| 翻訳と辞書 |
| Rhynie chert ： ウィキペディア英語版 |
Rhynie chert
The Rhynie chert is an Early Devonian sedimentary deposit exhibiting extraordinary fossil detail or completeness (a Lagerstätte). It is exposed near the village of Rhynie, Aberdeenshire, Scotland; a second unit, the Windyfield chert, is located some 700 m away. The Rhynie chert contains exceptionally preserved plant, fungus, lichen and animal material preserved in place by an overlying volcanic deposit. The bulk of the fossil bed consists of primitive plants (which had water-conducting cells and sporangia, but no true leaves), along with arthropods, lichens, algae and fungi.
This fossil bed is remarkable for two reasons. First, the age of the site (Pragian, Early Devonian, formed about ) places it at an early stage in the colonisation of land. Second, these cherts are famous for their exceptional state of ultrastructural preservation, with individual cell walls easily visible in polished specimens. Stomata have been counted and lignin remnants detected in the plant material, and the breathing apparatus of trigonotarbids—of the class Arachnida—(known as book lungs) can be seen in cross-sections. Fungal hyphae can be seen entering plant material, acting as decomposers and mycorrhizal symbionts.
==Location==
The bed is under at least 1 metre of overburden, in a small field near the village of Rhynie, so is effectively inaccessible to collectors; besides which, the site is a Site of Special Scientific Interest. A second unit, the Windyfield chert, is some 700 m from the Rhynie. The Rhynie chert extends for at least 80 m along strike and 90 m down-dip.〔
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「Rhynie chert」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.
|
|