电阻率剖面法探测深度的研究

在考虑了异常体的形态、异常体和围岩的电性差异、供电极和接收极测量误差、供电电流误差、仪器测量精度,以及外界干扰等因素的基础上,提出了用电位异常来描述电阻率剖面法中探测深度的定义。通过编程,计算得到各向同性均匀半空间中球体异常,在电阻率剖面法中的电位异常,得出在特定条件下的探测深度。定量分析了联合剖面法中探测深度与电极距AO、供电电流和外界干扰的关系。制作并完成了软件的各种正演计算,可以为电阻率剖面法野外施工前的电极距大小、供电电流的设计等提供参考。     

基于剖面声呐的海底微地貌观测研究*

海底地貌是海水覆盖下的固体地球表面形态的总称。海底地貌巨变往往与海底地质灾害息息相关,会对海底管线和海上平台等海洋工程设施造成危害,因而对海底地貌进行原位观测具有重要意义。本研究基于前人研究成果和团队常年自主研发仪器经验,研制出了剖面声呐海底微地貌原位观测系统,详细介绍了观测系统的组成、功能、工作原理和工作模式,并提出了观测数据的处理分析方法;然后,使用观测系统进行了标志物检验实验,通过将观测系统测量数据与其他设备测量数据相对比,验证了观测系统的可行性和数据准确性;最后,使用观测系统在舟山海域朱家尖滑坡区进行原位观测,进一步验证了观测系统的可行性。观测结果进一步表明剖面声呐观测系统可以用于海底微地貌的观测研究。     

Geophysical profiling across the Sulu ultra-high-pressure metamorphic belt, eastern China

The largest ultra-high pressure metamorphic (UHPM) belt in the world is located along the Dabie–Sulu region, which tectonically belongs to the east part of the central orogenic belt of China. Integrated geophysical investigations of using deep seismic reflection, MT, and geothermal observations have been carried out in the Sulu area since 1997. The results of integrated interpretation suggest the existence of three features: (1) a rift beneath the Lianshui basin by the Jiashan–Xionshui fault; (2) a special crustal pattern, called the magmatic multi-arch structure occurs beneath the northern Sulu UHPM zone; and (3) a northwest-dipping regional thrust crosses the Sulu crust, representing the intracontinental subduction of the Yangtze craton beneath the Sulu metamorphic belts after collision between the Yangtze and Sino-Korean cratons. A magmatic multi-arch structure consists of some arched reflectors that occur in both the lower and the upper crust where arched reflectors coincide with granitoid plutons. The multi-arch structures are common in eastern China where many Mesozoic granitoid plutons of different scales occur. The crustal structures in the Sulu metamorphic belts resulted from intensive dynamic processes following the Triassic collision between the Yangtze and Sino-Korean cratons. The formation and exhumation of UHPM rocks followed the collision, and then intracontinental subduction of the Yangtze craton beneath the Dabie–Sulu terranes took place in the early and middle Jurassic. In the late Jurassic, the Sulu lithosphere turned to an extensional regime, large-scale granitic intrusions occurred in eastern China; these likely resulted from lithospheric thinning and asthenospheric uplifting. The granitic intrusions came to a climax during the Cretaceous and were followed by rifting along existing faults in the early Eogene, resulting in many petroleum basins. The granitoid emplacement that generated the magmatic multi-arch structure and the rift were consequences of the lithospheric thinning process, and deep intracontinental subduction of the Yangtze craton beneath the Sulu metamorphic belt might partially contribute to the lithospheric thinning.     

Structure of the Cobar Basin,New South Wales,based on seismic reflection profiling

The Cobar Basin in central western New South Wales is a mineral‐rich Early Devonian basin typical of those that characterize the Siluro‐Devonian history of the Lachlan Orogen of southeastern Australia. One hundred and seventy kilometres of seismic profiling in three lines across the basin have shown it to be asymmetrical in shape with an east‐dipping western margin that is steeper than the moderately west‐dipping eastern margin. Maximum basin thickness is around 6 km, but there are significant thickness changes, especially from south to north, which reflect the effect of synsedimentary faulting. Seismic profiling suggests that the basin deformed by thin‐skinned tectonics; postulated strike‐slip effects were not visible on the sections. The seismic profiling has, for the first time, imaged the western synrift basin margin which is generally not exposed. Strain variations during deformation along this edge were taken up by the formation of a major jog ('dog‐leg') which has propagated into the basin as a tear fault. Intrabasinal tears, as well as thrusts, which link into one or more detachments, provide potential pathways for mineralizing fluids during basin inversion.     

