Sulfur Content and Isotopic Ratio of Cambro-Ordovician Carbonate Rocks from South Korea: A Possible Source for Mesozoic Magmatic-hydrothermal Ore Sulfur

Abstract: Carbonate rocks of Cambrian (18 samples) and lower-middle Ordovician (11 samples) ages from South Korea were analyzed for sulfur contents of structurally substituted sulfate (SSS) and sulfides and their δ³⁴S values. The δ³⁴S values of SSS ranging from +25.9 to +45.2 permil, are averaged as +33.6 and +33.5 permil for the Cambrian and Ordovician rocks, respectively, which indicate high δ³⁴S values of the Cambro-Ordovician seawater. The SSS contents in the carbonate rocks are low being 2.9 to 17.3 ppm S (averaged as 7.0 ppm S). Sulfide sulfur, on the contrary, is much abundant containing 3 to 1,880 ppm S and the δ³⁴S values range widely between –17.6 and +31.1 permil. Sulfide sulfur of the studied rocks excluding impure carbonates has an average content of 187 ppm S and δ³⁴S value of +12.8 permil (n=24). The estimated δ³⁴S (sulfate–sulfide) values, which range from 13.8 to 25.4 permil in general with a few exceptions from 36.5 up to 52.3 permil for some impure carbonates, may provide evidence for the persistent oceanic anoxia with its temporary recovery during the Cambro-Ordovician time.
The SSS and sulfide sulfurs have often higher δ³⁴S values than the Mesozoic-Cenozoic ore sulfur (Ishihara et al., 2000). Since carbonate rocks are very reactive with circulating hydrothermal ore solution, high δ³⁴S values of the Korean ore deposits might be caused to some extent by ³⁴S enrichment from the host carbonates, resulting in the low SSS contents observed.     

Estimation of azimuth and slowness of tele-seismic signals recorded by a local seismic network

Introduction The azimuth and slowness are two major features of seismic signals. The accurate estimation of them is quite important for both phase identification and event location. Generally, there are two types of seismic stations, i.e. 3-component stations (3C) and arrays. To estimate the two direc-tional parameters, the polarization analysis (Jurkevics, 1988) is commonly used for 3C stations and the frequency-wavenumber spectrum analysis ( f-k) (Capon, 1969; Kvaerna, Doornbos, 1986) is …     

由地方台网记录确定远震信号的方位角和慢度

介绍一种新的适合于地方遥测台网数据处理的方法，估算远震信号到达台站的方位角和慢度．该方法是根据信号在各台站上的到时与台站位置矢量在信号传播方向上的投影之间的相关性的原理．实际分析结果表明，应用该方法对地方台网的记录进行处理时可以准确地计算出信号的方位角和慢度，并能准确快捷地对地方台网记录的远震信号进行解释．      

大型维歇特地震仪的记录特征及其在地震速报中的作用

大型维歇特地震仪自德国引进南京地震台已近70年。本文简要叙述了该仪器的性能；并以南京地震台的大型维歇特地震仪的记录为例，介绍了该仪器在300-2000km范围内的记录特征，回顾了该仪器在地震速报中所起的历史作用。     

2001年昆仑山口8.1级巨震后中国大陆、云南地震趋势研究

分析研究了2001年11月14日昆仑山口8．1级巨震对中国大陆云南未来几年地震趋势的影响，指出巨震后6年大陆可能仍然处于地震活跃期，其间大陆西部发生7．0级以上大震可能性较大；受2000－2001年欧亚带东南段大震活动过程及巨震调整影响，未来1－3年云南省可能进入新的活跃期，6．5级以上强震危险性增加。     

Testate amoebae as paleoindicators of surface-moisture changes on Michigan peatlands: modern ecology and hydrological calibration

Peatland testate amoebae are sensitive indicators of local hydrology and have been used as proxies for surface moisture conditions in fossil studies. However, few regional calibration datasets exist in North America, and knowledge of testate amoeba ecology and distribution patterns are limited. The objectives of this study were to (1) investigate the relationship between testate amoebae, environment, and Sphagnum species in Michigan peatlands; (2) generate transfer functions from this dataset that can be applied to fossil data; and (3) describe vertical variation of testate amoebae inhabiting Sphagnum moss. Testate amoeba assemblages from 139 microsites within 11 peatlands in Michigan were compared to assess variability between and within peatlands. Most peatlands contained similar testate amoeba assemblages, although within individual peatlands the amount of assemblage variability is correlated to the amount of environmental heterogeneity. Of the measured environmental variables, depth to water table showed the strongest relationship with testate amoebae. Depth to water table can be reconstructed from fossil data with a mean error of ±7.5 cm, although predictive ability deteriorates in extremely dry environments (>30 cm water table depth). Vertical variation in testate amoeba assemblages was investigated at 89 Sphagnum-dominated microsites by directly comparing amoeba assemblages and the abundance and frequency of common taxa in upper and lower portions of the Sphagnum stem. Except for extremely dry microsites, considerable vertical variation in assemblage composition exists. Many agglutinate taxa are more abundant on lower portions of the Sphagnum stem, and taxa containing symbiotic zoochlorellae are more abundant on upper portions. Refinements in sampling procedures and analysis may improve the predictive ability of transfer functions.     

南极考察站废弃物对贼鸥食性的影响

对南极乔治王岛菲尔德斯半岛贼鸥的食性生态进行观测与研究 ,结果表明 ,本区贼鸥的食物结构中 ,自然生态类食物百分组成 ,棕贼鸥 (C .s.lonnbergi)占 63.4% ,灰贼鸥 (C .maccormic ki)占 77.8%。同期 ,取自考察站的人类废弃物中垃圾食物的百分组成分别为 36.6%和 2 2 .3%。贼鸥食性对考察站废弃物有一定的依赖性 ,与本区环境质量下降 ,尤其考察站对废弃物的疏于管理有着直接的关系。由此表明 ,强化南极考察人员环境意识 ,建立封闭式废弃物管理系统 ,对保护南极环境有重要意义     

A FOOD GEOGRAPHY OF THE GREAT PLAINS

ABSTRACT. This article explores the regional identity of the Great Plains through its foodways using 744 responses from a mailed survey that asked participants to plan a representative menu for their locale. The strongest association is with beef—not surprising in an area known for cattle ranching. Other commonalities include potatoes, beans, and corn. Differentiation within the region is marked by preparation methods for beef as well as emphases on cornbread and peach cobbler in the south, rhubarb pie in the north, tortillas and sopapillas in the southwest, and pickles in two separate clusterings.     

当前地震台站财务管理工作之浅见

本文简要介绍了台站财务管理的现状 ,针对目前台站管理中出现的一些问题 ,阐明加强台站财务管理与会计核算改革的必要性 ,并粗略提出地震台站财务管理工作的改革方向与对策。     

格尔木地磁台观测环境测试与分析

通过实验测试和计算，分析了高压输出电线等干扰源对格尔木地磁台观测环境的影响，进一步对格尔木地磁台观测环境现状，及今后观测环境保护工作的要点进行了综合分析讨论。