金沙江虎跳峡成因及形成时代探讨

虎跳峡是金沙江峡谷的典型代表,其成因及形成时代涉及金沙江-长江水系发育及其环境效应问题。文中分析研究了虎跳峡附近发育的夷平面、剥蚀面、阶地等区域性的层状地貌,并认为虎跳峡上下游河谷发育历史具有一致性;从地质构造上的分析表明,虎跳峡两侧的玉龙雪山、哈巴雪山为一相对完整的地块,不存在虎跳峡大断裂,因而虎跳峡峡谷是在区域地壳抬升、先成河深切作用下而形成的。根据相关盆地沉积物、玉龙雪山的冰川发育状况、前人在附近发现的哺乳动物化石等,初步认为虎跳峡峡谷形成于中更新世。     

金在地幔矿物中的赋存形式及其赋存介质转化的可能模式:以中国北方一些地幔橄榄岩包体为例

采集中国北方玄武岩中橄榄岩包体样品21件。测定了其中的主元素、微量元素、稀土元素(REE)和Au等的含量。橄榄岩包体中的Au含量与CaO含量的相关性表明,其中的Au可能主要赋存于单斜辉石中,反映Au含量可能与地幔演化及熔融程度有关;橄榄岩包体后期受地幔流体交代作用的影响,Au转而以硫化物形式存在,这一过程是在橄榄岩包体原有Au的物质基础上进行的。     

陆源碎屑与碳酸盐混合沉积研究中的几点思考

在前人研究的基础上，结合一些具体研究实例，对混合沉积的定义进行了修正和补充；对混积岩和混积层系重新进行分类和命名；根据混合沉积的定义、成因、成分、结构、沉积构造及接触关系等因素，按照“沉积事件+剖面结构”的原则，提出了渐变式、突变式和复合式3种成因类型，对前人的研究成果进行了概括和归纳；对混合沉积的控制因素进行了深入讨论；在以碳酸盐沉积为主和以陆源碎屑沉积为主的2类沉积背景下详细论述了层序格架中混合沉积的发育情况；结合混合沉积本身的特点讨论了混合沉积与油气的关系。最后针对混合沉积研究现状，指出了该领域研究中存在的问题，并对未来的研究方向进行了展望。     

1999年夏季中昆仑山北坡诸河冰雪大洪水及其成因分析

1999年盛夏中昆仑山北坡大多数河流出现了有正式水文记录以来的最大洪峰,各河流最大洪峰出现时间存在不一致性,洪峰变化复杂.应用主要河流出山口水文站的逐日流量和降水量,和田气象站的逐日0℃层高度,500 hPa气温以及NCEP/NCAR 500 hPa高度场资料,分析了1999年夏季中昆仑山北坡诸河出现的历史特大洪水特性及其气象成因.这次特大洪水是高空持续高温引起的冰雪融水与产流区出现的暴雨共同作用下的混合型洪水.洪水前期春季到初夏该区域山区降水偏多,高空气温和0℃层高度持续偏低,对高山区的积雪积累极为有利;7月底至8月初和田高空气温和0℃层高度迅速上升并维持数日,使冰雪快速消融,同时山区出现大降水是引发洪水的直接气象成因.在青藏高原东部柴达木盆地上空存在有500 hPa稳定高压,使中亚副热带大槽东移中昆仑山北坡是这次特大洪水发生的环流系统特点.     

镇康芦子园铅锌矿床特征及成因

芦子园铅锌矿产于镇康复背斜核部寒武系沙河厂组大理岩、板岩、片岩地层中，沿背斜轴部产生的断层及层间破碎带是主要的容矿构造，成矿物质来源于地层、酸性及基性岩浆热液，矿床成因为沉积-热液改造叠生型铅锌矿床。     

绿色招商与县域经济可持续发展——以河南省为例

以河南省县域经济发展为例论述了招商引资对于县域经济发展的重要性,并从可持续发展的角度对当前全民招商的现象进行了反思.在此基础上,讨论了绿色招商的内涵和主要原则,指出绿色招商和循环经济是实现县域经济可持续发展的关键所在.根据县城经济发展的特点,以河南省新郑市和义马市循环经济发展为例,从理论和实证的角度,对县域农业和工业循环经济两大体系构建进行了论述,并对县域绿色招商中应注意的问题,如市场有效性、招商载体构建、实体虚拟产业循环结合等进行了探讨.     

