大别山碧溪岭深色榴辉岩和片麻状花岗质岩石SHRIMP分析：晋宁期？…

本文报道大别山安徽省岳西县碧溪岭深色榴辉岩和片麻状花岗质岩石的锆石SHRIMP分析结果.深色榴辉岩的原岩为基性凝灰岩,锆石在岩石中主要产于石英、石榴子石和绿辉石内,为高压-超高压变质作用的产物,内部主体形成年龄约为757±7 Ma,代表高压-超高压榴辉岩相变质事件的时代;经受了后期流体改造的锆石边部年龄为223±3 Ma.在片麻状花岗质岩石中,发育韵律环带结构的深熔锆石形成于约727±15 Ma,受后期流体改造的锆石边部年龄为219±3 Ma.综合野外地质关系、区域地质背景和锆石的岩相学特征,笔者提出了碧溪岭榴辉岩相岩石高压-超高压变质作用发生于晋宁期,印支期仅代表一次后期流体改造事件的观点.     

流体包裹体轻烃有机气体组成及对矿床成因的制约

嵩溪银(锑)矿是一个新发现的大型独立银矿。矿物流体包裹体超高真空四极气相质谱系统测定显示，该矿成矿流体中存在多种轻烃有机气体，主要由C     

地球历史中矿产资源分布之规律

现有的矿产资源分布资料可以说明地球历史中亲铁和亲铜元素成矿的一般规律。铁矿床在元古宙地核分离之后最为发育。除个别显著成矿高峰外 ,金的储量分布与铁类似。亲铁元素矿物的成矿潜力在古元古代也最大 ,以后逐渐降低 ,只是在显生宙 ,因地壳的再循环和古老矿床中矿石物质的活化而再次增大。元素的行为则完全不同 ,在前寒武纪时期它们的活动性为中等。亲铜矿物矿床的总量 ,在显生宙因再循环而达到最高 ,亲铜矿物矿床成矿能力较之亲铁矿物强得多 ,因为硫化物比铁金属氧化物更为活泼。地球演化的旋回性表现为超大陆形成的周期性 ,它与矿产的分布颇为一致。铁矿、亲铁元素和金成矿作用的突然激增 ,显然是在超大陆形成之后 ,并且与其早期裂解的脉动相对应。亲铜元素堆积的高峰期往往与超大陆的形成期相对应。尽管亲铜元素成矿的第三次脉动与中生代古陆 (Mesogea)的形成并不一致 ,但却与劳亚古陆及冈瓦纳古陆的裂解相一致。此种成矿堆积现象可以借助地幔内非稳态化学密度对流所诱发的地壳发展周期性来解释。根据超大陆形成的周期性推断地幔对流巨旋回的主期应为 80 0Ma ,此种周期性亦反映了具原始地幔印记的亲铁、金和亲铜元素的聚集作用过程。因此 ,地球圈层中地幔对流作用的周期性亦显著地控制了包括地幔     

A new interpretation for the origin of the Norilsk typePGEeCueNi sulfide deposits

The origin of PGEeCueNi sulfide deposits of Norilsk and Talnakh located in the northwest flank of the Triassic basalt trap formation of Siberia is considered. It is shown that ore elements of these deposits (probably, except Fe) are derived from the crust rather than from the mantle. They entered the basalts owing to a remobilization (recycling) of ore elements from the Paleoproterozoic sediments and from the rocks of the Siberian platform’s basement. Prospecting criteria for similar deposits are as follows: (1) a presence of a large Paleoproterozoic aulacogen and a related magmatic sulfide CueNi mineralization; (2) a confinement of perspective areas to troughs associated with long-lived deep fault zones; (3) association with mobile orogenic belts, island-arc systems and tectonomagmatic activation zones; (4) temporal association with boundaries of global periods characterized by active processes of continental breakup and large-scale trap magmatism. A combination of several factors (the first one is obligatory) is favorable for the discovery of a large ore body.     

青海共和盆地达连海湖泊流域表土花粉-气候响应面分析

孢粉分析是研究过去全球变化的一种重要方法,而研究花粉与现代气候之间的相互关系是古气候定量重建研究中的前沿课题。要预测未来气候的中长期变化,必须从花粉记录中定量提取古气候信息,建立的多种孢粉-气候数学模型必须经过不同边界条件下的古气候数据检验校正才能应用到实际当中。花粉-气候响应面方法是考虑了花粉与气候间的非线形关系上,提出的将现代花粉丰度在地理空间的分布转换为气候空间的分布,并以提供定量的古气候数据,已被广泛应用于COHMAP等各种重要古气候研究项目。本文就是利用该方法,以青藏高原东北部共和盆地达连海湖泊流域54个表土样品中的花粉丰度及采样点的气候参数为基础数据,通过主成分分析选择了特征值高且指示意义明显的4种花粉类型,对其丰度与7月平均温度及年平均降水量两个气候参数进行多项式回归分析,其结果显示模型对数据拟合较好,为定量重建该区古气候变化提出了较为准确的数量指标。     

