Sedimentological and geoarchaeological evidence of multiple tsunamigenic imprint on the Bay of Palairos-Pogonia (Akarnania, NW Greece)
Sedimentological and geoarchaeological evidence of multiple tsunamigenic imprint on the Bay of Palairos-Pogonia (Akarnania, NW Greece)
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帕莱罗斯-波格尼亚湾（希腊西北部阿卡纳尼亚）多重海啸痕迹的沉积学和地质考古证据
DOI：
10.1016/j.quaint.2010.11.002
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发表时间：
2010
影响因子：
2.2
通讯作者：
Anja Zander
中科院分区：
文献类型：
--
作者：
A. Vött;F. Lang;H. Brückner;K. Gaki;H. Maroukian;D. Papanastassiou;A. Giannikos;H. Hadler;M. Handl;Konstantin Ntageretzis;T. Willershäuser;Anja Zander
本文提出的证据多海啸的影响海湾Palairos-Pogonia，希腊西北部，在全新世的基础上详细的地质科学研究。总共钻了41个振动岩心，以探测地层记录中的高能影响。在Palairos沿海平原、Pogonia海滩的海滩或泥灰岩基岩单元顶部以及Pogonia悬崖段沿着，发现了与原地细粒背海滩沉积物相交的粗粒异地海洋沉积物层。高能矿床与特定的沉积结构有关，如向上变细的层序、裂陷碎屑、基底侵蚀接触、双峰至多峰粒度分布、层压以及圆形和棱角分明的组分共存，所有这些都是海啸影响的典型特征。宏观和微观动物群分析显示，海啸相关的输入到静止的淡水和微咸水环境的高能量和长距离运输的许多异地海洋物种和大多数角壳碎片。地球物理学方法有助于发现地下结构和掌握海啸层的横向范围。来自XRF测量的钙铁比被用来追踪海啸对内陆的影响。最重要的是海啸的广泛空间分布，在Pogonia悬崖段的横向范围为70米，在Pogonia海滩为200米，在Palairos平原中部为1公里，以及向内陆变细和变薄的总体趋势。海啸的最高海拔被发现在波戈尼亚村附近，约为1000米。7.5ma.s.l. Vibracore数据表明，整体海岸演变受到强烈影响，局部甚至受到多次高能撞击的控制。在波戈尼亚悬崖发现了一个明显的地质考古海啸，厚达1.5米，由混合海洋（沙子，鹅卵石，生物侵蚀蚀变的石头，贝壳碎片，有孔虫）和陆源物质（丰富的陶瓷碎片，骨骼，建筑材料）组成。它与一个被摧毁的古代鼹鼠的水下遗骸直接相关，它的建筑材料也被同一事件部分脱位。海啸的年代测定是通过对诊断碎片的考古年代测定以及放射性碳和发光年代测定技术完成的。强烈的海啸事件可以追溯到公元前6世纪初、公元前5世纪中期、公元前4/3世纪和公元前2千年晚期以及公元前4/3世纪。在区域尺度上，大地震的复发间隔约为1000年。500-1000年在全新世晚期，Palairos海岸平原至少有两次从北方和南方同时被洪水淹没。
This paper presents evidence of multiple tsunami impact on the Bay of Palairos-Pogonia, NW Greece, during the Holocene based on detailed geo-scientific studies. Altogether, 41 vibracores were drilled to detect high-energy influence in the stratigraphical record. Layers of coarse-grained allochthonous marine deposits were found intersecting autochthonous fine-grained back beach sediments in the Palairos coastal plain, on top of beach or marly bedrock units at Pogonia beach and along the Pogonia cliff section. High-energy deposits are associated with specific sedimentary structures such as fining upward sequences, rip up-clasts, basal erosional contact, bi- to multimodal grain size distribution, lamination, and co-existence of both well rounded and angular, sharply edged components, all of them typical of tsunami impact. Macro- and microfaunal analyses revealed tsunami-related input of numerous ex situ marine species and mostly angular shell debris into quiescent fresh- to brackish water environments by high-energy and long-distance transport. Geophysical methods helped to find subsurface structures and to seize the lateral extent of tsunami layers. Ca–Fe ratios derived from XRF measurements were used to trace tsunami influence inland. Most important is the widespread spatial distribution of the tsunamites with a lateral extent between 70m at the Pogonia cliff section, 200m at Pogonia beach, and 1km in the central Palairos plain, and overall tendencies of fining and thinning towards inland. Highest elevations of tsunamites were found around Pogonia village at ca. 7.5ma.s.l. Vibracore data give evidence that the overall coastal evolution has been strongly affected, locally even controlled by multiple high-energy impact. A conspicuous geoarchaeological tsunamite, up to 1.5m thick, was found at Pogonia cliff consisting of mixed marine (sand, pebbles, bio-erosively altered stones, shell debris, foraminifers) and terrigenous material (abundant ceramic fragments, bones, building material). It is directly associated with the submerged remains of an ancient mole which was destroyed and its building material partly dislocated by the same event. Dating of tsunamites was accomplished by archaeological age determination of diagnostic sherds and by radiocarbon and luminescence dating techniques. Strong tsunami events were dated to the beginning of the 6th, the mid-5th, the 4th/3rd and the late 2nd millennia BC as well as to the 4th/3rd century BC. On a regional scale, the recurrence interval for large events is ca. 500–1000 years. At least twice during the late Holocene, the Palairos coastal plain was flooded quasi-contemporaneously from both the northern and southern side.