GEOLOGICAL MARKS OF A POSSIBLE EXTRATERRESTRIAL IMPACT EVENT ON THE BOUNDARY BETWEEN SINIAN/CAMBRIAN IN TIANMENSHAN IN WESTERN HUNAN

Geologic marks related to extraterrestrial impact events, such as impact split gravels, impact brecciate layers, impact dikes, microirghizites, microtektites, especially meteoritic residues, were discovered on the boundary between Sinian/Cambrian at Tianmenshan of Western Hunan, which may possibly demonstrate that an extraterrestrial impact event has ever occurred there on the S/C boundary.     

GEOLOGICAL EVOLUTION AND OROGENY OF EAST KUNLUN TERRAIN ON THE NORTHERN QINGHAI—TIBET PLATEAU

GEOLOGICAL EVOLUTION AND OROGENY OF EAST KUNLUN TERRAIN ON THE NORTHERN QINGHAI—TIBET PLATEAU1　XuZQ ,YangJS ,ZhangJX ,etal.AcomparisonbetweenthetectonicunitsonthesidesoftheAltunsinistralstrike slipfaultandthemechanismoflithosphericshearing[J] :ActaGeologicaSinica,1999,73:193～ 2 0 5(inChinesewithEnglishabstract) . 2　YangJS ,XuZQ ,LiHB ,Wu ,etal.DiscoveryofeclogiteatthenorthernmarginofQaidambasin,NWChina[J] .Chi neseScienceBulletin,1998,4 3…     

RELATIONSHIP BETWEEN P-T CONTITIONS OF TWO PHASES OF TAN-LU STRIKE-SLIP SHEAR ZONES AND DELAMINATION OF OROGENIC BELTS ON THE EASTERN MARGIN OF THE DABIE MOUNTAINS

The Tan-Lu fault zone joins the Dabie Mountains on its eastern margin, and offsets the Dabie and Sulu orogenic belts sinistrally for about 500 kin. On the basis of calculation of temperature and pressure experienced by the two phases of the fault zone as well as the thermo-chronological information on mylonite from the earlier and later Tan-Lu fault zones on the eastern margin of the Dabie Mountains, this paper discusses the delamination history and uplifting magnitudes of the Dabie Mountains from earlier Jurassic to earlier Cretaceous. From mineral assemblages, mineral deformation and muscovite-chlorite geothermometry calculation, it is known that the temperature experienced by the two phases of Tan-Lu fault zones are between 40℃ and 450℃, and the confining pressures are between 0.25Gpa and 0.36GPa for the earlier shear zones and 0.24-0.39GPa for the late shear zones. According to the geobarometry of Si-in-phengite and by considering shear heating and tectonic over-pressure, it is concluded that the maximum formation depths for the two phases of the ductile shear zones are not more than 12 kin. Differential formation depths for the two phases of shear zones are 1-2 km at most. At about 190 Ma and 128 Ma, the Tan-Lu fault zone experienced two phases of cooling events. During this period, the eastem margin of the Dabie Mountains experienced a tectonic calm period and no uplifting. According to information from the Tan-Lu fault zone, the uplifting magnitudes of the Dabie orogenic belts are not more than 12 km during the earlier Cretaceous.     

PROCEEDINGS§ OF THE TENTH ANNUAL MEETING OF THE GEOLOGICAL SOCIETY OF CHINA HELD IN PEIPING AT THE NATIONAL TSINGHUA UNIVERSITY,THE YENCHING UNIVERSITY, THE NATIONAL UNIVERSITY OF PEKING AND THE GEOLOGICAL SURVEY LIBRARY, ON NOVEMBER 11TH-13TH,1933.

The first meeting was opened by President J. S. Lee at 10 o'clock in the morning in the auditorium of the Biological Building of the National Tsinghua University. The President made a short opening remark in which he congratulated on the growing activity of the Society and welcome the new     

CLASSIFICATION AND CORRELATION BASED ON THE DISTRIBUTION OF THE FUSULINA LIMESTONES

In view of the extensive distribution of the "Fusulina Limestone" in North China it was formerly suggested~1 that a careful study of the Fusulina might throw some light upon the vexed problem of the age of the Palaeozoic     

ON THE CENOZOIC GEOLOGY OF ITU,CHANGLO AND LINCHü DISTRICTS(SHANTUNG)

INTRODUCTION Since many years the occurrence of Early Pleistocene fossiliferousred loam (wrongly interpreted generally as "loess") was known,north ofthe Taishan range,along the Tsinan-Tsingtao railway.Chiefly in the     

THE CHENGTU CLAYS—DEPOSITS OF POSSIBLE LOESSIAL ORIGIN IN WESTERN AND NORTHWESTERN SZECHUAN BASIN

INTRODUCTION Heim and Bowles (2)~1 have described the occurrence of loessialdeposits in the mountain valleys and on the high plateaus northwest of     

ON THE FISSURE DEPOSITS OF CHINGHSINGHSIEN(井陘县) WITH REMARKS ON THE CENOZOIC GEOLOGY OF THE SAME AREA

In August 1933, the writers of the present paper were sent by the Geological Survey to Chinghsinghsien along the Chengtai Railway, on the Hopei and Shansi border, to examine the long known but not sufficiently surveyed     

