摘要
本文通过对长江中下游地区的溧水、宁芜等火山岩盆地、浙闽粤中生代火山岩带、广西等地的凝灰熔岩地质体的宏观和微观特征研究，总结了凝灰熔岩的相特征，建立了二相成因模式．对凝灰熔岩的成因机理、火山喷发方式、岩类归属等进行了深入讨论．提出了凝灰熔岩熔离成因的看法。
In the Mesozoic volcanic belt of Cuntinent of Southeastern China and basin of the Middle-Lower Yangtze River exists tufflava t which was once named as rhyolite, dacite, ignimbrite and liquation ignimbrite. It is different frum lava ur welded pyroclastic rock. It is characterized by containing 30-40% crystal and liquatiun banded body cemented by lava. It is distributed as sill or laccolith, which can be regarded as two facies: tufflava with flowage structure and tufflava respecting from rim to centre.They are distinguished by liquation banded buoy which exists in glassy matrix or not.Based on petrography, it belongs to pyruclastic lava, which is a transitional type from lava to pyroclastic rock.Tufflava first underwent crystallization differentiation and liquation in magma chamber,then erupted out to the surface and flowed along volcano slope After emplacements and accumulations it quickly cooled down and petrified. This formation process is Called dual-faciesgenetic modelling.
出处
《火山地质与矿产》
1995年第3期1-6,共6页
Volcanology & Mineral Resources
关键词
凝灰熔岩
相模式
熔离作用
岩相特征
成因
tufflava, facies model, liquation, bursting eruption, continent of southeast China, Middle-Lower Yangtze River area
