根据地图数字化点的位置生成ASCⅡ文件的程序——GSDIG     

GI Selner  RB Taylor  徐双  傅祥麟 《华东地质学院学报》1991,(3)

0 引言GSDIG3.0版本是一个利用数字化仪,从地图图件上取点,产生包括每个点的标号和坐标的ASCII文件的程序。坐标系可以是笛卡尔坐标或GSDIG支持的(与GSMAP6.0相同)大地测量坐标。生成的数据格式用于表格式实用程序(例如LOTUS-1,2,3)、数据库管理系统或GSMAP/GSDRAW程序。利用同一发布盘上的实用程序DIGGSM,可以把其中的大地测量坐标的数据直接转换为GSMAP的数据库。另一实用程序DIGGSD提供类似的功能,即将X,  相似文献   

南岭地区万洋山岩体锆石LA-ICP-MS U-Pb年龄和地球化学特征及其构造意义     

季文兵  路远发  付建明  程顺波  卢友月 《地质论评》2016,62(5):1329-1343

万洋山岩体位于湘赣两省交界地带,为加里东期多阶段岩浆活动的复式岩体,花岗岩主要岩石类型有黑云母二长花岗岩、黑云母花岗闪长岩和二云母二长花岗岩,以黑云母二长花岗岩分布面积最广。对岩体中黑云母二长花岗岩中的锆石样品进行激光剥蚀—多接收器电感耦合等离子体质谱(LA-ICP-MS)U-Pb定年,锆石的16个测点206Pb/238U的加权平均年龄为(446.0±3.4)Ma(n=16,MSWD=0.15)(95%置信度),反映该岩体形成于晚奥陶世至早志留世。岩石地球化学表明岩体中Si O2的含量为65.91%~73.35%,K2O的平均含量为4.20%,Na2O+K2O为5.90%~7.88%,K2O/Na2O平均值为1.64,Al2O3平均值为13.81%,ASI平均值为1.09%,总体属于高钾钙碱性过铝质花岗岩。微量元素组成中Ba、K、Sr、P、Ti表现出明显的亏损,Rb、Th、U、Nb、Zr、Hf等则相对富集,稀土元素总量中等(159.71×10-6~262.78×10-6),轻稀土富集LREE/HREE=6.16~10.01,(La/Yb)N=6.37~12.17,具明显的负Eu异常(δEu=0.30~0.59)。岩体的[n(87Sr)/n(86Sr)]i值为0.71223~0.72509,εSr(t)值为117.5~299.9Ma,εNd(t)值为-9.39~-7.30,两阶段Nd模式年龄(TDM2)为1.77~1.94 Ga。根据上述岩石地球化学特征表明万洋山岩体为来源于地壳的S型花岗岩,花岗岩氧化物和微量元素构造环境判别图解指示岩体形成于后碰撞构造环境。结合前人对华南加里东期岩体的研究成果,推断华南加里东期花岗岩岩体的具体形成机制为:在全球板块构造的影响,华夏板块与扬子板块拼接后,板块间的强烈挤压应力相对松弛、压力降低的后碰撞构造环境下,因地壳增厚而升温的中上地壳岩石减压熔融并向上侵位。  相似文献   

Factors affecting the distribution of benthic macrofauna in estuaries contaminated by urban runoff     

Morrisey DJ  Turner SJ  Mills GN  Williamson RB  Wise BE 《Marine environmental research》2003,55(2):113-136

Contaminants derived from urban runoff have been shown to accumulate in estuarine sediments, reaching concentrations potentially capable of causing biological effects. Demonstration of effects, however, is difficult due to strong natural environmental gradients and the effects of past or present point-sources of contamination. We used multivariate methods to test two hypotheses relating to the effects of urban-derived contaminants on estuarine benthic communities. First, that patterns of distribution and abundance of benthic invertebrates in two urbanised estuaries would be different from those in two non-urbanised estuaries. Second, that the distributions of benthic invertebrates within and among the four estuaries would be related to those of urban-derived contaminants. Concentrations of contaminants were larger in estuaries with urbanised catchments and concentrations of Cu, Pb, Zn and DDT in some samples exceeded those at which biological effects may be expected to appear. Tests of differences in composition of benthic communities among estuaries showed that the two urban estuaries were not significantly different, but that they differed from both rural estuaries, which also differed from each other. Distributions of benthic invertebrates were significantly related to those of environmental variables, and were ordinated along axes that correlated with both natural environmental variables (nature of the sediment, position in estuary) and contaminants. Differences in faunas between the urban and non-urban estuaries were not, however, clear-cut and nor were relationships between faunal assemblages and environmental variables (including contaminants) consistent between two times of sampling.  相似文献   

