2008 Vol. 41 No. 2
2008, 41(2): 1-21.
Abstract：
On the basis of the geological and geophysical characteristics of northw estern China continent, cratonic type and orogenic-type lithosphere represented by Junggar Basin and Tarim in northw estern China continent are distinguished. And orogenic-type lithosphere can be subdivided in to Paleozoic orogenic-type lithosphere represented by Ejinaqi (old material and new structure) and Cenozoic orogenic-type lithosphere including Tianshan Mountain, Altai and Kunlun (old material and new structure). In light of the petrologica. method, model of crust-mantle evolution, orogenic forming process, relationships between the seismic velocity and pet rochemistry composition, petrological structu reprisms corresponding with different lithospheric types have been set up, crust-mantle material structure in differen tlithospheric types, geologic meaning of crust and Mantle's thickness and its significance for prospecting have been discussed.
On the basis of the geological and geophysical characteristics of northw estern China continent, cratonic type and orogenic-type lithosphere represented by Junggar Basin and Tarim in northw estern China continent are distinguished. And orogenic-type lithosphere can be subdivided in to Paleozoic orogenic-type lithosphere represented by Ejinaqi (old material and new structure) and Cenozoic orogenic-type lithosphere including Tianshan Mountain, Altai and Kunlun (old material and new structure). In light of the petrologica. method, model of crust-mantle evolution, orogenic forming process, relationships between the seismic velocity and pet rochemistry composition, petrological structu reprisms corresponding with different lithospheric types have been set up, crust-mantle material structure in differen tlithospheric types, geologic meaning of crust and Mantle's thickness and its significance for prospecting have been discussed.
2008, 41(2): 22-30.
Abstract：
The Aretuobie monzonitic granite is located to the south side of the Mayinebo suture zone. It shares some characteristics of the A-type granite, such as high alkali and low alumina. However, comparing with typical A-type granite, it has relatively high MgO and CaO and low SiO2. In trace elements, their total REE ranges from 277 ppm to 326 ppm and the ratios of LREE/HREE are bet ween 5.6 and 6.9. Negative Eu anomalies (δEu=0.4-0.6) are present ed in the REE pat terns. The rocks are enriched in incompatible elements and havev ariable Sr, Ba, Nb, P and Ti troughs in their trace elements distribution patterns. Isot opically, they have low initial Sr ratios (0.70048-0.70547) and positive initial Nd values (2.6-3.2). Collectively, we suggest that the Aretuobie pluton was derived from partial melting of a juvenile maficlo wercrust in a postorogenic extensional background.
The Aretuobie monzonitic granite is located to the south side of the Mayinebo suture zone. It shares some characteristics of the A-type granite, such as high alkali and low alumina. However, comparing with typical A-type granite, it has relatively high MgO and CaO and low SiO2. In trace elements, their total REE ranges from 277 ppm to 326 ppm and the ratios of LREE/HREE are bet ween 5.6 and 6.9. Negative Eu anomalies (δEu=0.4-0.6) are present ed in the REE pat terns. The rocks are enriched in incompatible elements and havev ariable Sr, Ba, Nb, P and Ti troughs in their trace elements distribution patterns. Isot opically, they have low initial Sr ratios (0.70048-0.70547) and positive initial Nd values (2.6-3.2). Collectively, we suggest that the Aretuobie pluton was derived from partial melting of a juvenile maficlo wercrust in a postorogenic extensional background.
Abstract：
This paper deals with the petro logical, petrochemical and trace element ana lyses and studies of the volcanic rocks of Permian Gadikao Formation in Jiezha area no rthern Qiangtang basin. It provides the geochemical condition to understand the character of the north of Qiangtang basin and tectonic environment. The rock types mainly include basalt, andesite, dacite and littlerhyolites, lava brecciaetc. The rocks have the following chemical composition: SiO2,48.49%-74.52%, with ameanvalue of 60.87%, Al2O3 majority between 14.5%-18.86%, K2O mean contents 1.99%. This indicates the volcanic rocks with the character of autunite alkalescence siries, LREE/HREE=4.31-14.60, with a mean value of 8.74, (La/Yb)n=3.72-16.16, with amean value of 9.59, enrichment of LREE, δEu=0.61-1.11, with a mean value of 0.80, majority samples δEu<1.0, indicate Eu pronounced weak negative abnormalty or nopronounced Eu abnormalty. La×Nb/Zr×Zr>0.005, with ameanvalue of 0.025, Th×Ta/Hf×Hf>0.098, with ameanvalue of 0.210. These chemical composition sare similar to typical volcanic rocks of island arc. The above-mentioned characteristics suggest that thep lot of north Qiangtang locate in tectonic background of island arc environment in Early Permian.
