CENTRAL VOLCANOS AS SOURCES FOR THE ANTARCTIC PENINSULA VOLCANIC GROUP

被引：15

作者：

LEAT, PT

SCARROW, JH

机构：

[1] British Antarctic Survey, Natural Environment Research Council, High Cross, Cambridge, CB3 OET, kladingley Road

来源：

ANTARCTIC SCIENCE | 1994年 / 6卷 / 03期

关键词：

ANTARCTIC PENINSULA; VOLCANO; CALDERA; IGNIMBRITE; BRECCIA; LAVA;

D O I：

10.1017/S0954102094000568

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

From at least the Early Jurassic to the Miocene, eastward subduction of oceanic crust took place beneath the Antarctic Peninsula. Magmatism associated with the subduction generated a N-S linear belt of volcanic rocks known as the Antarctic Peninsula Volcanic Group (APVG), and which erosion has now exposed at about the plutonic/volcanic interface. Large central volcanoes from the APVG are described here for the first time. The structures are situated in north-west Palmer Land within the main Mesozoic magmatic arc. One centre, Zonda Towers, is recognized by the presence of a 160 m thick silicic ignimbrite, containing accidental lava blocks up to 25 m in diameter. This megabreccia is interpreted as a caldera-fill deposit which formed by land sliding of steep caldera walls during ignimbrite eruption and deposition. A larger centre, Mount Edgell-Wright Spires, is dominated by coarse-grained debris flow deposits and silicic ignimbrites which, with minor lavas and fine-grained tuffs, form a volcanic succession some 1.5 km thick. Basic intermediate and silicic sills c. 50 m thick intrude the succession. A central gabbro-granite intrusion is interpreted to be a high-level magma chamber of the Mount Edgell volcano.

引用

页码：365 / 374

页数：10

共 42 条

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