Developments in the stratigraphy of the Deccan Volcanic Province,peninsular India

The Deccan Volcanic Province has been considered as one of the largest magmatic regions, involving an aerial coverage of ca. 500,000 km². It is subdivided into four sub-provinces, and holds a unique position in global tectonic models for understanding earth's geodynamics and the impact of voluminous eruptions on the contemporary biosystem and climate system. Published stratigraphic data suggest that volcanic eruption took place from 69 to 64 million years (Ma) ago when the Indian plate passed over the Réunion hotspot. The main phase of volcanic activity consisting of about 80% of total basaltic lava, erupted rapidly, during a short span (<1 Ma) or even less (two or three hundred thousand years), close to chron 29R, straddling to the Cretaceous–Paleogene (K–Pg) boundary. Recent high-precision age data show that the main volcanic phase is genetically linked to the Chicxulub impact and plume-head of the hotspot, and largely contributed to the end-Cretaceous mass extinction. To assess the links of the province to the K–Pg boundary, Chicxulub impact, Réunion plume, and Late Cretaceous global climate crisis, it is crucial to have a current state of knowledge of the understanding of its stratigraphy. A review of published data shows a surge in the province research that has considerably advanced the understanding of its stratigraphy. This province is intercalated with numerous infra- and intertrappean sedimentary beds that have yielded diverse biota, providing a reliable relative time control for duration of the volcanic activity. This paper presents a review of the stratigraphic developments of the province (lithostratigraphy, chemostratigraphy, magnetostratigraphy, and chronostratigraphy) from the very beginning to the present, and discusses the role of the Réunion plume in its formation.     

江西晚三叠世安源煤系沉积特征及沉积环境探讨

江西省晚三叠世安源煤系，为江西省主要含煤地层之一，其煤种为烟煤，煤质好且为较好的动力用煤。然而，由于煤矿资源减少，造成我省乃至全国动力用煤的紧张状况，在一定程度上制约了经济的发展。通过对江西晚三叠世安源煤系（组）的沉积特征和沉积环境的分析，指出了研究区安源煤系的分布状况和赋存特征，对寻找后续煤炭资源具有一定的指导意义。     

陕西省渭河流域节水的必要性及措施

渭河流域是陕西经济社会的主体,区内水资源贫乏,水的有效利用率低,浪费严重,水资源供需矛盾突出,缺水已成为国民经济持续发展的重要制约因素.要解决其供需矛盾,首先应在农业、工业、生活等各个方面采取工程、技术、管理等节水措施,节约用水,建立节水型社会,以水资源的可持续利用保障经济社会的可持续发展.     

河北省北部张北县一带全新世中期砂层的成因

在冀北张北县发育一套特殊的砂层,因其内部赋存有数量众多的细石器而备受地质工作者的关注,但对其成因却有不同认识。从地层学、年代学、古生物学、砂粒表面及组合特征、砂体分布及产状等方面,对砂层进行了研究与分析。砂层分布于二级阶地或向阳低矮平缓山坡之上,临近水源,呈近东西向展布;堆积物呈灰褐色,分选性差、磨圆度差,不显层理,且其中含有细石器、陶器碎片、灰烬层等古人类文化遗存;粒度分析结果及扫描电镜研究表明,砂层形成于水动力条件中等的河流环境,后期又经过了改造;砂层之中富含丰富的哺乳动物化石及生成于温湿气候条件下的孢子花粉;测年资料证实砂层形成于全新世中期—全新世大暖期。诸多证据表明全新世中期砂层原始环境为河流环境,后期为古人类所利用,应为古人类活动而留下的遗存,属于人工堆积,为古村落遗址。     

都江堰市龙池镇黄央沟泥石流特征与防治工程效果分析

黄央沟位于"5.12"汶川地震的极重灾区四川省都江堰市龙池镇,地震使沟内山体发生大规模的滑坡和崩塌,其为泥石流的形成提供了丰富的松散固体物质。地震后黄央沟泥石流十分活跃,2010年8月13日、8月18日和2013年7月9日均暴发了泥石流,造成了严重的经济损失。笔者通过对黄央沟泥石流灾害现场进行实地调查,详细分析了黄央沟泥石流的形成条件和发育特征,并对已有防治工程效果进行了分析和探讨。针对防治工程存在的问题和黄央沟泥石流的特点,建议在沟道下游和堆积区修建排导沟,使泥石流顺畅排入龙溪河;采取工程和生物措施来稳定沟道内的崩滑堆积体和不稳定斜坡,减少泥石流物源;沟口公路采用高架桥跨越方式通过泥石流堆积扇。该研究结果可为强震区泥石流灾害的防治提供参考。     

