期刊文献+
共找到433篇文章
< 1 2 22 >
每页显示 20 50 100
Spatial-temporal distribution and geochemistry of highly evolved Mesozoic granites in Great Xing’an Range,NE China:Discriminant criteria and geological significance
1
作者 WU Haoran YANG Hao +4 位作者 GE Wenchun JI Zheng DONG Yu JING Yan JING Jiahao 《Global Geology》 2024年第1期20-34,共15页
Highly evolved granite is an important sign of the mature continent crust and closely associated with deposits of rare metals.In this work,the authors undertake systematically zircon U-Pb ages and whole rock elemental... Highly evolved granite is an important sign of the mature continent crust and closely associated with deposits of rare metals.In this work,the authors undertake systematically zircon U-Pb ages and whole rock elemental data for highly evolved granitic intrusions from the Great Xing’an Range(GXR),NE China,to elucidate their discriminant criteria,spatial-temporal distribution,differentiation and geodynamic mecha-nism.Geochemical data of these highly evolved granites suggest that high w(SiO_(2))(>70%)and differentiation index(DI>88)could be quantified indicators,while strong Eu depletion,high TE_(1,3),lowΣREE and low Zr/Hf,Nb/Ta,K/Rb could only be qualitative indicators.Zircon U-Pb ages suggest that the highly evolved gran-ites in the GXR were mainly formed in Late Mesozoic,which can be divided into two major stages:Late Ju-rassic-early Early Cretaceous(162-136 Ma,peak at 138 Ma),and late Early Cretaceous(136-106 Ma,peak at 126 Ma).The highly evolved granites are mainly distributed in the central-southern GXR,and display a weakly trend of getting younger from northwest to southeast,meanwhile indicating the metallogenic potential of rare metals within the central GXR.The spatial-temporal distribution,combined with regional geological data,indicates the highly evolved Mesozoic granites in the GXR were emplaced in an extensional environ-ment,of which the Late Jurassic-early Early Cretaceous extension was related to the closure of the Mongol-Okhotsk Ocean and roll-back of the Paleo-Pacific Plate,while the late Early Cretaceous extension was mainly related to the roll-back of the Paleo-Pacific Plate. 展开更多
关键词 highly evolved granite great xing’an Range spatial-temporal distribution extensional environment
下载PDF
SHRIMP Geochronology of Volcanics of the Zhangjiakou and Yixian Formations, Northern Hebei Province, with a Discussion on the Age of the Xing'anling Group of the Great Hinggan Mountains and Volcanic Strata of the Southeastern Coastal Area of China 被引量:64
2
作者 NIUBaogui HEZhengjun +2 位作者 SONGBiao RENJishun XIAOLiwei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第6期1214-1228,共15页
A zircon U-Pb geochronological study on the volcanic rocks reveals that both of the Zhangjiakou and Yixian Formations, northern Hebei Province, are of the Early Cretaceous, with ages of 135-130 Ma and 129-120 Ma, resp... A zircon U-Pb geochronological study on the volcanic rocks reveals that both of the Zhangjiakou and Yixian Formations, northern Hebei Province, are of the Early Cretaceous, with ages of 135-130 Ma and 129-120 Ma, respectively. It is pointed out that the ages of sedimentary basins and volcanism in the northern Hebei -western Liaoning area become younger from west to east, i. e. the volcanism of the Luanping Basin commenced at c. 135 Ma, the Luotuo Mount area of the Chengde Basin c. 130 Ma, and western Liaoning c. 128 Ma. With a correlation of geochronological stratigraphy and biostratigraphy, we deduce that the Xing'anling Group, which comprises the Great Hinggan Mountains volcanic rock belt in eastern China, is predominantly of the early-middle Early Cretaceous, while the Jiande and Shimaoshan Groups and their equivalents, which form the volcanic rock belt in the southeastern coast area of China, are of the mid-late Early Cretaceous, and both the Jehol and Jiande Biotas are of the Early Cretaceous, not Late Jurassic or Late Jurassic-Early Cretaceous. Combining the characteristics of the volcanic rocks and, in a large area, hiatus in the strata of the Late Jurassic or Late Jurassic-early Early Cretaceous between the formations mentioned above and the underlying sequences, we can make the conclusion that, in the Late Jurassic-early Early Cretaceous, the eastern China region was of high relief or plateau, where widespread post-orogenic volcanic series of the Early Cretaceous obviously became younger from