中国滇西南造山带变质岩的Sm-Nd和Rb-Sr同位素年代学

滇西南造山带的主体由多期变质的岩石单元组成。变质和变形年代的确定是研究它们构造演化的关键之一。哀牢山群和大勐龙群斜长角闪岩分别得到1367Ma和1436Ma的Sm-Nb等时线年龄,这代表了高级角闪岩相的变质时代。它们的形成年龄约为2000～1600Ma。崇山群黑云斜长片麻岩获得了与此相当的1900～1600Ma的Sm-Nd模式年龄。澜沧群的蓝片岩的Sm-Nd等时线年龄为1287Ma,绿片岩的Sm-Nd模式年龄为1300～1200Ma。上述各组岩石还获得了约为1000Ma、500～400Ma、300～180Ma和180～140Ma的几组Rb-Sr等时线或Sm-Nd和Rb-Sr模式年龄,分别代表了后期重要构造事件。     

宜章县界牌岭锡多金属矿床地质特征

界牌岭锡多金属矿床产于石炭系碳酸盐岩和泥岩、碎屑岩分布区中,区内北东、北西、东西向断裂发育,有浅成相花岗斑岩体产出,岩体接触带中,高温热液蚀变作用发育,锡多金属矿体有两种产状:沿构造裂隙产出的细脉带型矿体;沿层间裂隙产出的似层状矿体。矿石中锡含量0.12—3.38％,主要为锡石,硫化锡和胶态锡只占含锡量的2.88％。     

浙江省庆元县林业资源综合开发利用

地处浙江西南部的庆元县，竹木资源丰富，森林覆盖率７１．１％，有林地面积１３．０万ｈａ，县内采取综合开发利用的措施是：建设开发基地，成立营林公司，兴办林产工业，开发“名特优新稀”产品。由此充分发挥了林区优势，取得了甚高的经济效益。１９９１年县内林业产值１．８亿元，占全县工农业总产值的１／３。     

华南燕山期两种不同矿化花岗岩类中锆石标型特征的研究

华南地区燕山期两种不同矿化花岗岩类中锆石的标型特征有较明显区别。第一类花岗岩锆石的比重、硬度、红外光谱频率均低于第二类花岗岩锆石,而晶胞常数正相反,第一类花岗岩锆石较富含W、sn、Be、Nb、U、Th REE,第二类则富含Cu、Pb;第一类花岗岩锆石表面微结构特征有熔蚀坑、裂纹呈网状、附生物形态不定,第二类则表面无熔蚀坑,裂纹和附生物均较规则等。本中探讨了锆石标型特征控制因素和形成规律。为锆石及母岩的成因物质来源、成岩成矿提供矿物学标志和信息。     

根据钻孔崩落资料确定剑川地区应力场方向

本文论述了钻孔崩落的力学机制、产生环境及其与现今构造应力场的关系,介绍了超声波井下电视的测井原理、操作技术和钻孔崩落测井资料分析方法。根据一口800米深钻孔的超声波井下电视测井获得的崩落资料,确定剑川地震活动区最大水平主应力方向为N20°E。这与近两年来在该区采用水压致裂法测定的最大水平主压应力方向N15°E是十分一致的     

数字地图符号的识别和推理验证

本文根据地图要素的形态分离结果，通过相互间几何关系与拓扑关系的建立，以图论为基础，重点论述了水深符号的识别、等深线值的自动标注和形态分离与识别结果的推理验证。     

Phanerozoic high-pressure eclogite and intermediate-pressure granulite facies metamorphism in the Gyeonggi Massif, South Korea: Implications for the eastward extension of the Dabie–Sulu continental collision zone