Economic restructuring, social re-composition and recent urban changes in Portugal

The productive restructuring process has affected more than just the economic field, because its effects have been felt on urbanisation processes, on social relations, and on the spatial organisation of society. Starting from the ‘metapolis’ concept, developed by Ascher (1995), we analyse the evolution of new forms of urban space in Portugal, arguing that new urban forms generate new social inequalities and, in extreme cases, social exclusion. Portugal is a semi-peripheral country that combines certain of the trends in social and economic organisation common to core countries, with certain trends more common in the developing world. Thus the understanding of urban change in Portugal is a complex task, made more difficult by the rapidity of processes since the mid 1970s. The Lisbon Metropolitan Area has been deeply affected by the productive restructuring process. The role of economic and urban policies in the Lisbon region is discussed, and an assessment is made of certain measures aimed at solving economic and social problems. This revised version was published online in August 2006 with corrections to the Cover Date.     

贵州毕节地区煤炭资源与经济发展思路

贵州省毕节地区紧紧抓住自身具有的资源优势,提出了建设“绿色、能源、畜牧、旅游四大区”的发展思路,其中“立足能源资源优势,建设能源大区”是该近期经济发展最具拉动效果的有力举措。因此,该区成为国家和省规划的电煤基地、化工用煤基地、优质无烟煤出口基地,经济得到了快速的增长。     

Flooding trends and their impacts on coastal communities of Western Cape Province,South Africa

Climate change-induced extreme weather events have been at their worst increase in the past decade (2010–2020) across Africa and globally. This has proved disruptive to global socio-economic activities. One of the challenges that has been faced in this regard is the increased coastal flooding of cities. This study examined the trends and impacts of coastal flooding in the Western Cape province of South Africa. Making use of archival climate data and primary data from key informants and field observations, it emerged that there is a statistically significant increase in the frequency of flooding and consequent human and economic losses from such in the coastal cities of the province. Flooding in urban areas of the Western Cape is a factor of human and natural factors ranging from extreme rainfall, usually caused by persistent cut off-lows, midlatitude cyclones, cold fronts and intense storms. Such floods become compounded by poor drainage caused by vegetative overgrowth on waterways and land pollution that can be traced to poor drainage maintenance. Clogging of waterways and drainage systems enhances the risk of flooding. Increased urbanisation, overpopulation in some areas and non-adherence to environmental laws results in both the affluent and poor settling on vulnerable ecosystems. These include coastal areas, estuaries, and waterways, and this worsens the risk of flooding. The study recommends a comprehensive approach to deal with factors that increase the risk of flooding as informed by the provisions of both the Sustainable Development Goals framework and the Sendai Framework for Disaster Risk Reduction 2015–2030 in a bid to de-risking human settlement in South Africa.

     

陕西省水资源可持续利用面临的挑战和对策

陕西省是一个水资源短缺的省份，如何以水资源的可持续利用支持经济社会的可持续发展是当前面临的重要课题。本文通过对陕西省水资源特点和水资源开发利用中存在问题的分析，提出了实现水资源可持续利用的对策。     

矿产勘查的双控论与合理域模型

金属成矿省等级体制成矿研究保证程度与技术－经济条件研究保证程度双控制的和对其保证程度相对优选的合理区域,是深化认识矿产勘查－开发客观规律和合理进行评价的新发展,也是把以往仅按在一定地质构造背景基础上,研究不同类型矿床特征及其勘查类型的传统方法。变革为按“景、场、相、床”4个等级体制成矿序次及其随成矿史演化进程的耦合程度,以及有机地结合经济－技术条件进行勘查评价的新方法。重点阐述了等级体制成矿概念的形成、意义和研究内容,提出了地质、技术经济和合理投资的矿产勘查评价三原则,建立了以保证等级体制成矿研究程度和技术－经济条件研究程度双因素控制,以及研究程度相对合理优选区域的矿产勘查模型。     

Hydrochemistry and salt-water intrusion in the Van aquifer,east Turkey

Groundwater in the Van coastal aquifer is one of the main sources of potable, industrial and irrigational water in Van City, because of its semi-arid climate. Groundwater extraction has been in excess of replenishment owing to increased agricultural and economic activities and a growing population during the last 20 years. A hydrochemical survey of the Van aquifer provided data on the groundwater chemistry patterns and the main mineralization processes. The main processes influencing the groundwater chemistry are salinisation from salt-water intrusion, silicate mineral dissolution, cation exchange and human activity. Deterioration in water quality has resulted from intrusion of the salt water of Lake Van along the coastal regions into the Van plain. At present, the mixing rate of salt water in the Van aquifer is between 1 and 5.5% and salt water has already invaded about 5 km inland in the iskele and the airport region.     

