Opaline cherts associated with sublacustrine hydro
详细信息 PDF全文下载
- journal_title：Geology
- Contributor：Robin W. Renaut ; R. Bernhart Owen
- Publisher：Geological Society of America
- Date：1988-
- Format：text/html
- Language：en
- Identifier：10.1130/0091-7613(1988)016<0699:OCAWSH>2.3.CO;2
- journal_abbrev：Geology
- issn：0091-7613
- volume：16
- issue：8
- firstpage：699
摘要
An unusual group of cherts found at saline, alkaline Lake Bogoria in the Kenya Rift differs from the Magadi-type cherts commonly associated with saline, alkaline lakes. The cherts are opaline, rich in diatoms, and formed from a siliceous, probably gelatinous, precursor that precipitated around submerged alkaline hot springs during a Holocene phase of high lake level. Silica precipitation resulted from rapid drop in the temperature of the spring waters and, possibly, pH. Lithification began before subaerial exposure. Ancient analogous cherts are likely to be localized deposits along fault lines.