直升机大比例尺航空物探在深部找矿中的应用前景

为克服深部及矿区外围地面物探工作难度大、勘探周期长等不利因素,探讨了利用直升机快速获取高分辨率航空物探资料的方法。以成功应用实例,总结了直升机航空物探方法技术的特点和优势,并针对目前深部找矿工作区的部署特点,展望了直升机物探利用磁、电、能谱综合信息,挖掘矿山深部及外围资源潜力,直接为地质找矿服务的应用前景。     

A Study on Sequence Stratigraphy of Mesoproterozoic and Neoproterozoic in Southern North China Platform

INTRODUCTIONThestrataofMesoprotCrozoicandNeoproterozoicaredevelopedcompletelyinthesouthpartoftheNorthetnaplatformandconsistofthreesystems,inasCendingorder,Jixiaulan,QingbaikouanandSlman.BasedonadetailedinvestigationontheolltcropandthecomprehenSiveanalysis,wediscussthecharaCterofsequencestratigraphyandthecorrelationoftheMemo--Neoproterozoicinthearea.FnThRrsor~unCrsANDPARA~unCrsMeSO--NooprotffezoicRadonalfortigraphyThesouthernpartofNorthChinaplatformherereferstotheareasincluding…     

Metallogeny of the Baiyangping Lead‐Zinc Polymetallic Ore Concentration Area,Northern Lanping Basin of Yunnan Province,China

The Lanping Basin in the Nujiang‐Lancangjiang‐Jinshajiang (the Sanjiang) area of northeastern margin of the Tibetan Plateau is an important part of eastern Tethyan metallogenic domain. This basin hosts a number of large unique sediment‐hosted Pb‐Zn polymetallic deposits or ore districts, such as the Baiyangping ore concentration area which is one of the representative ore district. The Baiyangping ore concentration area can be divided into the east and west ore belts, which were formed in a folded tectogene of the India‐Asia continental collisional setting and was controlled by a large reverse fault. Field observations reveal that the Mesozoic and Cenozoic sedimentary strata were outcropped in the mining area, and that the orebodies are obviously controlled by faults and hosted in sandstone and carbonate rocks. However, the ore‐forming elements in the east ore belt are mainly Pb‐Zn‐Sr‐Ag, while Pb‐Zn‐Ag‐Cu‐Co elements are dominant in the west ore belt. Comparative analysis of the C‐O‐Sr‐S‐Pb isotopic compositions suggest that both ore belts had a homogeneous carbon source, and the carbon in hydrothermal calcite is derived from the dissolution of carbonate rock strata; the ore‐forming fluids were originated from formation water and precipitate water, which belonged to basin brine fluid system; sulfur was from organic thermal chemical sulfate reduction and biological sulfate reduction; the metal mineralization material was from sedimentary strata and basement, but the difference of the material source of the basement and the strata and the superimposed mineralization of the west ore belt resulted in the difference of metallogenic elements between the eastern and western metallogenic belts. The Pb‐Zn mineralization age of both ore belts was contemporary and formed in the same metallogenetic event. Both thrust formed at the same time and occurred at the Early Oligocene, which is consistent with the age constrained by field geological relationship.     

豫西前寒武纪汝阳群遗迹化石

本文研究的遗迹化石：Ｒｕｙａｎｇｉｃｈｎｕｓ ｌｏｙｕｅｎｓｉｓ ｉｃｈｎｏｇｅｎ，ｅｔ ｉｃｈｎｏｓｐ．ｎｏｖ．，Ｔｏｒｒｏｗａｎｇｅａ ｒｏｓｅｉ ｗｅｂｂｙ，Ｃｈａｎｇｃｈｅｎｇｉａ ｉｃｈｎｏｓｐ．，Ｓｑｕａｍｏｄｉｃｔ ｙｏｎ（？）ｉｃｈｎｏｓｐ．等发现于河南西部鲁山县和汝阳县的汝阳群云梦山组和北大尖组。根据同位素年龄值，微古植物和叠层石资料，产遗迹化石的汝阳群应相当于中元古代，可以和蓟     

露头层序地层研究中的几个基本问题

以豫西中－新元古界为例，探讨目前露头层序地层学研究中存在的几个重要的问题。认为地层堆积类型转换面及沉积相序向上突然变浅的间断面是层序界面的间接标志。深切谷并非存在于所有的Ｉ类层序界面，其产生与否主要取决于河流均衡剖面的坡度与暴露和海底地形的坡度差。此外，在露头研究中，副层序应该以沉积相序的演变及海泛面作为划分和鉴别的主要标志。     