陕西红柱石矿开发利用现状及其外围资源潜力分析

陕西省红柱石矿开发已有十多年的历史,有一套成熟的加工处理红柱石矿的方法和经验.矿石加工方法简单,也无须添加任何药剂,生产成本低,对周围环境影响小,矿山的经济效益和社会效益良好.在陕西宝鸡地区的眉县、太白境内分布有大量的花岗岩和花岗闪长岩,围绕岩体分布有大量的泥质板岩、千枚岩,成矿地质条件得天独厚,具有寻找、开发红柱石矿...     

河北省馆陶县地下水压采新模式

河北省水资源严重匮乏,由于连年超采地下水已引发了严重的环境地质问题.对馆陶县地下开采现状,指出地下水压采新模式.通过综合措施即种植结构调整、工程措施、管理制度措施、咸水微咸水合理利用等,开源与节流并举,使该区域水资源能够支撑其社会、经济和环境的可持续发展.     

甘肃省文县关家沟泥石流综合治理及效益分析

通过对甘肃省文县关家沟泥石流防治措施与效益的分析,阐述了经济效益的估算原则与方法,证估了防治工程投资与减灾效益比值,确定一最佳防治方案。     

Rapid formation of the Small Isles Tertiary centre constrained by precise Ar/Ar and U–Pb ages

The relative chronology of magmatic and tectonic events is key to an understanding of the influence of the Iceland plume on the North Atlantic. In particular, the location and duration of magmatism is of fundamental importance. Initial widespread flood basalt formation occurred in Baffin Island, Greenland, and Britain before complete plate break up at 56 Ma after which time magmatism became concentrated in the active rift zone.

Historically the British Tertiary Igneous Province (BTIP) has been instrumental in advancing many concepts of igneous petrology. However, the absolute age and duration of the province remains unresolved. Here, we present new internally consistent ⁴⁰Ar/³⁹Ar ages that help to constrain the volcanic activity in the Small Isles centre to within 2 my. This short duration has implications for the onset of magmatism in the larger North Atlantic province, the rapid unroofing of the Rum volcano, and more significantly, some of the evidence used to propose pulsing of the Iceland plume.     

Flexibility in return,reconstruction and livelihoods in displaced villages in Casamance,Senegal

The paper argues that livelihoods research in situations of violent conflict and its aftermath can contribute to geographical understandings of flexibility. Such settings paradoxically demand greater flexibility from economic actors while imposing new and sometimes severe constraints on them to exercise it. These constraints often have spatial aspects. The paper explores these issues through research on return of the displaced in Casamance, Senegal. It analyses the dynamics of reoccupation and exploitation by villagers of their former habitable and agricultural spaces amid improving but still problematic security conditions. Flexibility is most visible in the new settlement forms adopted in villages undergoing reconstruction, mainly reflecting security issues. It is also evident in shifting patterns of economic activity and the reconfiguration of local political space. However, such flexibility transcends the situation under study and has long been described in livelihoods research across the developing world, albeit in other terms.     

挖掘吉林省水资源潜力，解决水资源紧缺问题

吉林省是一个水资源紧缺的省份。随着社会经济进一步发展，人口不断增加和城市化进程加快，未来水资源的供城矛盾将日趋尖锐，供水紧缺已成为全省经济和社会发展的重要制约因素。为了充分挖掘全省水资源开发的潜力，解决水资源紧缺问题，该文按不同地区，从实际出发，有针对性地提出了现实的，应急的对策，同时也提出了许多对全省有长远战略意义和创新性的技术对策。如洪水资源的开发和修建地下水库等建议即是。     

鄂西地区茅口组重力流沉积特征及古地理意义

通过对鄂西地区中二叠统详细的野外剖面测量及沉积微相分析,发现鄂西地区中二叠统茅口组发育重力流沉积,沉积类型多样,发育于碳酸盐岩斜坡沉积环境中,自上而下分为滑塌沉积、碎屑流沉积、颗粒流沉积。滑塌沉积主要发育于湖南慈利江垭剖面,颗粒流与碎屑流发育于湖北长阳资丘剖面。滑塌沉积物主要由杂乱堆积的棱角状—次棱角状砾屑灰岩组成,分...     

