GPS 高程转换的总体最小二乘组合方法     

王乐洋  吴飞  吴良才 《测绘工程》2016,25(4):11-14

在现有GPS高程转换的研究中,通常只采用单一的解算方法,然而,不同的计算方法由于适用的条件不同,在对同一组数据进行解算时,解算的精度也各有优劣。针对以上问题,文中提出GPS高程转换的总体最小二乘组合方法,对多种不同的高程转换方法进行组合,运用总体最小二乘法计算不同方法的权值,结合实际工程数据,验证该方法的可行性。计算结果表明,提出的方法能够有效地提高高程转换精度。  相似文献   

基于遥感和GIS的石河子垦区土地覆被动态监测研究     

姜佃高  许珊娜 《北京测绘》2016,(4):32-37

应用遥感和GIS技术对新疆石河子垦区1980年、1990年、2002年和2014年的遥感影像资料进行处理,并从土地覆被总体状况、数量变化和土地覆被转移方向三方面作了动态监测分析。结果表明,草地、耕地、未利用土地是石河子垦区的主要土地覆被类型。1980到2014年间,草地面积大幅度减少,耕地面积大幅度增加,其中城乡、工矿、居民用地年变化率最大,林地动态度最低。分析结果为该区土地资源的可持续利用提供了重要的依据。  相似文献   

崖南凹陷Y1井崖三段煤系烃源岩发育规律     

张春良  沈玉林  秦勇  赵志刚  杨柳  谢国梁 《沉积学报》2016,34(5):1003-1010

基于Y1井煤系烃源岩样品微量元素分析、煤岩显微组分及热解测试结果,结合小波分析的米氏旋回划分结果,系统研究了崖南凹陷Y1井崖三段煤系烃源岩特征及发育规律。研究表明:①以104和260尺度结合岩芯沉积序列及地球化学测试结果,将崖三段划分为2个中期和5个短期米氏旋回,垂向上表现为旋回厚度及烃源岩比例向上增大的趋势,中期旋回上部为烃源岩优势发育层位,其中ⅠA2、ⅠA3和ⅠB2为煤系烃源岩发育的优势旋回;②煤系烃源岩有机显微组分表现为富镜质组、贫惰质组、贫壳质组+腐泥组,镜质组含量为44%~100%,平均为83%,以基质镜质体及镜屑体为主,烃源岩类型以Ⅲ型（腐殖型）有机质为主,少量为Ⅱ₂型（腐泥-腐殖型）有机质,烃源岩以产气为主,其成熟度较低,R_o值平均为1.12%,处于生烃阶段初期;③煤系烃源岩发育受多种因素控制,其中断陷盆地向坳陷盆地的转化时期是成煤的关键构造时期、强烈进积作用使得煤系烃源岩保存不全、区域海平面上升时期是成煤的关键时期、短期旋回小波曲线右偏拐点处为煤系烃源岩相对发育层位。  相似文献   

广东省典型铜矿床区域地球化学异常特征     

张伟  陈陵康  朱进守 《物探与化探》2016,(4):728-731

广东省铜矿床具产地分散、类型多样、储量集中的特点。以八个典型铜矿床为例,探讨铜异常及其元素组合特征,得出:1铜富集部位对已知矿的反映较好;2规模相似的不同类型铜矿床,其铜异常面积相近,但铜平均含量差异较大;3斑岩型铜矿的Cu、Mo、Sb组合,岩浆热液型、矽卡岩型、复成因型铜矿的Cu、Pb、Zn、Ag、Cd、Bi、Mo、W、Sn、Mn组合,火山岩型铜矿的Cu、Pb、Zn、Cd、Ag、As组合较稳定。这些结论为进一步了解广东省铜矿的成矿规律及开展地质勘查、地质评价工作提供了一定的科学依据。  相似文献   