inland in the west to continental margin in the east. This is not the result of an oceanward accretion of the subduction belt between the Paleo-Pacific ocean plate and the Asian continent, but rather reflects the extension feature, i.e. after the closure of the Paleo-Pacific ocean, the Paleo-Pacific ancient continent collided with the Asian continent and reached the peak of orogenesis, and then the compression waned and resulted in the retreating of the post-orogenic extension from outer orogenic zone to inner part (or collision zone). The determination of the eruption age of the volcanics of the Zhangjiakou Formation definitely constrains the switch period, which began in the Indosinian and finished in the Yanshanian, that is, 140-135 Ma. The switch is concretely the change from the approximate E-W Paleo-Asian tectonic system to the NE to NNE Pacific system, and the period is also the apex of a continent-continent collision and orogenesis of subduction, being consumed and eventually disappearing of the Paleo-Pacific ancient continent, and all the processes commenced in the Indosinian. While the following post-orogenic large-scale eruption in the Early Cretaceous marks the final completeness of the Paleo-Pacific structure dynamics system. 展开更多
关键词 Zhangjiakou Formation Yixian Formation zircon SHRIMP geochronology great Hinggan mountains VOLCANISM southeastern China
下载PDF
Natural Mongolian Pine Forests in the Great Xing'an Mountains,Northeast China 被引量:4
3
作者 ZhouZhiqiang LiuTong ZhouLin 《Forestry Studies in China》 CAS 2003年第3期1-5,共5页
Based upon 134 rel関es, the vegetation of the forests with Mongolian pine (Pinus sylvestris var. mongolica) of the Great Xingan Mountains in the northeast China was classified into 3 communities, 7 types and 4 subtype... Based upon 134 rel関es, the vegetation of the forests with Mongolian pine (Pinus sylvestris var. mongolica) of the Great Xingan Mountains in the northeast China was classified into 3 communities, 7 types and 4 subtypes by numerical cluster analysis. 1) The Pinus sylvestris var. mongolica-Populus davidiana-community was found on relatively dry sites. It was subdivided into a Quercus mongolica-type, consisting of a Adenophora tetraphylla subtype, a Pulsatilla dahurica subtype, and a pure type; 2) The Pinus sylvestris var. mongolica-Rhododendron dauricum-community occurred on medium dry sites. It included a Calamagrostis angustifolia type, consisting of a Cladonia arbuscula subtype, a pure subtype, and a Rubus idaeus-type; 3) The Pinus sylvestris var. mongolica-Ledum palustre-community was found on periodically wet sites. It included a Picea koraiensis type, a Vaccinium uliginosum type, and a pure type. 展开更多
关键词 great xingan mountains northeast China PINE Pinus sylvestris var. mongolica forest VEGETATION numerical classification
下载PDF
Supercritical extracts of forest fuels in Great Xing'an Mountains 被引量:1
4
作者 Fengjun Zhao Mingyu Wang +2 位作者 Lifu Shu Xiaorui Tian Kezhen Liu 《Journal of Forestry Research》 SCIE CAS CSCD 2016年第5期1143-1151,共9页
Extracts are important components of fuels. Fatty-extracts with high heating value (HV) are hypothe- sized by researchers as positively related to the HV of fuels. The Soxhlet extractor is typically used to extract ... Extracts are important components of fuels. Fatty-extracts with high heating value (HV) are hypothe- sized by researchers as positively related to the HV of fuels. The Soxhlet extractor is typically used to extract fatty-extracts but it has shortcomings, including long processing time (8-10 h) and the requirement for large amounts of organic solvent. Supercritical extraction is an alternate and useful technique for extraction of natural products. However, published studies rarely discuss the relationship between extracts and HV. In this study, we assessed the supercritical extracts (SUE) of forest fuels in the Great Xing'an Mountains. Our results indicated that the optimum conditions for extraction of SuEs were 40-60 mesh, 40-50 MPa, 45℃, 80 min and a CO2 flow rate of 1.5-2.0 dm3/min. The Soxhlet extracts contents and the SuE contents were all related to HV. However, R2 of the coniferous samples (0.8499) and needle samples (0.9722) demonstrated that the correlation between HV and the SuE content was closer. We conclude that supercritical fatty-extracts provide a useful index of the HV of fuels, especially coniferous fuels. SuE data can be used in fire management, for example to estimate the rate of fire spread or fire intensity. 展开更多
