the central part of Ningxia Hui Autonomous Region. The fault-related folds are the typical structures in this area. Based on the analysis about these structures and their relationships, the processes by which these structures of the Miboshan Formation were formed are reconstructed, and the strata underwent about three stages of deformation: (1) horizontal shortening, (2) folding, and (3) thrusting. And the fact that the Niushou Mountain is the leading edge of an old thrust sheet was proved, the Niushou Mountain,the Daluo Mountain and the Xiaoluo Mountain together constitute the front part of this old thrust zone,so the Niushou Mountain and the Ordovician strata in the central and southern parts of Ningxia now are likely allochthons. In the period from middle Ordovician to Devonian, the areas of the central and southern Ningxia belonged to the back-arc foreland basin of North Qilianshan orogen, which was adjacent to the continent in the north. In the later part of the early Paleozoic period, the Niushou Mountain was formed after the closure of the back-arc foreland basin.