DGPS方法在新构造研究中的应用探讨

DGPS方法是一种小区域范围内(≤20km)精确测量的有效手段,已在许多领域和地点得到应用。但是,由于地质科学研究的独特性,高精度的测量还缺乏有效的应用。近年来,随着新构造定量研究的逐步深入,如何定性或定量评价新构造时期弱活动区断裂的活动性、盆地内隐伏断裂的活动性、冲断带内的盲断层及其相关褶皱活动性等问题日渐明显。为了解决这些问题,一些新的方法和手段得到尝试和应用。运用DGPS方法可以获得精确的层状地质地貌面数据,通过数据分析,可以得到新构造时期不同时间尺度内构造演化过程。文中以近几年的应用实例为基础,系统介绍DGPS测线的设计、野外操作注意事项、精度分析和数据处理等过程。同时分析新构造时期三种时间尺度内的研究成果,认为DGPS方法获得的数据精度满足地质地貌调查和对比的要求,从而为在弱活动区内或盆地内部等不利条件下定量评价断裂的活动性提供有利的手段。     

Environmental justice as subtext or omission: Examining discourses of anti-incineration campaigning in Ireland

The incineration of waste is a controversial issue marked by a history of opposition from community groups and environmentalists around the globe. Opponents, particularly in the USA, have frequently adopted a discourse of environmental justice to challenge the legitimacy of incineration. In line with these broad geographies of resistance recent proposals to introduce municipal solid waste incinerators in Ireland have sparked a series of opposition campaigns. However an examination of the discourses of resistance adopted by campaigners in one specific site of resistance, the Galway region on the west coast of Ireland, indicates that the vocabulary of environmental justice has not been publicly articulated. This paper investigates this absence of environmental justice in the language of opposition. The research reveals an interwoven set of contingent conditions that conspire to inhibit the adoption of environmental justice discourses in Ireland. However these conditions are not static and a combination of pressures, both within and beyond Ireland, are creating a dynamic context that could promote the emergence of environmental justice discourses in the future.     

Orogenic structure of the Eastern Alps, Europe, from TRANSALP deep seismic reflection profiling

The TRANSALP Group, comprising of partner institutions from Italy, Austria and Germany, acquired data on a 340 km long deep seismic reflection line crossing the Eastern Alps between Munich and Venice. Although the field work was split into four campaigns, between fall 1998 and summer 2001, the project gathered for the first time a continuous profile across the Alps using consistent field acquisition and data processing parameters. These sections span the orogen itself, at its broadest width, as well as the editor Fred Davey and the two adjacent basins. Vibroseis and explosion data, complementary in their depth penetration and resolution characteristics, were obtained along with wide-angle and teleseismic data. The profile shows a bi-vergent asymmetric structure of the crust beneath the Alpine axis which reaches a maximum thickness of 55 km, and 80–100 km long transcrustal ramps, the southward dipping ‘Sub-Tauern-Ramp’ and the northward-dipping ‘Sub-Dolomites-Ramp’. Strongly reflective patterns of these ramps can be traced towards the north to the Inn Valley and towards the south to the Valsugana thrust belt, both of which show enhanced seismicity in the brittle upper crust. The seismic sections do not reveal any direct evidence for the presence of the Periadriatic Fault system, the presumed equivalent to the Insubric Line in the Western Alps. According to our new evolutionary model, the Sub-Tauern-Ramp is linked at depth with remnants of the subducted Penninic Ocean. The ‘crocodile’-type model describes an upper/lower crustal decoupling and wedging of both the European and the Adriatic–African continents.     

Detection of underground cavities by combining gravity,magnetic and ground penetrating radar surveys: a case study from the Zaragoza area,NE Spain

A geophysical survey routine is proposed to detect underground cavities and dolines; it is based on the sequential application of magnetic, low-frequency ground penetrating radar (GPR) and microgravity techniques. A case study near Zaragoza (Ebro valley, Spain) demonstrates the applicability of these methods. The strong contrast of magnetic and electromagnetic properties (and to a lesser scale, of density) between the doline filling and the surrounding stratified Tertiary and Quaternary rocks allows the shape of filled cavities to be clearly outlined by these methods.     

树木年轮学在环境变化研究中的应用

由于树木在其生长的过程中,需要从环境中吸收养分和能量并且从环境中汲取各种化学元素到每年的生长层(即年轮)中,所以树木年轮与它们的生长环境是密切相关的。树木年轮可以提供树轮生长的环境要素信息,其应用领域也日益扩大。文章综述了树木年轮长年表的建立以及在气候变化、环境污染等方面的若干应用,并且概述了树木年轮研究方法的进展。     

Gradient profiling for the investigation of groundwater saturated fractures in hard rocks of Uttar Pradesh,India

