2001 Vol. 7, No. 4

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GEOLOGICAL RECORD OF THE VICISSITUDES OF THE PALAEO-MONSOON IN NORTH PART OF THE EAST CHINA SEA DURING THE LAST STAGE OF LATE PLEISTOCENE
ZHAO Song-ling, YU Hong-jun, LI Guan-bao, YU Li-li
2001, 7(4): 289-295.
Abstract (176) PDF (235KB)(6)
Abstract:
The paleao-monsoon activities in East Asia experienced a change of vicissitudes since 18 kaBP. In the maximum phase of last glacial age,dry and cold climate prevailed,resulting in the desertization in most part of the Bohai Sea,the Yellow Sea and the East China Sea. Then,with the withering of dry and cold climate,there appeared stiff clay sediment in the delta of the Changjiang River. Because the further declining of paleao-monsoon and the gradual rising of sea level after 15ka approached,the northeast wind from shelf area was not the dry and cold air-current any more,but the cold and damp one with higher humidity,which produce an advantageous environment for the development of the swamp. As a result,a thin-layered turf was formed before the seawater transgression in Holocene. The developing process of the paleao-monsoon since the last stage of late Pleistocene is well correspondent to the formation of shelf desert, stiff clay and turf layer respectively. It is suggested that the such sequences in the delta region of the Changjiang River may be the best record of the vicissitudes of the palaeo-monsoon.
INITIAL STRATA OCCURRENCE OF THE SOUTH CHINA TEKTITE IN STRATA AND ITS IMPLICATION FOR EVENT-STRATIGRAPHY
ZHU Zhao-yu, ZHOU Hou-yun, QIAO Yu-lou, ZHANG Hai-xiang, LIANG Jun-ping
2001, 7(4): 296-302.
Abstract (185) PDF (251KB)(12)
Abstract:
The South China tektite,especially a type of big tektite,is solely found in Chinese continent at the early time,belonging to Asia-Australia strowed area. The tektites were distributed in the areas of Guangxi, Guangdong and Hainan Provinces. According to the investigations in two types of the stratigraphic profiles, which are the boundary section of Beihai Formation and Zhanjiang Formation and the section of weathering crust on the 3rd tableland, it is suggested that there are three type of big tektites in South China continent, which are imbeded-initial-strowed type,exposed-initial-strowed type and deuterogenic moved-type;the initial occurrence of the South China tektite in strata is in the middle horizon within Beihai Formation, which is the erosion surface on the top of the lower part of Beihai Formation, but not on the top of Zhanjiang Formation. The chemical compositions, average grain size and the palynology characteristics indicate that a seriesd of geological events occurred in the period of 0.1~0.8 MaBP, so that the tektite event and its initial stratum are a good time scale for the correlation of marine and continental event-stratigraphy as well as the global geodynamics. This paper is in memory of Prof. Wu Xihao who was an excellent scientist in the field of Neozoic geology.
VEGETATION AND ENVIRONMENTAL CHANGES IN THE XUANHUA BASIN OF HEBEI PROVINCE SINCE POSTGLACIAL
SUN Li-ming, XU Qing-hai, YAN Xiao-lan, LIANG Wen-dong, KONG Zhao-chen
2001, 7(4): 303-308.
Abstract (193) PDF (220KB)(7)
Abstract:
With the support of 14C dating,pollen analysis on Huangjiabu sections in Xuanhua Basin reflect the changes of palaeobotany and palaeoclimate. During 14000~9000aBP the vegetation in the Basin was conifer and broad-leaves forests dominated by Pinus and grassland. In some high mountains,there was coniferous forest composed of Abies and Picea,the climate was cool and wet. In 9000~2400aBP the vegetation changed into grassland dominated by Artemisia,while some deciduous broad-leaves trees such as Salix,Ulmus,Quercus and Betula also grown on some areas with suitable moisture and soil condition,the climate was warm and little dry. After 2400aBP the vegetation became desert grassland dominated by Chenopodiaceae,at the same time,the climate became cool and dry.
