塔中地良奥陶系地层格架与沉积演化

塔里木中部地区奥陶系大致以Ⅰ号断裂为界分东北和西南两个地层分区,自下而上分白云岩段、灰岩段、泥质灰岩段、泥岩夹灰岩段、泥岩夹砂岩段、砂砾岩段、泥岩夹砂岩段、泥岩灰岩互层段和砂岩段等9个岩性段。早奥陶世,塔中地区以碳酸盐岩台地相为主,自西向东为局限台地相、开阔台地相、台地边缘相和深水斜坡相。中——晚奥陶世,塔中地区西部以混积陆架相为主,东部以深水斜坡相为主。中—晚奥陶世,塔中东部及塔东地区在构造上具弧后前陆盆地性质。中—上奥陶统地层完整地记录了该盆地从形成发展到消亡的过程,即早期为深水斜坡相复理石活动沉积,晚期演化为浅海陆架相稳定沉积。     

A NUMERICAL MODEL OF SEDIMENT TRANSPORT IN HANDUN IRRIGATION DISTRICT

LABRIEFINTRODUCTIONOFRANDUNIRRIGATIONDISTRICTYellowRiverisoneofthemainWaterresourcesinNOrthChina.SincethefiftiesirrigationbydivertingwaterfromtheYellowforerdevelOPssteadily.AstheYdlowforerisaheavilysacmentsladenone,sedimentisdiVertedsimultaneouslywhenwaterisdiverted.HOwtoproperlytreatthedivertedsedimentboomesoneOfthekeyproblemsrestrichngthesustainingdevelOPmentofthCwaterresourcesinthatarea.LongchStanceconvopngsedimentisoneofthemainmeasuresfordealingwiththediVertedsedim…     

ALTERATIONS OF RIVER MORPHOLOGY DUE TO VEGETATION ON SLOPES AND FLOOD PLAINS

LRESEarCHACTIVITIESCharaCtCriedcofunlinedalluvialriVersisthe~linteractionbettVeenwaterflowandmovableriVerbed.Sedimenttransport,bedresistanceandriVermorphologydecisivelydependontheflowconditionsandviceversathesefactorsgovernthehydraulicprocesses.EVenundersimplifiedconditions,e.g.inlaboratorytests,theseillteractionsareeXtremelycomplexandrelldsraliZationmakesengineeringproblemsevenmored~.TomaketheseprocessesmoreunderstandablecomprehensiVeresearchprojectswereconductedatseveralGermanuniv…     

EROSION CONTROL AND RESOURCE MANAGEMENT ON UPLAND WATERSHEDS OF GRANITIC REGION

I.FEATURESOFSOILEROSIONINGRANITICREGIONS1.1IntroductionGuangdongProvinceislocatedinsubtropicalzoneandthenorthernborderofthetropicalzone.ThelatitudestCtchesfrom20'07'to25'31'N,thelongitudefrom108'33'tO117'20'E.Subtropicalclimateprevailsinmostoftheprovince.Theannualaveragerainfallis1500-1800mm,withstrongintensityandun-evendistribution.Thedeifyrainfallduringwnhoonstormsmayreach200-300mm:Thetotallandareaisabout178,100sq.km,inwhich25,100sq.kmarecultivated.12,000sq.km,6.7%oftotalP…     

从地震信息看中国东部垂直构造样式及油气

所讨论的垂直构造是石油勘探中最常见的小尺度局部升降作用所引起的各种构造 ,按成因可分为跨塌构造、压实构造、底辟构造三类样式。垮塌构造样式是碎屑岩沉积盆地基底的碳酸盐岩地层长期被地下水溶解形成地下大溶洞 ,造成上部地层垮塌而形成的堑背形构造样式 ;压实构造由沉积压实作用所致 ,可分为基底古隆起披覆构造样式和差异压实披覆构造样式等 ;底辟构造 (又称“挤入构造”)是塑性岩层在外力作用下发生底辟作用而产生的 ,分刺穿底辟和拱形底辟两种 ,或冷底辟和热底辟两类。莺歌海盆地发育众多的地震异常体 ,呈底辟状 ,但比较特殊 ,可称为气烟筒 ,与通常的底辟具本质之别。中国东部中、新生代盆地中普遍发育垂直构造 ,它们与沉积作用同步发生 ,一般无明显的挤压褶皱变形     

Study on automatic recognition of the first motion in a seismic event

IntroductionSeismic detection is one of the most effective methods to monitor underground explosions. When an underground explosion is conducted, like an earthquake, it will radiate seismic waves. Stimulating from sources, these seismic waves travel through the Earth(s interior and surface, propagating widespread. These waves can be recorded by seismograph systems on surface. By studying the recorded seismic signals, we can obtain much detailed information on such a seismic event. We can the…     

SHRIMP U-Pb Dating of Zircons of a Dark Eclogite and aGarnet-bearing Gneissic Granitic Rock from Bixiling, EasternDabie Area, Anhui Province: Isotope Chronological Evidenceof Neoproterozoic UHP Metamorphism

