2004 Vol. 10, No. 2

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PRE-SINIAN PALEOSTRUCTURAL FRAMEWORK AND MAJOR GEOLOGICAL EVENTS IN THE HUANGLING ANTICLINE,WESTERN HUBEI
XIONG Cheng-yun, WEI Chang-shan, JIN Guang-fu, TAN Wei-qing, LI Wen-xiang
2004, 10(2): 97-112.
Abstract (150) PDF (594KB)(10)
Abstract:
By using such integrated research methods as the tectonic sieving and genetic relation analysis, this paper further defines the Fuping (Wutai) movement, Lüliang (Xingshan) movement, Sibao (Shennong) movement and Jinning (Huashan) movement and their related magmatic and metamorphic events in the Huangling anticline, western Hubei.The authors have established the pre-Sinian time sequence of the Huangling (Kongling) complex and paleostructural spatial framework formed by compounding of nearly E-W-, NE-and NW-trending palaeostructural belt.This paper also firstly proposes the Quanyitang detachment structural system formed in the Mesoproterozoic (Sibaoan).
CHARACTERISTICS OF STRUCTURAL CONTROL OF ORE DEPOSITION IN SOUTH CHINA IN THE MESOZOIC
WEI Chang-shan, CAI Ming-hai, CAI Jin-hui, WANG Xiong-wu, CHE Qin-jian, DU Hai-yan
2004, 10(2): 113-121.
Abstract (160) PDF (284KB)(11)
Abstract:
According to the recent survey evaluation and integrated study of mineral resources in South China, this paper summaries the characteristics of structural control of ore deposition at different spatial lev els, from the lithosphere to microfracture networks, including deep lithosphere delamination and thinning and related geodynamic regime transition of tectono-metallogonic domains →control of distribution of metallogenic belts (ore concentration areas) by regional tectonic thinning zones and related alkali-rick (A-type) mogma assoications →control of distribution of small (porphyry) rock bodies and related ore fields (deposits) by structural compounding loci →control of occurrence of orebodies by major faults and their associated and derivative fracture networks →control of concentration of ore substances by dynamic transition of structure deformation and related hydrofracturing.It put special emphasis on the dominant role that tensile structural systems of different scales related to mesozoic lithospheric delamination play in controlling ore deposition.This has great significance for the metallogenic analysis and mineral exploration.
TYPES AND STRUCTURAL CONTROL OF GOLD DEPOSITS IN THE TONGGUANSHAN ORE FIELD,ANHUI PROVINCE
WAN Ren-hu
2004, 10(2): 122-128.
Abstract (138) PDF (233KB)(11)
Abstract:
Tongguanshan is a famous copper ore field and one of copper-producing areas of China. Recently a number of gold deposits have been found, which belong to the sulfide type and gossan type and are genetically related to copper deposits in the ore field. The paper mainly deals with the types, geological characteristics and structural controls of gold deposits, The author considers that both the two types of gold deposit belong to the magmatic hydrothermal type genetically related to Yanshanian intermediate and intermediate-acid intrusive rocks, and its outcropping as different types of ore deposit is just due to the differences in oxidation-denudation and preservation conditions. The attitude of gold ore bodies are strictly controlled by that of the strata in different parts of the Tongguanshan overturned anticline and interlayer faults.
CHARACTERISTICS OF GEOLOGICAL STRUCTURE OF THE XINCHENG GOLD DEPOSIT,JIAODONG,AND DIRECTION IN GOLD PROSPECTING AT DEPTH
ZHAO Hai, ZHAO Ke-guang, MA Yao-li, XIU Chun-hua
2004, 10(2): 129-136.
Abstract (175) PDF (241KB)(12)
Abstract:
The Xincheng gold deposit has been mined for more than 20 years and the service life of its remaining ore tonnage decreases gradually, thus affecting the sustainable development of the mine.The discovery of blind orebody No. V demonstrates that the deep part of the deposit has favorable geological conditions for ore deposition and thus provides grounds for ore search in the second concentration zone at depths of the mine.This paper furnishes information of important reference value for the study of the metallogeny of gold deposits in Jiaodong and the direction in ore prospecting in the deep part of the deposit.
