渤海西部沙东南构造带东营组古地貌特征及对沉积的控制作用     

康海亮  林畅松  牛成民 《地质力学学报》2021,27(1):19-30

渤海西部海域沙东南构造带处于沙垒田凸起向沙南凹陷的过渡部位,受继承性凸起、不同时期同沉积断裂和古沟谷多种因素影响,沉积相的发育较为复杂,制约了下步油气勘探。为此,通过分析由地层厚度法恢复的沙东南构造带东营组各三级层序沉积时期的古地貌,明确了研究区发育凸起区、斜坡区、古沟谷、断槽、浅洼和深洼陷区等多种地貌单元。同时,以北北东向转换断裂为界,划分出两种不同的地貌组合分区:西区为由侵蚀沟谷、古潜山斜坡和早期同沉积断裂组成的沟谷-斜坡-断坡地貌,东区为由侵蚀沟谷、2~3条同向不同期同沉积断层组成的沟谷-多级断坡地貌。研究表明两种构造地貌中位于凸起边缘的沟谷早期均为物源通道,晚期接受沉积充填,对沉积相类型、分布以及充填控制的差异主要受斜坡-断坡和多级断坡的影响:在沟谷-斜坡-断坡地貌中,沉积体系的分布和沉积充填过程主要受古斜坡-断坡控制,控制断坡的同沉积断裂在沙河街组活动较强,控制了沙河街组低位扇、浊积扇的沉积和充填,SQ-Ed3时期断裂活动逐渐减弱,继承性断坡地貌成为SQ-Ed3层序扇三角洲平原和前缘以及SQEd2^d,SQ-Edu2时期辫状河三角洲前缘和滨浅湖沉积的大致界限;在沟谷-多级断坡地貌中,形成于SQ-Ed3时期的沙东南1号断裂仅在SQ-Ed3时期活动,控制了深洼陷的形成和一级坡折之下小型扇三角洲的发育,形成于SQ-Ed2^d时期的沙南断裂主要活动时期也在SQ-Ed2^d,形成了分隔凸起与斜坡间的二级坡折,控制了SQ-Ed2^d小型扇三角洲的沉积充填。  相似文献   

石窟寺文物的数字化保护与利用     

李敏  刁常宇  葛云飞  裘霖山  李丽 《遥感学报》2021,25(12):2351-2364

随着信息技术的飞速发展,石窟寺文物的数字化保护与利用引起了国内外的广泛关注。文章从石窟寺文物数字化采集、保护和利用等方面进行系统梳理,重点分析石窟寺文物数字化保护中三维信息获取、三维重建评价以及三维打印等相关前沿信息技术的应用现状。并针对石窟寺文物数字化保护和利用工程实践中的难点,给出采用激光脉冲三维采集细部结合多视图重建采集整体形状的三维重建结合三维打印的解决方案。同时,针对摄影测量计算过程中可能出现的整体形状偏差,采用脉冲式激光三维扫描仪在石窟中进行整体扫描来建立石窟三维形状的框架,以对多视图重建计算中的空间解算误差进行约束。其中,提出了基于关键参数一致化的分布式集中约束调整方法,在保障精确度的同时得到更好的计算效率。然后通过云冈石窟和龙门石窟字化保护和利用的经典案例,具体分析工程实践中的难点,并探讨以上解决方案的可行性。综合考虑成本与效果等多种因素,该方案是当前技术条件下性价比相对较高,同时可以兼顾色彩与质感原真再现的解决思路。最后对未来趋势进行展望并给出相关技术和应用建议。  相似文献   