LOESS STRATIGRAPHY OF MANGLING IN HENAN PROVINCE
WANG Shu-bing, JIANG Fu-chu, WU Xi-hao, TIAN Guo-qiang, ZHAO Zhi-zhong, LIU Ke, WANG Zhi-ming
2001, 7(4): 309-314.
Abstract (163) PDF (166KB)(8)
Abstract:
In this paper,Kouma profile,located in Mengjin,Henan north of middle Mangling Plateau Form has been studied.This profile contains S11 and upwands loess-paleosol each loess and paleosol are clear.The magnetic susceptibility curve shows that the susceptibility value of S2 is lower than the others,while the thickness of L3 is very thin,showing abnovmal character.Palaeomagnetic stratigraphy shows that the depth of the boundary between Brunhes normal polarity chron and Matuyama reversed one is 38.9 meters,which located at the lower part of L8.Furthermore,two normal polarity intervals are revealed in the late Matuyama reversed polarity chron.
PALAEOCLIMATIC RECONSTRUCTION OF SPOROPOLLON RECORDED IN FANGXIANGSI PROFILE,TAIBAISHAN MOUNTAIN
ZHANG Jun-pai, TONG Min, WANG Shu-bing, TONG Guo-bang
2001, 7(4): 315-320.
Abstract (192) PDF (184KB)(9)
Abstract:
In this paper climatic reconstruction of sporopollen data from Fangxiangsi profile was studied,through the sporopollen-climatic model created by sporopollen from surface soil in Taibaishan,Qinling Mountains.Furthermore,the climatic sequence of past one thousand years was obtained (including annual mean temperature,January mean temperature,July mean temperature and annual precipitaion).The results show that the small ice age started at 1200a AD and ended at 1920a AD,in which the grand ice age was 1350~1700a AD,coincided with results of historical data,ancient lakes,tree rings and glaciers.The climatic changes of study area are closed to Foyechi area located in south slope of Taibaishan Mountain.Because the heigth above sea level of Fangxiangsi located at the north slope of Taibaishan Mountain,is lower than Foyechi's,the value,fluctuate range and dropping range of air temperature in Fangxiangsi area turn higher,and annual precipitation is a little greater.When the value of air temperature turns higher,the annual range turns higher;however it turns lower,the opposition.This indicated that July mean temperature is sensitive for climatic changes,showing that the rise and decline of summer monsoon can't be ignored.
STUDY ON THE ICE AGE MIS12 IN WESTERN CHINA
ZHOU Shang-zhe, YI Chao-lu, SHI Ya-feng, YE Yu-guang
2001, 7(4): 321-327.
Abstract (174) PDF (273KB)(8)
Abstract:
The dating is a very key problem in the study of Quaternary glaciation. Recent years, many technologies,for example,OSL (optically simulated luminescence),AMS (accelerating mass spectrometry), ESR (electron spin resonance) and so on, were used to date glacial deposits. Qilian Shan mounatains is the northeastern marginal mountains of the Qinghai-Tibetan Plateau and Tian Shan mountains is the big mountains in the center of Asia. The two mountains lie in the temperate arid region of Asia. However, because of appropriate precipitation in high attitude, there are a lot of contemporary glaciers in the two mountains. The glacial deposits and geomorphologies indicate that those glaciers occurred early and advanced for several times during Quaternary period. ESR technology was undertaken to define the timing of the glaciations and associated sediment deposition of the two mountains. The oldest moraine on the top of Zhonglianggan (2997m asl and 500m above the contemporary river level) in Bailang River Basin of Qilian Shan mountains was dated 462.9 ka BP. The oldest high Wafeng till (3450m asl and 250m above contemporary river level) of Urumqi River Basin, Tian Shan, was dated 477.1ka BP and 459.7ka BP.These datings show that the glaciers of the two mountains extended during marine isotopic stage 12(MIS12) and implicate a response of the uplifted mountains to the global climatic deterioration.