A method to evaluate REE-HFSE mineralised provinces by value creation potential,and an example of application: Gardar REE-HFSE province,Greenland

The rare earth elements and high-field-strength elements (REE-HFSE) exploration sector conducts most evaluations at deposit and smaller scales. It is not evident how the sector performs a preceding exploration stage—rating and prioritising REE-HFSE mineralised provinces—to determine which provinces are prospective enough to warrant investment. Here we present an objective, repeatable, low-cost method to screen any REE-HFSE province, as a foundation for district-scale investigations or asset evaluations. It is original for REE-HFSE screening, and adapted from regional scale copper, cobalt and petroleum exploration, and CO₂ storage, screening methods. It is centred upon a mineralised province’s favourability for potential value creation, and to identify: (a) its main information gaps; (b) its weakest links; (c) its exploration maturity and remaining potential category; (d) how it compares against other REE-HFSE provinces; and (e) if further investigation is justified. This method incorporates geoscience, strategy, economic and socio-environmental factors in a way that is understandable and directly usable across stakeholder groups. The workflow is systematic, yet flexible enough to accommodate organisation-specific criteria, and usable for other commodities. It provides the platform to build a global REE-HFSE province map and database consistently across national boundaries and organisations. Categories for the extent of province exploration maturity and remaining mineral potential are proposed. We illustrate the applicability of these methods using the Gardar REE-HFSE Province (GRHP) of south Greenland. We conclude that it is a moderate size, frontier province that is currently of questionable favourability for value creation. To move GRHP into a positive favourability class, its current weak links need strengthening by research, government policy and industry stakeholders: evaluate the mineral system; integrate all information geospatially and place it in the public domain; help the region improve some community health and safety issues; convert some mineral resources into an Ore Reserves category; commence mining and sales production.     

Late Quaternary geology of Ambitle Volcano,Feni Island Group,Papua New Guinea

Ambitle Volcano (new name) is the most recently active of four eruptive centres that make up the mainly Pliocene–Pleistocene Tabar–Lihir–Tanga–Feni (TLTF) alkalic volcanic province, located in the New Ireland Basin, Papua New Guinea. Ambitle Volcano is a submarine and subaerial stratovolcano occupying all of Ambitle Island. The volcano rises 2500 m above the surrounding sea floor to sea level and, with a maximum elevation of 479 m above sea level, indicates a structure nearly 3000 m high. Volcanic deposits rest unconformably on Oligocene basement rocks of the New Ireland Basin. The cone of Ambitle Volcano is constructed mainly of lavas and pyroclastic and epiclastic rocks; lavas are commonly vesiculated. These lavas are strongly undersaturated and intermediate in composition (phonolitic tephrite and tephritic phonolite) with alkali basalt, tephrite and basanite and trachybasalt and trachyandesite also present. Syenite porphyry and monzonite stocks intrude the cone-forming mafic–intermediate sequence at Kabang–Matangkaka and in the upper Nanum River. The central part of the Ambitle Volcano is now modified as a prominent semi-circular topographic rim around the Nanum Valley. The Nanum Valley Crater (new name) is the product of large-scale summit failure of the SW flanks of the summit of the Ambitle Volcano. This event is dated no younger than 0.68–0.49 Ma. The Ambitle Crater (new name), the product of Late Quaternary resurgence of volcanism following sector collapse of Ambitle Volcano, is located in the NE portion of the Nanum Valley Crater. The crater is elongated NNE and measures 900 m × 550 m at its widest development. The strong NNE–SSW linearity of the western rim of Ambitle Crater is structurally controlled by the Kabang Fault. Tephra was erupted from the Ambitle Crater at 2300 ± 100 a and is widely dispersed throughout the Nanum Valley Crater and beyond. This is the youngest volcanic event in the TLTF volcanic province. The Niffin graben is a major NW–SE-trending structural corridor that transects Ambitle Island. The structural corridor is parallel to the NW–SE strike of the TLTF volcanic province suggesting it has been an important control on magmatism and volcanism. Presently active geothermal systems are located along Niffin graben structures in the western valleys of the island and in the Nanum Valley Crater. The volcanic rocks of Ambitle Volcano host porphyry Cu–Au style mineralisation and epithermal Ladolam-type Au mineralisation. Extensive exploration including surface sampling and subsurface drilling completed since 1983 on many prospects has not defined an economic resource.