Lava rise ridges of the Toomba basalt flow, north Queensland, Australia
Lava rise ridges of the Toomba basalt flow, north Queensland, Australia
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澳大利亚昆士兰州北部 Toomba 玄武岩流的熔岩隆起山脊
DOI：
10.1029/98jb00029
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发表时间：
1998
影响因子：
--
通讯作者：
P. Stephenson
中科院分区：
文献类型：
--
作者：
P. Whitehead;P. Stephenson
异常长的熔岩上升发生在Toomba玄武岩流的远端部分，距离源头长达120公里。在Lolworth Creek地区，有三个平行的熔岩隆起脊，长6公里。其中两个山脊在整个6公里范围内是连续的。山脊平均高7米，宽35米至300米不等。熔岩膨胀裂缝是众多的，熔岩上升坑也出现。向下流动，一个单一的熔岩上升脊，平均高18米，宽达500米，延伸10公里。该脊具有大致水平的表面，具有陡峭的边缘，倾斜度在45°和90°之间。对海脊的精确测量表明，在某些情况下，表面曾有一些拉伸，可能是在突出的裂缝形成之前。这些山脊是由一个最初很薄的熔岩流形成的，这个熔岩流被一个连续的熔岩层膨胀，几乎覆盖了每个山脊的整个宽度，而不是由一个更有限尺寸的熔岩管系统形成的。充盈的材料占血流远端部分体积的90%以上。据估计，熔岩隆起脊膨胀所需的时间从60天到一年不等。
Unusually long lava rises occur in the distal portion of the Toomba basalt flow, up to 120 km from the source. In the Lolworth creek region, three parallel lava rise ridges occur over a 6 km section. Two of these ridges are continuous for the entire 6 km. The ridges average 7 m in height and range from 35 m to 300 m in width. Lava inflation clefts are numerous, and lava rise pits also occur. Down flow, a single lava rise ridge, averaging 18 m high and up to 500 m wide, extends for a further 10 km. This ridge has a generally level surface with abrupt edges sloping between 45° and 90°. Accurate surveys across the ridges show that in some cases there has been some stretching of the surface, presumably prior to the formation of the prominent clefts. The ridges were formed from an initially thin flow that was inflated by a continuous layer of lava that underlay almost the entire width of each ridge, rather than by a system of lava tubes of more limited dimensions. Inflated material represents over 90% of the volume of the distal parts of the flow. Estimates of the time required to inflate the lava rise ridges range from 60 days to a year.