THE MOTIVE FORCE OF PRESENT SHIFT OF THE CONTINENTAL CRUST IN CHINA
SUN Tai-yu
2001, 7(4): 328-334.
Abstract (138) PDF (216KB)(10)
Abstract:
That the cyclical change of the shape of the mantle produces potential energy force in earth's crust results in crustal movement.When the shape of the mantle changes from sphere to relative flat-sphere,the crust of region of high latitudes of Southern Hemisphere and Northern Hemisphere produces opposite pressure to the crust of the region of low latitudes;When the shape of the mantle changes from relative flat-sphere to sphere due to restoration to a balance of the isopotential surface,the crust of the region of the low latitudes of Southern Hemisphere and Northern Hemisphere produces respectively a pressure to the region of the high latitudes.The motive force of present shift of the continental crust in China results from proceeding still to a balance of the isopotential surface in the mantle in the west of China.
MECHANISM AND OWNERSHIP OF TECTONIC DOMAIN OF THE CENOZOIC NW-TRENDING SHEAR TECTONIC SYSTEM IN CHINA AND ITS SOUTH WEST ADJACENT AREA
QIU Yuan-xi
2001, 7(4): 335-345.
Abstract (164) PDF (321KB)(13)
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The Cenozoic NW-trending compress-shearing tectonic system is well-developed in the west China and extends intermittently to the east China. Although the NW-trending tectonic system consists of NW striking folds,WNW and NNW trending compress-shearing faults as well as NEE trending tensional-shearing faults,the tectonic direction is better developed in the WNW because of the effect of partial conjugate shearing. The formation of the Cenozoic NW-trending System,which usually is superimposed on the Paleo-Hexi System or "the West Domain System",is related to intraplate deformation resulting from the collision between the India Plate and the Europe-Asian Plate since the end of the Late-Cretaceous or the Eocene.
THE SWAYING PROBLEM OF UNIVERSAL TESTING MACHINE IN THE MEASUREMENT OF ROCK STRESS BY AE METHOD DING Yuan-chen,WANG Xi-hai,HE Pei-yuan
DING Yuan-chen, WANG Xi-hai, HE Pei-yuan
2001, 7(4): 346-350.
Abstract (195) PDF (158KB)(6)
Abstract:
In the measurement for memorized rock stress by AE method,the symmetrical disturbance for AE in limited receiving scope comes from the fraction between endsurfaces of specimen and pressure heads of universal testing machine.The magnitude and change of the disturbauce for AE can be obtained by the measurement of swaying magnitude and change of test rig of universal testing machine in the process for uniaxial compression test.The measuring results show that the sway and the corresponding disturbance for AE are all remarkable in the beginning stage of compressing specimen.The methods and the viewpoints for overcoming the symmetrical disturbance for AE are given by authors on the basis of the level for the measurement at present.
DISCOVERY AND STRATIGRAPHIC DIVISION OF ALKALIC ROCK IN BAIYUNZHANG VOLCANIC ERUPTIVE BASIN OF EASTERN GUANGDONG
ZHANG Zong-sheng, HONG Yu-yong, XU Han-sen
2001, 7(4): 351-358.
Abstract (267) PDF (236KB)(7)
Abstract:
Middle Jurassic-Early Cretaceous volcanic rock are widely distributed in Baiyunzhang volcanic eruptive basin of Dongguan-Huidong region of eastern Guangdong,where a suite of alkalic volcanic rock in upper part,mainly composed of alkali-feld-spar rhyolitic-trachytic pyroclastic rocks was discovered.In light of petrology,mineralogy,petrochemistry,petrogeochemistry,isotopic age and contact nature,the suite is named Baiyunzhan Formation.It lies between the Late Jurassic-Early Cretaceous Nanshancun Formation and lower part of the Early Cretaceous Guancaohu Formation,belonging to Late Jurassic-Early Cretaceous in age.