关键词 Forest fire Fuel - Soxhlet extracts Supercritical extracts Heating value. great xing'anmountains
下载PDF
Six new chrysophycean stomatocysts ornamented with reticulum from the Great Xing'an Mountains, China
5
作者 庞婉婷 王幼芳 王全喜 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第3期410-412,共3页
Six new chrysophycean stomatocysts ornamented with reticulum were illustrated based on SEM observation. They were described following the guidelines of the International Statospore Working Group (ISWG). All samples we... Six new chrysophycean stomatocysts ornamented with reticulum were illustrated based on SEM observation. They were described following the guidelines of the International Statospore Working Group (ISWG). All samples were collected from the Great Xing'an Mountains, China. Their taxonomic characteristics and habitats were described to provide new information on the biodiversity of chrysophycean stomatocysts. As is common with many morphotypes, their biological affinities remain unknown. 展开更多
关键词 chrysophycean stomatocyst China the great xing'an mountains
下载PDF
Molecular Organic Geochemical Characteristics and Coal Gas Potential Evaluation of Mesozoic Coal Seams in the Western Great Khingan Mountains 被引量:2
6
作者 QU Yue SHAN Xuanlong +2 位作者 DU Tiantian DU XianLi ZHAO Rongsheng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2020年第2期409-417,共9页
Coal-bearing strata are widespread in the western Great Khingan Mountains. Abundant coal resources have been found in the Jurassic Alatanheli Groups, the Cretaceous Bayanhua Groups, the Damoguaihe Formation and the Yi... Coal-bearing strata are widespread in the western Great Khingan Mountains. Abundant coal resources have been found in the Jurassic Alatanheli Groups, the Cretaceous Bayanhua Groups, the Damoguaihe Formation and the Yimin Formation. The organic geochemical characteristics were analyzed in combination with hydrocarbon source rock evaluation and molecular organic geochemistry experiments, and the coal gas potential of coal seams was evaluated. The source rock evaluation results indicated that the Mesozoic coal samples have the characteristics of high organic matter abundance(TOC>30%), low maturity(Ro values of approximately 0.6%), and type Ⅲ composition. The hydrocarbon generation potentials of the Alatanheli Groups and Bayanhua Groups are high, while the generation potentials of the Damoguaihe Formation and the Yimin Formation are low. The results of geochemistry show that the depositional environment of the coal seam was a lacustrine, oxidizing environment with a low salinity, and the source of the organic matter was mainly higher plants. Affected by weak degradation, the coal seams mainly formed low-maturity gas of thermal catalytic origin. The Cretaceous coal seams contain a large amount of phytoplankton groups deposited in a low-stability environment affected by a transgression event, and the potential range varied widely. For the Jurassic coal seams, the depositional environment was more stable, and the coal seams feature a higher coal-forming gas potential. 展开更多
关键词 COAL source rocks MOLECULAR organic matter geochemical characteristics low-maturity GAS COAL GAS western part of the great Khingan mountains
下载PDF
Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains,northeastern China 被引量:2
7
作者 XiaoLi Chang HuiJun Jin +1 位作者 YanLin Zhang HaiBin Sun 《Research in Cold and Arid Regions》 CSCD 2015年第6期666-674,共9页
Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of... Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of the soils in permafrost regions in the mid-latitudes and boreal regions, such as that on the westem flank of the Da Xing'anling (Hinggan) Mountains, northeastern China. This paper gives a detailed analysis on meteorological data series from 2001 to 2010 provided by the Gen'he Weather Station, which is located in a talik of discontinuous permafrost zone and with sparse meadow on the observation field. It is inferred that snow cover is important for the ground thermal regime in the middle Da Xing'anling Mountains. Snow cover of 10-cm in thickness and five to six months in duration (generally November to next March) can reduce the heat loss from the ground to the atmosphere by 28%, and by 71% if the snow depth increases to 36 cm. Moreover, the occurrence of snow cover resulted in mean annual ground surface temperatures 4.7-8.2℃ higher than the mean annual air temperatures recorded at the Gen'he Weather Station, The beginning date for stable snow cover establishment (SE date) and the initial snow depth (SDi) also had a great influences on the ground freezing process. Heavy snowfall before ground surface freeze-up could postpone and retard the freezing process in Gen'he. As a result, the duration of ground freezing was shortened by at least 20 days and the maximum depth of frost penetration was as much as 90 cm shallower. 展开更多