This paper deals with the petro logical, petrochemical and trace element ana lyses and studies of the volcanic rocks of Permian Gadikao Formation in Jiezha area no rthern Qiangtang basin. It provides the geochemical condition to understand the character of the north of Qiangtang basin and tectonic environment. The rock types mainly include basalt, andesite, dacite and littlerhyolites, lava brecciaetc. The rocks have the following chemical composition: SiO2,48.49%-74.52%, with ameanvalue of 60.87%, Al2O3 majority between 14.5%-18.86%, K2O mean contents 1.99%. This indicates the volcanic rocks with the character of autunite alkalescence siries, LREE/HREE=4.31-14.60, with a mean value of 8.74, (La/Yb)n=3.72-16.16, with amean value of 9.59, enrichment of LREE, δEu=0.61-1.11, with a mean value of 0.80, majority samples δEu<1.0, indicate Eu pronounced weak negative abnormalty or nopronounced Eu abnormalty. La×Nb/Zr×Zr>0.005, with ameanvalue of 0.025, Th×Ta/Hf×Hf>0.098, with ameanvalue of 0.210. These chemical composition sare similar to typical volcanic rocks of island arc. The above-mentioned characteristics suggest that thep lot of north Qiangtang locate in tectonic background of island arc environment in Early Permian.
2008, 41(2): 41-48.
Abstract：
Through the research on formation processes of basin, this article indicated that Fenghuoshan basin has passed four stages: basement, palaeogeom orphology basin, sedimentary basin and structural basin, formed in late Cretaceous deposit. The characteristics of status property indicated that the late Cretaceous Fenghuoshan mountains sandstones sonim rock complement and sandstone status are ore-bearing, sandstone sonim rock complement is main ore-bearing status, and have closerelation ship with coppermining. Deposit genetic analysis consider, as provenance area, up lifted a reaclose to basin and its late Triassic status and other shallow intrusive rock, provides sediment to deposit status, also provides copperto basin status deposit. In sand stones sonim rock complement and sand stone status, celadon detritus, deposit formed under reaera tion, alkali environment, become source of ore, and through last activates, relocation, concent ration, and form eddeposit, ie. the reformed lamellar copper deposit.
Through the research on formation processes of basin, this article indicated that Fenghuoshan basin has passed four stages: basement, palaeogeom orphology basin, sedimentary basin and structural basin, formed in late Cretaceous deposit. The characteristics of status property indicated that the late Cretaceous Fenghuoshan mountains sandstones sonim rock complement and sandstone status are ore-bearing, sandstone sonim rock complement is main ore-bearing status, and have closerelation ship with coppermining. Deposit genetic analysis consider, as provenance area, up lifted a reaclose to basin and its late Triassic status and other shallow intrusive rock, provides sediment to deposit status, also provides copperto basin status deposit. In sand stones sonim rock complement and sand stone status, celadon detritus, deposit formed under reaera tion, alkali environment, become source of ore, and through last activates, relocation, concent ration, and form eddeposit, ie. the reformed lamellar copper deposit.
2008, 41(2): 49-55.
Abstract：
There are ten mineralization bodies or ore bodies in the Baiyinha'er gold deposit, which occur along the SN, NND and EW structure fracture zones. The sizes of ore bodies are different, and the size of No.4 and 2 veins are bigger. The type of the Baiyinha'er gold deposit is quart zvein-alteration type, and the gold is found in many kinds of minerals as the natural gold. The ore bodies, which occur in the late Caledonian quart z-diorite, are cont rolled by faults. And wallrock alteration is found in the ore district.
There are ten mineralization bodies or ore bodies in the Baiyinha'er gold deposit, which occur along the SN, NND and EW structure fracture zones. The sizes of ore bodies are different, and the size of No.4 and 2 veins are bigger. The type of the Baiyinha'er gold deposit is quart zvein-alteration type, and the gold is found in many kinds of minerals as the natural gold. The ore bodies, which occur in the late Caledonian quart z-diorite, are cont rolled by faults. And wallrock alteration is found in the ore district.
Abstract：
Lots of blocky and nodular woodhouseite and crandallite series minerals, with paragenetic turquoise in interlayer-fracture zone of Cambrian Perild carbon-silicon-slate, Zhushan, Hubei province are caused by leaching of surface water. SO42- concentration was adeterminant factor of the for mation of a series of minerals. And the series minerals assemblaged a complex and microcrystalline mineral mixture, including essential minerals: hot sonite, woodhouseie, crandallite and viseite. Geochemical analysis results of samples indicate that it is able to adsorb many kinds of metals and anion groups. They are geochemical barrier to pro tect the environment, and ithas important signif icance for the ecological study.