RESPONSE OF TRIASSIC SEQUENCE STRATIGRAPHY OF LOWER YANGTZE TO THE COLLISION BETWEEN THE YANGTZE PLATE AND THE NORTH CHINA PLATE

The characteristics of the Triassic sequences developed in the Lower Yangtze area display some great changes in both environment and climate. The change of environment was a transition from marine to continent via alternating environments. The change of climate was a transition from tropic （torrid） to warm and wet climate via subtropic dry climate. The type variations of the sequences were from the marine sequences to the continental sequences, corresponding to the changes of environments and climates. Sequence 1 is a type II of sequence of mixed elastic and carbonate sediments; sequence 2 is a type I of sequence of carbonate platform; sequence 3 is a type I of sequence of carbonate tidal flat-salt lagoon, sequence 4 is a type iI of sequence of lacustrine within marine layers, and sequence 5 is a sequence of lacustrine-swamp. The development, distribution and preservation of those sequences reveal the tectonic controls and their changes in the background. The collision between the Yangtze plate and the North China plate was a great geological event in the geological history, but the timing of the collision is still disputed. However, the characteristics of Triassic sequence stratigraphy and sea level changes in the Lower Yangtze area responded to this collision. The collision started at the beginning of middle Triassic and the great regression in the Lower Yangtze area started 22Ma earlier than those in the world. The tectonic conditions occurred before and during the collision controlled the development of sequences and type changes.     

BULLETIN OF THE XI''''AN INSTITUTE OF GEOLOGY AND MINERAL RESOURCES,THE CHINESE ACADEMY OF GEOLOGICAL SCIENCES TOTAL CONTENTS NO.21-24,1988

No.21Fundamental Geologieal一Teetonie Features and Struetural Controlled Proeess in Metallogenesis,Changba Pb一Zn Depo‘it ···························……Li Yig耐,Y。月9 Zh的gta”9 and Zhao Dez从(13)The Charaeters and Teetonie Signifieanee of Ophiolite First Diseovered in the East Kunlun Area ························……Gao Ya”“称,才“X记ngnong and Zuo Guocha。(28)A Preliminary Study on the Palaeoplate’Feetonies inshangluoArea…     

U-PB ZIRCON AGES OF TIANZHUSHAN GRANITES IN THE EASTERN DABIE OROGEN AND THEIR GEOLOGICAL IMPLICATIONS

1.IntroductionManykindsofUHPmetamorphicrocksoutcroppedinDabieterrenehaveattractedmanygeologicalsciefltistsallaroundtheworld.Meanwhile,thegenesis,emplacementage,emplacementmechanismandthetimeandspacerelationswiththeUHPmetamorphicrocksforthegranitesinDabieareahavealsofascinatedmanygeologists.IncontrasttothewestDabiearea,wheresystematicstudieshavebeenmadeongranites,onlylessresearchworkhasbeendonefortheeasternpartofDabieterrene.Inordertoclearlyunderstandthegenesisofthegranitesandtheirrelations…     

THE STRUCTURE OF MINYA GONGKAR(貢噶) PRELIMINARY SKETCH,WITH Ⅰ SECTION AND 4 PHOTOGRAPHS.

The following sketch is presented through the invitation of Prof. Dr. Chu chia-hua. The chief object of the Szechuan-Tibet Expedition of Sunyatsen University~1, in 1930-31, was the geological study of the high mountains of the Tibetan     

SEDIMENTARY FACIES AND ELEMENT-GEOCHEMICAL CHARACTERS OF THETRIASSIC-JURASSIC BOUNDARY STRATAIN THE JIYUAN BASIN, HENAN

1.IntroductionTheJiyUandepressionalbasinislocatedinthenorthwestofHenanProvinceanthesouthendoftheTailiangshanMountains.ItisboundedonthesouthbySongshanhill,onthewestbytheDaimeichaiupliftandontheeastthroughtheWusherisebytheZhonglnodepression,entirelyextendingEW.ItwasasubsequentdevelOPmentoftheNorthChinaEarly-MiddleTriassicdepositionalbasin.ByMiddleTriassic,thenorthpartoftheNorthSouthChinaplatformbeganupliftunderinfluenceoftheindosinianmovement,whichmadeaLateTriassiclarge-scalelakebasin…     

THE INVERTED STREAM OF SUNGLINKOU(松林口),EASTERN HSIK''ANG(西康)

Participating to the Szechuan-Tibetan Expedition of Sun-Yatsen University, guided by Prof. Arnold Heim, I had an opportunity to study the geology as well as the physical geography of NE Hsik'ang (西康) from May 1930 to Feb. 1931. The entire trip lasted about Io months.     

ON THE EXISTENCE OF THE SHUANGTSüAN SERIES AND ITS TRIASSIC FLORA IN HSISHAN OR THE WESTERN HILLS OF PEIPING

During the summer of 1932,Y.S.Chi made a detailed study of thegeology of the Mentoukou (门头溝) and Sanchiatien (三家店) area of Hsishan,or the Sanchiatien Sheet~2 of the Ordnance Map in the scale 1 to 25,000.The