关键词 snow cover thermal regime ground freezing Da xing'anling mountains northeastern China
下载PDF
Zircon U-Pb geochronology,geochemistry and tectonic implication of volcanic rocks from Manketouebo Formation in Keyihe area of northern Great Xing'an Range
8
作者 JIA Jinfeng WANG Yang LI Pengchuan 《Global Geology》 2023年第3期133-145,共13页
Zircon U-Pb isotope dating and whole-rock geochemical analyses were undertaken for the rhyolite,rhyolitic lithic crystal tuff and dacitic tuff from the Manketouebo Formation in the Keyihe area,in order to constrain th... Zircon U-Pb isotope dating and whole-rock geochemical analyses were undertaken for the rhyolite,rhyolitic lithic crystal tuff and dacitic tuff from the Manketouebo Formation in the Keyihe area,in order to constrain their genesis and tectonic significance.Zircon LA-ICP-MS U-Pb data indicate that the rhyolite and rhyolitic lithic crystal tuff were formed during 137±5 Ma and 143±1 Ma,respectively.These volcanic rocks have high SiO2(70.03%–76.46%)and K2O+Na2O(8.10%–9.52%)contents,but low CaO(0.03%–0.95%)and MgO(0.07%–0.67%)contents,which belong to the peraluminous and high-K calc-alkaline rocks.They are enriched in light rare earth elements(REEs),and exhibit fractionation of light over heavy REEs,withδEu values of 0.37–0.83.The volcanic rocks are enriched in LILEs(e.g.,Rb,U and K)and depleted in HFSEs(e.g.,Nb,Ti,P and Ta).The chemical composition suggests that these volcanic rocks formed by partial melting of crust material.Combined with previous regional research results,the authors consider that the volcanic rocks of the Manketouebo Formation in the Keyihe area were formed under an extensional environment related to the closure of the Mongolia–Okhotsk Ocean. 展开更多
关键词 Manketouebo Formation zircon U-Pb geochronology GEOCHEMISTRY great xing’an Range
下载PDF
Geochemical Characteristics and Geological Significance of Early Permian Baya'ertuhushuo Gabbro in South Great Xing'an Range 被引量:13
9
作者 LIU Jianfeng CHI Xiaoguo +4 位作者 ZHAO Zhi ZHANG Xingzhou MA Zhihong WANG Tiefu HU Zhaochu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2011年第1期116-129,共14页
Field geological investigation and geochemical analysis are carried out on Baya'ertuhushuo Gabbro in South Great Xing'an Range. Field investigation reveals that the gabbro is a magmatic intrusion rather than a compo... Field geological investigation and geochemical analysis are carried out on Baya'ertuhushuo Gabbro in South Great Xing'an Range. Field investigation reveals that the gabbro is a magmatic intrusion rather than a component of an ophiolite suite as previously thought. Zircon laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS) U-Pb dating indicates the gabbro was formed in 274-275 Ma, just as the widespread volcanic rocks of Dashizhai Formation (P1d), monzogranites and miarolitic alkali-feldspar granites in the study area. The gabbro has SiO2 content between 47.23 wt% and 50.17 wt%, high MgO and FeOT contents of 6.95-11.29 wt% and 7.32- 12.24wt%, respectively, and it belongs to low-K tholeiitic series in the SiO2-K2O diagram. The Chondrite-normalized rare earth element (REE) patterns and primitive mantle-normalized spider diagrams of the gabbro are similar to those of Normal Mid-Ocean Ridge Basalt (N-MORB) except for the enrichment of large ion lithophfle elements (LILE), such as Rb, Ba and K. In trace element tectonic discriminative diagrams, the samples are mainly plotted in the N-MORB field, and Zircon in situ Lu-Hf isotopic analysis also indicates the gabbro originated from depleted mantle. Through synthetic studies of the geochemical characteristics and petrogenesis of Baya'ertuhushuo gabbro, volcanic rocks of Dashizhai Formation and granitoids in the area, it is suggested that the early Permian magmatism in the Xilinhot-Xiwuqi area formed in the tectonic setting of asthenosphere upwelling, which was caused by breaking-off of the subducted Paleo-Asian Ocean slab. 展开更多
