| 翻訳と辞書 |
| Desert varnish ： ウィキペディア英語版 |
Desert varnish
Desert varnish or rock varnish is an orange-yellow to black coating found on exposed rock surfaces in arid environments. Desert varnish is usually around one micrometer thick and represents nanometre-scale layering.〔David Krinsley, Ronald Dorn, N. K. Tovey 1995. Nanometre-Scale Layering in Rock Varnish: Implications for Genesis and Paleoenvironmental Interpretation, The Journal of Geology, 103(1): 106-113〕 Rock rust and desert patina are other terms which are also used for the condition, but less often.
==Formation ==
Desert varnish forms only on physically stable rock surfaces that are no longer subject to frequent precipitation, fracturing or wind abrasion. The varnish is primarily composed of particles of clay along with iron and manganese oxides.〔Perry, R.S. and Adams, J.B. 1978. Desert varnish: evidence for cyclic deposition of manganese. Nature 276(5687):489-491.〕 There is also a host of trace elements and almost always some organic matter. The colour of the varnish varies from shades of brown to black.〔Chernicoff, Stanley and Whitney, Donna 2007. Geologly: An Introduction to Physical Geologly 4th ed. Pearson Education p. 585〕
It has been suggested that desert varnish should be investigated as a potential candidate for a "shadow biosphere".〔Cleland, C.E. (2007) (Epistemological issues in the study of microbial life: alternative biospheres ). Studies in the History and Philosophy of Biological and Biomedical Sciences 38:847–861.〕〔("Life on Earth… but not as we know it" ), Robin McKie, 14 April 2013, The Guardian〕
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「Desert varnish」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.
|
|