岩石学报
巖石學報
암석학보
ACTA PETROLOGICA SINICA
2010年
1期
309-317
,共9页
高危言%李江海%毛翔%张天然
高危言%李江海%毛翔%張天然
고위언%리강해%모상%장천연
五大连池火山群%喷气锥%基性岩浆%粘度%水蒸气
五大連池火山群%噴氣錐%基性巖漿%粘度%水蒸氣
오대련지화산군%분기추%기성암장%점도%수증기
Wudalianchi volcanic field%Homito%Basic magma%Viscosity%Vapor
五大连池火山群1537个喷气锥中,多数分布在火烧山熔岩流中,在水量充足的五池到四池之间的熔岩台地上,喷气锥数量集中、个体较大、发育良好.通过对五大连池火山群喷气锥的形态结构和集中分布特点进行分析,认为水蒸气在混合气体形成喷气锥中起主导作用,重力也在喷气锥形态塑造上有一定意义.含挥发分的基性岩浆溢流到在靠近水域的地区时表层冷凝固结,内部熔岩仍温度高、粘度低,与地下水作用形成火山气体和水蒸气构成的混合气体,气体冲破表层间歇溢出时,带动熔岩外掀堆叠在喷气孔周围形成喷气锥,中央保留气体多次逸出的通道形成中空结构.当气体压力不足以使熔岩从喷口溢出,喷气锥的生长停止.
五大連池火山群1537箇噴氣錐中,多數分佈在火燒山鎔巖流中,在水量充足的五池到四池之間的鎔巖檯地上,噴氣錐數量集中、箇體較大、髮育良好.通過對五大連池火山群噴氣錐的形態結構和集中分佈特點進行分析,認為水蒸氣在混閤氣體形成噴氣錐中起主導作用,重力也在噴氣錐形態塑造上有一定意義.含揮髮分的基性巖漿溢流到在靠近水域的地區時錶層冷凝固結,內部鎔巖仍溫度高、粘度低,與地下水作用形成火山氣體和水蒸氣構成的混閤氣體,氣體遲破錶層間歇溢齣時,帶動鎔巖外掀堆疊在噴氣孔週圍形成噴氣錐,中央保留氣體多次逸齣的通道形成中空結構.噹氣體壓力不足以使鎔巖從噴口溢齣,噴氣錐的生長停止.
오대련지화산군1537개분기추중,다수분포재화소산용암류중,재수량충족적오지도사지지간적용암태지상,분기추수량집중、개체교대、발육량호.통과대오대련지화산군분기추적형태결구화집중분포특점진행분석,인위수증기재혼합기체형성분기추중기주도작용,중력야재분기추형태소조상유일정의의.함휘발분적기성암장일류도재고근수역적지구시표층냉응고결,내부용암잉온도고、점도저,여지하수작용형성화산기체화수증기구성적혼합기체,기체충파표층간헐일출시,대동용암외흔퇴첩재분기공주위형성분기추,중앙보류기체다차일출적통도형성중공결구.당기체압력불족이사용암종분구일출,분기추적생장정지.
Majority of 1537 hornitos in Wudalianchi volcanic field distribute in lava flows of Huoshaoshan. Especially, lava plateau between Fourth and Fifth pools with sufficient water, has hornitos concentrated distributed, in the largest scale and best developed. After morphologic and concentrated distribution characteristic analysis, it comes to the conclusion that vapor in mixed gas is dominant in the formation of hornito, and gravity is also of some importance to shape a homito. When the basic lava with volatile overflowed near to water area, the surface of lava condensated and consolidated while inside remained high temperature and low viscosity. Mixed gas containing volcanic gas and vapor started to aggregate after lava meeting groundwater, and intermittently broke surface of lava to escape, together with some lava spattering up and stacking around the vent to form a hornito, the inside of which stayed hollow as the route way for gas to escape. When air pressure failed to eject lava from top jet, growth of a hornito ended.