关键词 GABBRO geochemistry early Permian zircon U-Pb age south great xing'an Range
下载PDF
Effects of meteorological factors on the defoliation dynamics of the larch caterpillar(Dendrolimus superans Butler)in the Great Xing’an boreal forests 被引量:4
10
作者 Lei Fang Yue Yu +5 位作者 Guofei Fang Xu Zhang Zhijun Yu Xudong Zhang Ellen Crocker Jian Yang 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第6期2683-2697,共15页
Larch caterpillars are widely distributed in the Great Xing’an boreal forests;however,the relationship between caterpillar defoliation dynamics and climatic factors is poorly understood.The aims of this study are to ... Larch caterpillars are widely distributed in the Great Xing’an boreal forests;however,the relationship between caterpillar defoliation dynamics and climatic factors is poorly understood.The aims of this study are to investigate the primary weather conditions that might influence forest defoliation and to identify the most important life stage of the larch caterpillar at which forest defoliation might be mitigated by incorporating more inhibitory influences from climatic factors.The life cycle of the larch caterpillar was partitioned into four stages and multiple linear regression and mixed effect models were combined with a relative weight analysis approach to evaluate the importance and influence of meteorological variables on defoliation dynamics.The results show that warmer temperatures in growing seasons and overwintering periods can increase the defoliation area,while rainy and humid growing seasons decrease the defoliation area.Total precipitation during the early instar larval period had the greatest power to explain the variance in defoliation dynamics and had a very strong inhibitory effect,followed by the accumulative temperatures of the late instar larval period which had a positive impact,and precipitation during the middle instar larval period which had a negative impact.Weather conditions during the early instar larval period had the greatest influence on the area defoliated and accounted for 40%of the explained variance.This study demonstrates that climatic warming and drying will increase the risk of larch caterpillar outbreaks in the Great Xing’an Mountains. 展开更多
关键词 Larch caterpillar Defoliation area Climatic warming Life cycle great xing’an mountains Relative importance
下载PDF
Early Cretaceous Adakitic Rocks in the Northern Great Xing’an Range, NE China: Implications for the Final Closure of Mongol-Okhotsk Ocean and Regional Extensional Setting 被引量:5
11
作者 ZHANG Lingyu LI Shichao +1 位作者 CHU Xiaolei SHANG Yinmin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第5期1544-1558,共15页
A large amount of igneous rocks in NE China formed in an extensional setting during Late Mesozoic. However, there is still controversy about how the Mongol-Okhotsk Ocean and the Paleo-Pacific Ocean effected the lithos... A large amount of igneous rocks in NE China formed in an extensional setting during Late Mesozoic. However, there is still controversy about how the Mongol-Okhotsk Ocean and the Paleo-Pacific Ocean effected the lithosphere in NE China. In this paper, we carried out a comprehensive study for andesites from the Keyihe area using LA-ICP-MS zircon UPb dating and geochemical and Hf isotopic analysis to investigate the petrogenesis and tectonic setting of these andesites. The U-Pb dating yields an Early Cretaceous crystallization age of 128.3±0.4 Ma. Geochemically, the andesites contain high Sr(686-930 ppm) and HREE contents, low Y(11.9-19.8 ppm) and Yb(1.08-1.52 ppm) contents, and they therefore have high Sr/Y(42-63) and La/Yb(24-36) ratios, showing the characteristics of adakitic rocks. Moreover, they exhibit high K2O/Na2O ratios(0.57-0.81), low Mg O contents(0.77-3.06 wt%), low Mg# value(17-49) and negative εHf(t) values(-1.7 to-8.5) with no negative Eu anomalies, indicating that they are not related to the oceanic plate subduction. Based on the geochemical and isotopic data provided in this paper and regional geological data, it can be concluded that the Keyihe adakitic rocks were affected by the Mongol-Okhotsk tectonic regime, forming in a transition setting from crustal thickening to regional extension thinning. They were derived from the partial melting of the thickened lower crust. The closure of the Mongol-Okhotsk Ocean may finish in early Early Cretaceous, followed by the collisional orogenic process. The southern part region of its suture belt was in a post-orogenic extensional setting in the late Early Cretaceous. 展开更多