近年国外传统村镇旅游研究进展及启示

近年来,随着传统村镇旅游的日益兴起,有关传统村镇的旅游学研究日益受到学术界重视和关注.总结了国内外关于传统村镇的旅游学研究进展,指出国外研究成果主要集中在传统村镇旅游发展影响研究、传统村镇旅游发展与文化原真性保持之间的关系、传统村镇旅游可持续发展等方面.国内研究与之相比,在研究内容、方法、领域、深度等方面仍有很大差距,有待进一步扩展和深入.今后应注意以下几方面问题:研究内容流于表层,应加强研究领域的延伸和深度的扩展;研究方法、手段较为单一,研究理论和方法焏待提高;理论研究滞后于旅游发展实践的现状焏待改善.     

Investigation of the Calibration Function of Local Earthquake Magnitude （ ML ） in the Fujian-Taiwan Region

The author carefully selected earthquakes with M_L=4.0～5.0, 215 occurring in the crust in the Taiwan region. The attenuation characteristics of maximum displacement recorded by the Fujian digital network have been obtained by multi-analysis as follows:logA=2.07 231.1/Δ (150km≤Δ≤650km) And the corresponding expression of calibration function is, R(Δ)=3.45-231.1(1/Δ-0.01) (150km≤Δ≤650km) Then, the author determined the magnitude and its error with the data from the Fujian network using the calibration function brought forward in 1997 and the above formula for 790 earthquakes occurring in the crust in the Taiwan region from September 1997 ～ August 2005. The result indicates that the average error of the network is 0.20 with the former and 0.18 with the latter. The average error is 0.13 with the latter with station correction. Compared with the magnitude determined by Taiwan seismologists, the magnitude value with the former is lower by 0.50 on average and that with the latter is higher by 0.08 on average.     

High-resolution climate variability of southwest China during 57-70 ka reflected in a stalagmite δ18O record from Xinya Cave

A 26-cm-long stalagmite (XY2) from Xinya Cave in northeastern Chongqing of China has been ICP-MS ²³⁰Th/U dated, showing a depositional hiatus at 2.3 cm depth from the top. The growth of the 2.3–26 cm interval determined by four dates was between 57 ka and 70 ka, with a linear growth rate of 0.023 mm/a. We have analyzed 190 samples for δ ¹⁸O and δ ¹³C, mostly in the 2.3–26 cm part. The δ ¹⁸O and δ ¹³C values between 57 ka and 70 ka reveal decadal-to-centennial climatic variability during the glacial interval of Marine Isotope Stage 4 (MIS4), exhibiting much higher resolution than that of the published Hulu and Dongge records during this interval. Speleothem δ ¹⁸O in eastern China, including our study area can be used as a proxy of summer monsoon strength, with lighter values pointing to stronger summer monsoon and higher precipitation, and vice versa. Two decreases in the δ ¹⁸O signature of XY2 record around 59.5 and 64.5 Ka are argued to correspond to the Dansgaard-Oeschger (D-O) events 17 and 18 respectively. The Heinrich event 6 (H6) can be identified in the record as a heavy δ ¹⁸O peak around 60 ka, indicating significant weakening of the monsoon in Chongqing during the cold period. The XY2 δ ¹⁸O record shows very rapid change toward to the interstadial condition of the D-O event, but more gradual change toward to the cold stadial condition. This phenomenon found in the Greenland ice core records is rarely observed so clearly in previously published speleothem records. According to SPECMAP δ ¹⁸O record, the glacial maximum of MIS 4 was around 64.5 ka with the boundary of MIS 3/4 around 60 ka. Unlike the marine record, the speleothem record of XY2, China, exhibits much high frequency variations without an apparent glacial maximum during MIS 4. However, the timing of MIS 3/4 boundary seems to be around 60 ka when the H6 terminated, in agreement with the marine chronology. The growth period of sample XY2 during glacial times probably reflects a local karstic routing of water, rather than having climatic significance. Supported by the National Natural Science Foundation of China (Grant Nos. 40672165, 90511004, 40672202) and the Academician Special Project of Chongqing Science Committee (Grant No. 2003-7835)