A Holocene lacustrine rock platform around Storavatnet, Osterøy, western Norway
A Holocene lacustrine rock platform around Storavatnet, Osterøy, western Norway
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挪威西部奥斯特罗伊 Storavatnet 周围的全新世湖相岩台
DOI：
10.1191/0959683604hl736rp
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
H. Fossen
中科院分区：
文献类型：
--
作者：
I. Aarseth;H. Fossen
最近发现的低海拔湖岩平台位于挪威西部卑尔根附近的奥斯特罗伊岛上的一个1 Okm 2湖泊旁，沿着存在。该湖于1920年被改造成水库，因此水位经常变化，高于和低于以前的自然水位151.5米。该岩台宽达20 m，发育于强烈面理变质的元古宙和古生代岩体内。突出的缺口和小洞穴沿着基岩裂缝在沿着平台的一些地方发育，平台通常向湖倾斜5至10度，并镶有悬崖上的棱角碎片。研究区在10 000 14 C yr BP的更新世/全新世过渡期冰川消退，并在约6000 14 C yr BP的冰川反弹倾斜完成。全新世后期挪威西海岸的气候，高降水和冬季频繁的冻融循环，导致湖泊水位高度波动。这些条件与冻土风化作用形成台地的结论相一致。来自陡坡的物质运动，加上冰破裂时的冰推，是碎片运输的原因。由于湖周围的平台基本上处于同一水平，它必须在全新世中期和公元1920年之间形成。
A recently discovered lacustrine rock platform at low altitude exists along a 1Okm2 lake on the Osterøy Island near Bergen, western Norway. The lake was converted to a reservoir in 1920 and therefore is subject to frequent changes in level above and below the previous natural level of 151.5 m a.s.l. The rock platform, up to 20 m wide, is developed in strongly foliated metamorphic Proterozoic and Palaeozoic berock. Overhanging notches and small caves are developed along bedrock fractures in some places along the platform, which typically tilts 5 to 10 degrees towards the lake and is veneered with angular debris from the cliffs. The study area was deglaciated at the Pleistocene/Holocene transition 10 000 14C yr BP, and the tilting of the glacial rebound was complete about 6000 14C yr BP. The west-coast climate in Norway duing the latter part of the Holocene, with high precipitation and frequent freeze-thaw cycles during winter, resulted in highly fluctuating lake levels. These conditions are consistent with the conclusion that the plaform was formed by frost weathering. Mass movement from the steep slopes, together with ice-push duing ice breakup, was responsible for transportation of the debris. Because the platform around the lake is essentially at the same level, it must have been formed between the mid-Holocene and AD 1920.