检索结果-南通市图书馆

s.me s.0}ges.ed Fu.u.e Directions.ofQu.ntitative Res.u.ce As.es.ments

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Jou.nal of China u.ivers.ty of Geos.iences 2001年第1期12卷 40-44页

作者： s.nger Donald A u. s. geological survey, 345 Middlefield Road, Menlo Park, California 94025, u.A u. s. geological survey 345 Middlefield Road Menlo Park

Fu.u.e qu.ntitative as.es.ments.will be expected to es.imate qu.ntities. valu.s. and locations.of u.dis.overed mineral res.u.ces.in a form that conveys.both economic viability and u.certainty as.ociated with the res.u.ces. His.orically, declining metal prices.point to the need for larger depos.ts.over time. s.ns.tivity analys.s.demons.rates.that the greates. opportu.ity for redu.ing u.certainty in as.es.ments.lies.in lowering u.certainty as.ociated with tonnage es.imates. Of all errors.pos.ible in as.es.ments. thes. affecting tonnage es.imates.are by far the mos. important. s.lecting the correct depos.t model is.the mos. important way of controlling errors.becau.e of the dominance of tonnage-depos.t models.are the bes. known predictors.of tonnage. Mu.h of the s.0}face is.covered with apparently barren rocks.and s.diments.in many large regions. Becau.e many expos.d mineral depos.ts.are believed to have been fou.d, a prime concern is.the pres.nce of pos.ible mineralized rock u.der cover. As.es.ments. of areas.with res.u.ces.u.der cover mu.t rely on extrapolation from s.0}rou.ding areas. new geologic maps.of rocks.u.der cover, or analogy with other well-explored areas.that can be cons.dered training tracts. Cover has.a profou.d effect on u.certainty and on methods.and procedu.es.of as.es.ments.becau.e geology is.s.ldom known and geophys.cal methods.typically have attenu.ted res.ons.s. Many earlier as.es.ment methods.were bas.d on relations.ips.of geochemical and geophys.cal variables.to depos.ts.learned from depos.ts.expos.d on the s.0}face-thes. will need to be relearned bas.d on covered depos.ts. Mineral-depos.t models.are important in qu.ntitative res.u.ce as.es.ments.for two reas.ns. (1) grades.and tonnages.of mos. depos.t types.are s.gnificantly different, and (2) depos.t types.are pres.nt in different geologic s.ttings.that can be identified from geologic maps. Mineral-depos.t models.are the keys.one in combining the divers. geos.ience information on geology, mineral occu.rences. geophys.cs. and geochemi

关键词： depos.t models grade and tonnage models economic models exploration ris..

Petrogenes.s.and Tectonic Implications.of the Early Trias.ic Nianzi Adakitic Granite u.it in the Yans.an Fold and Thru.t Belt:New Cons.raints.from u.Pb Geochronology and s.-Nd-Hf Is.topes

在线全文

学校读者我要写书评

暂无评论

Acta Geologica s.nica(Englis. Edition) 2024年第1期98卷 50-66页

作者： ZHANG Hu.ju. Wu.Chu.HE Fu.ing WANG Biren Cu. Yu.in LIu.Zhenghu. YOu.s.ina DONG Jing Development and Res.arch Center of the China geological survey Beijing 100037China Beijing Ins.itu.e of the geological survey Beijing 100095China Ins.itu.e of Dis.s.er Prevention LangfangHebei 065201China

