倾斜立体影像的Shi-Tomasi特征匹配     

赵琛琛  龚志辉  龙怡灿  孙晓昱  李劲澎 《测绘科学技术学报》2015,(1):66-71

针对倾斜影像畸变大的现象,提出一种适用于倾斜立体影像匹配的方法。首先采用基于SIFT算法的匹配点对消除影像间的射影失真;然后提取Shi-Tomasi特征并采用多窗口的归一化互相关系数(NCC)计算相似性测度,获得稳定的匹配点对;最后使用两组倾斜影像将该算法同SIFT算法和ASIFT算法进行综合对比分析。实验结果表明,所提算法在正确匹配点对数量、匹配点对分布及匹配精度上均优于其他两种算法。  相似文献   

大别山北淮阳带奥陶纪花岗岩的厘定及其对北秦岭东延的启示     

刘贻灿  侯克斌  杨阳  李洋  宋彪 《大地构造与成矿学》2021,45(2):401-412

详细的野外地质调查以及锆石SHRIMP U-Pb定年和初步的岩石学研究表明,大别山北淮阳带东段发育早古生代奥陶纪花岗岩。这些花岗岩经过了强烈的构造变形、局部发育片麻理和绿帘角闪岩相变质作用,形成时代为457±2 Ma,与北淮阳带西段马畈闪长岩的形成时代以及北秦岭?桐柏造山带一期与大洋俯冲相关的早古生代岛弧岩浆作用时代一致。结合区域地质背景和盆地沉积分析,证明北秦岭古生代俯冲增生造山带至少向东延伸到大别山北淮阳带的金寨及相邻地区。研究区古生代花岗岩及相关岩石的进一步研究,将为大别山碰撞造山带的古生代构造演化以及华南与华北板块之间的汇聚?拼贴过程提供新的制约。  相似文献   

大别山北部石榴二辉麻粒岩变质结构和水活度及其演化特征   总被引：3，自引：0，他引：3       下载免费PDF全文

苏文  徐树桐 《地球科学》2000,25(2):152-158

通过对大别山北部石榴二辉麻粒岩岩相学、矿物地质温压计和热力学计算, 获得4个主要的变质演化阶段的矿物共生组合、温压条件和相应的水活度条件: (1) 榴辉岩相阶段(M₁), 以Cpx (含Jd) +Q +Ru +Gt组合为代表的残留矿物, 并呈包体的形式产于石榴石中, t=612~750℃; (2)麻粒岩相阶段(M₂), 以Opx+Cpx +Gt+Q +Ti+Mt矿物组合为特征, 其相应的t =837~887℃, p=1.03~1.25GPa, 水活度为0.718~0.799; (3) 角闪岩相阶段(M₃), 矿物组合为Cpx +Gt+Amp +Pl+Mt, t=530~660℃, p=0.85~0.95GPa, 其相应的水活度为0.2 3~ 0.2 4;和(4) 低角闪岩相阶段(M₄), 其形成的温压条件为t=495℃, p=0.5 6~ 0.70GPa, 相应的水活度为0.11~ 0.13.石榴二辉麻粒岩变质反应、变质结构、矿物组合及其演化, 不仅受控于形成时的温压条件, 而且与形成时体系中水活度的演化有着密切的成因关系.水活度的演化特征表明, 变质流体在变质作用过程中, 对变质反应温度起着一定的缓冲作用.   相似文献   

Eclogites from the Northern Dabie Mountains,eastern China: Geochemical characteristics,Sr−Nd isotopic compositions and tectonic implications     

Liu Yican  Xu Shutong  Li Shuguang  Jiang Laili  Wu Weiping  Chen Guanbao  Su Wen 《中国科学D辑(英文版)》2000,43(1):178-188

The petrologic geochemical and Sr?Nd isotopic compositions of the eclogites from the mafic-ultramafic rock belt (MUMRB) in the Northern Dabie Mountains indicate that: (1) the protoliths of most of eclogites are tholeitic basalt and a few may be gabbro, and most of them produced from the Yangtze subducted continental crust (lower crust and formed during the deep subduction) and a part may be from paleo-oceanic relics between the Yangtze and North China continental plates; (2) their positive Nb anomalies and related trace element characteristics show that they did not form in the island-arc setting; (3) the metamorphosed MUMRB with eclogite and meta-peridotite blocks along the southern part of the Mozitan-Xiaotian fault zone may represent the suture zone produced during the collision between the Yangtze and North China continental plates, which included the Yangtze subducted continental crust and paleo-oceanic relics.  相似文献   

Eclogites from the Northern Dabie Mountains,eastern China: Geochemical characteristics,Sr−Nd isotopic compositions and tectonic implications     

Liu  Yican  Xu  Shutong  Li  Shuguang  Jiang  Laili  Wu  Weiping  Chen  Guanbao  Su  Wen 《中国科学:地球科学(英文版)》2000,43(1):178-188

The petrologic geochemical and Sr−Nd isotopic compositions of the eclogites from the mafic-ultramafic rock belt (MUMRB) in the Northern Dabie Mountains indicate that: (1) the protoliths of most of eclogites are tholeitic basalt and a few may be gabbro, and most of them produced from the Yangtze subducted continental crust (lower crust and formed during the deep subduction) and a part may be from paleo-oceanic relics between the Yangtze and North China continental plates; (2) their positive Nb anomalies and related trace element characteristics show that they did not form in the island-arc setting; (3) the metamorphosed MUMRB with eclogite and meta-peridotite blocks along the southern part of the Mozitan-Xiaotian fault zone may represent the suture zone produced during the collision between the Yangtze and North China continental plates, which included the Yangtze subducted continental crust and paleo-oceanic relics.

