Cross-formational hydrocarbon fluid flows in the Tertiary deltaic system of the Beaufort–Mackenzie Basin     

Maowen Li  Yongqiang Xiong  Lloyd R. Snowdon  Dale Issler 《Journal of Geochemical Exploration》2006,89(1-3):214

Molecular and isotopic compositions of crude oils in the Beaufort–Mackenzie Basin confirm three genetic end-member oil groups and suggest extensive cross-formational hydrocarbon fluid flows in the Tertiary deltaic system. Inter- and intra-fractional variations in the geochemistry of the Tertiary-reservoired oils indicate that the oil source/maturity signatures were substantially masked by biomarkers that were picked up along migration pathways. Thus, many of the previously recognized “immature non-marine oils” are in fact thermally mature, probably derived from unpenetrated deeper marine source rocks. Although the effective source rock volumes have not been evaluated and their exact stratigraphic levels remain unknown, the relative timing of oil generation versus trap formation, rather than poor source quality, may be the cause of under-filled traps in the offshore area.  相似文献   

梁子湖水体P的季节变化与沉积物P释放初步研究   总被引：4，自引：0，他引：4  

熊汉锋  陈治平  黄世宽  谭启玲  丰民义  王运华 《湿地科学》2006,4(3):174-178

采用分级测定的方法对梁子湖沉积物中无机磷酸盐进行了分析,测定了梁子湖水体P的季节变化,并以室内模拟的方法研究梁子湖沉积物在pH值和温度控制下P的释放特征。研究表明,梁子湖水体P的含量呈明显的季节变化,冬季高,夏季低。沉积物无机磷(P i)中以钙磷(Ca—P)为主(55%~61%),铁磷(Fe—P)次之(28%~33%),铝磷(A l—P)最少(3%~5%)。在梁子湖的入水口和出水口,由于沉积环境影响到P的形态,P的释放明显较湖心高。在试验初期,由于扰动的影响,使得P的释放在第1天比第2天和第3天高,其后P的释放量则迅速增加。温度对P释放影响明显,其具体表现为,30℃时P释放达到峰值的时间比4℃时提前4 d,而且前者峰值比后者高出9倍。pH值对沉积物P释放同样有明显的影响,与正常状态下的湖水条件(pH值为8.5)相比,偏酸(pH值为5.5)和偏碱(pH值为11.5)条件下,P的释放量增加。  相似文献   

国外城市群经济联系空间研究进展   总被引：28，自引：1，他引：28  

熊剑平  刘承良  袁俊 《世界地理研究》2006,15(1):63-70

城市群经济联系的复杂性空间规律已经成为城市地理学、区域地理学、经济地理学研究的重点范畴。现代意义的城市群经济联系空间发展研究始于50年代,城市群体化现象大规模出现,城市化进程迅速发展的时期。经过二战前的启蒙发展、二战后-60年代的初步发展、70-80年代的丰富深化、90年代的全面发展阶段,50多年来城市群空间研究领域不断深化、研究队伍不断壮大、研究成果不断涌现、研究范式不断丰富,呈现多视角、多层次、多尺度,理论与实证、定性与定量相结合的研究体系,研究内容上文章着重对国外大都市区、都市带等城市群经济联系的空间组织与结构研究进行总结,并指出当前研究的热点与焦点。  相似文献   

Petrogenesis of Cretaceous adakitic and shoshonitic igneous rocks in the Luzong area, Anhui Province (eastern China): Implications for geodynamics and Cu–Au mineralization     

Qiang Wang  Derek A. Wyman  Ji-Feng Xu  Zhen-Hua Zhao  Ping Jian  Xiao-Lin Xiong  Zhi-Wei Bao  Chao-Feng Li  Zheng-Hua Bai 《Lithos》2006,89(3-4):424-446