The Nianzi granite u.it,which inclu.es.the Nianzi,Xiaolianghou.and Xiawopu.granitic intru.ions.is.a s.gnificant component of the northern part of the North China Craton(NCC)and is.s.tu.ted in the Yans.an fold and thru.t belt(YFTB).However,there is.s.ill debate regarding the tectonic evolu.ionary his.ory of the YFTB du.ing the late Permian to Trias.ic period,s.ecifically regarding the timing of s.0}du.tion and collis.on between the NCC and the Paleo-As.an Ocean.The Nianzi granite u.it exhibits.u.iqu. petrological,geochronological and geochemical s.gnatu.es.that s.ed light on the tectonic evolu.ionary his.ory of the YFTB.This.s.u.y pres.nts.detailed petrology,whole-rock geochemis.ry,together with s.-Nd is.topic,zircon u.Pb dating and Lu.Hf is.topic data of the granites.within the Nianzi granite u.it.Ou. findings.demons.rate that the granites.primarily cons.s. of s.0}hedral K-felds.ar,plagioclas.,qu.rtz,minor biotite and hornblende,with acces.ory titanite,apatite,magnetite and zircon.Zircon u.Pb dating indicates.that the Xiaolianghou.granite was.emplaced at 247.5±0.62 Ma.Additionally,the adakitic characteris.ics.of the Nianzi,Xiawopu.and Xiaolianghou.granitic intru.ions.s.0}h as.high s. and Ba contents.and high ratios.of s./Y and(La/Yb)N,combined with negative s.-Nd and Lu.Hf is.topes.87s./86s.)i=0.705681–0.7057433,εNd(t)=−21.98 to−20.97,zirconεHf(t)=−20.26 to−9.92,as.well as.the I-type granite featu.es.of high s.O_(2),Na_(2)O and K_(2)O/Na_(2)O ratios.enriched Rb,K,s. and Ba,along with depleted Th,u.Nb,Ta,P and Ti,s.0}ges. that the Nianzi granitic u.it was.mainly derived from the partial melting of a thickened lower cru.t containing hydrou.,calc-alkaline to high-K calc-alkaline,mafic to intermediate metamorphic rocks.In light of thes. parameters.we fu.ther integrate ou. data with previou. s.u.ies.and conclu.e that the Nianzi granitic u.it was.generated in a pos.-collis.onal extens.onal environment du.ing the Early Trias.ic.

关键词： tectonic evolu.ion zircon geochronology s.-Nd-Hf is.topes Nianzi granite u.it Yans.an fold and thru.t belt

Genes.s.of the Nu.i Cu.W-Mo Depos.t,Tibet,China:Cons.raints.from in s.tu.Trace Elements.and s. Is.topic Analys.s.of s.heelite

在线全文

学校读者我要写书评

暂无评论

Acta Geologica s.nica(Englis. Edition) 2024年第1期98卷 117-131页

作者： WANG Yiyu. Wu.Zhis.an CHEN Wenqing Du.Qing’an TANG Liwei s.I Hongzhao MA Gu.tao ZHANG Zhi LIANG Wei Wu.Bo MIAO Hengyi Chengdu.Center China Geological Survey(Geoscience Innovation Center of Southwest China)Chengdu 610081China The s.cond geological Ins.itu.e of China’s.Metallu.gical Geology Bu.eau Fuzhou 351111China

The Nu.i depos.t is.the only Cu.W-Mo polymetallic depos.t with large-s.ale WO3 res.u.ces.in the eas.ern s.ction of the Gangdes. metallogenic belt,Tibet,China.However,the genetic type of this.depos.t has.been controvers.al s.nce its.dis.overy.Bas.d on a s.u.y of the geological characteris.ics.of the depos.t,this.s.u.y pres.nts.mineralization s.ages.focu.ing on the oxide s.age and the qu.rtz-s.0}fide s.age where s.heelite is.mainly formed,referred to as.s.h-A and s.h-B,res.ectively.Throu.h LA-ICP-Ms.trace element and s. is.tope analys.s.the origin,evolu.ionary proces. of the oreforming flu.d and genes.s.of the ore depos.t are inves.igated.s.anning Electron Micros.ope-Cathodolu.ines.ence(s.MCL)obs.rvations.reveal that s.h-A cons.s.s.of three generations.with dark gray homogenou. s.h-A1 being replaced by relatively lighter and homogeneou. s.h-A2 and s.h-A3,with s.h-A2 dis.laying a gray CL image color with vagu. and u.even growth bands.and s.h-A3 has.a light gray CL image color with hardly any growth band.In contras.,s.h-B exhibits.a‘core-rim’s.ru.tu.e,with the core part(s.h-B1)being dark gray and dis.laying a u.iform growth band,while the rim part(s.h-B2)is.light gray and homogeneou..The normalized dis.ribu.ion pattern of rare earth elements.in s.heelite and s. is.tope data s.0}ges. that the early ore-forming flu.d in the Nu.i depos.t originated from granodiorite porphyry and,later on,s.me cou.try rock material was.mixed in,du. to s.rong water-rock interaction.Combining the O-H is.tope data fu.ther indicates.that the ore-forming flu.d in the Nu.i depos.t originated from magmatic-hydrothermal s.u.ces.with contribu.ions.from metamorphic water cau.ed by water-rock interaction du.ing the mineralization proces.,as.well as.later meteoric water.The intens. water-rock interaction likely played a cru.ial role in the precipitation of s.heelite,leading to varying Eu.anomalies.in different generations.of s.heelite from the oxide s.age to the qu.rtz-s.0}fide s.age,while als. cau.ing a gradu.l decreas. in oxygen fu.acity(fO2)and a s.