关键词 Mongol-Okhotsk OCEAN northern great xing’an RANGE Early Cretaceous adakitic rocks lower crust
下载PDF
Recognition of Early Paleozoic Magmatisms in the Supposed Proterozoic Basements of Zhalantun, Great Xing’an Range, NE China 被引量:3
12
作者 QIN Tao GUO Rongrong +5 位作者 ZANG Yanqing QIAN Cheng WANG Yan SI Qiuliang SUN Wei MA Yongfei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第5期1434-1455,共22页
The Zhalantun terrane from the Xing’an massif, northeast China, was used to be considered as Proterozoic basements. However, amounts of detrital zircon ages from the meta-sedimentary rocks deny the existence of Preca... The Zhalantun terrane from the Xing’an massif, northeast China, was used to be considered as Proterozoic basements. However, amounts of detrital zircon ages from the meta-sedimentary rocks deny the existence of Precambrian basements recently. Notably, magmatic rocks were barely reported to limit the exact ages of the Zhalantun basements. In this study, we collected rhyolite, gabbro and quartz diorite for zircon in-situ U-Pb isotopic dating, which yield crystallization ages of ~505 Ma, ~447 Ma and ~125 Ma, respectively. Muscovite schist and siltstone define maximum depositional ages of ~499 Ma and ~489 Ma, respectively. Additionally, these dated supracrustal rocks and plutons also yield ancient detrital/xenocryst zircon ages of ~600-1000 Ma, ~1600-2220 Ma, ~2400 Ma, ~2600-2860 Ma. Based on the whole-rock major and trace element compositions, the ~505 Ma rhyolites display high SiO2 and alkaline contents, low Fe2O3T, TiO2 and Al2O3, and relatively high Mg O and Mg#, which exhibit calc-alkaline characteristics. These rhyolites yield fractionated REE patterns and negative Nb, Ta, Ti, Sr, P and Eu anomalies and positive Zr anomalies. The geochemistry, petrology and Lu-Hf isotopes imply that rhyolites were derived from the partial melting of continental basalt induced by upwelling of sub-arc mantle magmas, and then experienced fractional crystallization of plagioclase, which points to a continental arc regime. The ~447 Ma gabbros exhibit low Si O2 and alkaline contents, high Fe2 O3 T, Ti O2, Mg O and Mg#. They show minor depletions of La and Ce, flat MREE and HREE patterns, and negative Nb, Ta, Zr and Hf anomalies. Both sub-arc mantle and N-MORB-like mantle were involved in the formation of the gabbros, indicative of a probable back-arc basin tectonic setting. Given that, the previously believed Proterozoic supracrustal rocks and several plutons from the Zhalantun Precambrian basements were proved to be Paleozoic to Mesozoic rocks, among which these Paleozoic magmatic rocks were generally related to subduction regime. So far, none Proterozoic rocks have been identified from the Zhalantun Precambrian basement, though some ~600-3210 Ma ancient detrital/xenocryst zircons were reported. Combined with ancient zircon ages and newly reported ~2.5 Ga and ~1.8 Ga granites from the south of the Zhalantun, therefore, the Precambrian rocks probably once exposed in the Zhalantun while they were re-worked and consumed during later long tectonic evolutionary history, resulting in absence of Precambrian rocks in the Zhalantun. 展开更多
关键词 early Paleozoic magmatism xinghuadukou Group Jiageda Formation Zhalantun TERRANE great xing’an RANGE Central Asian OROGENIC Belt
下载PDF
Felsic Igneous Rocks in the Hua'aobaote Pb-Zn-Ag Polymetallic Orefield,Southern Great Xing'an Range:Genesis,Metallogenetic and Tectonic Significance 被引量:4
13
作者 SHANG Zhi CHEN Yongqing GUO Xiangguo 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2022年第1期221-239,共19页
