太白维山山前断裂活动特征的初步研究   总被引：1，自引：0，他引：1  

申旭辉  汪一鹏 《华北地震科学》1994,12(3):17-26

本文立足于大量的野外第一手资料，综合解剖了太白维山山前断裂的几何结构，并就其运动学特征进行了初步探讨。认为：太白维山山前断裂第四纪以来的活动表现为正断型，其几何结构和运动特征都有着相同的分段性。我们将其划分为三段，西段结构简单，晚更新世以来无明显活动；中段结构复杂，一直强烈活动；东段活动强度较低。晚更新世晚期以来断裂（中段）的平均滑动速率０．４ｍｍ／ａ，全新世以来达到０．６７ｍｍ／ａ，而且这种速率  相似文献   

1994年4－6月的全球地震动态     

吴佳翼 《国际地震动态》1994,(12)

１９９４年第二季度，全球地震活动仍维持中等水平。爪哇岛以南爪哇海沟内发生以７．２级地震为主的强震序列。南美洲接连发生深震，６月９日玻利维亚北部发生大深震，有感范围极大。大洋岛弧带地震频数占全球半数以上，本季度最大地震也发生在此。亚欧带继续维持中等水平的活动，亚欧带西段地震活动的发展需要继续监视和跟踪。  相似文献   

煤矿大口径喷射钻进技术研究     

张平占  张根志  叶礼明  耿洪州  宋毅新 《吉林大学学报(地球科学版)》1994,(4)

结合煤矿大口径施工现有条件，研究出适于低泵压情况下的喷射钻进最佳水力参数设计方法。详细介绍了设计步骤，并在实践中取得明显的经济和社会效益。它对煤炭、地质及冶金系统开展喷射钻进优化设计有重要指导意义  相似文献   

虚拟权平差在矿山大型贯通近井网设计中的应用   总被引：1，自引：0，他引：1  

覃辉  张启苏 《四川测绘》1994,17(2):70-74,53

本文将虚拟权平差法引入矿山大型贯通近井网的设计中，解决了相距甚远的两井口近井网精度基准不统一的问题，通过对一矿山大到贯通近井网的重新设计证明：该法具有良好的应用前景．  相似文献   

小像幅航空摄影中若干技术要求的研究   总被引：1，自引：0，他引：1  

宣家斌  李相华  孙和利 《武汉大学学报(信息科学版)》1994,(2)

本文系统研究了小像幅航摄资料用于小面积大比例尺地形图测绘的可能性以及实施中的技术要求，并用调制传递函数测定了小像幅航摄资料的分解力。  相似文献   

广东珠海大桥直径2m桥桩孔成孔施工实践          下载免费PDF全文

连鹿声 《探矿工程》1994,(1):16-18

在珠海大桥桥桩孔的成孔施工实践中采用了滚刀钻头、泵吸反循环工艺，施工２．０ｍ和２．２ｍ大口径桥桩孔，对施工工艺参数、水上平台作业对大口径施工机械设备的技术要求、事故处理以及滚刀钻头在软土地层中钻进的可行性等方面进行了探讨。  相似文献   

A Simulation Study of Smoothness Methods In Recovery of Regional Gravity Fields   总被引：8，自引：0，他引：8  

Peiliang Xu  Reiner Rummel 《Geophysical Journal International》1994,117(2):472-486

  相似文献   

Evolution of paleoproterozoic magmatism: Geology, geochemistry, and isotopic constraints     

