Preliminary excavation of Oakbank Crannog, Loch Tay: interim report
Preliminary excavation of Oakbank Crannog, Loch Tay: interim report
复制标题
泰湖 Oakbank Crannog 的初步发掘：临时报告
DOI：
10.1111/j.1095-9270.1981.tb00003.x
复制
发表时间：
1981
影响因子：
0.5
通讯作者：
T. N. Dixon
中科院分区：
文献类型：
--
作者：
T. N. Dixon
1978年，爱丁堡大学考古系和爱丁堡大学苏巴夸俱乐部的成员对洛赫泰湖的crannogs进行了调查（在新闻界）。这项调查基本上遵循了与I博士进行的调查相同的程序。莫里森和D. 1973年，在洛赫奥威湖的麦卡德尔，在此期间，20 crannogs被确定。在洛赫泰勘测期间，识别并记录了17个明确的裂隙。其中一个位于洛赫北岸的Fearnan村的Oakbank Cottage附近，包括通往海岸的堤道的遗迹，西侧的一个延伸区域暗示着登陆阶段的遗迹。在现场的许多地方都可以看到木材，包括垂直的柱子和水平的木板和横梁。在调查之前，对其中两种木材进行了放射性碳测年。大多数crannogs的遗骸现在被淹没的洛赫泰和洛赫奥维调查证明，其中25个网站完全水下全年或大部分时间。在过去，这使得挖掘是不可能的，除非是为了农业发展或水力发电计划而排水的场地，但随着过去20年来水下工作技术的发展，这种挖掘不仅可行，而且在crannogs的情况下是可取的。这种愿望是两件事的结果。首先，这些遗址的主要部分是木结构建筑，其次，由于浸泡在洛克斯冰冷的泥炭水中，有机材料，包括木材，得到了极好的保护。当然，建筑的木材部分是浸水的，但在水下，它们的重量很轻，对脆弱的分层结构或碎片文物的压力很小。同样的木材离开水后会承担更大的重量，主要是因为它含有大量的水，并对排水遗址的重要特征施加破坏和扭曲的力量。此外，当crannog暴露在空气中时，有机残留物立即开始变质，部分或全部残留物将被破坏。水下挖掘总是需要对该介质做出让步。特许权的成本与水深、离海岸的距离和供应线的远近等因素直接相关。Oakbank Crannog的挖掘可被视为在财务和体力方面更具成本效益的水下挖掘之一，因为场地的最深部分仅在约5 m的水中，而主要的上部居住层在1-5- 2 m，这取决于洛赫的水位，在正常年份可能会变化约1 m。根据施工现场的不同，到海岸的距离在20到50米之间，道路和供应中心的通道也很好。空气可通过低压压缩机从海岸轻松供应，只要挖掘机有足够的防寒保护（仅在3月和4月山上积雪融化时才严重），则可预期在水中工作6小时以上。与陆地上的挖掘相比，不存在无法克服的障碍来阻止有效的挖掘。1980年挖掘中的两个主要问题是约0.50 m高的短波浪，伴随着持续的西南风，内耳感染可能是由于洛赫表面上的细菌引起的。波没有P。事件潜水，并没有对暴露的有机物造成多大损害
In 1978 a survey (in the press) of the crannogs in Loch Tay was carried out by members of Edinburgh University Department of Archaeology and Edinburgh University Subaqua Club. This survey followed basically the same procedures as that carried out by Drs I. Morrison and D. McArdle in Loch Awe in 1973 during which 20 crannogs were identified. During the Loch Tay survey 17 definite crannogs were recognized and recorded. One of these, situated off Oakbank Cottage in the village of Fearnan on the north shore of the loch, included the remains of a causeway to the shore and an extended area on the west side suggested the remains of a landing stage.. Timbers, both vertical posts and horizontal planks and beams, were observed on many parts of the site. Two of these timbers were sampled for radiocarbon dating prior to the survey. The remains of most crannogs are now submerged as attested by the Loch Tay and Loch Awe surveys where 25 of the 37 sites are completely underwater either all year round or for most of the year. In the past this has made excavation impossible, except in the case of sites drained for agricultural development or hydroelectric power schemes, but with the development of underwater working techniques in the last 20 years such excavations have become not only viable but, in the case of crannogs, desirable. This desirability is a result of two things. Firstly, the fact that the major parts of these sites are of timber construction, and secondly, the excellent preservation of organic materials, including the timbers, due to immersion in the cold peaty water of the lochs. The timber parts of the structure are, of course, waterlogged but while underwater they weigh very little and put little strain on delicate stratified layers or fragde artefacts. The same timber out of water assumes a very much greater weight, mainly due to the substantial amount of water it contains, and exerts damaging and distorting forces upon the archaedogicaily important features of a drained site. Also, when a crannog is exposed to the air, deterioration of the organic remains begins immediately and either part or all of those remains will be destroyed.Excavation under water will always require concessions to that medium. The cost of the concession relates directly to factors like the depth of water, distance from shore and access to supply lines. The excavation of Oakbank Crannog may be seen as one of the more cost effective excavations under water, both in terms of finance and physical effort, as the deepest part of the site is in only about 5 m of water while the main upper habitation layer is in 1-5-2m depending upon the level in the loch, which during normal years may vary by about 1 m. Depending upon which part of the site is being worked the distance to shore is between 20 and 50m and access to roads and supply centres is good. Air is readily supplied from the shore by a low pressure compressor and so long as the excavators have adequate protection from the cold, which is only severe when snow melts from the mountains in March and April, a working day of up to and sometimes over 6 h in the water may be expected. No insurmountable barriers exist to prevent efficient excavation comparable with that on land sites and the two main problems in the 1980 excavation were short choppy waves about 0.50 m high which accompanied sus-tained southwest winds, and inner ear infections probably due to bacteria on the urface of the loch water. The waves did not p.. event diving and did little damage to exposed organic