The Hua’aobaote Pb-Zn-Ag Polymetallic orefield is situated in the southern section of the Great Xing’an Range(GXAR),which has experienced extensive magmatism.Since the Paleozoic,there are two stages of magmatism in ... The Hua’aobaote Pb-Zn-Ag Polymetallic orefield is situated in the southern section of the Great Xing’an Range(GXAR),which has experienced extensive magmatism.Since the Paleozoic,there are two stages of magmatism in Hua’aobaote orefield occurred in the Paleozoic and Mesozoic.The Mesozoic magmatism is of great significance for the PbZn-Ag Polymetallic mineralization in Hua’aobaote orefield.In this study,new geochemical data was obtained to discuss the timing and petrogenesis of the magmatic rocks and its geodynamic and metallogenic significance.Zircon U-Pb ages reveal that the felsic igneous rocks from the Hua’aobaote orefield were formed in the Early Permian(294.8±3.2 Ma)and Early Cretaceous(132.6±1.4 Ma).Geochemically,the Early Permian granodiorite porphyrite is characterized by high Sr/Y(42-63)ratios and Mg^(#)(62.24-70.74)values and low heavy rare earth element(HREE)(5.09-6.79 ppm)contents.The granodiorite porphyrite is also characterized by depleted Sr-Nd initial isotopic signatures[ε_(Nd)(t)=5.91-7.59,(^(87)Sr/^(86)Sr)i=0.7029-0.7030],exhibiting adakitic characteristics.The Early Cretaceous granite porphyry and rhyolite are A-type felsic igneous rocks,and demonstrate high SiO_(2),Na_(2)O+K_(2)O and rare earth element(REE)contents,low CaO and MgO contents,low(^(87)Sr/^(86)Sr)i ratios(0.7044-0.7058),and positive ε_(Nd)(t)values(2.57-4.65).Whole-rock Pb isotopic compositions in granodiorite porphyrite are:206Pb/204Pb=17.631-18.149,^(207)Pb/^(204)Pb=15.422-15.450,and ^(208)Pb/^(204)Pb=37.325-37.729.The granite porphyry and rhyolite have initial ^(206)Pb/^(204)Pb,^(207)Pb/^(204)Pb,and ^(208)Pb/^(204)Pb ratios of 18.106-19.309,15.489-15.539,and 37.821-38.05,respectively.Sr-Nd-Pb isotopic evidence suggests that the Early Permian granodiorite porphyrite is likely to derive from slab melts and modified by peridotitic mantle wedge in the subduction tectonic setting of the Paleo-Asian Ocean.The Early Cretaceous A-type felsic igneous rocks were derived from juvenile lower crust,accompanied by limited crustal contamination and various degree of fractional crystallisation during magma emplacement.The Early Cretaceous magmatism and related mineralization were formed in a post-orogenic tectonic setting that attributed to the closure of the Mongol-Okhotsk Ocean.Pb isotopic data for the various rock units in the study area indicate that the Mesozoic magma source contributed substantial Pb,Zn,and Ag to the Hua’aobaote deposit. 展开更多
关键词 southern great xing’an Range Hua’aobaote zircon U-Pb age Sr-Nd-Pb isotopes metallogenetic and tectonic significance petrogenesis
下载PDF
Magmatic Evolution and Mineralization Process of the Super-Large Shihuiyao Rb–Nb–Ta Deposit,Southern Great Xing'an Range,China 被引量:3
14
作者 ZHOU Zhenhua CHE Hewei +1 位作者 MA Xinghua GAO Xu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第6期2275-2276,共2页
Rare metal ore reserves are an important strategic resource, and their metallogenic mechanism and mineralization studies have also been received widespread international attention.
关键词 In Nb Magmatic Evolution and Mineralization Process of the Super-Large Shihuiyao Rb Ta Deposit Southern great xing’an Range China
下载PDF
The Cu-Mo Mineralization of the Late Jurassic Porphyry in the Northern Great Xing'an Range: Constraints from Zircon U-Pb Ages of the Ore-Causative Granites 被引量:1
15
作者 DENG Changzhou LI Guanghui 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第1期236-237,共2页
The Great Xing’an Range(GXAR)is one of the most important metallogenic belts in China.Previous study has shown that porphyry Cu-Mo deposit distributed in the northern Great Xing’an Range formed mainly in two stages:... The Great Xing’an Range(GXAR)is one of the most important metallogenic belts in China.Previous study has shown that porphyry Cu-Mo deposit distributed in the northern Great Xing’an Range formed mainly in two stages:(1)Early Ordovician,such as Duobaoshan and Tongshan deposits(Liu et al.,2017);2)Triassic-Early Jurassic,including Wunugetushan,Taipingchuan and Badaguan deposits(Tang et al.,2016).In recent years,two potential porphyry Cu-Mo deposits,Huoluotai and Xiaokele,were discovered in the Erguna Block,northern GXAR(Figs.1a–b).However,the ore formation ages and regional metallogenic regularity are ambiguous due to the lack of isotopic ages.Two zircon U-Pb ages from the ore-causative granites were reported in this paper,with the aims to constrain the metallogenic ages and provide evidence for study of the regional metallogenic regularity and ore prospect prediction. 展开更多
关键词 The great xing’an Range(GXAR) GRANITES Cu-Mo
下载PDF
New Discovery of the Late Triassic Terrigenous Sediments in the Great Xing''an Range Region,NE China and its Geological Significance 被引量:3
16