泰安地区近震波速及地壳厚度的测定

本文第一部分选取泰安台473型地震仪1985—1990年记录的70个地震资料,通过计算,得到泰安台附近的地壳厚度为H=36.5km,直达波的平均传播速度:V_P=6.18km/s、V_s=3.55km/s;反射波的传播速度:V_(P11)=6.45km/s、V_(S11)=3.79km/s;绕射波的传播速度:V_(Pn)=7.95km/s;平均虚波速度:V_φ=8.34km/s;平均波速比K=1.74。第二部分选取了泰安台基式地震仪有SP′震相记录的地震21个,求出了泰安台附近的地壳厚度为37km,并分析了SP′震相在泰安台的记录特征,初步得到SP′震相可观测范围为25°—60°。     

Research on scale effect of histogram

To describe the spatial relationship among the earth objects compactly, in this paper, we raised the concept of histo-variogram based on the analysis of the characteristics of other spatial analyzing methods such as variogram, information entropy. And we also raised a new spatial analysis method of histogram decomposition based on the definition of standing pixel and contour pixel. At the end of this paper, we demonstrated the characteristics of histo-variogram by two experiments, one for spatial analysis, the other for image fusion.     

南天山造山带中段推覆体内部变形及其与逆冲构造的关系

南天山造山带是古生代期间塔里木板块与伊犁—伊塞克湖板块对接、碰撞的产物 ,主体由向南逆冲的推覆体组成。推覆体内部变形构造在垂直于主断面方向上呈规律性变化。从推覆体底部向上 ,褶皱从 A型褶皱 ,紧闭、等斜的 B型褶皱 ,前翼褶皱经斜歪、倒转褶皱渐变为对称的尖棱或箱状 B型褶皱 ;构造面理从发育主断面近平行的 S-面理及剪切滑移的 C-面理渐变为只发育与主断面近垂直的 D-面理。据此 ,可把推覆体自下而上划分成为递进剪切、过渡和等轴挤压三个变形域。变形过程分析表明 ,存在水平挤压变形和随后的简单剪切变形两个变形阶段 ,前者发育于主断裂面形成之前 ,后者发育于主断裂面形成之后。这指示南天山造山带以变形扩展速率高于断裂扩展速率为特征     

Crytic period analysis model of hydrological process and its application

It is difficult to analyse the crytic period of the hydrological process, because hydrological time series is probably characterized by heteroscedasticity. To find out the crytic period, a model is constructed as follows: (1) after using zero‐mean transformation for the data, to do Augmented Dickey–Fuller stationary test for the sequence, to build the corresponding AR(p) model and then to do ARCH effects test and white noise test for residual series; (2) for those time series that cannot pass through ARCH test, using logarithm transformation to reduce the heteroscedasticity, and then to redo step (1) until they pass through ARCH test and stationary test; (3) using periodogram analysis to determine all the possible the prime periods and further to put forward three kinds of tests to determine significance level of those prime periods. As examples, the hydrological processes of streamflow from 1784 to 1997 for the gauging stations of Alaer and Xinquman along Tarim River are analysed. After reducing their heteroscedasticity, AR(4) and AR(2) models are developed, respectively. Our results show that the streamflows from the two gauging stations have the same cryptic period of 42·7 years. Furthermore, the reliability for the crytic period model is testified by variance analysis, which shows that the crytic period model is useful and reliable. Copyright © 2009 John Wiley & Sons, Ltd.     

云南永平县水泄辉长岩锆石U- Pb年代学、地球化学及地质意义

滇西地区二叠纪—三叠纪岩浆岩展布还不清楚,导致相关古特提斯构造演化模型还存在争议。本文对兰坪-思茅盆地西缘水泄地区的辉长岩开展了LA-ICP-MS锆石U-Pb定年、锆石Hf同位素、全岩主微量元素及Sr-Nd同位素分析,探讨了岩石成因及地质意义。水泄辉长岩2件样品的锆石U-Pb年龄分别为237.8±3.4 Ma和240.8±3.3 Ma,代表其结晶年龄,属于中三叠世。样品具有较高的Na₂O/K₂O(3.81～49.14),明显富集Ba、Rb、Th、U等大离子亲石元素,相对亏损Nb、Ta等高场强元素,稀土元素弱分馏,轻稀土弱富集,δEu值为0.87～1.07,无明显的Eu异常。锆石ε_Hf(t)值全为正值,主要介于+5.67～+15.75,全岩初始⁸⁷Sr/⁸⁶Sr比值为0.70453～0.70776,ε_Nd(t)值全为正值,介于+4.9～+5.2。地球化学特征显示水泄辉长岩来源于亏损地幔的部分熔融,在岩浆演化过程中发生了镁铁质矿物和铁钛矿物的分离结晶作用。水泄...