秦皇岛市地质灾害土地资源易损性评价

旨在为秦皇岛市地质灾害风险区划提供依据,提出地质灾害土地资源易损性的综合评价方法.在充分论证评价因子的基础上,对2008年秦皇岛市地质灾害土地资源易损性进行综合评价和区划.     

青藏高原地面有效辐射变化及其对表层土温的影响

利用青藏高原格尔木、狮泉河、昌都日射站及中国科学院冰冻圈观测研究站的观测资料,分析了高原有效辐射的变化,在此基础上结合土壤温度资料讨论了高原北部有效辐射的变化对表层土壤热状况的影响.结果显示：1）青藏高原有效辐射变化因所处的区域不同而异,高原东北部、西部及高原腹地有效辐射总体呈减小的趋势,高原东南部有效辐射呈增大的趋势...     

闽西武夷山建宁—泰宁地区白垩纪火山-沉积序列:对华南东部晚中生代构造演化的制约

闽西武夷山建宁—泰宁地区发育2套白垩纪火山-沉积序列,构成2个火山-沉积旋回,每套序列由下部火山岩和上部沉积岩地层组成.锆石U-Pb年代学和地球化学分析显示,早期中酸性火山岩喷发时代为早白垩世141～135 Ma,具有陆缘火山弧的地球化学亲缘性,并富集Hf同位素(-20.2～1.9);而晚期火山岩活动集中在早、晚白垩世...     

Metallogeny of Shoshonite-Hosted Copper-Gold Deposits in Middle-South Parts of Tancheng-Lujiang Deep Fault Zone and Its Vicinity,Eastern China

ＩＮＴＲＯＤＵＣＴＩＯＮＳｈｏｓｈｏｎｉｔｅｓａｒｅｐｏｔａｓｓｉｃｉｇｎｅｏｕｓｒｏｃｋｓｗｈｉｃｈｏｃｃｕｒｍａｉｎ－ｌｙｉｎｓｕｂｄｕｃｔｉｏｎ－ｒｅｌａｔｅｄｔｅｃｔｏｎｉｃｓｅｔｔｉｎｇｓ（Ｍｏｒｒｉｓｏｎ,１９８０）．Ｔｈｅｙａｒｅｃｏｍ...     

陕西金堆城斑岩钼矿床成矿流体研究

陕西金堆城斑岩钼矿床是中国最大的钼矿床之一,按照脉体相互切割关系,成矿过程可分为两期十个阶段。矿区内流体包裹体研究表明：成矿流体以富CO2为特征,温度介于83℃～142℃之间,盐度介于27.5～42.5wt％NaCl两个区间内,具有典型的双配分模式特征。氢氧同位素特征研究表明成矿物质主要来源于岩浆流体。晚阶段有大量雨水混入热液流体中,导致流体的温度、盐度和δ18OH2O、δD值下降,引起了成矿流体中的钼金属沉淀,形成了金堆城超大型斑岩钼矿床。     

雁南煤矿北二采区充水因素及开采影响评价

在全面分析大雁矿业集团公司雁南煤矿北二采区的水文地质条件及煤层开采矿井充水因素的基础上,计算了开采27^1号煤层时导水裂隙带发育高度．得出了北二采区各煤层工作面开采即不会受到上部砂砾含水层的影响,雁南煤矿铁路涵洞以西的胜利河冲击沟也不会受到北二采区的采动塌陷影响的结论。     

Study on rain-runoff process in the peripheral mountainous area of the Sichuan Basin

Studies on rain-runoff process in the peripheral mountainous area of the Sichuan Basin, which is regarded as a key ecological shelter, will contribute to flood control and environmental protection for the Upper Yangtze River Basin. In two typical catchments--the Fujiang River Catchment and the Wujiang River Catchment, rainfall simulations have been conducted to study the rain-runoff processes of yellow soil and limestone soil in three types of land use--forestland, farmland and grassland. Results showed that （1） within the same rainfall process, overland flow occurs first on farmland, then on grassland, and finally on forestland; （2） soil surface coverage has a great impact on the occurrence and amount of overland flow. The runoff amount can increase 2-4 times after the coverage is removed; （3） the infiltration before the occurrence of overland flow will decrease because of higher gravel contents of soil, but it takes no effect on infiltration once overland flow becomes stable; （4） the runoff coefficient of the limestone soil forestland is greater than that of the yellow soil forest land, but less than that of the farmland; （5） three empirical infiltration models, including Horton＇ model, Kostiakov＇ model, and modified Kostiakov＇ model, were compared by using the observed results under rainfall simulation. The results showed that the Kostiakov＇ model performed better than both the Horton＇ model and modified Kostiakov model. According to the results of this research, the Kostiakov＇s model can be used to simulate rainfall infiltration when water erosion is modeled in the peripheral mountainous area of the Sichuan Basin.     

An absolute paleotemperature record from 10 to 6 Ka inferred from fluid inclusion D/H ratios of a stalagmite from Vancouver Island, British Columbia, Canada

By using continuous helium flow during the crushing of calcite speleothem samples, we are able to recover liberated inclusion waters without isotopic fractionation. A paleotemperature record for the Jacklah Jill Cave locality, Vancouver Island, BC, was obtained from a 30-cm tall stalagmite that grew 10.3-6.3 Ka ago, using δ¹⁸O values of the crushed calcite and of the inclusion water as inferred from its δD. It is found that the locality experienced mean annual temperature variations up to 11 °C over a 4-Ka period in the early Holocene. At the beginning of the period, local temperature quickly increased from a minimum of ∼1 °C to around 10 °C, but this early climate optimum, about 3 °C warmer than today, only lasted for ∼1200 years. About 8.6 Ka ago, temperature had declined to ∼7 °C, approximately the same as the modern cave temperature. Since then, the study area has experienced only minor temperature fluctuations, but there was a brief fall to ∼4 °C at around 7 Ka ago, which might be caused by a short lived expansion of local alpine glaciers. The long-term T-dependence of δD was 1.47‰/°C, identical to the value in modern precipitation.