Lots of blocky and nodular woodhouseite and crandallite series minerals, with paragenetic turquoise in interlayer-fracture zone of Cambrian Perild carbon-silicon-slate, Zhushan, Hubei province are caused by leaching of surface water. SO42- concentration was adeterminant factor of the for mation of a series of minerals. And the series minerals assemblaged a complex and microcrystalline mineral mixture, including essential minerals: hot sonite, woodhouseie, crandallite and viseite. Geochemical analysis results of samples indicate that it is able to adsorb many kinds of metals and anion groups. They are geochemical barrier to pro tect the environment, and ithas important signif icance for the ecological study.
2008, 41(2): 63-72.
Abstract：
The potash-resource status of our country is described in this paper. The distribution and forming disciplines of large potash deposits in the world are concluded: foundation of substance, geological constructions, facies and paleo-geography condition sand special climate. The general situation sand the history of the geological evolution of Tarim basin between the late Cretaceous Period and the early Tertiary are analyzed. Then it analyzes the characters of the facies of the late Cretaceous Period and the early Tertiary. And two concentration centers—Kuche sag and Tarim south-west sag are achieved. This paper also reviews the status of seeking potash deposits in Tarim basin. A favorable geological foundation is set up for seeking potash deposits.
The potash-resource status of our country is described in this paper. The distribution and forming disciplines of large potash deposits in the world are concluded: foundation of substance, geological constructions, facies and paleo-geography condition sand special climate. The general situation sand the history of the geological evolution of Tarim basin between the late Cretaceous Period and the early Tertiary are analyzed. Then it analyzes the characters of the facies of the late Cretaceous Period and the early Tertiary. And two concentration centers—Kuche sag and Tarim south-west sag are achieved. This paper also reviews the status of seeking potash deposits in Tarim basin. A favorable geological foundation is set up for seeking potash deposits.
2008, 41(2): 73-80.
Abstract：
Guided by high-resolution sequence stratigraphy theory, combined with lots of logging data and core observation, areservoir-scale high-resolution sequence stratigraphy framework of the Eogene first member of Shahejie for mation and the third member of Dong ying fo rmation has beenest ablished in Hongxing area. 43rd order sequences and 194th order paramsequence sets and series of 5th order paramsequences have been classified in this paper. Acco rding to the logginganalysis and coreobservation, several of sedimentary microfacies of Sha1 and Dong3 have been recognized, such as fandelta front sub-distritary channel, mouth bar, front delta, flooding fan, distributary interval and soon. The depositional systems mapping of 4th order sequence show that different sedimentary microfacies form different sand configuration and distribution and physical characteristic of reservoir. Because fan delta front sub-distributary channel or distribut ary channel is the major depositional microfacies of Sha1, the reser voirmainly is coarsegrade and single thick sand. While braided or braided delta is the major depositional system of Dong3, the reservoir mainly is fine grade and single thin sand. In literally, there shows the evolutiont rend from northeast and southwest distributaries channel sand to delta front far barsand. The distribution configuration of depositional system controlled the sand types and distribution.
Guided by high-resolution sequence stratigraphy theory, combined with lots of logging data and core observation, areservoir-scale high-resolution sequence stratigraphy framework of the Eogene first member of Shahejie for mation and the third member of Dong ying fo rmation has beenest ablished in Hongxing area. 43rd order sequences and 194th order paramsequence sets and series of 5th order paramsequences have been classified in this paper. Acco rding to the logginganalysis and coreobservation, several of sedimentary microfacies of Sha1 and Dong3 have been recognized, such as fandelta front sub-distritary channel, mouth bar, front delta, flooding fan, distributary interval and soon. The depositional systems mapping of 4th order sequence show that different sedimentary microfacies form different sand configuration and distribution and physical characteristic of reservoir. Because fan delta front sub-distributary channel or distribut ary channel is the major depositional microfacies of Sha1, the reser voirmainly is coarsegrade and single thick sand. While braided or braided delta is the major depositional system of Dong3, the reservoir mainly is fine grade and single thin sand. In literally, there shows the evolutiont rend from northeast and southwest distributaries channel sand to delta front far barsand. The distribution configuration of depositional system controlled the sand types and distribution.
2008, 41(2): 81-86.
