2岩石各论沉积岩石学整理教材.ppt

火山碎屑岩的构造 火山泥球构造-球状，内部有同心纹层。为火山喷发遇大雨，火山灰被水作用形成。 假流纹构造—熔结凝灰岩中塑性岩屑被压扁拉长，形成似流纹的定向构造。 层理构造 斑杂构造—成分不均匀分布。 Structure of volcaniclastic rock Volcanic mud ball structure – spherical, there are concentric laminaes in the interior. It is the product of volcanic ash under the action of water during heavy rains and volcanic eruption. False fludidal structure—the plastic debris in ignimbrite is flattened and elongated to form a similar rhyolite directional structure. Taxitic structure—its composition is not evenly distributed. 火山碎屑岩的分类及主要类型 火山碎屑岩的分类 常见火山碎屑岩的主要类型 Classification and main types of volcaniclastic rock Classification of volcaniclastic rock Common types of volcaniclastic rock 火山碎屑岩的分类 Classification of volcaniclastic rock 正常火山碎屑岩类 Ⅰ、熔结火山碎屑岩—以塑性火山碎屑为主，＞90% 熔结集块岩 熔结火山角砾岩 熔结凝灰岩 Ordinary volcaniclastic rock type Ⅰ, Welded volcaniclastic rock, mainly consists of plastic tephra, and it occupies more than 90% Welded agglomerate Welded volcanic breccia Welded tuff Ⅱ、正常火山碎屑岩—火山碎屑＞90%，塑性者少。 火山集块岩 火山角砾岩 凝灰岩 Ⅱ、Ordinary volcaniclastic rock—volcaniclastic rock 90%, little plastic. Volcanic agglomerate Volcanic breccia Tuff 向熔岩过渡类型—火山碎屑熔岩类 Lava transition type - volcaniclastic lava 集块熔岩Agglomerate lava 角砾熔岩Breccia lava 凝灰熔岩Tuff lava 向沉积岩过渡类型Sedimentary rock transition type 沉积火山碎屑岩：火山碎屑90-50%，陆源沉积＜50% 火山碎屑沉积岩：火山碎屑50-10%，陆源沉积＞50% Sedimentary volcaniclastic rocks: volcaniclastic rocks 90-50%, terrigenous sediments50% Volcaniclastic sedimentary rocks: volcaniclastic rocks 50-10%, terrigenous sediments 50% 常见火山碎屑岩的主要类型 Common types of volcaniclastic rock 熔结凝灰岩 火山碎屑超过90%，以粒径小于2mm的塑性玻屑和塑性岩屑为主，含少量晶屑。塑性火山碎屑被压扁拉长，定向排列，具熔结凝灰结构，假流纹构造。 Welded tuff Tephra content is more than 90%, mainly consists of plastic vitric fragment and plastic rock debris, and contains a little crystal pyroclast. Plastic volcaniclastic rocks are flattened and elongated, directionally align, possesses welded tuff structure and false fludidal structure. 火山角砾岩 由大小不等的熔结角砾组成，64-2mm角砾占50%以