阿尔金和东昆仑造山带中酸性侵入岩地质、地球化学特征及地质意义   总被引：3，自引：0，他引：3  

高永宝  李文渊  李侃  张照伟  张江伟 《新疆地质》2011,29(4):359-366

据青藏高原北部1∶25万区域地质调查资料引对阿尔金和东昆仑造山带中主要出露的中酸性侵入岩类岩体地质、岩石地球化学特征进行对比研究,探讨原始古陆系统隶属关系结果得出:岩体类型、岩石类型组合、成岩时代、岩浆系列、岩浆源岩物性及形成的地球动力学背景均可完全进行对比,认为前晋宁和晋宁期S型花岗岩类,可能是在碰撞造山地球动力学背景下,由成年期TTG陆壳局部或循环熔融形成;加里东和华力西期以I型和A型花岗岩类为主,推测是在一种大陆岩石圈伸展减薄或是大陆裂谷动力学背景下,由地幔基性超基性岩浆上侵引起中下地壳岩石局部熔融产生的一种岩浆作用产物,源区可能是副变质类型榴辉岩相和麻粒岩相下地壳结合前人研究成果,初步提出阿尔金和东昆仑造山带古老基底同属一个古陆系统.  相似文献   

Permian Tectonic Evolution in Southwestern Khanka Massif: Evidence from Zircon U‐Pb Chronology,Hf isotope and Geochemistry of Gabbro and Diorite   总被引：8，自引：0，他引：8  

CAO Huahu  XU Wenliang  PEI Fuping  ZHANG Xingzhou 《《地质学报》英文版》2011,85(6):1390-1402

Laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb dating and geochemical data for the Permian gabbros and diorites in the Hunchun area are presented to constrain the regional tectonic evolution in the study area. Zircons from gabbro and diorite are euhedral-subhedral in shape and display fine-scale oscillatory zoning as well as high Th/U ratios (0.26–1.22), implying their magmatic origin. The dating results indicate that the gabbro and diorite formed in the Early Permian (282±2 Ma) and in the Late Permian (255±3 Ma), respectively. In addition, the captured zircons with the weighted mean age of 279±4 Ma are also found in the diorite, consistent with the formation age of the gabbro within uncertainty. The gabbros belong chemically to low-K tholeiitic series, and are characterized by low rare earth element (REE) abundances, flat REE pattern, weak positive Eu anomalies (δEu), and depletion in high field strength elements (HFSEs, Nb, Ta, and Ti), similar to the high-aluminum basalts from island arc setting. Initial Hf isotopic ratios of zircons from the gabbro range from +7.63 to +14.6, suggesting that its primary magma could be mainly derived from partial melting of a depleted lithospheric mantle. The diorites belong to middle K calc-alkaline series. Compared with the gabbros, the diorites have higher REE abundance, weak negative Eu anomalies, and more depletion in HFSEs (Nb, Ta, and Ti), similar chemically to the volcanic rocks from an active continental margin setting. Initial Hf isotopic ratios and Hf two-stage model ages of zircons from the diorite range from +11.22 to +14.17 and from 424 to 692 Ma, respectively, suggesting that its primary magma could be mainly derived from partial melting of the Early Paleozoic and/or Neoproterozoic accretted lower crust. Taken together, it is suggested that geochemical variations from the Early Permian gabbros to the Late Permian diorites reveal that the subduction of the Paleo-Asian oceanic plate beneath the Khanka Massif and collision between the arc and continent (Khanka Massif) happened in the late stage of the Late Paleozoic.  相似文献   

内蒙古东部额尔古纳地块古变质岩地球化学特征及成因环境探讨   总被引：2，自引：0，他引：2  

刘树杰  李玉龙  王德福 《吉林地质》2011,30(1):19-28

额尔古纳地块古老变质岩系重新厘定为古元古界兴华渡口群与风水山片麻杂岩.对兴华渡口群与风水山片麻杂岩的岩石学、岩石化学化学与地球化学特征进行了分析,论述了本区的变质作用特征,并对额尔古纳地块的基底构造背景及成因模式进行了探讨.  相似文献   

古气候变化与地下热水中氢氧稳定同位的关系   总被引：1，自引：0，他引：1  

李婷  胡伟伟  马致远  豆惠萍 《地下水》2011,(1):4-7,24

关中盆地地下热水中氢氧稳定同位素的研究表明：研究区地下热水中氢氧稳定同位素组成变化与当地古气候变化具有良好的对应关系,古气候变化直接影响了地下热水接受补给时的氢氧稳定同位素组成。研究区地下热水的补给为更新世前古代大气降水。大约在8.2～10.2 kaB.P.和18.1～19.2 kaB.P.这两个时间段,可能是由于当时温度较低导致关中盆地地下热水补给偏少;关中盆地地下热水的补给过程受古气候的变化影响呈现非等速补给特征,可能存在一定的古地下水形成期。  相似文献   

