五大连池老黑山西部熔岩流的张裂特征及其成因

【中文摘要】 地质张裂系统广泛见于熔岩流、地面沉降和张性构造发育的地区。而基性熔岩流的张裂体系具有独特性,是地下水(或矿泉水)和油气的重要储体和运移通道。本文通过对老黑山西部熔岩流的张裂体系的野外实地观察,结合高分辨率的遥感图象,对张裂体系的信息进行了提取和分析,试图探寻老黑山玄武质熔岩流张裂体系的分布规律及其成因。五大连池老黑山西侧熔岩流的张裂隙非常发育,长短、宽窄不一。根据高分辨率QuickBird全色波段遥感数据可对张裂宽度大于0.5米和长度大于3米的张裂可以分辨的能力,本次工作对老黑山西部熔岩流的张裂进行了系统提取。所获得的数据在地理信息系统软件中进行了空间分析。对张裂的空间分布特征的分析和描述包括张裂的分布方向、区域单位面积内张裂的长度、区域单位面积内张裂的条数(即张裂的分布密度)。在张裂整体优势方向确定后,在研究区内选取了15个张裂集中分布区,分别统计了区内张裂分布的特点:优势方向、单位面积区域内张裂的长度、单位面积区域内张裂的条数(即张裂的分布密度)。这些区域有些是属于同期的熔岩流、有些则不是同期的熔岩流。它们的方向分布反映了该区域熔岩流的张裂特点。对五大连池老黑山西部熔岩流边缘的一股较大规模次级溢流体上的熔岩穹丘的分析,得到了21个熔岩穹丘的面积、周长和长宽比信息。通过以上工作,得出了下面几点结论性的认识:1.老黑山西部熔岩流的张裂分布存在着不同的组合结构,这些组合结构与产生张裂的不同类型和期次的熔岩流之间存在着紧密的相关性。2.根据遥感影像判读及实地观察,老黑山西部熔岩流的张裂有三组优势方向,它们反映了熔岩流的流动方向。大规模熔岩流的总流动方向是东西向和北西向,而北东向的熔岩流可能是这些大规模熔岩流的次级溢流,甚至是更小规模的次级溢流。3.随着距离老黑山火山锥位置的不同和熔岩流的类型(如席状熔岩流、小规模次级溢流体)不同,张裂呈现不同的特征。

【英文摘要】 The geological systems of tension fissures are widely found in the regions of lava flows, ground subsidence and development of extension structures. However, the fissure systems on the basaltic lava flows are very outstanding, which are the important storage media and migration pathway of groundwater (or mineral water), oil and gas. Through the field observations of the tension fissures on the western lava flows of Laoheishan volcano and the uses of high-resolution remote sensing data, we explored and analyzed the information of the systems of tension fissures and attempt to reveal the law of their spatial distribution and their causes.The tension fissures on the western lava flows of Laoheishan volcano are very rich and have different length and width. According to the ability of high-resolution panchromatic band of Quickbird remote sensing data to identify the tension fissures with the width > 0.5 meter and the length of >3 meter, we took out the data of tension fissures on the western lava flows of Laoheishan volcano. Then the data were analyzed on their spatial distributions by the software of geographic information system. The spatial distribution characteristics of the tension fissures were also analyze and described, such as the distribution of fissure direction, the fissure length within unit area and the fissure number within unit area. After the determination of the overall advantage direction, we chose fifteen interest areas with amounts of tension fissures and studied the distribution characteristics of fissures in each interest areas, including advantage direction, the length and number of fissures within unit area.Some of these areas are the lava flows forming in the same period, while others are not. Their direction distributions reflect the characteristics of fissures in the area. In addition, we measured the information of area, perimeter and aspect ratio of twenty-one tumuli and lava collapse of larger sub-overflow in the edge of western lava flows of Laoheishan volcano, Wudalianchi. The conclusions are as follows:1. There exists the characteristic combination structures of the tension fissures in the western lava flows of Laoheishan volcano. These combination structures have close relationship with the different types and stages of lava flows.2. According to the interpretation of remote sensing data and the field observations, three groups of the fissure advantage-directions in the western lava flows of Laoheishan volcano are recognized, which reflects the directions of lava flows. The overall flow directions of large lava flows is east-west and north-west,but the north-east flow direction of lava flows may be the sub-overflow of large lava flows or the smaller ones.3. With the different distances between fissures and Laoheishan volcanic cone and the types of lava flows (sheet lava flows or small sub-overflows), the tension fissures show the different features.

【中文关键词】 五大连池; 老黑山; 熔岩流; 熔岩穹丘; 张裂