河岸带潜流层温度示踪流速计算方法          下载免费PDF全文

李英玉  赵坚  吕辉  陈斌 《水科学进展》2016,27(3):423-429

为揭示低温水影响下的河岸带潜流层的温度场和流场分布特性,利用野外水温水位实时监测试验,研究河岸带潜流层温度场在不同季节、不同空间位置上的分布特性,并利用水温资料计算获得地下水流速。结果表明:河岸带潜流层温度场在夏季和冬季分别呈现出"上暖下冷"和 "上冷下暖"的温度分层现象;通过对温度示踪方法的4种计算方法进行分析比较,得到Hatch相位法计算的地下水流速具有较高的准确性,在2014年12月15—31日时段内流速大小为1.03×10-4~7.96×10-4m/s,在空间上,断面深度增加,地下水流速降低,且不同深度流速曲线接近平行。  相似文献   

辽河油田东部凹陷玄武岩测井特征分析     

左程吉  陆哲昆  王宏伟  王祝文 《世界地质》2016,35(4):1095-1100

针对辽河油田东部凹陷地区复杂火成岩岩性中玄武岩的测井特征,根据东部凹陷的测井数据及取芯段的薄片识别,共找到4种不同类型的玄武岩地层,分两组进行对比分析。第一组:气孔玄武岩、角砾化玄武岩;第二组:玄武岩、含油水层的玄武岩。利用玄武岩地层对应数据制作测井响应统计表,对比不同类型测井参数的差别制作交会图,得到角砾化玄武岩相对气孔玄武岩有较高的自然电位值,含油水层的玄武岩相对玄武岩有较高自然伽马值及中子值等特征。分析原因为气孔玄武岩及角砾化玄武岩孔隙裂缝发育,密度较低,黏土矿物充填角砾化玄武岩孔隙使自然电位值相对较高;含油水层的玄武岩中大量氢元素使中子值及自然伽马值相对玄武岩有所增加。  相似文献   

基于变动范围法(RVA)的信江水文改变及生态流量研究   总被引：2，自引：0，他引：2       下载免费PDF全文

刘贵花  朱婧瑄  熊梦雅  王点  齐述华 《水文》2016,36(1):51-57

选择信江下游梅港站1950~2010年日径流量,根据流域大型水库界牌枢纽运行时间将梅港站径流序列分为建库前(1953~2001)和建库后(2002~2010)两个时段。采用变动范围法(Range of Variability Approach,简称:RVA)分析水库运行对下游梅港站流域生态水文指标改变度,并分析了信江下游生态流量。研究表明:33个水文指标有22个发生中高度改变,11个指标发生低度改变,其水文综合改变度为0.51,属于中度改变;梅港站生态流量值均在RVA阈值内,基本能够保持河流稳定流量,但2月、7~9月及12月河道生态流量大于RVA下限。可适量增大水库下泄水量,降低对下游河段生态系统的威胁。  相似文献   

Seismic geomorphology of cretaceous megaslides offshore Namibia (Orange Basin): Insights into segmentation and degradation of gravity-driven linked systems     

《Marine and Petroleum Geology》2016

This study applies modern seismic geomorphology techniques to deep-water collapse features in the Orange Basin (Namibian margin, Southwest Africa) in order to provide unprecedented insights into the segmentation and degradation processes of gravity-driven linked systems. The seismic analysis was carried out using a high-quality, depth-migrated 3D volume that images the Upper Cretaceous post-rift succession of the basin, where two buried collapse features with strongly contrasting seismic expression are observed. The lower Megaslide Complex is a typical margin-scale, extensional-contractional gravity-driven linked system that deformed at least 2 km of post-rift section. The complex is laterally segmented into scoop-shaped megaslides up to 20 km wide that extend downdip for distances in excess of 30 km. The megaslides comprise extensional headwall fault systems with associated 3D rollover structures and thrust imbricates at their toes. Lateral segmentation occurs along sidewall fault systems which, in the proximal part of the megaslides, exhibit oblique extensional motion and define horst structures up to 6 km wide between individual megaslides. In the toe areas, reverse slip along these same sidewall faults, creates lateral ramps with hanging wall thrust-related folds up to 2 km wide. Headwall rollover anticlines, sidewall horsts and ramp anticlines may represent novel traps for hydrocarbon exploration on the Namibian margin.The Megaslide Complex is unconformably overlain by few hundreds of metres of highly contorted strata which define an upper Slump Complex. Combined seismic attributes and detailed seismic facies analysis allowed mapping of headscarps, thrust imbrications and longitudinal shear zones within the Slump Complex that indicate a dominantly downslope movement of a number of coalesced collapse systems. Spatial and stratal relationships between these shallow failures and the underlying megaslides suggest that the Slump Complex was likely triggered by the development of topography created by the activation of the main structural elements of the lower Megaslide Complex.This study reveals that gravity-driven linked systems undergo lateral segmentation during their evolution, and that their upper section can become unstable, favouring the initiation of a number of shallow failures that produce widespread degradation of the underlying megaslide structures. Gravity-driven linked systems along other margins are likely to share similar processes of segmentation and degradation, implying that the megaslide-related, hydrocarbon trapping structures discovered in the Namibian margin may be common elsewhere, making megaslides an attractive element of deep-water exploration along other gravitationally unstable margins.  相似文献   

