翻訳と辞書 Words near each other ・ Biridepalli ・ Biridiya ・ Birieux ・ Birifor language ・ Birigui ・ Birikken ・ Birillus ・ Birilyant ・ Birilyussky District ・ Birim Central Municipal District ・ Birim North District ・ Birim River ・ Birim River (New Guinea) ・ Birim South District ・ Birimak ・ Birimian ・ Birimirtsi ・ Birin ・ Birinchi Kumar Barua ・ Birinchi May ・ Birinci Alıbəyli ・ Birinci Aral ・ Birinci Ağalı ・ Birinci Aşıqlı ・ Birinci Baharlı ・ Birinci Biləcik ・ Birinci Dördyol ・ Birinci ferik ・ Birinci İpək ・ Birinci Mahmudlu Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Birimian ： ウィキペディア英語版 Birimian The Birimian rocks are major sources of gold and diamonds that extend through Ghana, Côte d'Ivoire, Guinea, Mali and Burkina Faso. They are named after the Birim River, one of the main tributaries of the Pra River in Ghana and the country's most important diamond-producing area. Ghana and Mali are the second and third largest producers of gold in Africa.〔 〕 The Birimian terranes in the south part of the West African craton are a mix of metamorphosed volcanic, sedimentary and plutonic rocks and low grade metavolcanics and metasediments. Almost half of the terranes consist of alkaline granites. The rocks formed over a period of about 50 million years between 2.200 Ga and 2.100 Ga years ago. ==Location== The Birimian rocks stretch across the countries to the north of the Gulf of Guinea, forming parallel belts that generally trend northeasterly and are 40 to 50 km wide and about 90 km apart. They consist of interlayered sedimentary and volcanic flow rocks metamorphosed to low greenschist facies. Most rivers draining the Birimian rocks hold alluvial gold deposits. They are overlaid in places by quartz-pebble conglomerates within the Tarkwaian System, name after Tarkwa, the second largest source of gold in Ghana.〔(【引用サイトリンク】title=GEOLOGY AND MINERAL DEPOSITS )〕 However, recent research indicates that the gold found in the Tarkwaian rocks is not derived from the Birimian terranes. 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「Birimian」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.