盆地火山地层时空属性和岩石地层单位

发布时间：2018-03-04 11:09

本文选题：火山地层单位　切入点：火山机构　出处：《吉林大学学报(地球科学版)》2017年04期 　论文类型：期刊论文

【摘要】：火山地层具有如下显著特征:建造短暂和剥蚀长久的时间属性,受喷发方式和古地形控制的空间属性,地层产状变化规律与喷出口相关。尝试以地层界面反映时间属性、岩石组合和几何外形反映空间属性,结合产状变化规律对火山地层单位进行了厘定,从常用的地层单位中选用术语,从小到大依次是层、堆积单元、火山机构、段、组和群。本文详细介绍前三类单位的分类和识别标志:层是根据颜色、化学成分和岩石组构的差异划分;堆积单元依据喷发方式和就位环境划分为熔岩流/火山碎屑流/再搬运火山碎屑流3类,单元内地层产状变化连续,单元之间常以喷发不整合/整合界面分隔;火山机构是堆积单元有序叠置的产物,火山地层沿喷发口向四周倾斜、向边缘过渡时地层倾角逐渐变缓,火山机构间常以喷发间断不整合界面分隔。指出盆地火山地层格架的建立需要突出地层的空间属性、火山地层埋藏史应该基于火山机构的中心和远源两个区域来分析,基于重新厘定的火山地层单位建立的地层格架更有利于对储层分布规律的认识。
[Abstract]:The volcanic strata have the following remarkable characteristics: the temporal attributes of the formation are short and denuded, the spatial attributes controlled by the eruption mode and the paleotopography, the regularity of formation occurrence and the outburst are related to the outburst. Rock assemblages and geometric shapes reflect spatial attributes, combined with the law of occurrence and variation, volcanic stratigraphic units are determined. Terms are selected from common stratigraphic units, from small to large in order of layer, accumulation unit, volcanic mechanism, segment, etc. In this paper, the classification and identification marks of the first three types of units are introduced in detail: the layer is divided according to the difference of color, chemical composition and rock fabric; According to the eruption mode and the emplacement environment, the accumulative units can be divided into three types: lava flow / pyroclastic flow / retransporting pyroclastic flow. The occurrence changes of the interior layer of the unit are continuous, and the units are often separated by the eruption unconformity / conformity interface. Volcanic mechanism is the product of stacking unit stacking unit in order. Volcanic strata incline around the eruption mouth, and gradually slow down the dip angle when the volcanic strata are transitioning to the margin. Volcanic bodies are often separated by eruptive discontinuous unconformities. It is pointed out that the establishment of volcanic stratigraphic framework in the basin needs to highlight the spatial attributes of the strata, and the burial history of volcanic strata should be analyzed on the basis of the central and distant regions of the volcanic mechanism. The stratigraphic framework based on the redefined volcanic stratigraphic units is more beneficial to the understanding of reservoir distribution law.
【作者单位】：吉林大学地球科学学院;吉林大学地层与古生物研究中心;
【基金】：国家“973”计划项目(2012CB822002) 国家自然科学基金项目(41472304)~~
【分类号】：P535;P618.13

【相似文献】