Preliminary investigation of Late Pleistocene fauna from Ryonggok Cave No. 1, Sangwon County,North Hwanghae Province,Democratic People's Republic of Korea

The investigation of a limestone cave on the Ryonggok-ri of Sangwon County, North Hwanghae Province, DPRK, has yielded many faunal remains including Late Pleistocene deer, brown bears and horses. Uranium series dating of fossil teeth yielded dates of ~72ka at the base of Layer 2 – the bone-bearing unit – and ~44ka at the top. The rich and diverse mammal remains of Ryonggok Cave No. 1 are indicative of warm and humid temperate conditions during the Late Pleistocene, and reflect the presence of both dense forests and open grassland. In addition, pollen and spores from the site include two families and 24 genera of trees, six families and a genus of grasses and herbs, and two families and six genera of ferns, corroborating the environments inferred from the faunal remains.     

黔桂地区最近16万年高分辨率石笋记录的气候事件

全球变化研究是当今地球科学最前沿的课题。要了解地球系统长期演变的动力过程 ,预测未来气候变化 ,就必须首先研究和重建最后 2次冰期高分辨率的气候变化历史。本项研究选择中国南方广西、贵州地区几个大型石笋 ,在沉积学研究的基础上 ,采用碳氧稳定同位素、α谱U系法、TIMSU系 (2 3 0 Th/2 3 4U)法等方法提取高分辨率的气候记录。本区 16万年来石笋气候记录可以与海洋记录的16阶段进行对比。末次冰期的起始点及终止点通过石笋记录分别确定为 (130 1± 1 0 )kaB P 及(11 2± 0 1)kaB P ,其准确性大大高于目前其它记录。所揭示的Heinrich型气候波动事件 ,其时限分别为 :H114～ 15kaB P ,H2 2 1～ 2 3kaB P ,H32 5～ 2 7kaB P ,H44 1～ 42kaB P ,另外在 35～ 37kaB P 也存在振幅很大的冷事件 ,与北大西洋沉积及格陵兰冰芯记录可以逐一对比。长周期的气候旋回以及短期的突变事件 ,在时限上所谓存在几千年以上滞后或超前 ,可能是测试方法和测试对象的不同带来的差错 (包括测试误差 ) ;具有全球意义的一些气候突变事件 ,在发生的时间上可能都具有同时性。这种短期突变事件发生的动力机制问题 ,可能也是目前人类尚未识别出来的天文因素的驱动所致。     

末次冰期短尺度气候突变事件:西南地区石笋记录的证据

本文研究了广西和贵州 3个大型石笋的δ1 8O及δ1 3 C记录 ,末次冰期晚期所揭示的 10 2 ～ 10 3 a级的冷跃变事件 ,其时限为 11.4～ 12 .4kaB .P .,14.5kaB .P .,2 0kaB .P .,2 7kaB .P .,36～ 37kaB .P .及 41kaB .P .等。可与北欧和北大西洋的新仙女木及Heinrich型气候波动事件逐一对比 ,这些短周期的气候突变事件 ,时限上的各种记录可能有差异 ,也许是测试方法和测试对象的不同带来的误差 (包括测试误差 )。具有全球意义的一些气候突变事件 ,如果在发生的时间上都具有同时性 ,那么这种短期突变事件发生的动力机制问题 ,是否是目前人类尚未识别出来的天文因素的驱动 ,值得今后进一步研究。     

Correlation between high-resolution climate records from a Nanjing stalagmite and GRIP ice core during the last glaciation

A 400-mm-long stalagmite from Tangshan Cave, Nanjing has been analyzed by a high-precision TIMS-U series dating method and also determined for oxygen and carbon stable isotopic compositions. The results provided a high-resolution paleoclimate record for eastern China during a time interval (from 54 000 to 19 000 aBP) of the last glaciation. The continuous record of oxygen-18 variations in the stalagmite, indicating a precipitation history of the East Asian monsoon, shows not only signals of the Heinrich events, but also the Dansgaard-Oeschger cycles which are first found in the last glacial climate record of the East Asian monsoon area. Although the stalagmite-based climatic signals match well with the GRIP ice core record, some differences between the two records can be recognized: (1) The last glacial climate changes in eastern China exhibited a long-term remarkably cooling trend, superimposed on which were four successive Bond’s cycles illustrated by the δ¹⁸O curve. This strong cooling tendency may be an effect of the strong summer monsoon event during the MIS 3 over the Tibetan Plateau. (2) There exist some phase differences of 1000–2000 years between the cooling events in the stalagmite-based climate signal and the GRIP ice core record. Such differences should be further verified by calibrations of multiple dating methods     

Legal protection for caves in the United States

This study reviews significant state and federal laws that can be used to protect karst, caves, and associated unique minerals and biota. The first state cave protection act was passed in Colorado in 1883; unfortunately it was repealed in 1971. From that modest beginning there are now a total of 22 states, Puerto Rico, and the Cherokee Nation that have specific cave protection acts. Most of these have been legislated during the last 20 years. There are a number of laws on the federal level that can be used for cave protection. The most important of these is the Federal Cave Resources Protection Act of 1988, which mandates cave conservation for many federal land management agencies. The Endangered Species Act of 1973 and the Federal Archaeological Resources Protection Act of 1976 can also be of significant use in the conservation of caves on federal land. The effects of these acts are variable. One factor is how important agency officials and law enforcement officers regard caves. It has not been unusual that little was done in the way of protection or prosecution even when the perpetrators have been apprehended. This attitude is changing rapidly primarily because those involved in enforcing the laws have been educated to the uniqueness and values of caves and their contents.     