Both adakitic and shoshonitic igneous rocks in the Luzong area, Anhui Province, eastern China are associated with Cretaceous Cu–Au mineralization. The Shaxi quartz diorite porphyrites exhibit adakite-like geochemical features, such as light rare earth element (LREE) enrichment, heavy REE (HREE) depletion, high Al₂O₃, MgO, Sr, Sr / Y and La / Yb values, and low Y and Yb contents. They have low ε_Nd(t) values (− 3.46 to − 6.28) and high (⁸⁷Sr / ⁸⁶Sr)_i ratios (0.7051–0.7057). Sensitive High-Resolution Ion Microprobe (SHRIMP) zircon analyses indicate a crystallization age of 136 ± 3 Ma for the adakitic rocks. Most volcanic rocks and the majority of monzonites and syenites in the Luzong area are K-rich (or shoshonitic) and were also produced during the Cretaceous (140–125 Ma). They are enriched in LREE and large-ion lithophile elements, and depleted in Ti, and Nb and Ba and exhibit relatively lower ε_Nd(t) values ranging from − 4.65 to − 7.03 and relatively higher (⁸⁷Sr / ⁸⁶Sr)_i ratios varying between 0.7057 and 0.7062. The shoshonitic and adakitic rocks in the Luzong area have similar Pb isotopic compositions (²⁰⁶Pb / ²⁰⁴Pb = 17.90–18.83, ²⁰⁷Pb / ²⁰⁴Pb = 15.45–15.62 and ²⁰⁸Pb / ²⁰⁴Pb = 38.07–38.80). Geological data from the Luzong area suggest that the Cretaceous igneous rocks are distributed along NE fault zones (e.g., Tanlu and Yangtze River fault zones) in eastern China and were likely formed in an extensional setting within the Yangtze Block. The Shaxi adakitic rocks were probably derived by the partial melting of delaminated lower crust at pressures equivalent to crustal thickness of > 50 km (i.e., 1.5 GPa), possibly leaving rutile-bearing eclogitic residue. The shoshonitic magmas, in contrast, originated mainly from an enriched mantle metasomatized by subducted oceanic sediments. They underwent early high-pressure (> 1.5 GPa) fractional crystallization at the boundary between thickened (> 50 km) lower crust and lithospheric mantle and late low-pressure (< 1.5 GPa) fractional crystallization in the shallow (< 50 km) crust. The adakitic and shoshonitic rocks appear to be linked to an intra-continental extensional setting where partial melting of enriched mantle and delaminated lower crust was probably controlled by lithospheric thinning and upwelling of hot asthenosphere along NE fault zones (e.g., Tanlu and Yangtze River fault zones) in eastern China. Both the shoshonitic and adakitic magmas were fertile with respect to Cu–Au mineralization.  相似文献   

金沙江干热河谷区土壤侵蚀危险度评价——以云南元谋为例     

周红艺  熊东红杨忠 《山地学报》2006,24(B10):52-56

利用空间主成分分析方法，选取降水、坡度、植被、土地利用、土壤类型、人口、高程等作为评价指标，建立空间主成分评价模型Pi=0．78X1＋0．06X2＋0．05X3＋0．04X4，将研究区分为无险型、轻险型、危险型、强险型和极险型五种类型，较为准确地得到了危险度综合评价结果。因此，空间主成分分析模型，在土壤侵蚀危险程度评价方面的应用较为成功，是一种科学有效的研究方法。  相似文献   

基于数据手套和跟踪器的虚拟手臂建模     

刘颖真  万刚  游雄 《测绘科学技术学报》2005,22(4):272-274

文中利用数据手套和跟踪器获取手臂各关节运动数据,根据关节运动限制对所获取数据进行处理,建立了符合人体运动规律的虚拟手臂数学模型,实现了虚拟环境中与试验者的手臂同步运动、效果逼真的虚拟手臂模型.  相似文献   

纹理映射失真处理中的LOD技术     

王菲  卢晨琰夏青 游雄 《测绘学院学报》2005,22(4):304-306

纹理映射是计算机图形学中广泛应用的一项重要技术,纹理图像可以描述景物表面各点处的反射属性,模拟景物表面丰富的纹理细节,减少建模的工作量,提高计算机生成图形的真实性.但是由于纹理都为栅格图像,放大和缩小会产生一定程度的失真,所以要对纹理进行细节分层处理.文中主要介绍纹理的重采样和建立金字塔技术,提出减少纹理映射失真的方法.  相似文献   

少量地面控制点的遥感图像精纠正与定位技术探讨     

张宝印  熊兴华赵琪 《测绘科学与工程》2005,25(4):5-7

本文主要讨论了利用空间投影一空间斜墨卡托（SOM）投影进行卫星遥感图像精纠正与定位，解决缺少控制点地区卫星遥感图像精纠正与定位问题，并根据正反算公式讨论了卫星遥感图像纠正的空间投影数学基础。  相似文献   

一种短期气候预测集成技术的应用研究     

吉廷艳  熊方  黄继用 《高原气象》2002,21(5):522-525

以递归正权综合决策方案为基础，结合实际情况，首先对多种预报方法进行筛选，选取预报效果较好并且较为稳定的几种方法参与集成，并将集成结果写成Micaps数据格式，最终以图形方式显示出来。评分结果表明：该集成方法对温度预报和灾害指数预报较权重平均集成法效果好；而对月雨量预报和季度雨量、温度预报则与权重平均方法相当；但是对季度雨量、温度预报来说，集成后预测精度有明显提高。同时，将集成结果通过Micaps工作平台以图形方式显示，不仅客观、定量，而且更一目了然．  相似文献   

赣北中元古界双桥山群低变质强变形行为与格林威尔期造山作用   总被引：4，自引：1，他引：4  

秦松贤  章泽军  张志  赵温霞  蔡雄飞  顾延生 《地质科技情报》2002,21(2):8-12

广泛分布于赣北地区的中元古界双桥山群，以低级区域变质作用、强烈构造变形、具陆内造山带构造变形特征；其成果系在华夏古陆与扬子古陆的碰撞拼接过程中，其应力向陆内传递的结果；时间大致在1100－800Ma，与全球格林威尔期造山作用相当。  相似文献