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1.
本文通过对分布于胶西北地区南部的秦姑庵花岗岩体开展详细的岩石学、岩石地球化学、锆石UPb年代学和锆石LuHf同位素地球化学研究,识别出粗中粒二长花岗岩、斑状中粒二长花岗岩和细粒黑云母二长花岗岩,它们具有相同的地球化学特征和同位素组成,呈连续演化关系,为同源岩浆活动的产物。岩石地球化学研究表明,花岗岩具有高的SiO2（68.73％～75.27％）、全碱（K2O+Na2O=8.39％～8.93％）,低的Al2O3（13.38％～15.84％）、MgO（0.14％～0.98%）、P2O5（0.02％～0.13%）、Sr（118×10-6～520×10-6）、Y（7.03×10-6～12.30×10-6）、Yb（0.78×10-6～1.34×10-6）含量特征,轻稀土（LREE）富集、重稀土（HREE）相对亏损（LREE／HREE=18.39～26.72）,轻、重稀土元素分馏明显［(La/Yb)N＝17.13～42.58］,Eu中等负异常（δEu=0.49～0.76）,富集大离子亲石元素（LILE）,亏损高场强元素（HFSE）。锆石SHRIMP定年结果表明,斑状中粒二长花岗岩形成于（119.9±1.3）Ma,秦姑庵岩体形成于早白垩世晚期,时代上与胶东地区伟德山型花岗岩一致。锆石原位LuHf同位素分析表明,εHf（t）为24.07～19.27,二阶段模式年龄TDM2为2398～2696 Ma,岩浆源区主要来源于古元古代物质的部分熔融,少部分为新太古代基底岩石。岩体形成于加厚下地壳的下部,其残留相可能由斜长石+辉石+角闪石+石榴石组成,相当于麻粒岩相或石榴石麻粒岩相。花岗岩的同位素年龄与胶西北金矿床的成矿时代一致,指示120Ma左右的岩浆活动为金成矿提供了流体和热动力条件。 相似文献
2.
西秦岭大水金矿岩浆岩年代学、地球化学特征 总被引：1，自引：0，他引：1
西秦岭大水金矿床与其周围伴生的中酸性小岩体的成因关系,直接影响矿床成因的划分和深部资源的开发。中酸性岩浆岩的成因、源区性质及岩体规模对金矿成矿有重要影响。大水金矿岩浆岩地球化学研究结果显示:岩浆系列属于高钾钙碱性系列;岩体球粒陨石标准化稀土元素配分模式具有轻稀土元素富集、重稀土元素亏损、Eu正异常的特征;岩体洋中脊花岗岩标准化微量元素蛛网图显示其富集大离子亲石元素K、Rb、Ba、Th等,亏损高场强元素Nb、Ta、Hf、Zr、Sm、Y、Yb等,花岗岩的w(Sr)-w(Yb)分类属于高Sr、低Yb"C"型埃达克岩。LA-ICP-MS锆石U-Pb法测年获得大水金矿格尔括合岩体和竖井941岩脉的锆石U-Pb年龄分别为(215.8±1.3)、(202.9±1.5)Ma;成矿热液蚀变叠加在脉岩之上,成矿年龄应晚于202.9 Ma的脉岩年龄。Sr-Nd同位素组成具有高初始N(87Sr)/N(86Sr)值、低εNd的特点,模式年龄为1.29~1.47Ga。εSr(t)-εNd(t)图解表明岩浆源区为下地壳;εNd(t)-初始N(87Sr)/N(86Sr)图解暗示西秦岭存在统一的岩浆源区。因此,西秦岭大水金矿在成因上与高Sr、低Yb"C"型埃达克岩密切相关。 相似文献
3.
笔架山东基性—超基性岩体位于塔里木板块东北部的新疆北山地区,是笔架山岩带中最东边的一个岩体,岩体形态为椭圆状,出露面积约5 km2.由含长单辉橄榄岩、橄榄辉长岩、含橄辉长岩、辉长岩以及辉绿岩组成.含橄榄石较多的岩石属拉斑玄武岩系列,而辉长岩属钙碱性系列.岩相学、岩石化学和微量元素地球化学特征表明岩浆演化过程中经历了橄榄石、辉石、斜长石的分离结晶作用.Nd、Sr、Pb同位素组成和岩石地球化学特征反映出岩浆与围岩之间存在物质交换.笔架山东岩体的岩浆源区为OIB型地幔源区,原生岩浆为高镁拉斑玄武岩浆[w(MgO)=11.2％],这些性质与塔里木板块东北部其他基性-超基性岩体的特征相似,表明塔里木板块东北部二叠纪基性—超基性岩体的源区主要为OIB型地幔,可能与地幔柱有关. 相似文献
4.