关键词： trace elements in s.tu.s. is.topes tu.gs.en mineralization Gangdes. metallogenic belt Tibet

Zircon u.Pb ages.in the Nu.atau.ophiolitic mélange in the s.u.hern Tians.an,u.bekis.an:Implication for the clos.0}e of Paleo-As.an Ocean

在线全文

学校读者我要写书评

暂无评论

China Geology 2024年第2期7卷 365-368,I0004-I0007页

作者： Kai Weng Ji-fei Cao Divayev-Farid Karibovich Jahongir-Ju.abekovich Movlanov Bo Chen Zhong-ping Ma Xi’an Center of geological survey China Geological SurveyXi’an 710119China The Center for Geoinnovation Technologies.Doctor of s.iences.in Geology and Mineralogy University of Geological ScienceTashkent 100060Uzbekistan

1.Objective The Central As.an Orogenic Belt(CAOB),which is.located between the Eu.opean craton,s.berian craton,and Tarim-North China craton(Fig.1a),is.the larges. phanerozoic accretionary orogen in the world.It res.0}ted from the longterm s.0}du.tion and accretion of the Paleo-As.an Ocean(PAO).The PAO has.been in exis.ence s.nce at leas. the late Mes.proterozoic(abou. 1020 Ma).However,there has.been debate abou. the clos.ng time of the PAO.

关键词： As.an Paleo Tians.an

Recognizing Relative Depth of Porphyry s.s.ems.Cas. His.ories.of the Wenqu.n and Taiyangs.an depos.ts.Wes.ern Qinling, China

在线全文

学校读者我要写书评

暂无评论

吉林大学学报(地球科学版) 2015年第S1期 787-788页

作者： Ku.feng Qiu.Ju. Deng Liqiang Yang James.Reynolds.Thomas.Monecke China u.ivers.ty of Geos.iences u. s. geological survey Denver Federal Center FLu.D INC. Denver Colorado 80202 USA Colorado s.hool of Mines Golden Colorado 80401 USA

Porphyry s.s.ems.i.e.,inclu.ing porphyry copper,s.arn,and epithermal depos.ts.,defined as.large volu.es.of hydrothermally altered rock centered on porphyry s.ocks.are one of the world’s.mos. important repos.tories.of copper,molybdenu.,and gold.Therefore,cons.ru.ting detailed genetic models.for porphyry s.s.ems.is.ins.ru.ental to increas. ou. capability to dis.over a category of mineral depos.ts.to ou. economy.Porphyry

关键词： ins.ru.ental cons.ru.ting altered molybdenu. s.ocks rock qu.rtz inclu.ion magma s.linity

Timing and Tectonic s.tting of the Gaoaobei Tu.gs.enMolybdenu. Depos.t in Nanling Range, s.u.h China

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Jou.nal of Earth s.ience 2024年第3期35卷 890-904页

作者： Jianfeng Li Kemeng Ma You.u. Lu.Jianming Fu.s.u.bo Cheng Yu.n Li Chu.nbiao Li College of Geographical s.ience Liaoning Normal UniversityDalian 116029China Wu.an Center of geological survey China Geological SurveyWuhan 430205China Granite Diagenes.s.and Mineralization Geology Res.arch Center China Geological SurveyWuhan 430205China Mineral Res.u.ces.survey Ins.itu.e of Hu.an Province Changsha 410083China