Abstract：
Based on directions of palaeo-flow, mineral combination characteristic and REE characteristic in Ordos Basin, directions of palaeo-flow of the early Yanchang Formation comesfrom circum to center, and five source directions can be found, which are northeast, ea st, south, southwest and northwest directions. The mainsource directions are northeast, southwest and northwest directions. The northeast source obviously dominates, and influencearea of south source is narrower. The main parent rock of the early Yanchang Formation is complex metamorphic rock of A rchean and metavolcanic rock-sed imentary rock system. The northeast source comes from the sustained source offered by the old Yinshan and the Daqingshan, so delta deposit develops grossly. The south source mainly comes from gneiss and granide of early Palaeozoic in the Qinling and Qilianshan fold orogenic zone, the characteristics of which are close to the provenance and sediment size obviously wider than the northeast source.
Based on directions of palaeo-flow, mineral combination characteristic and REE characteristic in Ordos Basin, directions of palaeo-flow of the early Yanchang Formation comesfrom circum to center, and five source directions can be found, which are northeast, ea st, south, southwest and northwest directions. The mainsource directions are northeast, southwest and northwest directions. The northeast source obviously dominates, and influencearea of south source is narrower. The main parent rock of the early Yanchang Formation is complex metamorphic rock of A rchean and metavolcanic rock-sed imentary rock system. The northeast source comes from the sustained source offered by the old Yinshan and the Daqingshan, so delta deposit develops grossly. The south source mainly comes from gneiss and granide of early Palaeozoic in the Qinling and Qilianshan fold orogenic zone, the characteristics of which are close to the provenance and sediment size obviously wider than the northeast source.
Abstract：
The analysis and research of heavymineral of the sandstone in southeastern of the Kongque River slopes of the Tarim basin in the Middle-Late Ordovician show that the stable heavy mineral composition of Kuruktag Outcrop samples is Zircon-Tourmaline-Garnet-Magnetite-Cheklimonite. The stable heavymineral composition of the well Kongque 1 is Zircon-Garnet-Tourmaline-Leucoxene. There are some differences between the two compositions, but the analytical results reflect the same characteristics of source rocks. The source rocks in the study area aremainly fromacid, in termediate-basicigneous rocks and some metamorphic rocks. They are mixed products. Through the analysis of the Seismic profiles, this paper hold the opinionthat the sediment source of the study a reacomes from the south (Altun Orogen) and the north (Kuruktag uplift). According to the "ZRT" index of the stable heavymineral, the sediments proved coming from south and northmetin area around the well Kongque 1, then migrated and deposited along theirownway.
The analysis and research of heavymineral of the sandstone in southeastern of the Kongque River slopes of the Tarim basin in the Middle-Late Ordovician show that the stable heavy mineral composition of Kuruktag Outcrop samples is Zircon-Tourmaline-Garnet-Magnetite-Cheklimonite. The stable heavymineral composition of the well Kongque 1 is Zircon-Garnet-Tourmaline-Leucoxene. There are some differences between the two compositions, but the analytical results reflect the same characteristics of source rocks. The source rocks in the study area aremainly fromacid, in termediate-basicigneous rocks and some metamorphic rocks. They are mixed products. Through the analysis of the Seismic profiles, this paper hold the opinionthat the sediment source of the study a reacomes from the south (Altun Orogen) and the north (Kuruktag uplift). According to the "ZRT" index of the stable heavymineral, the sediments proved coming from south and northmetin area around the well Kongque 1, then migrated and deposited along theirownway.
2008, 41(2): 93-100.
Abstract：
The step dam development in Jianzha county of the Yellow river Has caused most of the frontage of landslides to be submerged. Old coll apses and landslides lost stability. Some new collapses and landslides will be produced. This brings direct threat to production and living of the local people and seriously influences sustainable social and economic development. In this study the types, quantity and manifestations of existing geologic hazards in the urban study area and the interrelations between geologic hazards and geological environment term were ascert ained rapidly by using the remote sensing technique, thus offering an accurate and reliable basis for the prevention and control of geolo gical hazards in the area. The application of the remote sensing technique yielded good results.
The step dam development in Jianzha county of the Yellow river Has caused most of the frontage of landslides to be submerged. Old coll apses and landslides lost stability. Some new collapses and landslides will be produced. This brings direct threat to production and living of the local people and seriously influences sustainable social and economic development. In this study the types, quantity and manifestations of existing geologic hazards in the urban study area and the interrelations between geologic hazards and geological environment term were ascert ained rapidly by using the remote sensing technique, thus offering an accurate and reliable basis for the prevention and control of geolo gical hazards in the area. The application of the remote sensing technique yielded good results.
2008, 41(2): 101-109.