  相似文献   

Exhumation of deeply subducted crust: Review and outlook     

Liu  Yican  Zhang  Chengwei 《中国科学:地球科学(英文版)》2020,63(12):1904-1924

Science China Earth Sciences - The discovery of ultrahigh-pressure (UHP) index minerals such as coesite and micro-diamond in supracrustal rocks indicate that a large amount of crustal rocks were...  相似文献   

大别山区（安徽部分）的构造格局和演化过程   总被引：70，自引：8，他引：70  

徐树侗  江来利 《地质学报》1992,66(1):1-14,T001

大别山区是扬子和中朝大陆板块之间的碰撞造山带,由扬子大陆板块中的前陆褶冲带、俯冲盖层和俯冲基底、包含在俯冲基底中的含柯石英和金刚石的超高压变质帝、变质蛇绿混杂岩带、中朝大陆板块南缘的弧前复理石推覆体以及其北缘的反向褶冲带、北部边缘为磨拉斯的后继盆地组成。古大别海洋板块于早古生代向北俯冲时,中朝大陆板块南缘可能出现过火山弧和弧后盆地。卷入前陆褶冲带的地层以及榴辉岩的Sm/Nd同位素定时表明,两个大陆板块的强烈碰撞发生在中生代早期。  相似文献   

Detrital Zircon Geochronology and Provenance of Metasedimentary Rocks from the Susong Complex Zone in the Dabie Orogen     

WU Zheng  YANG Yang  LIU Yican  ZHANG Chengwei 《《地质学报》英文版》2023,97(5):1335-1354

The Susong complex zone is a relatively low-grade metamorphic unit located in the southern part of the Dabie orogen and preserves a variety of metasedimentary rocks, mostly with epidote–amphibolite facies. However, their depositional age, provenance and tectonic setting of sedimentary protolith remain controversial due to the lack of fossils, precise dating and integrated geochemical investigation. This study has conducted whole-rock elemental, and zircon U-Pb SHRIMP dating and Lu-Hf isotope ana...  相似文献   

大别山北部镁铁-超镁铁质岩带中榴辉岩的分布与变质温压条件   总被引：27，自引：3，他引：27  

刘贻灿  徐树桐  李曙光  陈冠宝  江来利  周存亭  吴维平 《地质学报》2001,75(3):385-395

大别山北部镁铁-超镁铁质岩带中的榴辉岩主要有两种产状,一是产于变形较强(面理化)的橄榄岩中,另一种是产于片麻岩中。其中,绿辉石中硬玉端元组分大多为Jd=20mol％～52mol％。产于橄榄岩和片麻岩中榴辉岩的石榴子石成分分别相当于Coleman的B型和C型榴辉岩。石榴子石成分特征及钠质单斜辉石中石英针状出溶体的出现表明,本区榴辉岩早期可能经历过超高压变质作用,且至少经历了3个变质阶段,即:①榴辉岩相峰期变质阶段,主要矿物共生组合为石榴子石+绿辉石+金红石±蓝晶石+石英(或柯石英假象?),p≥2.5GPa、t=595～874℃;②高压麻粒岩相变质阶段,主要矿物共生组合为石榴子石+透辉石+紫苏辉石+钛铁矿+尖晶石+斜长石等,p=1.1～1.37GPa、t=817～909℃;③角闪岩相变质阶段,主要矿物共生组合为角闪石+斜长石+磁铁矿等,p=0.5～0.6GPa、t=500～600℃。该区榴辉岩独特的麻粒岩相退变质阶段,表明榴辉岩在折返初期并未能上升到中上地壳,而处于下地壳,它与南部超高压变质岩有不同的p-t演化史,即在榴辉岩相峰期变质之后经历了近等温减压(或稍升温减压)和降温减压变质过程。  相似文献   

大别山东部榴辉岩带中的变质花岗岩及其大地构造意义   总被引：41，自引：3，他引：38  

徐树桐  吴维平 《岩石学报》1998,14(1):42-59

大别山高－超高压变质带中的变质花岗岩类是碱性花岗岩。它以其下列特征与本区未变质花岗岩和围绕它的低压花岗质片麻岩相区别：（１）有标型矿物多硅白云母和长石的石榴石反应边;（２）主要为花岗变晶结构但有残留的岩浆结构,岩体边部有片麻状构造;（３）与超高压围岩之间有残留侵入接触关系,两者共同受到第二期褶皱影响;（４）化学成分富硅和富碱,Ｋ２Ｏ和Ｎａ２Ｏ含量变化不定,大部分样品的Ｎａ２Ｏ大于Ｋ２Ｏ含量,Ｋ２Ｏ＋Ｎａ２Ｏ总量大于７％;（５）矿物组合表明变质级为角闪岩相;（６）Ｒｂ－Ｓｒ等时线年龄１８１Ｍａ（全岩,黑云母）;（７）其中常有高－超高压变质岩相的捕虏体。这些特征表明,这里的变质花岗岩类是高－超高压变质带折返到中地壳时侵入其中并随之共同变质变形的,因此是高－超高压变质带的特殊成员。这对理解超高压变质带的折返速率是非常重要的。  相似文献