CHARACTERISTICS OF MAJOR FAULT ZONES IN THE QIANJIA AREA AND ANALYSIS OF ROCK AND ORE CONTROL
LI Sun-xiong, MO Wei-ming, YUN Ping, FAN Yuan
2004, 10(2): 137-145.
Abstract (231) PDF (308KB)(7)
Abstract:
The fault zones in the Qianjia area are mainly of NW, NE and N-S trends and geomechanically of tenso-shear and compresso-shear origin.They originated in the Yanshanian period. The N-S-trending fault zone has been most strongly deformed and altered and is characterized by strong enrichment in Mo, Ag, Pb, Zn, Au and Mo, a very strong capacity of element fractionation and concentration, a pronounced phenomenon of element zoning and relatively strong ore-controlling effect. In the NE-trending fault zone the element contents vary greatly, generally exhibiting zones of different element assemblages.For the NW-trending fault zone, its ore-controlling effect is relatively weak, the element contents show a small variation, the capacity of element concentration is relatively poor and the degree of element fractionation is low.
MANIFESTATIONS OF THE COMPLEXITY OF SEDIMENTARY BASINS OF CHINA AND ANALYSIS OF THEIR ORIGIN
TONG Heng-mao, CAO Dai-yong, QIN Hong
2004, 10(2): 146-154.
Abstract (178) PDF (289KB)(18)
Abstract:
The complexity of sedimentary basins of China is mainly manifested in the following nine aspects:(1) large number, small size and wide distribution;(2) a great variety of basin types;(3) prevalence of the phenomenon of multi-stage basin superimposition and compounding;(4) dominance of continental sedimentary basins;(5) occurrence of numerous, very active faults;(6) strong reworking in the late stage;(7) repeated and extensive magmatic activities;(8) rapid filling rate and migration of most depocenters;(9) inhomogeneous space of the geothermal field.On the basis of this analysis, the authors analyze the origin of the complexity of sedimentary basins of China and point out that the special tectonic position, small and less stable continental block, large-scale and active mobile belt and complex plate tectonic framework and tectonic evolutionary history are the root-causes for the complexity of sedimentary basins of China and caused these basins to have their distinguishing characteristics of petroleum occurrence.
GEODYNAMICS PROCESS IN THE JUNGGAR BASIN
CHEN Ye-quan, WANG Wei-feng
2004, 10(2): 155-164.
Abstract (196) PDF (307KB)(12)
Abstract:
The Junggar basin is surrounded by Paleozoic sutures and the mountains around the basin have been thrust toward the basin, showing that this basin has been in a long-continued, compressional regime.The change of volcanic rocks from marine facies to continental facies and change of volcanism from strong to weak indicate that after the Permian the upper mantle materials had long been in a constrictive stage, and that the whole basin sank continuously to receive deposits, thus resulting in crustal thickening.During the basin evolution stage in the Permian, the basin was affected by the late Hercynian, Indosinian, Yanshanian and Himalayan phases of tectonic stress fields, resulting in N-S extensional deformation, N-S and NW collisional compressional deformation, alternating N-S and NW extensional and compressional deformations and N-S compresso-shear, thrusting, strike-slip and gravitational sliding deformation, and finally a great variety of complex tectonic types were formed.
CENOZOIC SEQUENCE STRATIGRAPHY AND CHARACTERISTICS OF THE SEDIMENTARY SYSTEM IN THE SHUBEI AREA,LIAOHE BASIN
LI Wen-quan, LIU Li, JIAO Li-juan, WANG Li
2004, 10(2): 165-171.
