CALDERA FORMATION ON SANTORINI AND THE PHYSIOGRAPHY OF THE ISLANDS IN THE LATE BRONZE-AGE

被引：97

作者：

DRUITT, TH

FRANCAVIGLIA, V

机构：

[1] Department of Geology, University of Wales, Cardiff

[2] Istituto per Le Tecnologie Applicate ai Beni Culturali, C.N.R., Rome

来源：

BULLETIN OF VOLCANOLOGY | 1992年 / 54卷 / 06期

关键词：

D O I：

10.1007/BF00301394

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

The caldera of Santorini is a composite structure with a subsidence history extending over 100 ka or more. Geomorphological mapping shows that the present-day caldera wall is a complex assemblage of cliff surfaces of different ages, and that collapse at Santorini has repeatedly exhumed earlier caldera cliffs and unconformities. Cliffs bounding the southern, southeastern and northwestern rims of the caldera are morphologically fresh and probably formed during or soon after the Minoan eruption in the late Bronze Age. The well-scalloped shape of these cliffs is attributed to large-scale rotational landslip around the margins of the Minoan caldera. The deposit from one landslip is preserved subaerially. Minoan landslips in southeast Santorini detached along the basement unconformity, exposing a cliff of the prevolcanic island. The caldera wall in the north, northeast and east preserves evidence for three generations of cliff: those of Minoan age and two earlier generations of caldera wall. The two early calderas can be dated relative to a well-established statigraphy of lavas and tuffs. The presence of in situ Minoan tephra plastered onto the present-day caldera wall provides evidence that these ancient caldera cliffs had already been exhumed prior to the Minoan eruption. Field relationships permit reconstruction of the physiography of Bronze-Age Santorini immediately before the Minoan eruption. The reconstruction differs from some previously published versions and is believed to be the most accurate to date. Bronze-Age Santorini had a large flooded caldera formed 21 ka ago. This caldera must have acted as an excellent harbour for the Bronze-Age inhabitants of the island. The 3.6 ka Minoan eruption deepened and widened the extant caldera. The volume of Minoan collapse (approximately 25 km3) is in good agreement with published estimates for the volume of discharged magma if between 5 and 8 km3 of Minoan ignimbrite ponded as intracaldera tuff.

引用

页码：484 / 493

页数：10

共 28 条

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