Hydrothermal Fluid Sources of the Fengjia Barite–fluorite Deposit in Southeast Sichuan,China: Evidence from Fluid Inclusions and Hydrogen and Oxygen Isotopes          下载免费PDF全文

Hao Zou  Shou‐ting Zhang  An‐qing Chen  Yi Fang  Zhao‐fa Zeng 《Resource Geology》2016,66(1):24-36

The Fengjia barite–fluorite deposit in southeast Sichuan is a stratabound ore deposit which occurs mainly in Lower Ordovician carbonate rocks. Here we present results from fluid inclusion and oxygen and hydrogen isotope studies to determine the nature and origin of the hydrothermal fluids that generated the deposit. The temperature of the ore‐forming fluid shows a range of 86 to 302 °C. Our detailed microthermometric data show that the temperature during mineralization of the fluorite and barite in the early ore‐forming stage was higher than that during the formation of the calcite in the late ore‐forming stage. The salinity varied substantially from 0.18% to 21.19% NaCl eqv., whereas the density was around 1.00 g/cm³. The fluid composition was mainly H₂O (>91.33%), followed by CO₂, CH₄ and traces of C₂H₆, CO, Ar, and H₂S. The dominant cation was Na⁺ and the dominant anion Cl^‐, followed by Ca²⁺, SO₄^2‐, K⁺, and Mg²⁺, indicating a mid–low‐temperature, mid‐low‐salinity, low‐density NaCl–H₂O system. Our results demonstrate that the temperature decreased during the ore‐forming process and the fluid system changed from a closed reducing environment to an open oxidizing environment. The hydrogen and oxygen isotope data demonstrate that the hydrothermal fluids in the study area had multiple sources, primarily formation water, as well as meteoric water and metamorphic water. Combined with the geological setting and mineralization features we infer that the stratabound barite–fluorite deposits originated from mid–low‐temperature hydrothermal fluids and formed vein filling in the fault zone.  相似文献   

Thermal history of the giant Qulong Cu–Mo deposit,Gangdese metallogenic belt,Tibet: Constraints on magmatic–hydrothermal evolution and exhumation     

《Gondwana Research》2016

A complete thermal history for the Qulong porphyry Cu–Mo deposit, Tibet is presented. Zircon U–Pb geochronology indicates that the mineralization at Qulong resulted from brecciation-veining events associated with the emplacement of a series of intermediate-felsic intrusions. Combined with previously published ages, our results reveal a whole intrusive history of the Qulong composite pluton. Causative porphyries were emplaced at ~ 16.0 Ma as revealed by ⁴⁰Ar–³⁹Ar dating of hydrothermal biotite (15.7 ± 0.2 Ma) and sericite (15.7 ± 0.2 Ma). Zircon and apatite (U–Th)/He (ZHe and AHe) dating of Qulong revealed that both followed similar, monotonic thermal trajectories from 900 °C (U–Pb ages: 17.5–15.9 Ma) to 200 °C (ZHe: 15.7–14.0 Ma), and that the causative porphyries experienced faster cooling at a maximum rate of greater than 200 °C/myr. The Qulong deposit was exhumed between 13.6 Ma and 12.4 Ma (AHe) at an estimated rate of 0.16–0.24 mm/y, which is consistent with previous estimates for other Gangdese Miocene porphyry deposits. Our AHe thermochronology results suggest that neither the Gangdese thrust system, nor the Yadong–Gulu graben affected or accelerated exhumation at the Qulong deposit.  相似文献