飞机排放的NOx对中国地区NOx和臭氧的影响

根据2000年亚音速飞机排放的NO_x,利用三维全球化学输送模式(OSLOCTM2)研究亚音速飞机排放的NO_x对中国地区NO_x和臭氧的影响。模式结果表明:亚音速飞机排放的NO_x明显地影响中国北方地区,在1月份,250hPa高度NO_x的浓度增加大约50pptv,最大的相对变化为60％;在4月份,250hPa高度臭氧增加8ppbv,相对变化为5％。NO_x的增加主要是由于输送过程引起的,但臭氧的增加则是化学过程生成的结果。由于中国地区亚音速飞机排放的NO_x造成的NO_x的增加不超过10pptv,而且臭氧增加小于0.4ppbv。即使中国地区亚音速飞机排放的NO_x增加一倍,这个影响仍然比较小。     

An approach to the intercalibration of benthic ecological status assessment in the North Atlantic ecoregion, according to the European Water Framework Directive

The European Water Framework Directive (WFD) establishes a framework for the protection and improvement of transitional and coastal waters; its final objective is to achieve at least 'good water status' for all waters, by 2015. The WFD requires Member States (MSs) to assess the Ecological Status (ES) of water bodies. This assessment will be based upon the status of the biological, hydromorphological and physico-chemical quality elements, by comparing data obtained from monitoring networks to reference (undisturbed) conditions, and then deriving an Ecological Quality Ratio (EQR). One of the biological quality elements to be considered is the benthic invertebrate component and some structural parameters (composition, diversity and disturbance-sensitive taxa) must be included in the ES assessment. Following these criteria, several approaches to benthic invertebrate assessment have been proposed by MSs. The WFD requires that these approaches are intercalibrated. This contribution describes the comparison of the different methodologies proposed by United Kingdom, Spain, Denmark and Norway. Results show a high consistency between the approaches, both with regard to determining the EQR and boundary settings for the ES.     

Aliphatic and aromatic hydrocarbons in coastal Caspian Sea sediments

This investigation represents the first extensive study of the spatial distribution and sources of aliphatic (n-alkanes and unresolved complex mixture of fossil hydrocarbons) and polycyclic aromatic hydrocarbons (PAHs) in coastal sediments from the Caspian Sea. PAH concentrations, n-alkanes and biomarker profiles all suggested that there was limited petrogenic contamination in the shallow North Caspian Sea sediments, which are coarse with a low total organic carbon content. In contrast, moderate to high petrogenic contamination was found in the South Caspian Sea, in particular in the offshore oil fields near Baku, Azerbaijan. Contaminant patterns indicated that the PAHs were mainly from fossil sources, with higher contributions of pyrolytic only near industrialized and urban areas. A high contribution of perylene, a geochemically derived PAH, to the total PAHs was found in the west and south at sites influenced by the Kura, Safid Rud, Terek, Sulak and Samur Rivers.     

俄罗斯内生金矿床勘查的若干问题 ——兼论俄罗斯库顿金矿类型与勘探程度

俄罗斯为世界上六大产金国之一, 金矿床勘查规范独具特点。通过俄联邦自然资源部颁布的《矿床储量与固体矿产预测资源量分类》、《金矿床储量分类方法指南》与中国国土资源部颁布的《岩金矿地质勘查规范》的对比, 剖析中俄两国规范内容的异同。     

Scientific management of Mediterranean coastal zone: a hybrid ocean forecasting system for oil spill and search and rescue operations

The oil spill from Prestige tanker showed the importance of scientifically based protocols to minimize the impacts on the environment. In this work, we describe a new forecasting system to predict oil spill trajectories and their potential impacts on the coastal zone. The system is formed of three main interconnected modules that address different capabilities: (1) an operational circulation sub-system that includes nested models at different scales, data collection with near-real time assimilation, new tools for initialization or assimilation based on genetic algorithms and feature-oriented strategic sampling; (2) an oil spill coastal sub-system that allows simulation of the trajectories and fate of spilled oil together with evaluation of coastal zone vulnerability using environmental sensitivity indexes; (3) a risk management sub-system for decision support based on GIS technology. The system is applied to the Mediterranean Sea where surface currents are highly variable in space and time, and interactions between local, sub-basin and basin scale increase the non-linear interactions effects which need to be adequately resolved at each one of the intervening scales. Besides the Mediterranean Sea is a complex reduced scale ocean representing a real scientific and technological challenge for operational oceanography and particularly for oil spill response and search and rescue operations.