E. V. Sharkov  M. M. Bogina 《Stratigraphy and Geological Correlation》2006,14(4):345-367

Evolution of tectono-magmatic processes in the Paleoproterozoic is divisible into four stages each controlled by its own type of endogenic activity. The critical moment in geological history was at the third stage onset 2.05 Ga ago, when the Archean style of evolution gave way to subsequent one. Magmas of siliceous high-Mg (boninite-like) series (SHMS) dominant during the first stage (2.5–2.3 Ga) had the mixed mantle-crust genesis. They originated in highly depleted ultramafic reservoir of asthenospheric mantle being contaminated by the Archean crustal material during ascent to the surface. Typical of the SHMS magmas were the high content of silica, Al, Mg, Cr and elevated concentrations of Ni, Co, Cu, V, PGE and incompatible elements, LREE included, while concentrations of Fe, Ti, Nb and alkalies, especially K, were at a relatively low level. Magmatism of K-granitoid type was of a limited significance. The second stage, especially its second substage (2.3–2.05 Ga), was distinct because of mass eruptions of picritic and basaltic magmas enriched in Fe, Ti, Mn, P and incompatible elements, LREE in particular, which also had elevated Cr, Ni, Co, Cu and Ba concentration being relatively depleted in Mg and Al. This change in geochemistry of magmatism was independent of tectonic processes, which retained the former style. The third stage (2.05–1.8 Ga) was marked by opening of first oceans (Jormua, Purtuniq and other ophiolites) and by formation of orogens comparable with Phanerozoic orogens that was associated with development of subduction zones and back-arc basins with relevant magmatism. High Mg, Fe, Ti, Cr, Ni, Cu, V but low Th concentrations were typical of intense picrite-basaltic volcanism marking onset of the third stage. Magmas of suprasubduction genesis had considerably higher Si, Al, P, Zn, Th concentrations and very low CaO/Al₂O₃ ratios. Development of orogens came to the end 1.82–1.80 Ga ago. Appearance of giant belts of intraplate, usually silicic high-K volcanism juxtaposed on stabilized Paleoproterozoic orogens with abnormally thick crust was confined to the fourth stage spanning besides the initial Mesoproterozoic (1.8–1.5 Ga). Anorthosite-rapakivi granitoid batholiths, which originated above mantle plume heads, corresponded to intermediate magma chambers of relevant magmatic systems. As is suggested, juvenile basaltic melts of this stage retained within the crust provoking a large-scale melting of sialic material. The high K, Ti, Zn, Pb, Zr and elevated Be, Sn, Y, Nb, Rb, F, W, Mo, Li and U contents characterized geochemistry of magmas, which originated at the fourth stage  相似文献   

江西张十八大型铅-锌矿床地质特征     

高文亮  许建华  肖锷  詹国年 《矿产与地质》2006,20(4):383-388

张十八铅-锌矿床是赣北地区新探明的大型铅-锌-银隐伏矿床，总结其矿床地质特征，提高对其矿床成因及其控矿因素的认识，对指导今后类似隐伏矿床的找矿具有重要意义。文章在对该矿床的成矿地质背景、矿区地质特征认识的基础上，着重研究了矿体特征、矿石特征及矿床硫同位素特征。初步研究认为，其成矿元素来源于深部隐伏花岗岩，矿床成因属岩浆期后中温热液交代矿床，并根据控矿因素，以三种控制条件以及Pb、Zn、Cu、Sn综合化探异常作为该矿床的直接找矿标志。  相似文献   

峨眉山大火成岩省Cu-Ni-PGE成矿作用——几个典型矿床岩石地球化学特征的分析   总被引：2，自引：0，他引：2  

陶琰  胡瑞忠  王兴阵  朱丹  宋谢炎  冯家毅 《矿物岩石地球化学通报》2006,25(3):236-244

峨眉山大火成岩省岩浆型Cu-Ni-PGE矿化岩体广泛分布,构成峨眉山地幔柱成矿系统中一个非常重要的成矿系列。本文剖析了峨眉山大火成岩省该类矿床的分布及部分典型矿床的地质地球化学特征和矿化特征,揭示了成矿岩体统一的地幔柱成因,阐述了Cu-Ni-PGE成矿作用与峨眉山地幔柱岩浆活动体系的关系,探讨了由于岩浆演化过程及硫化物熔离富集过程的差异所导致的矿化类型变异。指出Cu-Ni-PGE矿床成矿岩体原始岩浆为地幔柱高程度熔融的高镁玄武岩浆,成矿岩体与峨眉山低钛玄武岩同源,矿化岩体主要产于峨眉山地幔柱活动模型的内带低钛玄武岩分布区;金宝山、朱布、力马河、杨柳坪矿床分别代表峨眉山地幔柱Cu-Ni-PGE成矿作用不同成矿机制的端员类型。  相似文献