航海传统的延续——风帆训练舰

现在有24个国家的海军拥有风帆训练舰。保留风帆训练舰的国家主要集中在注重航海传统的欧洲和美洲。对于中国海军来说,风帆训练舰并不陌生,各国海军访华时常常就有风帆训练舰。现在有24个国家的海军拥有风帆训练舰。最新加入这个"风帆训练舰俱乐部"的国家是巴基斯坦。     

巴基斯坦达什特卡恩斑岩型铜矿地质特征及找矿潜力

达什特卡恩斑岩型铜矿位于巴基斯坦查盖斑岩型铜矿带北端的阿富汗-巴基斯坦边境上,迄今为止,矿区内已发现有两个规模很大的铜矿化体。笔者在以往勘查资料和野外地质找矿工作的基础上,对成矿地质背景、矿床地质特征、矿床地球化学和地球物理特征及找矿潜力进行了初步分析。矿区出露东西两个矿化体,主要与两个英云闪长斑岩岩株以及一个侵入角砾岩管有关;斑岩体中蚀变以钾化和绢英岩化为主,泥化较弱,青磐岩化分布在蚀变带最外围。氧化矿石矿物以孔雀石和硅孔雀石为主,次生矿石矿物以辉铜矿和铜蓝为主,原生矿石矿物以黄铜矿和斑铜矿为主。1∶1万土壤地球化学测量显示西部矿化体铜元素异常面积约0.45 km2,平均值482.97×10-6,东部角砾岩矿化体异常面积约0.32 km2,平均值2238×10-6,矿区钼含量平均值为21×10-6,经调查铜异常为矿致异常。激发极化法测量显示西部异常范围小,电阻率很低,在45~90 m范围内可能是含硫化物所致,而东部异常范围大,电阻率低,经查证与热液侵入角砾岩管有关。在西部矿化体施工了3个钻孔进行异常查证,结果显示铜平均含量0.079%~0.28%。经分析研究认为,在达什特卡恩深部具有良好的找矿前景。     

Seismic Hazard Assessment of District Mansehra,Khyber Pakhtoonkhawa,Pakistan

The site of Mansehra is located seismically in an active regime, known as the Crystalline Nappe Zone and Hazara-Kashmir Syntaxis in NW Himalayas, Pakistan. Seismic Hazard Assessment （SHA） for the site has been carried out by considering the earthquake source zones, selection of appropriate attenuation equations, near fault effects and maximum potential magnitude estimation. The Mansehra Thrust, Oghi Fault, Banna Thrust, Balakot Shear Zone, Main Boundary Thrust, Panjal Thrust, Jhelum Fault and Muzaffarabad Fault and, further to the south, the Sanghargali, Nathiagali, and Thandiani Thrusts are the most critical tectonic features within the 50 km radius of Mansehra. Using the available instrumental seismological data from 1904 to 2007, SHA has been carried out. Other reactivated critical tectonic features in the area have been investigated. Among them the Balakot-Bagh fault, with the fault length of 120 km from Balakot to Poonch, has been considered as the most critical tectonic feature on the basis of geological/structural/seismological data. The potential earthquake of maximum magnitude 7.8 has been assigned to the Balakot-Bagh fault using four regression relations. The peak ground acceleration value of 0.25 g （10% probability of exceedance for 50 years） and 0.5 g has been calculated with the help of the attenuation equation using probabilistic and deterministic approaches.     

2013年巴基斯坦Mw7.7地震震源参数特征及烈度分布估计

2013年9月24日巴基斯坦中南部发生Mw7.7地震,震中位于巴基斯坦阿瓦兰县北部69 km处,发震断层为走滑断层机制,极震区烈度达到Ⅸ度以上.我们计算了巴基斯坦地震的视应力、应力降等震源参数,明确该地震为断层动态摩擦过程中的应力上调模式;进一步选取发震断层面上滑动位移的反演结果,构建有限断层模型,对近断层区域的强地面运动进行估算,并基于强地面运动模拟结果给出震区的烈度分布图.结果显示,模拟的巴基斯坦地震烈度图极震区烈度达到Ⅸ度,Ⅶ度烈度影响范围与美国地质调查局震后给出的震动图(ShakeMap)较为一致.强烈地震发生后,基于强地面运动模拟计算给出的烈度分布情况具备较好的合理性,对震区给出及时的震情判定和开展相应的救灾工作具有较高的实际价值.     

