Microseismicity and structure of the Germencik area, western Turkey

Microseismicity at the boundary between two segments of the Büyük Menderes active normal fault zone, western Turkey, was monitored for two weeks during 1990 April and May, using a dense network of six portable seismographs with spacing ∼1–2 km. Extension rate across this fault zone is investigated by three independent methods; our preferred estimate is 1.2 ± 0.4 mm yr⁻¹. The area contains a geothermal field, but microseismicity appears unrelated to geothermal well positions and was thus lower than expected; six local events were recorded, none larger than magnitude 2. Microearthquakes in this size range contribute negligibly to local tectonic deformation. However, frequency of occurrence of these and local magnitude 7 events both satisfy the standard Gutenberg-Richter relationship. The local geomorphology includes an example of river capture associated with elevation changes accompanying changing patterns of slip on individual fault segments, which appears to have occurred less than 1 Myr ago.     

辽东早元古造山带隆滑构造初析

辽东早元古代裂谷带内的隆滑构造是在吕梁造山前期伸展体制下的第一幕变形期间形成的。本区隆滑构造的内核隆起部位大致与中南岩基空间分布一致，由同构造侵位的二长花岗岩（辽吉花岗岩）组成，在裂谷带西区和东区，辽吉花岗岩皆顺基底与盖层之间的接合面呈席状侵位。由于辽吉花岗岩局部隆起，引起外壳内多层滑脱型韧性剪切带（简称韧变带）及流褶层的形成，在递进变形过程中流褶层会发生尖灭。因变形分解作用，在形成韧变带及流褶层的同时，也形成一些巨型透镜体，它们为弱变形域或未变形域，其内原生构造保存完整。对流褶层内流动褶皱的倒向及拉伸线理的统计，结果进一步表明中南岩基为辽河群内隆滑构造的隆起部位。现今东区和西区的穹形构造是初始席状侵位的叠加性构造，即在吕梁运动期间收缩体制下，辽吉花岗岩仍呈塑性并向背斜部位聚集，呈底辟式重就位；第三幕构造形迹横跨叠加于第二幕构造形迹之上，从而最终使辽吉花岗岩有规律地分布于穹形构造核部。     

华东南中新生代伸展构造类型及其主要特征

本文根据华东南地区中新生代伸展构造的发育特点，划分出热隆伸展、裂陷伸展和重力伸展等３种伸展构造类型。其中，热隆伸展构造又可进一步划分为浅层次热隆伸展构造和深层次变质核杂岩构造两种亚类。不同类型伸展构造在构造样式、组合型式、运动方式、同构造期岩浆作用及形成作用特征等方面均存在明显的差异，文中分别对其进行了初步总结。     

小波变换在煤田高分辨地震资料处理中的应用研究

研究了小波变换的定义及小波变换的性质，构造了适合于我们要求的子波序列。用小波变换作一维滤波克服了传统的窗口傅里叶方法易出现的吉布斯效应。用小波变换的多分辨率成像技术适当地选择小波函数和伸缩尺度参数，让薄层的局部化特征明显，提高地震剖面对薄层的分辨率，让薄层的局部特征明显地表现出来，精确地进行分析判定。     

黄骅坳陷中北区和歧口凹陷断裂构造特征及古应力分析

主要分析了黄骅坳陷中北区和歧口凹陷断裂构造特征。根据三维地震资料编制的Ｔ４和Ｔ０断裂纲要图表明，研究区断裂为伸展正断层，以ＮＥ向、ＮＮＥ向和ＥＷ向断裂为主。在不同时期，歧口凹陷断层走向发生明显变化，由沙一下段ＮＥ向变为上第三系的近ＥＷ向。在不同地段，伸展断裂具有不同的优势方向。横向变换带上发育的断裂也为伸展断裂，具有与主断层垂直相交的方向。通过对断裂古应力分析，黄骅盆地是伸展型盆地，推测其伸展作用为三维放射状，横向变换带也具有三维伸展特征，不存在横向挤压和走滑剪切作用。     

High-grade metamorphism and hydrous melting of metapelites in the Pinos terrane (W Cuba): Evidence for crustal thickening and extension in the northern Caribbean collisional belt

