Onset of the persistent activity at Stromboli Volcano (Italy)
Onset of the persistent activity at Stromboli Volcano (Italy)
复制标题
斯特龙博利火山（意大利）开始持续活动
DOI：
10.1007/s004450000098
复制
发表时间：
2000
影响因子：
3.5
通讯作者：
P. Landi
中科院分区：
文献类型：
--
作者：
M. Rosi;A. Bertagnini;P. Landi
抽象的。斯特龙博利在世界范围内被誉为“地中海灯塔”，人们普遍认为它在过去2000-2500年间一直处于持续活动的状态。然而，公元1000年以前的历史资料并不够准确，无法评估火山的活动是否与我们现在看到的完全相同。为了试图确定目前喷发制度的开始，并评估它是否在一段时间内保持了相同的特征，对最近的特弗拉矿床进行了地层学和放射性研究。在火山东北侧翼约500米的高度挖掘的长达4米深的地层战壕，暴露出一个整合的包含木炭碎片的火山灰堆。最有趣的发现之一是在地表以下约3米处发现了一层7厘米厚的风化层，富含有机质(薄的古土壤)。古土壤下面的层序由分米厚的火山灰沉降层和火山灰沉积物交替组成，火山灰沉积物含有经过校准的小木炭，年代从公元前4世纪到公元1世纪。古土壤上方的层序是无木炭的，由粗灰沉积组成，其中离散的厘米厚的青金石陨落床由贫晶的金色浮石和从属的富含晶体的黑色斯科石组成，类似于在现代活动更具活力的爆炸期间释放出来的火山灰/浮石对。收集的数据表明，在公元3世纪和7世纪之间，经过一段时间的平静之后，活动以与现在相同的喷发方式重新开始。我们得出结论，“地中海灯塔”实际上开始活动的时间比之前认为的要晚得多。
Abstract. Stromboli, known worldwide as the "Lighthouse of the Mediterranean", is commonly believed to have been in a state of persistent activity for the past 2000–2500 years. However, historical sources older than 1000 A.D. are not accurate enough to assess if the activity of the volcano was exactly the same as we see at present. In order to attempt to identify the onset of the present eruptive regime, and assess if it has been maintained with the same characteristics through time, stratigraphic and radiometric studies of the recent tephra deposits were undertaken. Up to 4-m-deep stratigraphic trenches, dug at a height of approximately 500 m on the NE flank of the volcano, exposed a conformable tephra pile containing charcoal fragments. One of the most interesting finds was the discovery of a 7-cm-thick weathered bed rich in organic matter (thin palaeosol) approximately 3 m below the surface. The sequence underneath the palaeosol consists of decimetre-thick lapilli fallout beds alternating with ash deposits bearing small charcoals with calibrated ages of between the fourth century B.C. and the first century A.D. The sequence above the palaeosol is charcoal free and consists of coarse-ash deposits with discrete, centimetre-thick lapilli fallout beds composed of crystal-poor golden pumice and subordinate crystal-rich black scoriae similar to scoria/pumice pairs emitted during the more energetic explosions of the present-day activity. The data collected indicate that between the third and seventh centuries A.D., after a period of quiescence, the activity resumed with an eruptive style identical to the present one. We conclude that the "Lighthouse of the Mediterranean" actually began its activity in a period much later than previously thought.