Abstract：
Following with the development of mineral exploration practices and the difficulties in prospect forores, mine area large -scale ore body fast locating prediction has became an important research topic in the domain of mineral exploration. The advan tages of VLF-EM method are portable, simple, economic and efficient. As a superficial-layer geophysical prospecting technology, its effect is good through practical check of mineral exploration in China and abroad. This paper briefly discusses the basic principle of VLF method and its data processing technology. On the basis of deposit geology research, this article establishes ageology-geophysics fast loca lization prediction model of the target ore body by using the verylow frequency elect romagnetic (VLF-EM) technology in Fengning Menying CU polymetallic deposit; practice shows that, utilizing this method to collectlarge-scale geophysical data and combined with studies of Fraser filtering and linear filtering. This method can be successfully applied to determine spatial occurrence and extension of buriedore bodies and can provideopt imaltarget area for the employment of exploration engineering. It is worth to pointout that, because of the in terference of geology noise and environment electromagnetic noise, geological characteristic analysis and comparative study of in terp retation results and their 2D、3D expression is the critical factor to extract ore induced anomaly.
Following with the development of mineral exploration practices and the difficulties in prospect forores, mine area large -scale ore body fast locating prediction has became an important research topic in the domain of mineral exploration. The advan tages of VLF-EM method are portable, simple, economic and efficient. As a superficial-layer geophysical prospecting technology, its effect is good through practical check of mineral exploration in China and abroad. This paper briefly discusses the basic principle of VLF method and its data processing technology. On the basis of deposit geology research, this article establishes ageology-geophysics fast loca lization prediction model of the target ore body by using the verylow frequency elect romagnetic (VLF-EM) technology in Fengning Menying CU polymetallic deposit; practice shows that, utilizing this method to collectlarge-scale geophysical data and combined with studies of Fraser filtering and linear filtering. This method can be successfully applied to determine spatial occurrence and extension of buriedore bodies and can provideopt imaltarget area for the employment of exploration engineering. It is worth to pointout that, because of the in terference of geology noise and environment electromagnetic noise, geological characteristic analysis and comparative study of in terp retation results and their 2D、3D expression is the critical factor to extract ore induced anomaly.
2008, 41(2): 110-114.
Abstract：
On the large-scale stratig raphic succession of Shanwang Formation, Shanwang Basin, a new type of gravity gliding tectonic is identified. It consists of three parts: the underl ying system; the gliding floor and the gliding system. Interior of the gliding system can be dividedint of our sections: the parallel gliding section; the symmetric compressional section; the flexible creeping section and the folding nappe section. The classic flexible folding effectis found in microscopic distinction of the gliding system. The differ encebetweeng ravity glidingt ectonic of Shanwang Formation is discussed. The genesis of gravity gliding tectonic of Shanwang For mation is possibly relevant tovolcanism. The acquisition of gravity gliding tectonic of Shanwang Formation is important to understand the formation and evolution of Shanwang Basin.
On the large-scale stratig raphic succession of Shanwang Formation, Shanwang Basin, a new type of gravity gliding tectonic is identified. It consists of three parts: the underl ying system; the gliding floor and the gliding system. Interior of the gliding system can be dividedint of our sections: the parallel gliding section; the symmetric compressional section; the flexible creeping section and the folding nappe section. The classic flexible folding effectis found in microscopic distinction of the gliding system. The differ encebetweeng ravity glidingt ectonic of Shanwang Formation is discussed. The genesis of gravity gliding tectonic of Shanwang For mation is possibly relevant tovolcanism. The acquisition of gravity gliding tectonic of Shanwang Formation is important to understand the formation and evolution of Shanwang Basin.
2008, 41(2): 115-120.
Abstract：
Luonan-luanchuan fault is an important boundary of dividing the southern margin of NC block and North Qinling. Oolitelime of Cambrian Zhangxia group emerged widely in Loucun area north beyond the fault and oolite deformation is widely developed. By studying deformed oolite in the microcosmic way, on the base of underst anding the macroscopic deformed mechanism and structure evolution sequence, the ratioamong the three axis (X:Y:Z) and Flinn parameters (K) can be calculated and the character of oolite deformation can be known. It is indicated that oolite deformation is charact erized by monad compression (0
Luonan-luanchuan fault is an important boundary of dividing the southern margin of NC block and North Qinling. Oolitelime of Cambrian Zhangxia group emerged widely in Loucun area north beyond the fault and oolite deformation is widely developed. By studying deformed oolite in the microcosmic way, on the base of underst anding the macroscopic deformed mechanism and structure evolution sequence, the ratioamong the three axis (X:Y:Z) and Flinn parameters (K) can be calculated and the character of oolite deformation can be known. It is indicated that oolite deformation is charact erized by monad compression (0