Influences of agricultural practices on water quality of Tumbling Creek cave stream in Taney County,Missouri

Influences of agricultural practices on water quality of the Tumbling Creek cave stream are of particular interest because of the karst nature of the area and the recent implementation of a Better Management Practice (BMP). Water quality parameters, measured bi-weekly during one year, consisted of pH, turbidity, water temperature, specific conductivity, total dissolved solids, alkalinity, and chloride. Heavy metals, nutrient and bacteria levels were also monitored during the study. Effects of land use were most obvious in turbidity, nitrate, chloride, and bacteria levels. Sites within the recharge area that pose a major threat to its water quality were identified. Results provide a baseline for these water quality parameters and their seasonal variability that can be used in future studies to address the effects of water quality and stream sediment contamination on the caves ecosystem and to determine the effectiveness of the BMP implemented in this karst area.     

Chemistry of waters from selected caves in Slovakia—a reconnaissance study

The chemical composition of water samples was studied from different caves in Slovakia. The water samples were collected from caves of two karst regions: (1) the Demänovský Cave System (DCS), situated in the Low Tatra Mountains (Northern Slovakia), which is mainly formed of limestone and dolomites; and (2) the Slovakian Karst to the Southeast is formed of limestone. A considerable difference between water from the two regions was shown. The waters from the DCS, that were controlled by vadose water percolating through different types of host rocks, contained more Mg ions than those from the Slovakian Karst caves whereas, the concentration of SO₄ was controlled by the dissolution of displacive gypsum and/or oxidation of pyrite. The distribution of NO₃ in the studied samples was random, hence nitrates probably derived from few pollution sources. The total mineralization of the water was covariant with calcite and aragonite saturation indices. In general, both parameters are higher in the Slovakian Karst caves than in the DCS. It is controlled probably by differences in climatic conditions, soil and plant covers between these two regions. The main goal of this article is to characterize the major-ion water chemistry within the studied caves as well as some microelements. The results have confirmed the dominant role of the bedrock petrography in forming the general chemistry of cave waters.     

神农架全新世东亚季风演化及其热带辐合带控制*

文章基于湖北神农架山宝洞3支石笋的13个²³⁰Th年龄和505个氧同位素数据,建立了全新世8.45~0.46kaB.P.东亚季风降水序列,其长期演化趋势与33°N夏季太阳辐射能量变化曲线基本一致。神农架山宝洞与阿曼Qunf洞和贵州董哥洞的石笋高分辨率δ¹⁸ O记录整体相关(r 分别为0.75和0.94), 说明全新世东亚季风、印度季风系统的演化主要受控于同一驱动机制,即北半球夏季太阳辐射控制下赤道热带辐合带逐渐南移,导致亚洲季风降水持续减弱。功率谱分析表明:5ka以来山宝洞石笋记录具有显著的550a周期旋回,与树轮Δ¹⁴ C和北大西洋温盐环流周期基本一致。     

高分辨率洞穴石笋中稳定同位素应用——北京元大都建立后对森林资源的破坏—δ~(13)C记录

对采自北京西山石花洞内的石笋进行了δ~(18)O,δ~(13)C和Mg/Sr分析,获得分辨率为25a的北京地区3000a以来的古气候和古环境信息。以δ~(18)O和D_(Mg/Ca)作为气候变化信息,证实石笋δ~(13)C反映了古气候变化对植被的影响。当石笋δ~(13)C值增大时,表示C_3/C_4植物比值降低,气候变干热;当石笋δ~(13)C值减小时,表示C_3/C_4植物比值升高,气候变湿冷。同时,笔者也发现了北京元大都建立以来对森林资源的破坏。在650B P至360B P,从元大都建立到明代晚期北京外城的增筑,北京西山林木被砍伐用于建筑和烧制木炭,使得这一地区的植被遭受重大改变。C_3/C_4植物的比值大幅度降低,石笋的δ~(13)C值增大3‰。尽管在此之后的气候条件有利于C_3植物的发育,但这一地区的植被没有恢复到受人类破坏前的水平。通过与历史资料对比,证明石笋中的δ~(13)C记录的确能反映C_3/C_4植物比值的分配变化,从而可以间接地反演古气候和人类活动的影响。     

洞穴碳酸钙微层理在中国的首次发现及其对全球变化研究的意义

研究我国北部季风气候区石笋的微生长层及其气候意义，在北京石花洞石笋中发现微生长层。通过年代测定、气候事件控制分析，初步提出了石笋微层的年层时标含义及层厚变化主要响应降水变化的气候意义。试图利用微层的层厚－降水响应关系，重建北京地区最近1130年来干湿变化的年分辨率趋势，通过功率谱分析发现136年、50年、16～18年、11年、5．8年的降水周期变化。