The 1974 spill of the Bouchard 65 oil barge: petroleum hydrocarbons persist in Winsor Cove salt marsh sediments     

Peacock EE  Hampson GR  Nelson RK  Xu L  Frysinger GS  Gaines RB  Farrington JW  Tripp BW  Reddy CM 《Marine pollution bulletin》2007,54(2):214-225

Petroleum hydrocarbons persist in salt marsh sediments in Winsor Cove (Buzzards Bay, Massachusetts) impacted from the 1974 spill of No. 2 fuel oil by the barge Bouchard 65. Intertidal sediment cores were collected from 2001 to 2005 and analyzed for total petroleum hydrocarbons (TPHs). TPHs content was greatest (as high as 8.7 mg g(-1) dry weight) in the surface sediments and decreased with distance landward. Select samples were analyzed for polycyclic aromatic hydrocarbons (PAHs) with values as high as 16.7 microg g(-1) for total naphthalenes and phenanthrenes/anthracenes. These remaining PAHs are mainly C(4)-naphthalenes and C(1)-, C(2)-, and C(3)-phenanthrenes/anthracenes revealing preferential loss of almost all of the naphthalenes and the parent compound phenanthrene. Inspection of the data indicates that biodegradation, water-washing and evaporation were major removal processes for many of the petroleum hydrocarbons in the marsh sediments. In addition, historical data and photographs combined with their recent counterparts indicate that erosion has physically removed these contaminants from this site.  相似文献   

巴西戈亚斯州玛丽亚拉扎拉太古代金矿床的多阶段矿化特征     

Miche  D 路远发 《国外花岗岩类地质与矿产》1995,(2):19-23

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水库与地震     

Meade  RB 司富安 《地震地质译丛》1993,15(6):1-8

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宾夕法尼亚纪煤中植物大化石的鉴定     

Wins.  RB 方爱民 《川煤地勘》1994,(11):71-75

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估算待发现铀矿床的矿床规模频率法     

McCa.  RB 尉成臣 《世界地质》1994,13(2):123-127

矿床规模频率法（ＤＳＦ）是“国家铀矿资源评价（ＮＵＲＥ）”项目中用于估算美国铀矿资源量方法的进一步归纳和总结。ＤＳＦ解决了ＮＵＲＥ项目中进行下述主观概率估算的难题：（１）有利于铀矿床产出的成矿有利区占研究区的比例（因子Ｆ）；（２）成矿有利区中单位面积岩石吨数（因子Ｔ）。由于几乎所有地质学家对因子Ｆ和Ｔ的量度都不熟悉，大多数工作者只能估算出成矿有利区可能产出的铀矿床的数目及它们的平均规模。ＤＳＦ把因子Ｆ和因子Ｔ合并为成矿有利区内待发现铀矿的单位面积岩石吨数因子（Ｆ＊Ｔ）。这样，地质学家所提供的因子Ｆ·Ｔ就是特定矿床规模分类中单位面积内待发现矿床的估算数目。矿床规模分类的数目及每类规模间距是以已知（控制）区内的矿床资料为基础的。与ＮＵＲＥ法相比，ＤＳＦ法在主观估算中涉及范围更广，并且更多地突出了勘探工作者的日常经验。利用ＤＳＦ法对华盛顿州和爱达荷州的时代新、富含有机质的在生铀矿及亚利桑那州的大峡谷和附近犹他们等地区的溶蚀滑塌角砾岩筒型铀矿进行了重新评价。  相似文献   

南岭地区产于碳酸盐岩中铅锌矿床的成因   总被引：2，自引：0，他引：2  

路远发 《湖南地质》1993,12(1):23-28

根据南岭地区产于碳酸盐岩中铅锌矿床的实际资料,按成矿物质来源将本区铅锌矿床划分为岩浆源铅锌矿床(I)和和地层源铅锌矿床(Ⅱ)两类。重点讨论了铅、硫同位素地球化学特征在判别矿床成因方面的应用。首次提出了(~(207)pb/~(204)pb)_u。参数及其与成矿物质来源的关系。讨论了不同成因类型铅锌矿床的成矿条件,指出上古生界(D—P)的含水性是成矿过程中具有特殊地位的关键因素之一。  相似文献   

The potential listing of Acropora species under the US Endangered Species Act     

Precht WF  Robbart ML  Aronson RB 《Marine pollution bulletin》2004,49(7-8):534-536

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