本文在详细的岩相学观察基础上,分析研究岩体和矿物的微量元素及稀土元素的特征。结果表明,郗山—关帝庙碱性杂岩体富集Ba、U、Pb、Th及La、Ce,亏损Nb、Ta、Zr、Hf; Nb>Ta,富集轻稀土元素、亏损重稀土元素,轻重稀土分异显著,Ce、Eu无明显异常,关帝庙岩体与郗山岩体的微量元素配分曲线均为右倾型,表明研究区内碱性岩体为同源岩浆,推测初始成岩物质来源于岩石圈地幔部分熔融,其母岩浆为碳酸盐化硅酸岩熔体。郗山岩体发现岩浆型磷灰石和热液型磷灰石,表明郗山岩体的岩浆经历了较强的结晶分异和一定程度的混合作用,并在热液阶段形成大量的轻稀土矿物。 相似文献
5.
对粤东北新丰地区基性岩脉进行了年代学、元素地球化学研究。结 果 表 明:新 丰 地 区 近 ＳＮ 向 和 ＮＷＷ 向 基 性 岩 脉 的锆石 Ｕ－Ｐｂ年龄分别为（１４８．６±４．１）Ｍａ（ＭＳＷＤ＝１．３）和（８５．７±２．０）Ｍａ（ＭＳＷＤ＝１．４）,成岩时代为晚侏罗世和晚白垩世。基性岩脉具低碱富钠、较高钛含量、富铁、中等镁含量和准铝质特征。稀土元素标准化曲线呈小角度右倾斜型,轻重稀土元素中等分馏、轻稀土元素富集。微量元素表现出富集 Ｂａ、Ｒｂ、Ｋ,亏损 Ｔａ、Ｎｂ、Ｚｒ、Ｈｆ和 Ｐ等 特 征。晚侏罗世基性岩脉轻微 Ｃｅ负 异 常（δＣｅ＝０．８９～０．９３）和弱 Ｅｕ正异常（δＥｕ＝１．００～１．０５）,Ｔｈ／Ｙｂ比值比较高,表明岩浆源区可能遭受过富 Ｔｈ俯 冲流 体 交 代。２组 基性岩脉岩浆源区均来自地幔,可能经历了石榴石－尖晶石二辉橄榄岩的部分熔融,并发生了单斜辉石、Ｔｉ－Ｆｅ氧化物矿物的分离结晶作用。新丰地区基性岩脉具有大陆裂谷玄武岩特征,形成于陆内裂谷环境,但早期基性岩脉（１４８．６Ｍａ）较晚期 （８５．７ Ｍａ）具有相对较浅的岩浆源区。 相似文献
6.
潘店岩体为近年山东省齐河—禹城地区新发现的潘店铁矿的成矿岩体,主要由辉石闪长岩组成。对郭店地区潘店岩体辉石闪长岩进行了SHRIMP锆石UPb定年,其结果为（124.4±1.4）Ma,表明该岩体形成于早白垩世。潘店岩体SiO2、K2O和Na2O含量分别介于59.68%～62.71%、0.13%～3.30%和6.57%～8.42%,Mg#值为54.23～78.17,A/CNK为0.52～0.71,具有轻稀土富集,重稀土亏损的右倾型稀土配分模式,轻、重稀土分馏明显,具中—弱Eu负异常。富集大离子亲石元素Ba、Sr和高场强元素U、Pb、Zr,与相邻元素相比大离子亲石元素Rb、K和高场强元素Nb、Ce、P、Ti明显亏损。Nb/Ta、Zr/Hf比值及Nb、Ta的亏损等特征暗示原始岩浆可能来源于岩石圈地幔的部分熔融,并在岩浆上升侵位的过程中有地壳物质的同化混染。潘店岩体形成于岩石圈大规模快速减薄期,与燕山晚期太平洋板块俯冲作用密切相关。 相似文献
7.
出露于甘肃康县南部阳坝镇一带的阳坝岩体具有典型的岩浆混合特征,岩体中暗色微粒包体发育,主要类型为暗色细粒微粒闪长质及石英闪长质岩浆包体,岩浆包体与寄主岩石界限清晰。岩浆包体具淬火结构:角闪石呈长柱状,黑云母呈长条片状,磷灰石呈针状,包体中出现石英颗粒集合体及发育熔蚀环的斜长石捕虏晶。岩石学、地球化学研究表明,微粒闪长质包体的(La/Yb)N、Rb/Sr值都比寄主岩石高,且铕亏损程度更大,包体和寄主岩石的Mg#高(寄主岩石Mg#=50.8~54.5,暗色包体Mg#=55.6~60.1)。结合岩相学特征可以认为,暗色微粒包体可能是幔源的高温偏基性岩浆侵入到花岗闪长质岩浆中淬火结晶的产物,在此过程中,花岗质岩浆受到幔源物质混染,表明在中三叠世,扬子板块西北缘曾发生壳-幔混合作用。 相似文献
8.
