基于LiDAR数据的流域水系网络提取方法研究

LiDAR技术能够提供高分辨率DEM数据,可用于准确提取流域水系网络信息。研究中针对LiDAR系统提供的高精度DEM数据中存在的噪声,提出采用各向异性扩散滤波算法进行噪声平滑,与常用的DEM滤波算法比较,该方法既能有效去除噪声,同时又能保留高梯度的地形信息。在DEM噪声去除的基础上,采用基于局部地形曲面几何分析的Peuker&Douglas算法初步提取水系网络原型,进一步利用改进的基于坡面流物理模拟分析的加权D8算法提取水系网络,构建了基于LiDAR数据水系网络提取的技术流程。通过鹤壁市某小流域的LiDAR数据水系网络提取试验证明了该方法准确提取水系网络的有效性。     

山西地震前兆台网系统运行维护

针对山西地震前兆台网系统运行的实际需要,从前兆管理系统维护、Oracle数据库维护、数据库备份及恢复三方面进行详细阐述,并对系统运行维护提出一些建议和解决办法。     

对汶川8.0级地震前四川地区地下流体观测异常的研究

研究给出汶川8.0级地震前四川地区地下水位、温泉水温、水化学和气体组分观测异常:地下水位观测点20个,汶川8.0级地震前,有4个观测点观测值出现异常,异常台比例P=4/20=0.20;温泉水温观测点26个,出现异常的5个测点,分布在四川西部地区,P=0.19;水氡观测点12个,出现短期异常1个,P=0.08;气体观测点4个,出现异常1个,P=0.25。同时对疑似或有争议的异常测项进行分析说明。汶川8.0级地震前观测到的地下水水位、温泉水温、水化学和气体组分观测异常的地区,不是分布在龙门山断裂带。震前异常数量少,异常种类和长、中、短、临异常的配套性不明显。同时给出2002年1月至2008年4月四川地区周、月震情会商给出的此类异常项数均值供参阅。     

中国煤炭物探技术的现状与发展

总结了近年来我国煤田物探与矿井物探技术的6大突出进展,即三维地震应用领域不断扩大、地震资料精细处理与动态解释得到推广、地震勘探正在实现从构造勘探向岩性勘探的跨越、地面瞬变电磁技术得到广泛应用、矿井物探技术重新得到重视、以“嵌入式”服务为标志的煤矿安全生产地质保障模式出现了可喜创新等;通过与国内外同类技术发展水平的对比分析,找出了我们存在的差距,提出了加快我国煤炭物探技术发展的对策与建议,并对今后煤炭物探技术与装备的发展前景进行了展望.     

柴达木盆地石炭系地球物理特征及解释

柴达木盆地具有丰富的油气资源,柴北缘、柴西、粜东三湖地区分别以侏罗系、古近系、新近系和第四系为主要勘探目的层.随着北疆石炭系研究的进展和钻探的成功,石炭系已经成为中国西部地区重要的勘探层系,柴达木盆地的石炭系也引起了勘探家的注意,地面地质调查表明石炭系为柴达木盆地一套潜在烃源岩.为了落实石炭系在柴达木盆地内的分布,笔者充分利用近10年来在柴达木盆地及周缘完成的重、磁、电等资料进行了针对石炭系的资料解释、剥层反演和综合研究,明确了石炭系的分布特征,为柴达木盆地石炭系油气勘探指明了方向.     

泥页岩油气藏水平井评价对策与实践

随着泥页岩油气藏勘探程度不断深入,水平井数量成倍增长,给水平井测井评价带来机遇与挑战,但水平并测井解释方法还停留在直井思维上,且水平并响应特征与直并存在较大差剐.而泥页岩储层砂泥薄互层发育,各向异性、非均值性非常严重,砂体横向上不连续,给测井解释评价造成很大困难.本文根据实际资料,采用交互式反演方法,以寻找井眼轨迹与目的层的精细关系为目的,探索了泥页岩油气藏水平井测井评价方法以及应注意的事项.     