Abstract (134) PDF (251KB)(10)
Abstract:
The Shubei area is a secondary unit of the West subbasin of the Liaohe basin and a Cenozoic rift basin that developed on the Archean and Meso-and Neoproterozoic basements.The Cenozoic strata may be divided in ascending order into the Paleogene Fangshenpao Formation, Shahejie Formation and Dongying Formation and the Neogene Guantao Formation, overlain by Quaternary deposits.By an integrated study of the seismic, logging and geological data and application of the time-frequency analytical technique, the Cenozoic rift deposits may be divided into 1 continental rift megasequence, 1 continental postrift heat-sink supersequence, 1 synrift sink supersequence, 4 sequences and 14 systems tracts, and there exist type I sequences and type Ⅱ sequences.A sequence stratigraphic model of the gentle slope in a down-faulted lake basin has been constructed.The authors propose that the developments of sedimentary systems in different systems tracts have different characteristics.Between the transgressive systems tract (TST) and highstand systems tract (HST) there usually occurs a large suite of shale, which forms the main source rock and sealing rock, and the reservoir rock forms on the margins of various systems tracts.The sequence stratigraphic division in the area has great significance for the search for good-quality reservoirs and the study of the characteristics of petroleum concentration.
APPLICATION OF ACOUSTIC EMISSION IN THE STUDY OF THE NUMBER OF CENOZOIC TECTONIC PHASES IN THE DONGYING SUBBASIN
XU Jian-chun, DAI Jun-sheng
2004, 10(2): 172-178.
Abstract (161) PDF (206KB)(8)
Abstract:
Acoustic emission as a method of measuring ground stresses has aroused increasing interset. Rock has the function of "memory" of its stress history.By using this function, the authors applied acoustic emission to the analysis of rock samples from the Dongying subbasin and obtained the ground stress memory values and memory occurrence rates and thus further revealed the phase number and intensity of tectonic activities that this area underwent.The results of the measurements demonstrate that the paleo-stress memory values coincide with the stress history in the tectonic cycles.Furthermore, the paper briefly introduces the basic principle of acoustic emission.
TECTONIC STRESS FIELD IN THE DA'ANZHAI MEMBER OF THE LANGZHONG AREA,NORTHERN SICHUAN,AND FORECAST OF PETROLEUM ACCUMULATIONS
CAO Cheng-jie, ZHOU Xin-gui, SHU Neng-yi, YAN Bin, LUO Guo-shi, XING Zhen-hui
2004, 10(2): 179-187.
Abstract (164) PDF (384KB)(10)
Abstract:
On the basis of a tectonic analysis, the authors have studied the basic characteristics of the tectonic field since the Mesozoic in the Da'anzhai Member of the Langzhong area, northern Sichuan.An attempt has been made to forecast petroleum accumulations in the Da'anzhai Member using the theory and method of oil expulsion, and present favorable areas of petroleum occurrence have been suggested. These provide reference for rolling petroleum exploration in the Langzhong area, northern Sichuan.
APPLICATION OF LOGGING-CONSTRAINED INVERSION IN THE PREDICTION OF SUBTLE PETROLEUM ACCUMULATIONS-A CASE STUDY OF THE K46 WELL AREA OF THE DAGANG OILFIELD
HOU Bo-gang, FAN Jun-xia, HUANG Guo-ping, WU Bo-fu, LU Feng-ting
2004, 10(2): 188-192.
Abstract (147) PDF (199KB)(7)
Abstract:
The prediction of reservoirs is a key point as well a difficult point in exploration for subtle petroleum accumulations.Logging-constrained inversion is an effective method for predicting subtle reservoirs.A rational initial acoustic impedance model was constructed by correcting the log data, extracting seismic wavelets, calibrating downhole seismic records and constructing a precise geological model under the guidance of the sedimentary concept, and the distribution of the reservoir was predicted according to the known geological regularity and by taking the well logs as the constraints.The sparse impulse inversion method was applied in the K46 well area of the Dagang oilfield and a subtle reservoir was successfully predicted there.