在山东沂源地区进行金刚石矿远景调查时发现超基性岩体,经岩矿鉴定为橄榄玄武岩。通过人工重砂,选获大量的金刚石找矿指示矿物。该文运用岩矿鉴定、化学分析、稀土元素分析,指示矿物铬铁矿电子探针微区分析,对岩体进行了研究,结果表明,岩体具有富铁、富镁的特征,岩石里特曼指数介于-3.60～5.40之间,根据划分标准,调查区橄榄玄武岩为钙碱性—碱性岩。岩石固结指数(SI)介于35.21～47.15之间,显示岩浆分异程度中等;金刚石找矿指示矿物铬铁矿来自金刚石原生矿母岩岩体;橄榄玄武岩岩体REE总量偏低,轻稀土富集,重稀土含量偏低,轻重稀土分馏十分明显,没有明显的Eu异常。橄榄玄武岩化学成分与蒙阴地区金伯利岩化学成分、伴生矿物、稀土元素具有相似性。因此,它们在成因上应该具有内在联系,应属于同一构造环境下岩浆活动的产物。 相似文献
9.
天水坪道花岗岩体的地球化学特征及构造环境 总被引：3，自引：2，他引：1
坪道岩体由早期到晚期可分出斜长花岗岩→花岗闪长岩→黑云二长花岗岩→含斑黑云二长花岗岩→正长花岗岩共5期岩浆活动。岩体碱值为0．49～0．62，ANKC大于1，多见白云母，CIPW计算中多见刚玉，属钙碱性铝过饱和型。随SiO2增加，TiO2，TeO，MgO，CaO,Na2O均逐渐缓慢减少，而Fe2O3，K2O剧增。岩石化学显示其源岩为上地壳杂砂岩类、碎屑岩类。岩体相对富集轻稀土，δEu值为0．35～0．7，铕亏损强烈。岩体贫Ba，Rb，Sr，Y，Cu,Zr，Ga，Ni，富Nb，Ta,Bi,Th，Cr，Sn,Mo，Hf，Sc，异常富Hf，Sn，Sc。构造地球化学信息显示岩体是大陆裂谷型花岗岩。 相似文献
10.
青海牛鼻子梁铜镍矿床地质特征及成因探讨 总被引：1，自引：0，他引：1
近年来随着地质勘查力度的加大,通过化探异常查证、结合工程揭露验证,在柴达木地块周缘发现了与基性-超基性岩有关的牛鼻子梁、夏日哈木等铜镍硫化物矿床。其中牛鼻子梁铜镍矿床地处柴达木盆地西北缘古陆块上,其成矿与镁铁质-超镁铁质层状杂岩体有关。岩体出露面积约8km2,平面形态呈长条状,岩体具有复合杂岩体特征,多属闪长岩-辉长岩-辉石岩-橄榄岩型镁铁-超镁铁质岩。本文通过岩体岩石特征、矿体特征、矿相学特征、岩石稀土与微量元素地球化学特征分析研究,对矿床成因进行了初步探讨。认为牛鼻子梁基性-超基性岩体产于大陆边缘环境,形成于晚泥盆世,岩浆分异充分,岩石类型丰富,岩体中硫化物丰富,矿床至少经历了岩浆期、矿浆期、热液期3个成矿期和4个成矿阶段,成矿类型应为岩浆熔离型、熔离贯入改造型,并有后期热液叠加。 相似文献
11.
The contents of nearly forty-elements in surface sediments in Jiaozhou Bay were determined using a Neutron Activation Analysis Technique(Grancini,et al.,1976;Li Peiquan et al.,1985,1986;Li Xiuxia etal.,1986).This paper's detailed discussion on only nine elements(Fe,Mn,Co,Cr,Sc,As,Sb,Zn andV)includes their distributions,concentrations,correlationships,material sources,background,etc.Based on Zavaristski's classification method,Fe,Mn,Co Cr and V belong to the second group;As and Sb to theeighth groups:Sc and Zn to the third and sixth groups.It was found that their notably good correla-tionship is mainly due to the similarity of their ionic structures and that their variation is controlled by theFe content(except Mn).The source of sediments is mainly terristrial material,and the composition ofsediment is similar to that of shale and shale+clay.The contents for a large number of ele-ments are within the scope of the background level,but there still is pollution of Zn and Cr,at least in a few stations. 相似文献
12.