岷县漳县6.6级地震后申都乡地窖宏观异常现象及其机理探讨

2013年7月22日甘肃岷县漳县M_s6.6地震后岷县申都乡某地窖出现冒白色烟雾的宏观异常现象。本文通过土壤气Rn、Hg现场检测和采样后气相色谱检测、生物显微镜观察结果,探讨了气体来源、赋存和运移机理以及异常形成的物理化学机制。认为该点具有灵敏的断层活动响应,可作为今后开展断层活动及未来甘东南地震趋势预测判定的断层土壤气监测点进行长期监测。     

Middle Triassic post-orogenic extension on Hainan Island: Chronology and geochemistry constraints of bimodal intrusive rocks

This work studies new petrological and geochemical data and zircon U-Pb ages for bimodal intrusive rocks from Xinglong region, Hainan Island. Zircon U-Pb dating yields mean 238 U/ 206 Pb ages of 238 ± 2 Ma and 234 ± 2 Ma for diabasic and granitic phases, respectively, representing the Middle Triassic emplacement. The diabase and granite bodies were formed from discrete mafic and acidic magma sources that experienced local mechanical mixing at their mutual contacts. Although SiO 2 content of intrusions is bimodal, trace element ratios indicate that both were formed in a post-orogenic extensional setting. Sr-Nd isotopic composition reflects a shared EMII type enriched mantle source component, possibly influenced by subduction-fluid metasomatism.     

Paleomagnetic data from the Late Carboniferous-Late Permian rocks in eastern Tibet and their implications for tectonic evolution of the northern Qiangtang-Qamdo block

We report paleomagnetic results from the Late Carboniferous-Late Permian strata in eastern Tibet (China), and aim to clarify the tectonic and paleogeographic evolution of the northern Qiangtang-Qamdo block, which is the key to the study of plate boundary between the Gondwanaland and the Eurasia during the late Paleozoic. Two hundred and nineteen samples-including limestone, muddy siltstone, basalt, lava, and tuff-were collected at 24 sites in the Upper Carboniferous and Middle-Upper Permian successions. A systematic study of rock magnetism and paleomagnetism yields three reliable paleomagnetic pole positions. Both hematite and magnetite occurred in the Late Carboniferous limestone samples. The demagnetization curve shows a characteristic double-component, with the remanent magnetization (ChRM) exhibiting a positive polarity (negative inclination). In the Late Permian limestone, tuff, and basalt, magnetic information were recorded primarily in magnetite, although a small fraction of them was found in hematite in basalt. The demagnetization curve illustrates a double or single component, with the ChRM showing a negative polarity (positive inclination), which has passed the classic fold test successfully. The single polarity features of the ChRM directions of the Late Carboniferous and Middle-Late Permian rocks are respectively related to the Kiaman positive and reversed polarities under the stratigraphic coordinates. This, in turn, indicates that both ChRMs directions represent the original remanence directions. By comparison with the previously published paleomagnetic results from the late Paleozoic rocks in the northern Qiangtang Range, we suggest that: (1) Qamdo and northern Qiangtang block were independent of each other during the Late Carboniferous to the Early Permian periods. The north Lancangjiang ocean basin between the two blocks may have closed before the Middle Permian and been involved in the continent-continent collision stage in the Late Permian-Early Triassic periods. (2) The northern Qiangtang-Qamdo Block paleogeographically was situated at low to intermediate latitudes in the Southern Hemisphere in the Late Carboniferous-Late Permian periods, and began to displace northward in the Early Triassic, with an amount of more than 5000 km northward transport from its current location.     

绩溪县洪坑板岩砚石矿的岩性、成分、物理化学性能特征分析

赋存于中元古代大谷运组上段地层中的绩溪县洪坑板岩类砚石,通过与歙砚石～歙县龙头石及江西龙尾石、九江石、大畈石、玉山石的物理化学参数测试资料对比分析,歙砚石其原岩均为泥砂质构造沉积岩,但岩性、成分、物理化学性能特征存在一定差异,与歙砚石—龙尾石属于不同成因机制的砚石。