古火山机体的划分与鉴别——以苏、浙、皖为例

    THE CLASSIFICATION AND IDENTIFICATION OF PALEOVOLCANOES, EXAMPLES FROM JIANGSU, ZHEJIANG AND ANHUI

    • 摘要: 一、现代火山分类古火山机体的划分与鉴别是火山地质学研究中的重要课題。古火山活动状况的复原再造在很大程度上取决于对古火山类别的认识。不同类别火山的活动方式不同,规模悬殊,火山堆积物的岩相、岩石类型组合和厚度各有其特点。有关火山著作中现代火山分类,如夏威夷式、伏尔干式、斯通博利式、庇里式等,主要针对爆发强度,着眼于大型火山和对人类生活影响较大的火山进行研究。在综合参数方面考虑不周全,难于应用于已不再爆发的火山。国际地球物理与大地测量联合会(IUGG)下属的国际火山学协会(IAVCE)为了编制后中新世世界火山目录曾提出一个火山分类方案,着重以形态和物质成份出发,照顾到火山活动方式,这一方案曾三次修改,最后得到采纳:

       

      Abstract: The authors suggest that the classification of post-Miocene volcanoes by IAVCE can also be applied to paleovolcanoes. Ⅰ. Fissure type Ⅱ. Central type (a) shield volcano (b) volcanic cone (c) stratovolcano (d) caldera (e) dome (f) volcanic depression Ⅲ. Composite type The vvord "caldera" has caused some confusion; it denotes both the crater of a volcano and a special kind of stratavolcano. Agglomerate and breccia can be formed in quite different cases, most of which have no relation with the volcanic vent. Case histories of different types are listed.

       

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