The paper reports SHRIMP U-Pb zircon data of a dark eclogite and a post-eclogite garnet-bearing gneissic granitic rock from the Bixiling area, Yuexi County, Anhui Province, in the eastern Dabie Mountains. The eclogite, which is metamorphosed basic tuff, contains very scarce zircons in omphacite or garnet, but more zircons in quartz. They usually exhibit a double-layered texture, as shown clearly in cathodoluminescence images. Their inner main parts give a 206Pb/238U age of 757±7 Ma, representing the approximate age of the high-pressure (HP)- ultrahigh-pressure (UHP) metamorphic event during which the eclogite was formed. The outer peripheral parts of the zircons, which have been modified by late-stage fluids, give an age of 223±3 Ma. The granitic rock contains more zircons of anatectic origin found mostly in feldspar and quartz and usually also showing a similar composite texture. The inner main parts of the anatectic zircons with oscillatory zoning give a 206Pb/238U age of 727±15 Ma for the approxim     

Uraniferous Black Shale and Related Uranium Mineralization Features in South China

: Black shales are marine sediments with argillaceous, silty and siliceous compositions and high contents of organic materials, disseminated pyrite and uranium. Uraniferous black shale has uranium content of more than 20 ppm.Black shales are widely distributed in 17 provinces or autonomous regions in northwestern and southern-central China. Their sedimentary ages are from the Sinian to the Tertiary and uraniferous black shales are mainly exposed in Yunnan, Guizhou, Sichuan, Hunan, Hubei, Jiangxi, and Zhejiang provinces and Guangxi Zhuang Autonomous Region and the economically significant uranium deposits associated with black shale occur in Hunan and Jiangxi provinces and Guangxi Zhuang Autonomous Region.Uranium mineralization associated with black shale has the following main features: (1) forming stratabound deposits; (2) controlled by structures such as interlayer and intersected faults and fractures; (3) associated with different ore-forming processes such as leaching and hydrothermal reworking; (4)     

Puziwan Gold Deposit in Shanxi, China: A Special Linear Cryptoexplosive Breccia Type Gold Deposit

The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic. belt of the most famous Au-Ag polymetallic metallogenic belt along the north margin of the North China platform. The secondary metallogenic belt is a synmagmatic tension-shear fault-fracture belt of ENE linear trend. The Indosinian cryptoexplosive breccia body, quartz monzonitic porphyry (beschtauite breccia), quartz monzonite (243.7 Ma, K-Ar), Yanshanian granite-porphyry (105±6 Ma, Rb-Sr) and orebodies mostly occur as dykes or veins and short lenses along the structural fracture belt. The orebodies are emplaced in the fractured cryptoexplosive breccia body in the tectonomagmatic belt and their attitude is consistent with that of the breccia body. The orebodies have two types: one is shallow-seated thick and big ones, which are short-lenticular in plan and wedge-shaped in cross section, shallow buried, large in size a     

Response of the Nile and its catchment to millennial-scale climatic change since the LGM from Sr isotopes and major elements of East Mediterranean sediments

Changes in ⁸⁷Sr/⁸⁶Sr and major element geochemistry, from two sediment cores (9509 and 9501) in the Eastern Mediterranean (EM), were used to resolve changes in sediment provenance and, hence, determine climate changes in the Nile catchment and Eastern Sahara desert over the past 25 ka. The sediment was described by a three end-member system comprising Blue Nile (BN; ⁸⁷Sr/⁸⁶Sr = 0.7506; Sr = 210 ppm), White Nile (WN; ⁸⁷Sr/⁸⁶Sr = 0.7094; Sr = 72.5 ppm) and Saharan dust (SD; ⁸⁷Sr/⁸⁶Sr = 0.7183; Sr = 99 ppm). The sedimentary record of these cores represents the suspended load carried down the Nile river and discharged into the S.E. Levantine basin and thus records palaeoclimatically controlled changes in erosion and transport in the catchment. During arid periods (0–5 ka BP) and prior to 11 ka BP, fluxes of BN sediment at 9509 (～6 g/cm²/yr & 10–12 g/cm²/yr, respectively) were greater than during the peak of the African Humid Period (AHP) from 5 to 11 ka BP (<2 g/cm²/yr); this latter period witnessed the deposition of the youngest organic-rich sediment, termed sapropel (S-1), in the EM basin. By contrast the flux of WN increased during the AHP from ～5 g/cm²/yr at ～13 ka BP to >15 g/cm²/yr. In the Ethiopian Highlands (BN catchment) increases in the amount and duration of the monsoon during the AHP caused more vegetation to grow resulting in less soil erosion. In the WN catchment increased rainfall caused more catchment erosion and higher sediment flux through the Sudd marshes. The sedimentation rate in core 9509 increased during the AHP because of the greater importance of the WN sediment flux relative to the BN sediment flux. Saharan dust flux also decreased during the AHP reaching a minimum at ～6 ka BP (core 9509) due to ‘greening’ of the Sahara desert. At the onset of S-1, the changes in Nile flow as determined by ⁸⁷Sr/⁸⁶Sr and climatic changes in the EM basin determined by δ¹⁸O of planktonic foraminifera were simultaneous, confirming that such isotopic tracers cannot be used directly to determine the cause of the circulation changes in the EM at this time. The increase in the proportion of BN sediment at 9509 with a somewhat higher grain size during the H-1 period (15–17 ka BP) was caused by erosion and redistribution of sediment from the Nile delta and/or the Israeli coast as sea-level rose.