氟、氯、溴、碘等卤族元素与人体健康的关系 总被引：1，自引：0，他引：1
卤族元素是人体的必需元素,正常情况下成人摄入量不超过F4 mg/d、C11.7～5.1g/d、I 100～200μg/d;少年不超过F 3 mg/d,儿童I1μg/kg-d,婴儿Cl0.3～1.2 g/d.过量摄入或缺乏卤族元素,都可能导致疾病的发生.而F含量0.5～1.0mg/L、C1＜50mg/L、Br＞100μg/L、I 10～100μg/L的饮用地下水,有利于人体健康. 相似文献
13.
A study was conducted on Cu, Zn, Cd, Fe, Co and Ni levels in Saanich Inlet anoxic seawater. Data on the concentration of these
trace metals and H2S, and other oceanographic parameters were obtained in four cruises.
Equilibrium models are presented together with in situ data. The results strongly support the assumption that the solubilities
of Cu, Zn, Cd, Fe, Co and Ni are controlled by bisulfide and/or polysulfide complexes. The species of Cu, Zn, Cd and Ni are
shown to be Cu(S4)
2
3−
and Cu(Sn4S5)3−, Zn(HS)
2
0
and ZnHS
2
−
, Cd(HS)
2
0
and Ni(HS)
2
0
, respectively. The solid species controlling Fe2+ and Co2+ are respectively the pyrohotites FeS and CoS. The data illustrates that thermodynamic equilibrium has been established in
the H2S-controlled seawater of Saanich Inlet, and that equilibrium has not been established in the H2S−O2-coexisted seawater of Saanich Inlet. The lack of equilibrium in the H2S−O2-coexisted seawater is a result of the flushing or mixing of oxygenated seawater with anoxic water. The new species of trace
metals are still in the processes of reduction and precipitation.
Contribution No. 1428 from Institute of Oceanology, Academia Sinica 相似文献
14.
《中国海洋湖沼学报》2017,(1)
Aquaculture production efficiency may increase by using feed additives. This study investigated the effects of different dietary additives [w/w: 2% small peptides, 0.01% probiotics( Bacillus licheniformis) and 0.2% prebiotics(inulin)] on growth performance, digestive enzyme activities, and oxidative stress in juvenile Epinephelus coioides reared in artificial seawater of two salt concentrations(13.5 vs. 28.5). Weight gain rate was significantly higher in fish fed the diet supplemented with small peptides, B. licheniformis, inulin, or synbiotics than that in fish fed the basal diet; the greatest weight gain rate was found in fish fed the small peptide treatment [56.0% higher than basal diet]. Higher feed efficiency was detected in fish fed the diet supplemented with small peptides than that of fish in the other dietary treatments. Total protease activity in the stomach and intestines was highest in fish fed the small peptide-treated diet, whereas lipase activity was highest in those fed synbiotics(combination of Bacillus licheniformis and inulin) than that in fish fed the other treatments. Antioxidant enzyme(total superoxide dismutase and catalase) activities and hepatic malondialdehyde content were higher in fish receiving the dietary supplements and maintained in artificial seawater containing 13.5 salinity compared with those in the control(28.5). Hepatic catalase activity in grouper fed the diets with small peptides or synbiotics decreased significantly compared with that in control fish. Overall, the three types of additives improved growth rate of juvenile grouper and digestive enzymes activities to varying degrees but did not effectively improve antioxidant capacity under low-salinity stress conditions. 相似文献
15.
Monthly investigatiom were made on the population of Chinese freshwater crab, Sinopotamon yangteskiense Bott, 1967 from April, 1984 to Match, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature. During the April to November growth period, the crabs' major development occured from June through October. One year was required for a fine white oocyte to develop into a mature egg. The reproduction period was June-October. Females bearing eggs were taken from June-August, and crabs with young were found from July-October. The females reproduced once a year but could for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from 30 to 100 eggs. New-bom crabs become mature after 1-2 yeats. The sex ratio was approximately 1:1 in the overall population. However, the larger crabs are predominantly male. The age distribution of S. yangtsekinese was estimated from size frequency histograms. There were more adult crabs 相似文献
16.
