矿产开发与环境保护

通过国内多个矿区实例，较系统地叙述了矿产资源开发导致的生态环境破坏和污染状况。表明矿产开发中对环境污染的途径包括河流、土壤、等。最后简要介绍了国内、国外几种对采矿污染比较有效的防治措施。     

Isotopic Characteristics and Key Factors Favoring the Formation of Fuwan Super-large Silver Deposit in Guangdong Province

Rb-Sr isochron age of fluid inclusions in quartz from the Fuwan super-large silver deposit is 68 - 6 Ma, the silver deposit is characterized by high μ values (10.67 - 10.95 ), which are much higher than those of the ore-hosted Paleozoic strata and are close to those of ores hosted in the Proterozoic metamorphic basement in western Guangdong Province. Based on the Pb isotopic characteristics, coupled with much high background silver contents (200-1000ng/g) in the Proterozoic basement and relatively low silver contents in the Paleozoic strata in the region of the Sanshui Basin, it is concluded that the ore-forming material of the super-large silver deposit came mainly from the old basement. The super-large silver deposit related genetically to the intense volcanic activities during the Upper Cretaceous to Eogene. The formation of the Fuwan super-large silver deposit is controlled by the following favorable geological conditions : ( 1 ) The intersection of deep faults and contemporaneous faults at the margin of the Sanshui Basin led to the formation of an excellent structure as passageway for ore fluids; (2) The special ore-hosted rock association forms a ore gathering-trap structure that favors the precipitation of ore; (3) The silver-rich old basement, multi-stage mineralization and multi-episode volcanic activities which constitute a geothermal convection system.     

1948—2001年全球大尺度区域 6～8月降水的长期变化

研究了1948-2001年南、北半球及欧亚大陆、非洲大陆、澳洲大陆、北美大陆、南美大陆、南极大陆和中国 7个大尺度区域 6～8月降水的长期趋势变化和年代际变化。结果表明，南、北半球 6～8月的降水都为负趋势，但南半球降水的负趋势在统计上不显著。在54年的时间段内，南半球 6～8月降水的递减速度为 0．12 mm／a，仅为北半球同期降水减幅（0．24 mm／a）的一半。南、北半球 6～8月降水量年代际尺度的振荡都非常明显，但是，南、北半球年代际变化的特征明显不同。目前北半球仍是在少雨时间段，而南半球处在降水量正常或多雨的时间段。分析还表明，非洲大陆 6～ 8月降水的年代际特征最明显，降水的负趋势也最为显著；欧亚大陆 6～8月降水也有着明显的年代际变化与明显的负趋势变化；澳洲大陆 6～8月降水的年际变化明显，年代际变化相对来说要小得多；北美大陆 6～8月降水的年际变化明显，但无明显的趋势变化。此外，分析了大尺度区域 6～ 8月降水之间的相关关系，发现部分区域大尺度降水量之间有明显的联系；分析了中国夏季降水的长期变化，发现中国夏季降水的年代际变化明显，但无明显的趋势变化。     

The Rotational Structure along the Eastern Segment of the Altyn Tagh Fault and Its Implications in Dynamics

As a result of the left-lateral strike-slipping of the Altyn Tagh fault in Neotectonic period, a contra-rotational structure, namely the Zhaobishan vortex structure, has developed at the juncture of the main Altyn Tagh fault and the northern fringe fault of the Qilian Mountains.Preliminary analysis on the deformation and evolution of the Zhaobishan vortex structure. In combination with the previous data, suggests that the tectonic transform between the Altyn Tagh fault and the northern fringe fault of the Qilian Mountains attributes to the deformation of the rotational structure. The existence of a series of rotational structures along the Altyn Tagh fault and on the northeastern edge of the Qinghai-Xizang(Tibet) plateau indicate that as the substance in the northern Qinghal-Xizang (Tibet) plateau moves clockwise around the eastern tectonic knot of the Himalayas, rotational structures become the principal mode on the northern marginal zone of the Plateau of transforming and absorbing tectonic deformation.     

天山山区近40a年降水变化特征与南、北疆的比较

本文分析了天山山区近40 a来年降水变化的基本特征，并与南疆、北疆进行了比较，所得的主要结果如下：(1)天山山区在年降水量干湿变化阶段上与北疆的相似性强于南疆。(2)年降水量的空间分布的同步变化性以北疆为最好，南疆最差，天山山区居中，而年降水量的空间分布的反向变化性，以天山山区为最大，北疆最小，南疆居中。(3)天山山区与南疆从60年代到90年代，年降水均表现出了持续的增加的趋势，北疆年降水从60年代到90年代，除70年代外，不断增多。     

