连续电磁剖面法在赛什腾山前逆掩推覆构造识别中的应用

柴达木盆地北缘赛什腾山前带逆掩推覆构造发育,地表条件差,地震勘探困难,为此在该区开展了连续电磁剖面法勘探研究。采用Robust、远参考、静态校正多种预处理方法有效压制了干扰,提高了数据品质。通过综合应用Bostick、CMI和二维连续介质反演方法突出了有效异常,清晰地揭示了赛什腾山前带逆掩推覆构造的发育特征,明确了山前逆掩推覆断裂下盘地层空间展布及该区的盆山接触关系。     

The Crater Mountain Deposit,Papua New Guinea: Porphyry‐related Au–Te System

Ore mineralization and wall rock alteration of Crater Mountain gold deposit, Papua New Guinea, were investigated using ore and host rock samples from drill holes for ore and alteration mineralogical study. The host rocks of the deposit are quartz‐feldspar porphyry, feldspar‐hornblende porphyry, andesitic volcanics and pyroclastics, and basaltic‐andesitic tuff. The main ore minerals are pyrite, sphalerite, galena, chalcopyrite and moderate amounts of tetrahedrite, tennantite, pyrrhotite, bornite and enargite. Small amounts of enargite, tetradymite, altaite, heyrovskyite, bismuthinite, bornite, idaite, cubanite, native gold, CuPbS₂, an unidentified Bi‐Te‐S mineral and argentopyrite occur as inclusions mainly in pyrite veins and grains. Native gold occurs significantly in the As‐rich pyrite veins in volcanic units, and coexists with Bi‐Te‐S mineral species and rarely with chalcopyrite and cubanite relics. Four mineralization stages were recognized based on the observations of ore textures. Stage I is characterized by quartz‐sericite‐calcite alteration with trace pyrite and chalcopyrite in the monomict diatreme breccias; Stage II is defined by the crystallization of pyrite and by weak quartz‐chlorite‐sericite‐calcite alteration; Stage III is a major ore formation episode where sulfides deposited as disseminated grains and veins that host native gold, and is divided into three sub‐stages; Stage IV is characterized by predominant carbonitization. Gold mineralization occurred in the sub‐stages 2 and 3 in Stage III. The fS₂ is considered to have decreased from ～10^?2 to 10^?14 atm with decreasing temperature of fluid.     

祁连山冻土区天然气水合物岩性和分布特征

2008~2009年实施的“祁连山冻土区天然气水合物科学钻探工程”,已完成DK-1、DK-2、DK-3和DK-4孔的钻探任务。施工期间多次钻获天然气水合物实物样品,证实祁连山冻土区存在天然气水合物。祁连山冻土区天然气水合物主要以裂隙型和孔隙型2种状态产出。基于天然气水合物存在的10个方面的特征,认为天然气水合物赋存层位主要为中侏罗统江仓组,产于冻土层之下,主要储集于133.0~396.0m区间,储集层岩性多以粉砂岩、油页岩、泥岩和细砂岩为主,含少量中砂岩。钻孔中天然气水合物纵向分布不具有连续性,钻孔间横向分布规律不明显。岩石质量指标(RQD)统计结果显示,RQD低值区与天然气水合物储集层段具有较好的一致性,表明裂缝系统对于该区天然气水合物的分布具有重要的控制作用。     

祁连山冻土区天然气水合物气体组分的 气相色谱法测定

建立了气相色谱法测定祁连山冻土区天然气水合物C1~C5气体组分的分析方法,对比研究了单点法与多点法校正、外标法与外标归一化法定量,以及顶空法与排水法2种气体收集方式的区别。结果表明：顶空法制备、单点法校正、外标归一化法定量计算为气相色谱法测定天然气水合物气体组分的最佳方法, 方法相对标准偏差（RSD）为0～1.06%,检出限为0.0003%~0.0127%。通过对祁连山冻土区DK-2孔10个天然气水合物样品的测定,发现C1含量为60.64%~78.76%,C2含量为8.99%~13.60%,C3含量为6.58%~21.24%,C4和C5含量较少,可见C2+气体组分含量丰富,具有较低的C1/C2+比值（1.5~3.7）,显示出明显的热解气特征。     

