CALDERA FORMATION ON SANTORINI AND THE PHYSIOGRAPHY OF THE ISLANDS IN THE LATE BRONZE-AGE
CALDERA FORMATION ON SANTORINI AND THE PHYSIOGRAPHY OF THE ISLANDS IN THE LATE BRONZE-AGE
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DOI：
10.1007/bf00301394
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发表时间：
1992-08-01
影响因子：
3.5
通讯作者：
FRANCAVIGLIA, V
中科院分区：
文献类型：
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作者：
DRUITT, TH;FRANCAVIGLIA, V
圣托里尼火山口是一个复合结构，其沉降历史超过100 ka或更长。地貌测绘显示，现今的破火山口壁是不同年代的悬崖表面的复杂组合，圣托里尼岛的崩塌反复挖掘出早期的破火山口悬崖和不整合面。火山口的南部、东南部和西北部边缘的悬崖在形态上是新鲜的，可能是在青铜时代晚期的米诺斯火山爆发期间或之后不久形成的。这些悬崖的扇形形状归因于米诺斯火山口边缘的大规模旋转滑坡。一处滑坡形成的存款被保存在空中。圣托里尼岛东南部的米诺斯滑坡沿着基底不整合面分离，暴露出火山前岛屿的悬崖。北部、东北部和东部的火山口墙保存了三代悬崖的证据：米诺斯时代的悬崖和两代更早的火山口墙。这两个早期的破火山口可以相对于一个完善的熔岩和凝灰岩的统计。在现今的火山口壁上发现的米诺斯火山灰提供了证据，证明这些古老的火山口悬崖在米诺斯火山爆发之前就已经被挖掘出来了。场的关系允许重建青铜时代圣托里尼的自然地理学之前，米诺斯火山爆发。重建不同于一些以前出版的版本，被认为是最准确的日期。青铜时代的圣托里尼岛有一个21万年前形成的大的被淹没的破火山口。这个破火山口一定是岛上青铜时代居民的绝佳港口。3.6 ka的米诺斯火山爆发加深并扩大了现存的破火山口。米诺斯崩溃的体积（约25立方公里）是在很好的协议与公布的估计量排出的岩浆，如果5和8立方公里之间的米诺斯熔结凝灰岩积水为intracaldera凝灰岩。
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.