Chief Editor:HOU Zengqian
Governing Body:China Association for Science and Technology
Organizer:Geological Society of China
start publication :1922
ISSN:ISSN 1000-9515
CN:CN 11-2001/P
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SONG Shuguang , SU LiXi''''an Institute of Geology , Mineral Resources , CAGS , East Youyi Rd. , Xi''''an , Shaanxi
1998, 72(2).
Abstract:This paper discusses in detail the deformation textures, glide system, petrofabrics and olivine dislocation microstructures of mantle peridotites at Yushigou in the North Qilian Mountains, northwestern China. The peridotites have undergone high-pressure, high-temperature and low-strain rate plastic flow deformation. According to the dynamic recrystallized-grain size of olivine and the average spacing between the dislocation walls as well as the chemical composition of enstatite, the authors calculated the rheological parameters of the ancient upper mantle in the study area as follows: temperatures 1025-1093℃; pressures 3043-4278 MPa; depths 95-132 km; deviatoric stress 28-32 MPa; strain rates 0.2×10-14-2.13×10-14s-1 and equivalent viscosities 0.45×1020-4.65×1020 Pa · s. These parameters suggest that the position where plastic flow took place was correspondent to the low-velocity zone beneath the oceanic lithosphere and that oceanization characterized by middle-velocity (1-3 cm/a) sea-floor spreadi
WANG Haiping , HU Yunzhong , Institute of Mineral Deposits , Chinese Academy of Geological Sciences , Beijing ZHANG Zonggui , CHEN WeiCentre of Aerogeophysical Prospecting , Remote Sensing , Ministry of Geology , Mineral Resources , Beijing Jiang Ruiliang
1998, 72(2).
Abstract:It has been inferred and proved by the remote sensing equations under rational hypotheses in atmospheric physics that there is a linear correlation between the ground reflective brightness Wij and the total reflective brightness Rij received in different bands with a remote sensor. Nine models delineating the ground-space correlation between the ground spectra and the optimal bands of images of the typical gold deposits have been established based on the ground-space correlativity and field measurements of the ground spectra of the typical gold deposits in the Ailaoshan area. According to the 9 correlation models, TM images were inverted into ground-space correlation images that are related to the typical gold deposits within the area and then recognized by a computer. Research on the ground . spectra and TM data in the Ailaoshan area shows that the correlation analysis of the ground spectra and TM data of gold deposits can be effectively applied to the prediction of gold deposits, location of prospecting targets, and extraction of imagery information of gold mineralization.
CHEN Wenming , ZHANG Chengxin , LU Jiren , DANG Zefa , Institute of Mineral Deposits , Chinese Academy of Geological Sciences , Baiwanzhang , Beijing LI Shuping , CUI Wenbin , NING Yuan , and CAO Yongjun Shanxi Institute of Geology , Mineral Resources , Taiyuan , Shanxi
1998, 72(2).
Abstract:The Tongkuangyu metaporphyry copper deposit formed in the Early Proterozoic is tectonically located in the northern part of the Zhongtiao X -type palaeorift depression, on the southern margin of the North China platform. The genesis of the deposit has long been a hot subject of research of geologists working on mineral deposits. By means of the protolith reconstruction and fluid inclusion and isotope studies of host rocks of the deposits, the authors hold that this deposit is the product of combined exogenic, endogenic and metamorphic processes. Its formation mainly involved the following four stages: (1) the stage of formation of Mg- and Fe-rich tuffaceous variegated cupriferous sand-shale and K-rich biomodal volcanic rocks; (2) the early stage of formation of the metaporphyry copper deposit; (3) the stage of formation of the metaporphyry copper deposit; and (4) the stage of reworking of the metaporphyry copper deposit.
ZHAO Changyi , DU Meili , SHAO Longyi , CHEN Jianping , CHENG Kerning , HE ZhonghuaResearch Institute of Petroleum Exploration , Development , China National Petroleum Corporation , Xueyuan Rd. , Beijing Beijing Graduate School of China University of Mining , Technology , Xueyuan Rd. , Beijing
1998, 72(2).
Abstract:This paper discusses the enviromental characteristics of carbonaceous mudstone and mudstone (coal-measure mudstone in short) of the Early and Middle Jurassic in the Turpan-Hami basin, which were formed in swamps. Through the organic facies study of the coal-measure mudstone in this area, the authors clarify that the flowing-water swamp is the most advanced organic facies belt. Furthermore, according to the practical materials of coal-measure mudstone in the area and with the evaluation criteria of lacustrine mudstone in the past, the authors have established the integrated symbol systems from the abundance of organic matter and the type of organic matter, which can be used in the source rock evaluation of the coal-measure mudstone.
SUN Weidong , PENG Zicheng , CHEN Daogong , ZHI Xiachen , WANG Zhaorong , GE NingjieDepartment of Earth & Space Sciences , University of Science & Technology of China , and Advanced Centre for Earth Sciences & Astronomy , The Third World Academyof Sciences , Hefei , Anhui Province Zhu Xiling
1998, 72(2).
Abstract:This paper presents a study of the major and trace element compositions of fresh mantle-derived spinel lherzolite and harzburgite inclusions from Cenozoic alkaline basalt in Mount Lianshan and Mount Panshi, Liuhe County, Jiangsu Province. An estimation is made of the contents of the major elements and some of the trace elements in the primitive mantle source region of the area, from which the authors have obtained MgO/Al2O3= 7.86. The contents of MgO and Al2O3 are also obtained as 37.58% and 4.78% respectively based on the correlation of MgO-Al2O3. Then, the contents of various elements in the primitive mantle are calculated using their regression equations with MgO, and the compositor) of the primitive mantle, a basic issue in geochemistry study, is discussed on that basis.
