黄龙CO_2成因质疑

在“不同岩溶动力系统的碳稳定同位素和地球化学特征及其意义”一文中,笔者提出黄龙系统的CO_2可能是深部岩浆起源及灰岩遇高温分解产生的CO_2的混合物,初步计算结果,来自岩浆的CO_2占77％。据现有文献资料,这是首次提出的黄龙CO_2来自地球内部属深源CO_2的看法,它不仅对黄龙钙华的成因开创了一种全新的认识,而且也为岩溶作用与碳循环的关系提供了新的信息。但是,在分析了该文所列资料后又产生了一些疑问。 (1)黄龙沟从上游到下游8个水点的δ~(13)C值有两个特点,一是分布区间窄,集中在2.0‰～3.7‰之间,另一是数值大,全部大于0。表明碳同位素非常重。这一测试结果,显然与目前公认的幔源CO_2的δ~(13)C值不在一个级别上。幔源碳的δ~(13)C值主要是通过金刚石、岩浆碳酸岩及幔源岩石的气液包裹体的研究获得的,目前公认的幔源碳的δ~(13)C值变化在-4.7‰～-8.0‰之间,平均值约为-5‰,云南腾冲热水中的碳同位素,在总计48个δ~(13)C数据中,-2.4‰～-8.0‰之间的有32个,占数据总数的66％,平均值为     

Evidence for enhanced bioavailability of trace elements in the marine ecosystem of Deception Island, a volcano in Antarctica

This study assessed whether trace elements present at Deception Island, an active submarine volcano in the Antarctic Peninsula, show enhanced biological availability to the local marine community. Using a weak acid extraction method to dissolve organic material and leach associated but not constitutive trace elements of sediments, fifteen elements were measured from seafloor sediment, seawater particulates, and tissues of benthic (bivalves, brittlestars, sea urchins) and pelagic (demersal and pelagic fishes, krill) organisms collected in the flooded caldera. The highest element concentrations were associated with seafloor sediment, the lowest with seawater particulates and organism tissues. In the case of Ag and Se, concentrations were highest in organism tissue, indicating contamination through the food chain and biomagnification of those elements. The elements Al, Fe, Mn, Sr, Ti, and to a lesser extent Zn, were the most concentrated of the trace elements for all sample types. This indicates that the whole ecosystem of Deception Island is contaminated with trace elements from local geothermal activity, which is also reflected in the pattern of element contamination in organisms. Accordingly, element concentrations were higher in organisms collected at Deception Island compared to those from the neighboring non-active volcanic King George Island, suggesting that volcanic activity enhances bioavailability of trace elements to marine organisms. Trace element concentrations were highest in digestive tissue of organisms, suggesting that elements at Deception Island are incorporated into the marine food web mainly through a dietary route.     

地下河流域岩溶水天然资源类型及评价方法

地下河流域区岩溶水资源评价中应计算什么量?采用什么方法?是目前岩溶水研究中的一个重要课题,也是地下水资源评价中比较困难的问题之一。近年来我们在岩溶区做过一些工作,对我国南方地下河流城区岩溶水天然资源的类型及评价方法提出一些讨论意见,不妥之处,请指正。成文之后曾得到周柔嘉、卫迦同志的宝贵意见,特致谢意。 一、岩溶水的贮存形式 据一些地下河出口的流量观测资料得出:在整个衰减动态过程中,衰减曲线的斜率是变化的。根据衰     

山区城市包气带对污染物双重功能的研究

本文以重庆为代表研究了山区城市基岩包气带对污染物传输和净化两种功能，从包气带的迁移通道入手总结了污染物经包气带进入生物体的几种途径，主要的迁移途径是污染物通过岩石裂隙和洞室系统的运动，这一途径迁移距离短，停滞时间少，形成了污染物的快速转移，显示出具有较强的传输功能。由岩石吸附作用而产生的净化能力是通过室内动态模拟研究的，根据四种岩石对六种离子的吸附量计算出净化量和净化系数，总体看来，岩石的净化量是     

中国南方地下河分布特征

<正>前言 地下河是中国南方碳酸盐岩地区最重要的岩溶现象之一,也是地下水赋存的一种独特形式,是南方各省岩溶地区主要供水水源。也是矿床充水、矿山建设的主要威胁,因而地下河成了岩溶水文地质工作研究的主要对象,它的分布、埋藏、水质、水量、开发治理就成了研究的课题。     

Assessment of economic losses from marine pollution: an introduction to economic principles and methods

This paper introduces economic concepts and theory pertaining to public policy issues and concerns about pollution in marine environments. Many of these concepts and theories are unfamiliar to individuals and professionals outside the field of economics, such as biologists, ecologists, environmental lawyers, and even public policymakers. Yet many of these individuals observe economics in action, often for the first time, within a public policy arena. Exposure and a better understanding of the concepts and ideas in economics that are particularly relevant for public policies can help to achieve efficiencies in the form of better designed policies, and help to bridge communications gaps across other professions and the economics profession.     

Removal fluxes of Mn and Fe from the nearshore waters along the west coast of Taiwan

Dissolved and particulate Mn and Fe in the nearshore waters were determined at 27 stations along the west coast of Taiwan during 19-23 November 2004. The latitudinal distributions of Mn and Fe were very similar; however, the concentration in the dissolved phase was lower, whereas that in the particulate phase was higher in the northern regime. The higher percentage of Fe than Mn that was associated with particles resulted in a two-order of magnitude higher particle-water partition coefficient for Fe, K_d(Fe), than that for Mn, K_d(Mn). The removal fluxes of Mn and Fe could be estimated by multiplying the particulate ²³⁴Th removal flux with the Mn/²³⁴Th and Fe/²³⁴Th ratios in suspended particles, which ranged from 0.1 to 3.8 mmol m⁻² d⁻¹ for Mn, and from 3.4 to 194.5 mmol m⁻² d⁻¹ for Fe. Residence times ranged from 1 to 20 days for Mn and Fe were estimated in the nearshore.     

山区城市环境系统的污染及其变异的典型研究

本文以重庆市为代表，讨论山区城市环境系统中大气、地表水、土壤、地下水、包气带、生物体等六个子系统的污染状况，并研究了由此而引发的环境系统的变异，它涉及到气候变迁，土壤酸化，物种退化，水质恶化，建筑物表面和文物的损害，人群和生物生存的潜在变化等诸多方面，为制定防治污染策略提供科学依据。