Zhenlai county in Jilin Province is taken as a typical area to explore the universal land use pattern under ecological security in ecotone between agriculture and animal husbandry in Northeastern China. Remote sensing...Zhenlai county in Jilin Province is taken as a typical area to explore the universal land use pattern under ecological security in ecotone between agriculture and animal husbandry in Northeastern China. Remote sensing data, relative thematic maps and corresponding social-economical statisitical and planning data were collected, and grey linear programming (GLP) model, together with the synthetic index estimating method was applied to develop an optimal land use model to evaluate the ecological security and analyze decision. The land use structure and optimal spatial allocation pattern of Zhenlai county in the year of 2010 regarded as a land use pattern under ecological security were simulated out by the mathematical models applied.展开更多
This paper presents a review on the rock associations, geochemistry, and spatial distribution of Mesozoic-Paleogene igneous rocks in Northeast Asia. The record of magmatism is used to evaluate the spatial-temporal ext...This paper presents a review on the rock associations, geochemistry, and spatial distribution of Mesozoic-Paleogene igneous rocks in Northeast Asia. The record of magmatism is used to evaluate the spatial-temporal extent and influence of multiple tectonic regimes during the Mesozoic, as well as the onset and history of Paleo-Pacific slab subduction beneath Eurasian continent. Mesozoic-Paleogene magmatism at the continental margin of Northeast Asia can be subdivided into nine stages that took place in the Early-Middle Triassic, Late Triassic, Early Jurassic, Middle Jurassic, Late Jurassic, early Early Cretaceous, late Early Cretaceous, Late Cretaceous, and Paleogene, respectively. The Triassic magmatism is mainly composed of adakitic rocks,bimodal rocks, alkaline igneous rocks, and A-type granites and rhyolites that formed in syn-collisional to post-collisional extensional settings related to the final closure of the Paleo-Asian Ocean. However, Triassic calc-alkaline igneous rocks in the Erguna-Xing'an massifs were associated with the southward subduction of the Mongol-Okhotsk oceanic slab. A passive continental margin setting existed in Northeast Asia during the Triassic. Early Jurassic calc-alkaline igneous rocks have a geochemical affinity to arc-like magmatism, whereas coeval intracontinental magmatism is composed of bimodal igneous rocks and A-type granites. Spatial variations in the potassium contents of Early Jurassic igneous rocks from the continental margin to intracontinental region, together with the presence of an Early Jurassic accretionary complex, reveal that the onset of the PaleoPacific slab subduction beneath Eurasian continent occurred in the Early Jurassic. Middle Jurassic to early Early Cretaceous magmatism did not take place at the continental margin of Northeast Asia. This observation, combined with the occurrence of low-altitude biological assemblages and the age population of detrital zircons in an Early Cretaceous accretionary complex,indicates that a strike-slip tectonic regime existed b展开更多
文摘Zhenlai county in Jilin Province is taken as a typical area to explore the universal land use pattern under ecological security in ecotone between agriculture and animal husbandry in Northeastern China. Remote sensing data, relative thematic maps and corresponding social-economical statisitical and planning data were collected, and grey linear programming (GLP) model, together with the synthetic index estimating method was applied to develop an optimal land use model to evaluate the ecological security and analyze decision. The land use structure and optimal spatial allocation pattern of Zhenlai county in the year of 2010 regarded as a land use pattern under ecological security were simulated out by the mathematical models applied.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41330206 & 41702051)the National Key Research and Development Project (Grant No. 2016YFC0600403)the China Postdoctoral Science Foundation (Grant Nos. 2017T100204 & 2017M611314)
文摘This paper presents a review on the rock associations, geochemistry, and spatial distribution of Mesozoic-Paleogene igneous rocks in Northeast Asia. The record of magmatism is used to evaluate the spatial-temporal extent and influence of multiple tectonic regimes during the Mesozoic, as well as the onset and history of Paleo-Pacific slab subduction beneath Eurasian continent. Mesozoic-Paleogene magmatism at the continental margin of Northeast Asia can be subdivided into nine stages that took place in the Early-Middle Triassic, Late Triassic, Early Jurassic, Middle Jurassic, Late Jurassic, early Early Cretaceous, late Early Cretaceous, Late Cretaceous, and Paleogene, respectively. The Triassic magmatism is mainly composed of adakitic rocks,bimodal rocks, alkaline igneous rocks, and A-type granites and rhyolites that formed in syn-collisional to post-collisional extensional settings related to the final closure of the Paleo-Asian Ocean. However, Triassic calc-alkaline igneous rocks in the Erguna-Xing'an massifs were associated with the southward subduction of the Mongol-Okhotsk oceanic slab. A passive continental margin setting existed in Northeast Asia during the Triassic. Early Jurassic calc-alkaline igneous rocks have a geochemical affinity to arc-like magmatism, whereas coeval intracontinental magmatism is composed of bimodal igneous rocks and A-type granites. Spatial variations in the potassium contents of Early Jurassic igneous rocks from the continental margin to intracontinental region, together with the presence of an Early Jurassic accretionary complex, reveal that the onset of the PaleoPacific slab subduction beneath Eurasian continent occurred in the Early Jurassic. Middle Jurassic to early Early Cretaceous magmatism did not take place at the continental margin of Northeast Asia. This observation, combined with the occurrence of low-altitude biological assemblages and the age population of detrital zircons in an Early Cretaceous accretionary complex,indicates that a strike-slip tectonic regime existed b