STUDY OF MESOZOIC PALAEOTECTONIC STRESS FIELD IN THE VOLCAMIC ROCK AREA OF HUZHONG,THE NORTHERN PART OF DAHINGANLING VOLCANIC ZONE
ZHAO Shu-yue, SUN Guang-rui, ZHAO Jie, LI Kai, ZHU Chun-yan
2001, 7(4): 359-367.
Abstract (175) PDF (280KB)(7)
Abstract:
In the volcanic rock area of Huzzhong in the northern part of Dahiinganling volcanic Zone, the maximum principal compressive strress of Middle-Late Juraassic were mainly oriented the direction of NW266°~316°;but one of Early Cretaceous of the direction NE12°~50°.It shows that Mesozoic stress fields were different in Jurassic and Cretaceous, but these fields are all in tensile environment. In Middle-Late Jurassic, the tectonic magma activity resulting from NNE-SSW tensile stress field in the northern part of this area formed upper Heilongjiang fault basin and NWW trending Jintao-Mengkeshan intermediate-basic volcanic belt, its induced NEE trending tenso-shear stress field made the Premesozoic basement tectonics rejuvenate and formed volcanic eruption of big area. But under the control of NE-SW tensile stress field of Early Cretaceous, in the eastern part of "Ergun Block" sag belt was formed and the basement tectonics is NE-NNE direction.
THE WATER RESOURCE PROBLEM AND ITS SOLUTION IN 21 CENTURY
HU Yi-ken, PENG Cong
2001, 7(4): 368-370.
Abstract (151) PDF (94KB)(5)
Abstract:
This article point out the serious problem in our country's water resource at first,bring out the viewpoint that the government should regard the irrigation works construction as one of the primary state polices. And the author's solution of our country's irrigation works problem is as follow:Firstly,we should make a general plan with the scientific and systemic means,and then build up our country's irrigation works network step by step. We should keep the water resource from polluting. Let every inch soil can be moistened by the water.
ON DUAL NATURE AND DEVELOPMENT POSTURE OF THE LAND RESOURCE AND GEOLOGIC HAZARDS
LIU Hui-min, ZHANG Ye-cheng, GAO Qing-hua
2001, 7(4): 371-376,334.
Abstract (164) PDF (198KB)(5)
Abstract:
There is an interaction between utilizing of land resource and occurrence of geologic hazards. The formation and development of both land resource and geologic hazards are not only caused by the evolution of Earth surface system and of climato-environment, but also are affected by human activities. A series of grave geologic hazards has resulted from irrational and excessive exploit of land resource during last several decades, in reverse, the serious geologic hazards have resulted in great damages to the land resource. This is a vicious circle which will greatly hamper human social and economic sustainablly deve-lopment. Therefore, in order to reduce geologic hazards and to utilize sustainablly land resource, it would be a best choice to control human social and economic activities and to conform to natural law in utilizing land resource based on understanding of regularity of natural environment.
APPLICATION OF MAPOBJECTS IMS IN THE DEVELOPMENT OF WORLD WIDE WEB GEOGRAPHIC INFORMATION SYSTEM
WANG Jin, SHAO Zhao-gang, LEI Wei-zhi
2001, 7(4): 377-382.
Abstract (194) PDF (211KB)(5)
Abstract:
This paper reviews the basic concept of GIS and WebGIS briefly. It summarizes some methods to build WebGIS system and their characteristics. According to the development practice from the application of WebGIS in "The Stress and Geologic Disaster Database System", it analyzes the compositions and capabilities of MapObjects Internet Map Server components and MapObjects components which were made by the Environmental System Research Institute, Inc. And it also introduces how to use MapObjects Internet Map Server components to creat and serve Internet mapping applications(called map services on the Internet) and to access maps from Web client applications.