Gradient profiling (GP) has been successfully utilized as a preliminary tool to identify fractured zones saturated with groundwater in hard-rock areas of Robertsganj, Sonebhadra district, Uttar Pradesh, India. Conducting geoelectrical sounding at randomly selected places may not provide fruitful results since fractures are sparsely distributed in hard rocks. In gradient profiling, current electrodes with large separation remain fixed while the potential dipole is moved between the current electrodes in the central one-third portion of the profile at a small station interval. A GP survey was conducted along seven profiles having different lengths in two small sectors of the study area. Low resistive zones have been identified which correspond to the fractured zones. A few geoelectrical soundings were carried out to investigate the depth and thickness of the fractured zones. Two test boreholes, one drilled in each sector, yielded continuous discharge of fresh water (18,000–24,000 L/h). The present study confirms the findings of previous work that the GP survey is a powerful initial technique that identifies the presence of a fractured zone, especially in a hard-rock area covered with a thin soil layer.     

TRANSALP—deep crustal Vibroseis and explosive seismic profiling in the Eastern Alps

The TRANSALP consortium, comprising institutions from Italy, Austria and Germany, carried out deep seismic reflection measurements in the Eastern Alps between Munich and Venice in 1998, 1999 and 2001. In order to complement each other in resolution and depth range, the Vibroseis technique was combined with simultaneous explosive source measurements. Additionally, passive cross-line recording provided three-dimensional control and alternative north–south sections. Profits were obtained by the combination of the three methods in sectors or depths where one method alone was less successful.The TRANSALP sections clearly image a thin-skinned wedge of tectonic nappes at the northern Alpine front zone, unexpected graben or half-graben structures within the European basement, and, thick-skinned back-thrusting in the southern frontal zone beneath the Dolomite Mountains. A bi-vergent structure at crustal scale is directed from the Alpine axis to the external parts. The Tauern Window obviously forms the hanging wall ramp anticline above a southward dipping, deep reaching reflection pattern interpreted as a tectonic ramp along which the Penninic units of the Tauern Window have been up-thrusted.The upper crystalline crust appears generally transparent. The lower crust in the European domain is characterized by a 6–7 km thick laminated structure. On the Adriatic side the lower crust displays a much thicker or twofold reflective pattern. The crustal root at about 55 km depth is shifted around 50 km to the south with respect to the main Alpine crest.     

大别山地震波速度剖面的重力拟合及花岗岩带

笔者对穿越大别山造山带的六安—大冶宽角反射地震剖面进行了重力拟合。拟合结果表明严格按宽角反射地震速度换算成的密度剖面所产生的是一个重力高,它反映出大别山是一个穹隆,与实测大别山重力低大相径庭。只有将位于大别山山根上,南北大别之间设置一个从地表直达莫霍界面的巨大低密度体,重力曲线才能得到很好的拟合。这个低密度体应为近北西走向的花岗岩带。它与反射地震剖面上石镇透明反射地震带位置吻合,但宽度远较反射地震透明带为大。重力曲线的拟合进一步说明,在华北陆块与扬子陆块碰撞后的白垩纪时,大别山出现一个伸展期,在这个时期,大别山穹隆形成,并伴随有大规模花岗岩的侵入,超高压变质岩从地壳中下部折返到地表。研究说明,联合应用反射地震、宽角反射地震和重力,进行综合解释是必要的,可以得到更令人信服的地质结论。     

微生物—矿物相互作用之环境意义的研究

微生物-矿物的相互作用是地球上广泛发生的一种地质作用，它直接导致矿物的溶解和沉淀，并进而对环境产生重要的影响。微生物-矿物相互作用对环境修复具有重要意义，如金属还原细菌（DMRB）可通过与Fe^3 -氧化物矿物的相互作用催化氧化降解含芳香环的化合物如苯酸盐、苯、甲苯等，或催化还原降解（聚）硝基芳香化合物及四氯化碳等，还可通过表面吸附作用或氧化还原作用使一些重金属元素如U、Np等高毒性的污染物固着或形成不溶的矿物形式，从而有效去除其毒性。另外，微生物亦可催化氧化形成对环境有高度污染的酸性矿山废水（AMD）等，总之，深入研究微生物-矿物的相互作用对环境的影响具有重要意义。     

Tectonic impact on the Lake Sevan environment (Armenia)

 The geology of Lake Sevan is characterized by the structure of a pull-apart basin. Methane emission from the lake surface correlates with evidence of physical and chemical water properties, remote sensing, etc., and suggests its possible emission from active fault zones at the lake bottom, as well as emission of biogenic methane from the fermentation of bottom organic remains. Correlation with anomalies in the lake bottom geochemistry suggests a high permeability of active fault zones and suggests that geodynamic, seismic and geochemical activity across the fault zones during the buildup to the M=7.1 Spitak earthquake led to plankton depression, which resulted in a large number of fish dying in 1984, and ended with a seismic disaster in 1988. Received: 2 November 1999 · Accepted: 27 January 2000     

