| 翻訳と辞書 |
Wheal Metal
Wheal Metal is a tin mining sett in west Cornwall, England, UK. Whilst not as famous as neighbouring Wheal Vor, it was thus described by the ''Mining Journal'' in July 1885: " Truly this is a wonderful mine--probably the richest tin mine in the world." It also hosts a very remarkable engine house of the mid 19th century that once stood over Trelawney's shaft on Wheal Vor, and since the Wheal Vor area itself has no visible remains, this is the only large surviving engine house of this group of mines which accounted for over a quarter of Cornish tin production in the mid 19th century.
==Geology==
Around 290 to 280 million years ago rising plutons of granite intruded the native sedimentary rocks locally known as killas. Several of the domes formed were eventually exposed after their sedimentary coverings were eroded.
Wheal Metal lies in the metamorphic area of two of the granitic hills thus exposed, Tregonning Hill and Godolphin Hill in the West of Cornwall. During the cooling periods that ensued, fractures opened in the granite and surrounding killas and provided a path for mineralising solutions to rise, and occupy the voids and enrich the surrounding rocks. Those mineral lodes vary in thickness from a few inches to several feet. Where the lodes outcrop on the surface, mineral-rich rocks were eroded and washed away in the streams, providing the early adventurers their first chance to recover the minerals exposed and locally accumulated in " placers ". This is essentially a tin producing sett with a limited output of arsenic, but little or no copper was extracted from it.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Wheal Metal」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|