从阿巴拉契亚-阿钦塔造山带看中国北方大陆南缘古生代的油气前景          下载免费PDF全文

梁传茂 《地学前缘》2011,18(4):193-200

阿巴拉契亚-阿钦塔造山带是北美乃至世界著名的大陆边缘挤压碰撞推覆造山带,是地质学研究的经典地区之一,也是许多经典地学理论和概念的发源地.其中,对地质学影响最大的当属地槽学说.继20世纪60年代由深海钻探带来地学革命之后,由COCORP实施的地震反射剖面和深钻揭示了该造山带的巨大推覆构造.人们惊奇地发现,在巨大推覆体之下...  相似文献   

Strong historical earthquakes in the northwestern Issyk Kul’ basin (northern Tien Shan)     

A.M. Korjenkov  S.V. Abdieva  A.B. Dzhumabaeva  A.B. Fortuna  E. Mamyrov  E.A. Morozova  L.A. Orlova  P.S. Vakhrameeva 《Russian Geology and Geophysics》2011,52(9):1007-1015

The northern Tien Shan is the northern front of the Himalayan mountain belt, which resulted from the collision between the Indian and Eurasian Plates. This region encompasses the most active seismic zones of the orogen, which generated the strongest (M > 8) earthquakes. Since there are scarcely any written accounts, the only way to trace back strong earthquakes is the paleoseismologic method. Since 1984 we have been studying the northwestern Issyk Kul’ basin, where there are differently directed anticlines, which constitute the Kungei meganticline. Here, several active tectonic structures (faults, folds) are located, whose development was accompanied by strong earthquakes. Our field studies of 2008 in the Iiri-Taldybulak Valley, along the adyrs (foothills) of the Kungei-Ala-Too Range, revealed two unknown historical earthquakes. The first one, which occurred along the southern rupture in the late 7th century A.D., gave rise to a seismic scarp; the latter broke through the river floodplain and a tash-koro (ancient settlement). The second one, which occurred along the northern rupture in the late 9th century A.D., increased the height of the seismic scarp, existing on the Early Holocene and older terraces. Note that this region already records a strong seismic event around 500 A.D. Archeologic data have revealed one more strong earthquake, which took place in the 14th century A.D. Note that the above-mentioned strong seismic events are coeval with the decline of the nomadic cultures (Wusun, Turkic, Mogul) in the northern Tien Shan and Zhetysu (Semirech’e).  相似文献   

三维古地貌重建技术在中生代羌塘地体古地理演化分析中的应用     

于淼  陈建平  严琼  武瞾  王春女  于萍萍 《地质通报》2011,30(5):694-701

近年来,从古地貌-沉积组合与油藏关系的角度进行油气远景评价成为研究热点。针对古地貌的复原研究,提出一种建立三维古地貌模型的方法,将二维平面古地理图通过对资料的整理、挖掘与转换,并结合GIS技术生成了三维立体模型,补充了区域地形地貌的相关信息。利用该方法,建立了青藏高原油气资源潜力最大的区域——羌塘地体在三叠纪和侏罗纪的一系列三维古地貌模型,进而对其古环境和演化过程进行分析,这对于该区域的沉积矿产资源的预测与评价有重要的参考价值。  相似文献   

基于高分辨率卫星遥感数据的铝土矿矿山环境调查研究     

闵艳艳  龚梅  李思发  李亮  芦正艳 《贵州地质》2011,28(2):154-157

选取以露天开采方式为主的黔中铝土矿小山坝矿区为研究区,以高分辨率的Quick-B ird卫星影像数据为主要信息源,通过数据处理、遥感解译与信息提取,分析了研究区内矿山环境的现状。研究表明QuickB ird图像对于小山坝矿区的调查效果理想,较好地实现了对矿业活动占地情况及矿山周边环境的调查。  相似文献