Petrological analysis, zircon trace element analysis and SHRIMP zircon U–Pb dating of retrogressed eclogite and garnet granulite from Bibong, Hongseong area, SW Gyeonggi Massif, South Korea provide compelling evidence for Triassic (231.4 ± 3.3 Ma) high-pressure (HP) eclogite facies (M1) metamorphisms at a peak pressure–temperature (P–T) of ca. 16.5–20.0 kb and 775–850 °C. This was followed by isothermal decompression (ITD), with a sharp decrease in pressure from 20 to 10 kb and a slight temperature rise from eclogite facies (M1) to granulite facies (M2), followed by uplift and cooling. Granitic orthogneiss surrounding the Baekdong garnet granulite and the ophiolite-related ultramafic lenticular body near Bibong records evidence for a later Silurian (418 ± 8 Ma) intermediate high-pressure (IHP) granulite facies metamorphism and a prograde P–T path with peak P–T conditions of ca. 13.5 kb and 800 °C. K–Ar ages of biotite from garnet granulites, amphibolites, and granitic orthogneisses in and around the Bibong metabasite lenticular body are 208–219 Ma, recording cooling to about 310 °C after the Early Triassic metamorphic peak. Neoproterozoic zircon cores in the retrogressed eclogite and granitic orthogneiss provide evidence that the protoliths of these rocks were  800 and  900 Ma old, respectively, similar to the ages of tectonic episodes in the Central Orogenic Belt of China. This, and the evidence for Triassic HP/UHP metamorphism in both China and Korea, is consistent with a regional tectonic link within Northeast Asia from the time of Rodinia amalgamation to Triassic continent–continent collision between the North and South China Blocks, and with an eastward extension of the Dabie–Sulu suture zone into the Hongseong area of South Korea.     

滇西北春夏连旱的环流特征分析

通过对1971~2000年云南丽江区域平均5月雨量与北半球100 hPa及500 hPa高度场的相关分析,得出影响丽江区域平均5月雨量的主要影响系统为100 hPa南亚高压5、00 hPa南海副高、孟加拉湾低值系统及中高纬度地区的新疆高压(脊),这4个关键因素的异常及强弱影响丽江5月雨量的多寡。通过对2005年5月100 hPa及500 hPa的实况场与距平场的对比分析,得出造成2005年严重春夏连旱的环流成因为南海副高偏强、孟加拉湾低值系统偏弱、南亚高压及新疆高脊偏弱,造成西南季风云团及冷空气难以在云南上空交汇而导致严重的干旱。     

原子干涉测量技术在大地测量领域中的应用分析

随着冷原子光学的发展尤其是原子干涉技术的发展，在测量重力场和定位定向等方面产生了新的方法手段，这将对大地测量领域产生很大的影响。本文首先论述了原子干涉技术的基本原理，进而阐述了原子重力梯度仪和原子干涉陀螺仪的设计结构，在此基础上分析了它在卫星重力梯度测量和惯性导航中的应用，指出利用原子干涉技术可以大大提高在上述方面的精度和可靠性。最后论述了现有原子干涉测量技术的不足和未来发展方向。     

A Generalized Markov Chain Approach for Conditional Simulation of Categorical Variables from Grid Samples

Complex categorical variables are usually classified into many classes with interclass dependencies, which conventional geostatistical methods have difficulties to incorporate. A two‐dimensional Markov chain approach has emerged recently for conditional simulation of categorical variables on line data, with the advantage of incorporating interclass dependencies. This paper extends the approach into a generalized method so that conditional simulation can be performed on grid point samples. Distant data interaction is accounted for through the transiogram – a transition probability‐based spatial measure. Experimental transiograms are estimated from samples and further fitted by mathematical models, which provide transition probabilities with continuous lags for Markov chain simulation. Simulated results conducted on two datasets of soil types show that when sufficient sample data are conditioned complex patterns of soil types can be captured and simulated realizations can reproduce transiograms with reasonable fluctuations; when data are sparse, a general pattern of major soil types still can be captured, with minor types being relatively underestimated. Therefore, at this stage the method is more suitable for cases where relatively dense samples are available. The computer algorithm can potentially deal with irregular point data with further development.