作者 LI Shichao ZHANG Lingyu +1 位作者 LIU Zhenghong XU Zhongyuan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第5期1928-1929,共2页
Objective The Great Xing'an Range is located in the eastern section of Central Asian Orogenic Belt(CAOB).As a superposed position of multiple tectonic domains,its structural evoIlution has always been a focused iss... Objective The Great Xing'an Range is located in the eastern section of Central Asian Orogenic Belt(CAOB).As a superposed position of multiple tectonic domains,its structural evoIlution has always been a focused issue of geological research. 展开更多
关键词 ICP MS Th New Discovery of the Late Triassic Terrigenous Sediments in the great xing’an Range Region NE China and its Geological Significance NE
下载PDF
Horizontal crustal movement in Chinese mainland before and after the great Kunlun Mountain M=8.1 earthquake in 2001
17
作者 顾国华 张晶 王武星 《Acta Seismologica Sinica(English Edition)》 CSCD 2003年第6期676-685,共10页
The continuous GPS observation at the fiducial stations in the Crustal Movement Observation Network of China (CMONOC) recorded the crustal movement of Chinese mainland before and after the great Kunlun Mountain earthq... The continuous GPS observation at the fiducial stations in the Crustal Movement Observation Network of China (CMONOC) recorded the crustal movement of Chinese mainland before and after the great Kunlun Mountain earthquake of M=8.1 on November 14, 2001, especially the horizontal crustal movement in the western part of China. Based on the datum defined by a group of stable stations with small mutual horizontal displacements for a few years, the time series of horizontal displacements at fiducial stations were obtained. Significant anomalous horizontal displacements had appeared at the fiducial stations in the western part of China since early November 2000 and several earthquakes with the magnitudes about 6.0 had occurred in Yunnan and Sichuan Provinces. The northward components of the horizontal displacement at the fiducial stations in west China had decreased signifi-cantly and even changed in the opposite sense since mid April 2001. After the earthquake, the northward dis-placements still decreased and there were significant westward displacements. The process of the crustal move-ment in the western part of Chinese mainland (in reference to east China) suggests that the main force source for this earthquake came from the northward pushing of the Indian plate. The great earthquake released a large amount of energy, as a result, the action applied by the Indian plate to Chinese mainland diminished significantly and after the great earthquake, the seismic activity in Chinese mainland decreased considerably until the end of 2002. 展开更多
关键词 crustal movement GPS earthquake prediction great Kunlun mountain earthquake of M=8.1 time series
下载PDF
A Report from Great Smoky Mountain
18
作者 宋瑾 《杂技与魔术》 2008年第5期27-,共1页
This is a report from Great Smoky Mountain. From this report, I will tell you a story about me and my team. After ten years of hardworking, we made some achievements in Branson, Missouri in America, and then we turned... This is a report from Great Smoky Mountain. From this report, I will tell you a story about me and my team. After ten years of hardworking, we made some achievements in Branson, Missouri in America, and then we turned to Great Smoky Mountain for another business. To my group and me, itis like a legend. 展开更多
关键词 A Report from great Smoky mountain
下载PDF
论“卷阿”形胜观的内涵与嬗递
19
作者 岳红记 唐赟 李艺静 《中国园林》 CSCD 北大核心 2024年第3期132-137,共6页
最早记载于《诗经》的“卷阿”有着独特的“飘风自南”自然山水景观。在考辨“有卷者阿”历史源流的基础上分析其发轫、形成及“形胜”特征,认为“卷阿”形胜观历经“自然景观空间-建筑空间-精神空间”的发展过程,由物质空间升华到精神... 最早记载于《诗经》的“卷阿”有着独特的“飘风自南”自然山水景观。在考辨“有卷者阿”历史源流的基础上分析其发轫、形成及“形胜”特征,认为“卷阿”形胜观历经“自然景观空间-建筑空间-精神空间”的发展过程,由物质空间升华到精神空间的文化意象。在皇权观念中,以高大广阔的建筑景观空间寓于“有卷者阿”形态,体现君王礼贤下士、君子纳才的宽广胸怀;对于贤臣来说,彰显其所追求修身治国之抱负和聿修厥德的情操。诠释“卷阿”山水格局并传承其文化内涵,构建蕴含人文精神的风景游赏地,形成物质与精神交融的山水景观空间,以达育人、化人的目的。 展开更多
关键词 风景园林 “卷阿” “山水形胜” 文化内涵
下载PDF
语图转换中的“山乡巨变”——论贺友直对《山乡巨变》的连环画改编
20
作者 李洪华 《长江学术》 2024年第3期29-40,共12页
贺友直根据周立波小说《山乡巨变》改编的同名连环画,在以图释文的艺术转换中,寓乡村风情于社会变革,运用“明显强烈的处理手法”,凸显人物在外貌、身份和性格等方面的主要特征,成功塑造了邓秀梅、李月辉、刘雨生、盛佑亭、陈先晋、王... 贺友直根据周立波小说《山乡巨变》改编的同名连环画,在以图释文的艺术转换中,寓乡村风情于社会变革,运用“明显强烈的处理手法”,凸显人物在外貌、身份和性格等方面的主要特征,成功塑造了邓秀梅、李月辉、刘雨生、盛佑亭、陈先晋、王菊生等一批新型乡村干群形象。贺友直善于在连环图像叙事中“做戏”和“制造情节”,将充满政治指涉的社会化内容纳入乡村家庭伦理生活叙事,生动再现了合作化运动给山乡人物带来的巨大影响。画家在以传统线描笔法构设山乡风情的同时,赋予山水风物以鲜明的时代蕴含,在原本紧张峻切的时代氛围中营构出轻松活泼的诗意空间。 展开更多
关键词 《山乡巨变》 贺友直 连环画改编 语图转换
下载PDF
上一页 1 2 22 下一页 到第
使用帮助 返回顶部