The Pinos terrane (Isle of Pines, W Cuba) is a coherent metamorphic complex that probably represents a portion of the continental margin of the Yucatan Block during the Mesozoic. Within the framework of other metamorphic terranes in the Greater Antilles, the Pinos terrane is characterized by the occurrence of high‐grade kyanite‐, sillimanite‐ and andalusite‐bearing metapelites and migmatites. Assessment and modelling of phase relations in these high grade rocks indicate that they reached a peak temperature of c. 750 °C at 11–12 kbar, and then underwent strong decompression to c. 3 kbar at c. 600 °C. Decompression was contemporaneous with the main synmetamorphic deformation in the area (D2), and was accompanied by segregation of trondhjemitic partial melts formed by wet melting of metapelites. Metamorphism terminated in the Uppermost Cretaceous (68 ± 2 Ma; ⁴⁰Ar/³⁹Ar dates on biotite and muscovite). The P–T–t‐deformation relations of the high‐grade rocks suggest that crustal thickening (during collision of this portion of the Yucatan margin with the Great Volcanic Arc of the Caribbean?) was followed by decompression interpreted to reflect exhumation by extension, possibly related to the initial development of the Yucatan Basin in the uppermost Cretaceous.     

Horizontal Strain Rate in Relation to Vein Formation of the Hishikari Gold Deposits, Southern Kyushu, Japan

Abstract: The Hishikari deposits comprise the Honko (Main), Yamada, and Sanjin deposits. The horizontal strain in the direction (approx. N40°W normal to the general NE-SW strike of the Hishikari vein system was calculated, based on the measured total vein widths to the distance along three crosscuts. Veins were assumed to accompany no significant fault displacement in the calculation. Veins in the eastern and the middle parts of the Honko-Sanjin deposits spatially occupy 3. 2% and 1. 3%, respectively, and veins in the Yamada deposit occupy 6. 7%. Significant local variation of strain is observed in some areas. Reported K-Ar ages on adularia-quartz veins indicate the duration of vein opening to be 2. 6 × 10⁵ yr in the Honko-Sanjin deposits and 5. 9 × 10⁵ yr in the Yamada deposit. Horizontal strain rates were calculated to be 5. 0–12 × 10^-8 yr^-1through the Hishikari deposits. The calculated strain rates at the Hishikari deposits are roughly comparable to the regional horizontal strain rate in the Recent. Widespread extensional movement in southern Kyushu seems to have been able to provide sufficient strain for the formation of the Hishikari deposits, rather than contribution of local movements.     

泥石流防治工程规划的可拓决策技术

泥石流防治工程规划属于一种半结构化的决策问题。可拓决策是根据物元的可拓性，采用定性分析与定量计算相结合的方法解决矛盾问题的一种决策技术。本文根据可拓学的基本理论与方法，提出了一种首先基于系统物元相容性评判进行方案比选；再对初选方案通过系统物元变换进行方案优化设计的可拓决策模型，并以成昆铁路大田箐沟泥石流防治方案的优化设计为例说明这种可拓决策技术的应用程式。     

大陆伸展盆地岩浆与伸展作用的定量关系分析及其初步应用

通过对无水石榴石橄榄岩地幔的绝热减压部分熔融模型进行详细的数学推导,本文建立了准确的数学表达式以定量描述伸展因子、地幔部分熔融系数以及熔融体厚度之间的动力学关系。在详细的地球化学研究基础上,认为软流圈的部分熔融是济阳坳陷新生代火山岩的来源,并利用该模型对济阳坳陷新生代伸展裂陷阶段形成的熔融体厚度进行了预测,取得了与深部地球物理探测较为接近的结果。认为中下地壳中赋存的高导低速体是软流圈熔融体释放气体后聚集的结果,是盆地内分布的火山岩的直接源区。     

云南金顶超大型铅锌矿床的成矿地质背景

采用构造－沉积综合分析的方法，研究了金顶超大型铅锌矿床成矿的盆地、构造和深部地质背景。研究表明，控矿的古新世－中始新世盆地为走滑拉张盆地，研究区先后经历了古新世－中始新世早期的走滑和拉伸，中始新世－渐新世的挤压推覆和中新世的隆升和走滑，分析了盆地演化、沉积体系、同生断裂活动和逆冲推覆等对金顶超大型铅锌矿床的控制作用，探讨了可能的成矿过程。