Under the combined influences of special topography and the long term mining in Nanfen Open Pit Iron Mine, many large scale landslide masses appeared in heading side of stope, and tens of millions of iron mine is buri...Under the combined influences of special topography and the long term mining in Nanfen Open Pit Iron Mine, many large scale landslide masses appeared in heading side of stope, and tens of millions of iron mine is buried underside, making great economic losses. In order to guide the safety mining and increase the supply quantity, this paper through the use of MSARMA-method and the ''MSARMA evaluation and analytical system for slope stability analysis'' based on this method, which aimed at the quantitative evaluating of the slope stability before and after the actual mining below the slip mass, and the sensitivity analysis for the main influencing factor, providing scientific proof for the parameter optimization of open mine surface slope, the security and sustainable exploitation.展开更多
Objective The Mugagangri group （MP）, named by Wen Shixuan （1979） in the southeast Mugegebori Mountain which is the main peak of Mugagangri, is a flysch formation with deep semi-deep marine sedimentary features i...Objective The Mugagangri group （MP）, named by Wen Shixuan （1979） in the southeast Mugegebori Mountain which is the main peak of Mugagangri, is a flysch formation with deep semi-deep marine sedimentary features in the Bangonghu -Nujiang suture zone （BNSZ）. The lithology is mainly composed of sandstones, graywackes, siltstones and silty mudstones with low-grade metamorphism. The previously defined Mugagangri group continues from east to west for nearly 2000 km in BNSZ as a matrix part associated with ophiolitic melange blocks, and is considered to be part of the deep marine sedimentary cover of ophiolites.展开更多
The Baingoin batholith is one of the largest granitic plutons in the North Lhasa terrane.Its petrogenesis and tectonic setting have been studied for decades,but remain controversial.Here we report data on geochronolog...The Baingoin batholith is one of the largest granitic plutons in the North Lhasa terrane.Its petrogenesis and tectonic setting have been studied for decades,but remain controversial.Here we report data on geochronology,geochemistry and isotopes of Early Cretaceous granitoids within the Baingoin batholith,which provide more evidence to uncover its petrogenesis and regional geodynamic processes.The Early Cretaceous magmatism yields ages of 134.4–132.0 Ma and can be divided into I-type,S-type and highly fractionated granites.The I-and S-type granites exhibit medium SiO2,high K_(2)O/Na_(2)O with negativeεNd(t)andεHf(t)values,whereas,the albite granites have very high SiO_(2)(79.04%–80.40%),very low K_(2)O/N_(2)O,negativeεNd(t)and a large variation inεHf(t).Our new data indicate that these granitoids are derived from unbalanced melting in a heterogeneous source area.The granodiorites involved had a hybrid origin from partial melting of basalt-derived and Al-rich rocks in the crust,the porphyritic monzogranites being derived from partial melting of pelitic rocks.The albite granites crystallized from residual melt separated from K-rich magma within the‘mush’process and underwent fractionation of K-feldspar.We believe that the Early Cretaceous magmatism formed in an extensional setting produced by the initial and continuous rollback of a northward-subducting slab of the NTO.展开更多
基金provided by the National Natural Science Foundation of China (No. 40972196)the Scientific Research Foundation of China University of Mining & Technology(Beijing) (No. 2010QL03)
文摘Under the combined influences of special topography and the long term mining in Nanfen Open Pit Iron Mine, many large scale landslide masses appeared in heading side of stope, and tens of millions of iron mine is buried underside, making great economic losses. In order to guide the safety mining and increase the supply quantity, this paper through the use of MSARMA-method and the ''MSARMA evaluation and analytical system for slope stability analysis'' based on this method, which aimed at the quantitative evaluating of the slope stability before and after the actual mining below the slip mass, and the sensitivity analysis for the main influencing factor, providing scientific proof for the parameter optimization of open mine surface slope, the security and sustainable exploitation.
基金finacially supported by China Geological Survey(grant No.DD20160026)the Central Public-Interest Scientific Institution BasalR esearch Fund(grant No.YK1604)
文摘Objective The Mugagangri group （MP）, named by Wen Shixuan （1979） in the southeast Mugegebori Mountain which is the main peak of Mugagangri, is a flysch formation with deep semi-deep marine sedimentary features in the Bangonghu -Nujiang suture zone （BNSZ）. The lithology is mainly composed of sandstones, graywackes, siltstones and silty mudstones with low-grade metamorphism. The previously defined Mugagangri group continues from east to west for nearly 2000 km in BNSZ as a matrix part associated with ophiolitic melange blocks, and is considered to be part of the deep marine sedimentary cover of ophiolites.
基金supported by grants from the National Key R&D Program of China(Nos.2022YFC2905001,2018YFC0604106 and 2018YFC0604101)the Program of the Chinese Geological Survey(Nos.DD20190167 and DD20221684)+1 种基金the Basic Research Fund of the Institute of Mineral Resources,Chinese Academy of Geological Sciences(Nos.SYSCR2019-03 and KK2017)the National Natural Science Foundation of China(No.41902097).
文摘The Baingoin batholith is one of the largest granitic plutons in the North Lhasa terrane.Its petrogenesis and tectonic setting have been studied for decades,but remain controversial.Here we report data on geochronology,geochemistry and isotopes of Early Cretaceous granitoids within the Baingoin batholith,which provide more evidence to uncover its petrogenesis and regional geodynamic processes.The Early Cretaceous magmatism yields ages of 134.4–132.0 Ma and can be divided into I-type,S-type and highly fractionated granites.The I-and S-type granites exhibit medium SiO2,high K_(2)O/Na_(2)O with negativeεNd(t)andεHf(t)values,whereas,the albite granites have very high SiO_(2)(79.04%–80.40%),very low K_(2)O/N_(2)O,negativeεNd(t)and a large variation inεHf(t).Our new data indicate that these granitoids are derived from unbalanced melting in a heterogeneous source area.The granodiorites involved had a hybrid origin from partial melting of basalt-derived and Al-rich rocks in the crust,the porphyritic monzogranites being derived from partial melting of pelitic rocks.The albite granites crystallized from residual melt separated from K-rich magma within the‘mush’process and underwent fractionation of K-feldspar.We believe that the Early Cretaceous magmatism formed in an extensional setting produced by the initial and continuous rollback of a northward-subducting slab of the NTO.