HE Ying , ZHU Xingguo Department of Geology , Northwest University , Xi''''an , Shaanxi and XU PeicangXi''''an Institute of Geology , Chinese Academy of Geological Sciences , Xi''''an , Shaanxi
1998, 72(2).
Abstract:Types of polymerized molecular network structure and degree of bond breakdown for glass phases of magmatic inclusions and glassy matrix in volcanic rocks from the Shengli oilfield have been defined by the laser Raman spectroscopic investigation. There are significant differences in types of polymerized molecular network structure and degree of bond 'breakdown of the magmatic glass phases between the non-CO2 and COa gas pools: magmatic glass phases of fluid inclusions and matrix in volcanic rocks from the CO2 gas pool contain more sheet network molecules and have a greater degree of bond beakdown than those from the non-CO2 gas pool; and when gas bubbles occur in evolving magma, magma saturated with volatile components has more sheet network molecules. The results suggest the magma-degassing mechanism of the formation of CO2 gas pools in the Shengli oilfield.
YANG Jian Southwest Institute of Technology , Mianyang , Sichuan and DING Lianfang Xi''''an Engineering University , Xi''''an , Shaanxi
1998, 72(2).
Abstract:No research has been made on such a lower rank boundary as the Sinian Doushantuo Formation-Dengying Formation boundary in the eastern region of the Yangtze Gorges. Elemental geochemical determination has revealed anomalies of REE and other trace elements around the boundary, which have relatively high contents than those in its overlying and underlying beds. The authors therefore think that a catastrophic event once occurred in the Miaohe area at the end of the Doushantuoan Period, which caused the mass extinction of the Miaohe biota.
LI Rufeng University of Petroleum , Shuiku Road , Changping , Beijing Liu Xinzhu
1998, 72(2).
Abstract:This paper discusses the distribution pattern and geological significance of the carbon and oxygen isotopes (δ13C and δ18O) in the depositional sequences of Gaoyuzhuangian, Yangzhuangian and Wumishanian ages of the established Middle and Upper Proterozoic sequence stratigraphic framework in the Ming Tombs area lying in western Yanshan Mountain of Beijing. Besides, sketchy determination of δ13C and δ18O was also performed for other formations and members. The analytical results show the following: under the condition of clear-water carbonate sediments, δ13C and δ18O, featuring smaller variation of δ13C but larger variation of δ18O, can well delineate the relative change of sea level, which reflects the difference of primary sedimentary settings; in the presence of terrigenous substances, δ13C values vary greatly while δ18O slightly; the carbon and oxygen isotopes show marked changes at sequence boundaries. Besides, particular patterns can be found in regard to the distribution of carbon and oxy
GUO Lihe , LIN Xingyuan , Institute of Mineral Deposits , CAGS , Baiwanzhuang , Beijing XIE Manze , FENG Jialin Shijiazhuang Economic Institute , Shijiazhuang , Hebei and WU Shuqi Institute of Rock , Mineral Analysis , Beijing
1998, 72(2).
Abstract:Minerals of various mantle-derived xenoliths from the Hannuoba basalt in Hebei Province have been studied by means of IR spectroscopy. The results show that all xenoliths from the mantle at depths <75 km contain trace amounts of water (0.45%-11.6×10-2 % H2O). The data of about 0.1% H2O contained in primary pyrolite estimated by earlier studies may be on the high side. The water might enter the frameworks of olivine, pyroxene and garnet earlier than it entered those of amphibole and phlogopite. The presence of water in amphibole and phlogopite may be a local phenomenon of water enrichment, which is related to relatively small-scale magmatic or metasomatic events although they can contain a hundred times more water than pyroxene contains. There is a little more water (1.11%-3.01×10-2 % of H2O mostly) in xenoliths from the Hannuoba basalt than in those from mid-ocean ridge basalt and kimberlites of South Africa (less than 1×10-2 % of H2O mostly). This indicates the heterogeneity of water in time and spa
ZHANG Chuanlin , Department of Earth Sciences , Nanjing University , Nanjing , Jiangsu LI Yong , YANG Zhihua Xi''''an Engineering College , Xi''''an , Shaanxi
1998, 72(2).
Abstract:It was previously considered that all of the Pb-Zn deposits in the Xicheng orefield belong to Devonian hydrothermal-sedimentary deposits or their reworked ones. Study proves that the host strata, besides the Devonian, include the Palaeoproterozoic. The super-large Changba-Lijiagou Pb-Zn deposit occurs in the Palaeoproterozoic strata. The deposits in this district are not hydrothermal-sedimentary deposits or their reworked ones, but Yanshanian-Himalayan epigenetic hydrothermal deposits. The modes of occurrence, sizes and positions of all the deposits in the Xicheng orefield are completely controlled by the choula (draw)-thrust sheet Therefore the previous grounds for the model of the Qinling-type Pb-Zn deposits cannot hold good. The authors propose that the Changba-type and Bijiashan-type Pb-Zn deposits be used to represent two mineral deposit models with different characteristics in the Xicheng orefield.
1998, 72(2).
Abstract:The reef-chert suite is an important rock assemblage, and consists mainly of four types of rocks with a fixed andorderiy relation in space and time. Its lower part is composed of carbonate rocks of reef facies (including reef,mound and organic bank); the upper part is represented by fine black detrital rocks; and the transitional partbetween the lower and upper parts is marked by hydrothermal sedimentary infilling, metasomatic and dynamicrocks (ores) characterized by cherts (nonbiogenic laminar, banded and massive cherts) and metal ore layers.
Chief Editor:HOU Zengqian
Governing Body:China Association for Science and Technology
Organizer:Geological Society of China
start publication :1922
ISSN:ISSN 1000-9515
CN:CN 11-2001/P