济南环境地质

济南市历史文化悠久,文物古迹众多,泉水驰名中外,古城格局独特,是融山、泉、湖、河、城为一体的山水城市,是国家级历史文化名城。本文分析了济南地质环境的形成条件及其独特的自然环境优势,对其地质环境现状进行了评价,提出了开发与保护建议,认为济南具有建设成为现代化多功能区域中心城市的优越环境条件。     

Formation and shortening deformation of a back-arc rift basin revealed by deep seismic profiling, central Japan

The northern Fossa Magna (NFM) basin is a Miocene rift system produced in the final stages of the opening of the Sea of Japan. It divides the major structure of Japan into two regions, with north-trending geological structures to the NE of the basin and EW trending structures to the west of the basin. The Itoigawa-Shizuoka Tectonic Line (ISTL) bounds the western part of the northern Fossa Magna and forms an active fault system that displays one of the largest slip rates (4–9 mm/year) in the Japanese islands. Deep seismic reflection and refraction/wide-angle reflection profiling were undertaken in 2002 across the northern part of ISTL in order to delineate structures in the crust, and the deep geometry of the active fault systems. The seismic images are interpreted based on the pattern of reflectors, the surface geology and velocities derived from refraction analysis. The 68-km-long seismic section suggests that the Miocene NFM basin was formed by an east dipping normal fault with a shallow flat segment to 6 km depth and a deeper ramp penetrating to 15 km depth. This low-angle normal fault originated as a comparatively shallow brittle/ductile detachment in a high thermal regime present in the Miocene. The NFM basin was filled by a thick (>6 km) accumulation of sediments. Shortening since the late Neogene is accommodated along NS to NE–SE trending thrust faults that previously accommodated extension and produce fault-related folds on their hanging wall. Based on our balanced geologic cross-section, the total amount of Miocene extension is ca. 42 km and the total amount of late Neogene to Quaternary shortening is ca. 23 km.     

Deep seismic reflection profiling across the Ou Backbone range, northern Honshu Island, Japan

Knowledge of the crustal structure, especially the geometry of seismogenic faults, is key to understanding active tectonic processes and assessing the size and frequency of future earthquakes. To reveal the relationship between crustal structure and earthquake activity in northern Honshu Island, common midpoint (CMP) deep reflection profiling and earthquake observations by densely deployed seismic stations were carried out across the active reverse faults that bound the Ou Backbone range. The 40-km-long CMP profiles portray a relatively simple fault geometry within the seismogenic layer. The reverse faults merge at a midcrustal detachment just below the base of the seismogenic layer, producing a pop-up structure that forms the Ou Backbone range. The top of the reflective middle to lower crust (4.5 s in travel time (TWT)) nearly coincides with the bottom of seismogenic layer. The P-wave velocity structure and surface geology suggest that the bounding faults are Miocene normal faults that have been reactivated as reverse faults.     

纤维水镁石的环境安全性研究

纤维水镁石的环境安全性研究＊董发勤万朴周开灿（西南工学院，绵阳６２１００２）刘杰罗素琼＊＊（陕南石棉矿，陕西宁强７２４４０１）（华西医科大学，成都６１００４４）关键词纤维水镁石环境矿物粉尘安全评估由于大量纤维日益广泛地应用于众多的工业领域，非职业接触...     

浅议不同规范对活动断裂定义的差异——以昆明市为例

现行的勘察设计行业《岩土工程勘察规范》(GB50021-2001/2009年版)、《建筑抗震设计规范》(GB50011-2010)、《工程场地地震安全性评价》(GB17741-2005),对于活动断裂的定义有一定差异,使得不同的勘察设计单位对同一条断裂的评价结果不一致,甚至相互矛盾。本文以昆明市为例,通过分析不同规范对于活动断裂的定义,指出其中的问题与差异,结合典型断层地质剖面与震害实例,简要阐述地质上判定活动断裂的主要依据,即不应以《岩土工程勘察规范》(GB50021-2001/2009年版)规定的全新地质时期(一万年)内有无地震活动来判定断裂是否为全新活动断裂,应以《工程场地地震安全性评价》(GB17741-2005)规定的断裂是否错动地表或近地表相应时代的地层,来判定其活动时代。     

天然气水合物的环境效应

天然气水合物是近些年来发现的一种新型超级洁：争能源，因其在能源勘探、海底灾害环境和全球气候变化研究中的重要性而日益引起世界各国的高度重视。本文综述了天然气水合物在形成、分解过程中的加剧全球气候变暖、海底灾害和影响海洋生物等环境效应；指出将地质历吏时期的重大事件与天然气水合物产生的这些环境效应结合将成为今后的主要研究方向。