The Gaoaobei tu.gs.en-molybdenu. depos.t is.a newly dis.overed large-s.ale qu.rtzvein-type depos.t in the Nanling metallogenic belt in s.u.h China.The ore bodies.are hos.ed in the Indos.nian granites.and the Cambrian Xiangnan Grou. s.ates.and are controlled by NWW-oriented fau.ts.which are obviou.ly different from the“five-s.ory bu.lding”model in s.u.hern Jiangxi Province.The magmatic rocks.in the s.u.y area are dominated by mediu.-to coars.-grained biotite monzogranite,with a few NW-oriented fine-grained granite dykes.The mediu.-to coars.-grained biotite monzogranite and fine-grained granite dykes.have zircon u.Pb ages.of 229.4±1.9 Ma(Ms.D=1.5)and 164.9±3.3 Ma(Ms.D=0.75),res.ectively,corres.onding to the Indos.nian and Yans.anian magmatis..The monzogranites.have higher contents.of FeO,CaO,K2O,P2O5,and TiO2,while the granite dykes.have s.ightly higher contents.of s.O2,Al2O3,MnO,and Na2O.Their A/CNK valu.s.are 1.11-1.75 and 1.19-2.25,and the contents.of CIPW normative coru.du. are 1.71%-6.66%and 2.41%-9.50%,s.0}ges.ing both the monzogranites.and granite dykes.are s.type granite.The total amou.t of rare earth elements.in the monzogranites.from 84.7 ppm to 129 ppm)is.s.ightly lower than that in the granite dykes.from 128 ppm to 133 ppm).The Eu.Eu.valu.s.range from 0.12 to 0.30 in monzogranites.and from 0.0011 to 0.0013 in granite dykes.indicating the fine-grained granites.u.derwent more intens. fractional crys.allization.The monzogranite and granite dykes.have high 87s./86s.i valu.s.of 0.7169-0.7193 and 0.72825-0.72880,lowεNd(t)valu.s.ranging from-10.2 to-9.6 and from-11.5 to-11.4,and TDM2 ages.of 1835-1785 and 1957-1946 Ma,res.ectively.Thes. is.tope data indicate their origin from the remelting of the Paleoproterozoic cru.tal materials.Combined with regional geology,it is.conclu.ed that the mediu.-to coars.-grained biotite monzogranite was.formed in a pos.-collis.onal extens.onal environment.In addition,40Ar-39Ar dating of the greis.n type tu.gs.en-molybdenu. ore gave cons.s.ent plateau.age of 164.0±1.2 Ma,is.chrona

关键词： zircon u.Pb age 40Ar-39Ar age geochemis.ry tu.gs.en molybdenu. depos.t Gaoaobei Nanling Range.

geological conditions.and res.rvoir characteris.ics.of variou. s.ales.in major s.alehos.ed regions.of China

在线全文

学校读者我要写书评

暂无评论

China Geology 2024年第1期7卷 138-149页

作者： s.u.jing Bao Tian-xu.Gu. Jin-tao Yin Wei-bin Liu.s.eng-jian Wang Hao-han Li Zhi Zhou.s.i-zhen Li Xiang-lin Chen The Key Laboratory of u.conventional Petroleu. Geology China Geological SurveyMinistry of Natural Resources100083 BeijingChina Oil and Gas.survey China Geological Survey100083 BeijingChina Res.arch Ins.itu.e of Yanchang Petroleu.(Grou.)CO.LTD 710076 Xi’anChina

China is.home to s.ales.of three facies.Marine s.ale,continental s.ale,and marine-continental trans.tional s.ale.Different types.of s.ale gas.are as.ociated with s.gnificantly different formation conditions.and major controlling factors.This.s.u.y compared the geological characteris.ics.of variou. s.ales.and analyzed the influ.nces.of different parameters.on the formation and accu.u.ation of s.ale gas.In general,s.ales.in China’s.s.veral regions.exhibit high total organic carbon(TOC)contents.which lays.a s.u.d material bas.s.for s.ale gas.generation.Marine s.rata generally s.ow high degrees.of thermal evolu.ion.In contras.,continental s.ales.manifes. low degrees.of thermal evolu.ion,neces.itating focu.ing on areas.with relatively high degrees.of thermal evolu.ion in the proces. of s.ale gas.surveys.for thes. s.ales.The s.ales.of the Wu.eng and s.lu.ian formations.cons.itu.e the mos. favorable s.ale gas.res.rvoirs.s.nce they exhibit the highes. poros.ty among the three types.of s.ales.Thes. s.ales.are followed by thos. in the Niu.itang and Longtan formations.In contras.,the s.ales.of the Dou.hantu.,Yanchang,and Qings.ankou.formations.manifes. low poros.ties.Fu.thermore,the s.ales.of the Wu.eng and Longmaxi formations.exhibit high brittle mineral contents.Des.ite a low s.liceou. mineral content,the s.ales.of the Dou.hantu. Formation featu.e a high carbonate mineral content,which can increas. the s.ales.brittlenes. to s.me extent.For marine-continental trans.tional s.ales.where thin interbeds.of tight s.nds.one with u.equ.l thicknes.es.are generally fou.d,it is.recommended that fractu.ing combined with drainage of mu.tiple s.ts.of lithologic s.rata s.ou.d be employed to enhance their s.ale gas.produ.tion.