2013年巴基斯坦7.7级地震与兴都库什的地震构造

针对2013年9月巴基斯坦7.7级地震活动过程的基本资料,就其构造环境、地震活动背景,以及地震的成因,进行了广泛的研究和讨论。研究结果表明,巴基斯坦7.7级地震是在东半球总体呈顺时针旋转的背景下形成兴都库什逆时针旋扭运动,从而致使Chaman断裂左行继承性活动而造成的,其深层次的原因是兴都库什地震柱活动的能量累积与控制,或有深部流体的参与,而致流体(气体或液体)的上涌与地表断层的错动并发。     

巴基斯坦北部前陆地区的扭曲断裂作用

Ｋｏｈａｔ高原位于巴基斯坦北部前陆。通过地震、重力、磁力资料的采集、处理及解释,并结合详细的地质图件对该区的构造模式进行了重新解释。采集的地质、地球物理资料的解释结果,以及对以前采集的数据和区域地质的结果表明,Ｋｏｈａｔ高原经历了多幕平移断裂作用、与基岩有关的逆断裂作用及小规模的逆掩断裂作用。这一解释与以前那种只存在南向的逆掩断裂作用的解释模式有所不同。地震资料进行重新解释的关键在于叠前深度偏移（     

Greenhouse Gas Emissions from Agro-Ecosystems and Their Contribution to Environmental Change in the Indus Basin of Pakistan

There is growing concern that increasing concentrations of greenhouse gases in the atmosphere have been responsible for global warming through their effect on radiation balance and temperature. The magnitude of emissions and the relative importance of different sources vary widely, regionally and locally. The Indus Basin of Pakistan is the food basket of the country and agricultural activities are vulnerable to the effects of global warming due to accelerated emissions of GHGs. Many developments have taken place in the agricultural sector of Pakistan in recent decades in the background of the changing role of the government and the encouragement of the private sector for investment in new ventures. These interventions have considerable GHG emission potential. Unfortunately, no published information is currently available on GHG concentrations in the Indus Basin to assess their magnitude and emission trends. The present study is an attempt to estimate GHG （CO2, CH4 and N2O） emissions arising from different agro-ecosystems of Indus Basin. The GHGs were estimated mostly using the IPCC Guidelines and data from the published literature. The results showed that CH4 emissions were the highest （4.126 Tg yr^-1） followed by N20 （0.265 Tg yr^-1） and CO2 （52.6 Tg yr^-1）. The sources of CH4 are enteric fermentation, rice cultivation and cultivation of other crops. N2O is formed by microbial denitrification of NO3 produced from applied fertilizer-N on cropped soils or by mineralization of native organic matter on fallow soils. CO2 is formed by the burning of plant residue and by soil respiration due to the decomposition of soil organic matter.     

巴基斯坦喜马拉雅以板块运动速度剥露的超高压榴辉岩

超高压榴辉岩产于全球许多造山带。这类岩石在俯冲和/或陆陆碰撞早期随陆壳的迁移形成于大于100km的深处。高压榴辉岩始见于巴基斯坦喜马拉雅和拉达克喜马拉雅,这两处均位于印度缝合带以南的印度板块北缘(即主地幔断层,MMT)。前者的温压条件为650±50℃和13~18kbar。Sm-Nd石榴子石-单斜辉石年龄显示的变质高峰期为49±6Ma,Rb-Sr多硅白云母和U-Pb金红石年龄揭示的冷却时间分别为43±1Ma和39~40Ma。后者温压条件为550±50℃和20±3kbar。变质作用高峰期为55±12Ma(Lu-Hf法;石榴子石-单斜辉石-金红石)、55±17Ma(U-Pb褐帘石)和55±7Ma(…     

巴基斯坦雷克迪克斑岩型Cu Au矿集区典型矿床闪长岩Pb、Sr、Nd同位素组成特征及其示踪意义

雷克迪克斑岩型Cu-Au矿集区是巴基斯坦最重要的斑岩型Cu-Au矿产地之一,发育20个斑岩型Cu-Au矿床(点),其中包括世界级的H14、H15矿床。本文在前人研究基础上重新分析探讨了Pb、Sr、Nd同位素的组成特征,计算了铅同位素的H-H单阶段演化模式年龄,以及Pb、Sr、Nd同位素的μ、ω、Th/U、△α、△β、εSr、εNd等重要参数。研究结果表明,雷克迪克矿集区成矿物质主要来源于受岩浆作用控制的壳幔混合物质,是新特提斯洋岩石圈俯冲及再循环或幔源岩浆注入地壳的结果。该矿集区的含矿斑岩可能是在岛弧碰撞造山带演化过程中伴随着特提斯构造域的演化而形成的,属于洋壳俯冲消减和大陆碰撞过程中导致地壳增生加厚的结果,它们与扬子地块具有亲缘关系,属于特提斯构造区,构成了特提斯构造域多岛洋体系的组成部分之一。该矿集区的铅主要为混入了放射性成因Pb的混合铅,具有典型DUPAL异常的特征。其中,异常铅(放射性铅)来源于富含U、Th的上地壳物质,而DUPAL异常可能直接产生于欧亚大陆南缘EMII与DM的混合源区,并以异常铅的形式表现出来。