同构非优旅游地理论与实证研究

同构非优旅游地是旅游资源非优区中的一种类型,由于原生性旅游资源缺乏且品位低、政策误读、规划失误等诸多因素影响,致使同构非优旅游地的生存现状岌岌可危。在分析同构非优旅游地及优势旅游地现状基础上,指出同构非优旅游地今后的发展之路只能是与优势旅游地整合或自我发展,并以天台山国家森林公园为例,实证分析其发展之路的可行性,以期指导同构非优旅游地走出困境。     

九华山森林生态系统生态服务价值评估

基于LY/T1721-2008((森林生态系统生态服务功能评估规范>,采用实证研究、意愿调查、文献研究等方法,估算了九华山森林生态系统生态服务价值,结果表明:2009年,九华山森林生态系统生态服务价值为84 208.50万元,实物生产价值为4 359.06万元,生态服务价值是实物生产价值的19.31倍.各项生态服务功能价值大小顺序为:涵养水源>保育土壤>生物多样性保护>固碳释氧>森林游憩>净化大气环境>积累营养物质.可为九华山管委会制定旅游、社会经济发展规划,合理开发九华山生态旅游资源,提供理论依据和数据支撑,也可增强人们对九华山森林资源保护的自觉性和主动性.     

A Potential Flood Hazard Caused by Tianchi Volcano Eruption in Changbai Mountain, Northeast China

Geohazards appear to be increasing in frequency globally. It is of necessity to actively manage these natural hazards to minimize loss of life and property. From an early warning perspective, this paper stresses the potential fatal flood hazard represented by the huge volume of water in Tianchi Lake, the unique geography of Changbai Mountain, and the limited flood control ability in the upstream of the Songhua River. Northeast Asian countries should keep a watchful eye on the Changbai volcano cooperatively,...     

Geographical variation on cone and seed production of natural Pinus halepensis Mill. forests in Tunisia

Aleppo pine (Pinus halepensis Mill.) is found in discontinuous bands along the Mediterranean Basin, usually at low elevations and in dry climates. This study was conducted to relate bioclimatic zones and geographic distribution with representative individual tree of populations for cone number and weight from the driest to the wettest Aleppo pine forest zones. Epidometric values were recorded in all sample stands in the monitoring plots set in 79 native populations from the Algerian border to the eastern coast of Tunisia, representing a wide range from each region in northern Africa. Simple and multiple regressions were performed on the data. Results showed that the canopy seed bank increased according to elevation, latitudinal and longitudinal gradients. The simple regression analysis showed a latitudinal effect positively relating increasing latitude to greater cone crop. Similarly, longitudinal and elevation variations were related to significant differences in cone dimensions. Higher average seed mass was related to populations located westwards or at higher elevation. The multiple regression analysis indicated that the longitudinal variations were the most determinant geo-positional factors in Aleppo pine cone dimensions and average seed mass in natural Aleppo pine forests in Tunisia.     

Types and formation mechanism of collapse in Tianchi region of Changbai Mountain

Collapse is a disaster in Changbai Mountain area. Based on the present stage of collapse, the anthors summarized three types of collapse and analyzed their formation mechanism. This research makes sense to further study.     

翠华山甘湫池景观地质遗迹成因

甘湫池是翠华山国家地质公园的一个新景点。实地调查发现,整个景区是一座罕见的基岩古滑坡,具有滑坡地貌可观察的景观形态特征。从空间分布和层序关系来看,上覆的崩塌乱石是后期堆积在古滑坡体上,甘湫池应是古滑坡形成的拉伸洼地,并非是由崩塌形成的堰塞湖,同时在景观形态上也与水湫池明显不同,这对于科学认识和开展地质遗迹旅游具有重要的意义。