孙建中 《地球科学与环境学报》1993,(Z2)
这里所指示的大气圈、水圈、岩石圈、生物圈以及人类的作用千变万化,从而对人类的生存造成巨大影响,构成了一个复杂的生态环境,讨论这些问题,对人类生存至关重要。 相似文献
17.
Monthly investigations were mae on the population of Chinese freshwater crab,Sinopotamon yangtsekiense Bott, 1967 from April, 1984 to March, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature.
During the April to November growth period, the crabs' major development occurred from June through October. One year was
required for a fine white oocyte to develop into a mature egg. The reproduction period was June–October. Females bearing eggs
were taken from June–August, and crabs with young were found from July–October. The females reproduced once a year but could
for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from
30 to 100 eggs. New-born crabs become mature after 1–2 years. The sex ratio was approximately 1∶1 in the overall population.
However, the larger crabs are predominantly male. The age distribution ofS. yangtsekinese was estimated from size frequency histograms. There were more adult crabs (over 70%) from June to October and more immature
crabs (over 50%) from November to May. 相似文献
18.
A study was conducted on Cu, Zn, Cd, Fe, Co and Ni levels in Saanich Inlet anoxic seawaler. Data on the concentrations of these trace metals and H2S, and other oceanographic parameters were obtained in four cruisesEquilibrium models are presented together with in situ data. The" results strongly support the assumption that the solubilities of Cu, Zn, Cd, Fe, Co and Ni are controlled by bisulfide and /or polysulfide complexes. The species of Cu, Zn, Cd and Ni are shown to be Cu(S4)23- and Cu(S4S5)3-, Zn(HS)20 and ZnHS2-, Cd(HS)20 and Ni(HS)20 respectively. The solid species controlling Fe2 + and Co2+ are respectively the pyrohotites FeS and CoS. The data illustrates that thermodynamic equilibrium has been established in the H2S-controlled seawater of Saanich Inlet, and that equilibrium has not been established in the H2S-O2-coexisted seawater of Saanich Inlet. The lack of equilibrium in the H2S-O2-coexisted seawater is a result of the flushing or mixing of oxygenated seawater with anoxic water. The new s 相似文献
19.
从石漠化的研究现状出发,依据我国西南岩溶石山地区石漠化特征,着重分析其主要控制介质为岩性、构造、地貌、气候、岩溶、地下水、植被等自然介质因子与森林砍伐、高坡开垦等人为介质因子.石漠化是以岩溶山区脆弱的岩溶生态环境为基础,以内、外地质作用和人类恶性生态地质作用为驱动力,以资源退化和恶化为本质,基岩不断裸露,生态环境不断恶化,周而复始的恶性循环过程.提出对石漠化的研究重点是成因机理研究,对石漠化的防治应着重于对石漠化的驱动力及其主导因子的防治,阐述了治山必须先治水等防治对策与建议. 相似文献
20.
Plate subduction is the largest natural factory that processes elements, which controls recycling and mineralization of a variety of elements. There are three major ore deposit belts in the world: the circumPaci?c, the central Asian, and the Tethys belts. All the three belts are closely associated with plate subductions, the mechanism remains obscure. We approached this problem from systematic studies on the behaviours of elements during geologic processes. This contribution summaries the recent progress of our research group. Our results suggest that porphyry Cu deposits form through partial melting of subducted young oceanic crust under oxygen fugacities higher than ? FMQ ～+1.5, which is promoted after the elevation of atmospheric oxygen at ca. 550 Ma. Tin deposits are associated with reducing magmatic rocks formed as a consequence of slab rollback. The Neo-Tethys tectonic regime hosts more than 60% of the world's total Sn reserves. This is due to the reducing environment formed during the subduction of organic rich sediments. For the same reason, porphyry Cu deposits formed in the late stages during the closure of the Neo-Tethys Ocean. Tungsten deposits are also controlled by slab rollback, but is not so sensitive to oxygen fugacity. Subduction related W/Sn deposits are mostly accompanied by abundant accessory ?uorites due to the breakdown of phengite and apatite. Decomposition of phengite is also signi?cant for hard rock lithium deposits, whereas orogenic belt resulted from plate subduction promote the formation of Li brine deposits. Cretaceous red bed basins near the Nanling region are favorable for Li brines. Both Mo and Re are enriched in the oxidationreduction cycle during surface processes, and may get further enriched once Mo-, Re-enriched sediments are subducted and involved in magmatism. During plate subduction, Mo and Re fractionate from each other. Molybdenum is mainly hosted in porphyry Mo deposits and to a less extent, porphyry Cu-Mo deposits, whereas Re is predominantly hosted in porphyry Cu-Mo deposits and sedimentary sul?de deposits. 相似文献