关键词： s.ale gas Marine s.ale Continental s.ale Marine-continental trans.tional s.ale Neoproterozoic-Cretaceou. s.rata geological conditions Res.rvoir characteris.ics Petroleu. geological survey engineering

Analys.s.of debris.flow control effect and hazard as.es.ment in Xinqiao Gu.ly,Wenchu.n M_(s.8.0 earthqu.ke area bas.d on nu.erical s.mu.ation

在线全文

学校读者我要写书评

暂无评论

China Geology 2024年第2期7卷 248-263页

作者： Chang Yang Yong-bo Tie Xian-zheng Zhang Yan-feng Zhang Zhi-jie Ning Zong-liang Li Chines. Academy of geological s.iences Beijing 100037China Chengdu.Center of China geological survey China Geological SurveyChengdu 610081China Technology innovation center for ris. prevention and mitigation of geohazard Ministry of Natural ResourcesChengdu 611734China Obs.rvation and Res.arch s.ation of Chengdu.geological Hazards Ministry of Natural ResourcesChengdu 610000China

Xinqiao Gu.ly is.located in the area of the 2008 Wenchu.n M_(s.8.0 earthqu.ke in s.chu.n province,China.Bas.d on the inves.igation of the 2023"6-26"Xinqiao Gu.ly debris.flow event,this.s.u.y as.es.ed the effectivenes. of the debris.flow control project and evalu.ted the debris.flow hazards.Throu.h field inves.igation and nu.erical s.mu.ation methods.the indicators.of flow intens.ty redu.tion rate and s.orage capacity fu.lnes. were propos.d to qu.ntify the effectivenes. of the engineering meas.0}es.in the debris.flow event.The s.mu.ation res.0}ts.s.ow that the debris.flow control project redu.ed the flow intens.ty by41.05%to 64.61%.The s.orage capacity of the dam decreas.s.gradu.lly from u.s.ream to the mou.h of the gu.ly,thu. effectively intercepting and controlling the debris.flow.By evalu.ting the debris.flow of different recu.rence intervals.fu.ther meas.0}es.are recommended for managing debris.flow events.

关键词： Lands.ide Debris.flow Hazard as.es.ment Nu.erical s.mu.ation OpenLIs.M Prevention and control project Wenchu.n M_(s.8.0 earthqu.ke Xinqiao Gu.ly s.chu.n province geological hazards.survey engineering

Mangrove wetlands.dis.ribu.ion s.atu. identification, changing trend analyzation and carbon s.orage as.es.ment of China

在线全文

学校读者我要写书评

暂无评论

China Geology 2024年第1期7卷 1-11页

作者： Chang Li Fu.Wang Peng Yang Fei-cu. Wang Yu.-zhu.ng Hu.Yan-lin Zhao Li-zhu.Tian Ru.-bin Zhao Tianjin Center(North China Center of Geos.ience Innovation) China Geological Survey(CGS)Tianjin 300170China Tangs.an Hydrological survey and Res.arch Center of Heibei Province Tangshan063000China Key Laboratory of Coas. Geo-Environment China Geological SurveyCGSTianjin 300170China Tianjin Key Laboratory of Coas. geological Proces.es.and Environmental s.fety Tianjin 300170China

This.res.arch inves.igates.the ecological importance,changes.and s.atu. of mangrove wetlands.along China’s.coas.line.Vis.0}l interpretation,geological surveys.and Is. clu.tering u.s.0}ervis.d clas.ification methods.are employed to interpret mangrove dis.ribu.ion from remote s.ns.ng images.from 2021,u.ilizing ArcGIs.s.ftware platform.Fu.thermore,the carbon s.orage capacity of mangrove wetlands.is.qu.ntified u.ing the carbon s.orage modu.e of InVEs. model.Res.0}ts.s.ow that the mangrove wetlands.in China covered an area of 278.85 km2 in 2021,predominantly dis.ribu.ed in Hainan,Gu.ngxi,Gu.ngdong,Fu.ian,Zhejiang,Taiwan,Hong Kong,and Macao.The total carbon s.orage is.as.es.ed at 2.11×10^(6) t,with s.ecific regional data provided.Trends.s.nce the 1950s.reveal periods.of increas.,decreas.,s.arp decreas.,and s.ight-s.eady increas.s.in mangrove areas.in China.An important finding is.the predominant replacement of natu.al coas.lines.adjacent to mangrove wetlands.by artificial ones.highlighting the need for creating s.0}table s.aces.for mangrove res.oration.This.s.u.y is.pois.d to gu.de fu.u.e mangroverelated inves.igations.and cons.rvation s.rategies.

关键词： Mangrove Wetland Carbon s.orage Ecological cons.rvation ArcGIs.s.ftware platform Res.oration InVEs. model Qu.ntitative analys.s Coas.al zone of China