粤北笋洞花岗岩的形成时代、地球化学特征与成因

笋洞花岗岩体是粤北贵东复式花岗岩体的一个重要组成部分。锆石U-Pb年龄为189.1±0.7Ma,是燕山早期岩浆活动产物。该岩体的主要元素显示富硅、富碱、强过铝质和低 CaO/Na_2O比值等特征;微量元素方面,富集Rb,Th,U,Ce,Sm,Y,亏损 Ba,Sr,P,Ti;LREE轻微富集(LREE/HREE=6.6～8.8,(La/Yb)_N=6.44～10.74),Eu亏损明显(δEu=0.14～0.31);它具有低的ε_(Nd)(t)(-11.4～-9.3),高的δ~(18)O(10.2～12.7‰)、(~(87)Sr/~(86)Sr);(0.72949～0.74923)、~(206)Pb/~(204)Pb(18.180～18.488)、~(207)Pb/~(204)Pb(15.655～15.661)和古老的Nd模式年龄(1762～1933Ma)。上述这些特征表明,笋洞岩体属于典型的壳源型花岗岩,是在地壳伸展-减薄的构造背景下,通过以泥质成分为主的古-中元古代变质沉积岩部分熔融的方式形成。     

A relationship between red tide outbreaks and urban development along the coasts of Guangdong Province

Red tides are one of the main coastal catastrophic events in Guangdong Province of southern China. The comparison between the number of red tide events and the development indexes of cities along the coasts of the province shows that the regional differences in red tide outbreaks has close relations with the coastal urban developments. The cause for an initiation of red tide blooms may be natural factors, while wastewater caused by the fast development of population, industry and aquiculture of the coastal cities enhanced the blooms. It may explain why the two periods of frequent outbreaks of the red tides over the last two decades matched the urban developments in the coastal areas of Guangdong not only spatially but also temporally. The red tides in the first period were restricted only to the coasts of middle Guangdong, where urbanization process was at a higher speed than the other coastal areas of the province. In the second period, fast development of the coastal cities in eastern Guangdong led to an increase in the occurrence of red tides in local sea areas of the same coasts.     

晋北区中小地震活动与晋冀蒙交界区6级地震的关系

分析了晋北区中小地震(3.0≤ML≤5.0)的活动特征。统计发现,在1989 年山西大同-阳高6.1、1996年内蒙包头6.4和1998年河北张北6.2 级中强地震前1~2 年内晋北地区的中小地震活动年频次有明显的增强-衰减-发震这一特征;震前主震近场区的地震条带活动对主震位置有预示意义,而较远场的地震活动仅反映主震前应力水平的增强。并有震前活动向未来强震区靠近的特征。     

An approach for quantifying geomorphological impacts for EIA of transportation infrastructures: a case study in northern Spain

A methodological proposal for the assessment of impacts due to linear infrastructures such as motorways, railways, etc. is presented. The approach proposed includes a series of specific issues to be addressed for each geomorphological feature analysed—both ‘static’ and ‘dynamic’—as well as a series of steps to be followed in the process.Geomorphic characteristics potentially affected were initially identified on the basis of a conceptual activities/impacts model that helps to single out geomorphic impacts related to environmental concerns for the area. The following issues were addressed for each individual impact: nature of potential effects; indicators that can be used to measure impacts; criteria of ‘geomorphologic performance’; procedure for measurement/prediction of changes; translation of geomorphologic impacts into significant terms from the viewpoint of human concerns; possible mitigation and/or compensation measures.The procedure has been applied to a case study corresponding to a new motorway in the Basque Country, northern Spain. Geomorphological impacts considered in this analysis included: (1) consumable resources; (2) sites of geomorphological interest; (3) land units with high potential for use, high productivity or value for conservation; (4) visual landscape; (5) slope instability processes. The procedure has been designed for implementation in a Geographic Information System (GIS) environment. Details are given on the application of the method to each individual impact analysed and results are presented in both numerical and map form.Impacts assessed were initially expressed by means of heterogeneous magnitudes, depending on the geomorphological feature considered. Those geomorphological impacts were then translated into significant terms and homogeneous magnitudes. Integration was carried out on the basis of impact values thus obtained. Final integrated results were also expressed in numerical and map form.The method proposed enables comparison of alternatives as well as ‘prediction’ and assessment of impacts in terms directly related to geomorphic characteristics. It also facilitates the expression of those impacts in terms that allow integration with other types of environmental impacts.     

Late Quaternary systematic stream offsets caused by repeated large seismic events along the Kunlun fault, northern Tibet

The Kunlun fault is one of the largest strike-slip faults in northern Tibet, China. In this paper, we focus upon the Kusai Lake–Kunlun Pass segment of the fault to understand the geomorphic development of offset streams caused by repeated large seismic events, based on tectono-geomorphic analysis of high-resolution satellite remote sensing images combined with field studies. The results indicate that systematic left-lateral stream offsets appear at various scales across the fault zone: Lateral offsets of small gullies caused by the 2001 M_w 7.8 Kunlun earthquake vary typically from 3 m to 6 m, meanwhile streams with cumulative offsets of 10 m, 25–30 m, 50–70 m, 250–300 m and 750–1400 m have resulted from repeated large seismic events during the late Quaternary. An average slip rate of 10 ± 1 mm/year has been estimated from the lateral stream offsets and ¹⁴C ages of alluvial fan surfaces incised by the streams. A three-dimensional model showing tectono-geomorphic features along a left-lateral strike-slip fault is also presented. The Kusai Lake–Kunlun Pass segment provides an opportunity to understand the relationship between geomorphic features produced by individual large seismic events and long-term geomorphic development caused by repeated large seismic events along a major strike-slip fault.