火山岩区填图单位划分探讨

Discussion on Classification of Cartographic Units of Volcanic Terrain

现行火山岩区填图是以岩石地层单位划分的群 -组 -段为基础 ,其中组是最基本的填图单位。由于火山作用的特殊性和火山活动的同期异相性等 ,这一划分还不能全面合理地反映火山岩区的基本面貌和火山作用过程 ,特别是调研主体——火山构造。以福建省东部中生代火山岩为例 ,提出以火山旋回 -火山构造单元 -岩相 (组合 )作为火山岩区的三级填图单位 ,其中火山构造单元为基本的填图单位。

At present the lithostratigraphic units(group,formation and member)are used in the mapping of volcanic terrain,in which the formation is a basic cartographic units.Because of the particularity of volcanism and coeval heropic characters of volcanic activities,the above mentioned division doesnt completely show up the basic situation of volcanic terrains and the volcanic process,especially volcanic structures.Taking Mesozoic volcanic rocks in Eastern Fujian as an example,the authors put forward a new cartographic unit of volcanic terrains(volcanic cycle,volcano tectonic element and lithofacies assemblage),in which the volcano tectonic element is a basic cartographic unit.