Late Precambrian glaciogenic sedimentary rocks in southern Africa: a compilation with definitions and correlations
Evidence of ancient glaciations is summarized, and the terminology dealing with glaciogenic and nonglaciogenic sedimentary rocks is discussed. The term tillite is used as a comprehensive genetic term for both continentally deposited and ice-rafted indurated tills. The glaciogenic origin of any rock...
| Principais autores: | , |
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| Formato: | Artigo |
| Idioma: | English |
| Publicado em: |
Geological Society of Finland
1973-06-01
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| coleção: | Bulletin of the Geological Society of Finland |
| Acesso em linha: | http://www.geologinenseura.fi/bulletin/Volume45/sgs_bt_045_1_pages_079_102.pdf |
| _version_ | 1828529973197012992 |
|---|---|
| author | A. Kröner K. Rankama |
| author_facet | A. Kröner K. Rankama |
| author_sort | A. Kröner |
| collection | DOAJ |
| description | Evidence of ancient glaciations is summarized, and the terminology dealing with glaciogenic and nonglaciogenic sedimentary rocks is discussed. The term tillite is used as a comprehensive genetic term for both continentally deposited and ice-rafted indurated tills. The glaciogenic origin of any rock called tillite must have been proved beyond doubt. The term mixtite is used for sedimentary rocks that resemble tillites but are of uncertain or unknown origin. A comprehensive compilation of all known Late Precambrian glaciogenic sedimentary rocks in South Africa and in South West Africa is presented. These rocks seem to form two distinct groups that may indicate the existence of two periods of glaciation. Glaciogenic rocks in other countries in Africa occupy similar stratigraphic positions. This evidence strengthens the possibility of the existence of a severe continentwide Late Precambrian glaciation in Africa. Comments on the Late Precambrian glaciation in Australia and in South America are given. |
| first_indexed | 2024-12-11T22:16:34Z |
| format | Article |
| id | doaj.art-9af742bf8e4c49a48e8055e70a8ffc9d |
| institution | Directory Open Access Journal |
| issn | 0367-5211 1799-4632 |
| language | English |
| last_indexed | 2024-12-11T22:16:34Z |
| publishDate | 1973-06-01 |
| publisher | Geological Society of Finland |
| record_format | Article |
| series | Bulletin of the Geological Society of Finland |
| spelling | doaj.art-9af742bf8e4c49a48e8055e70a8ffc9d2022-12-22T00:48:36ZengGeological Society of FinlandBulletin of the Geological Society of Finland0367-52111799-46321973-06-014517910210.17741/bgsf/45.1.012Late Precambrian glaciogenic sedimentary rocks in southern Africa: a compilation with definitions and correlationsA. KrönerK. RankamaEvidence of ancient glaciations is summarized, and the terminology dealing with glaciogenic and nonglaciogenic sedimentary rocks is discussed. The term tillite is used as a comprehensive genetic term for both continentally deposited and ice-rafted indurated tills. The glaciogenic origin of any rock called tillite must have been proved beyond doubt. The term mixtite is used for sedimentary rocks that resemble tillites but are of uncertain or unknown origin. A comprehensive compilation of all known Late Precambrian glaciogenic sedimentary rocks in South Africa and in South West Africa is presented. These rocks seem to form two distinct groups that may indicate the existence of two periods of glaciation. Glaciogenic rocks in other countries in Africa occupy similar stratigraphic positions. This evidence strengthens the possibility of the existence of a severe continentwide Late Precambrian glaciation in Africa. Comments on the Late Precambrian glaciation in Australia and in South America are given.http://www.geologinenseura.fi/bulletin/Volume45/sgs_bt_045_1_pages_079_102.pdf |
| spellingShingle | A. Kröner K. Rankama Late Precambrian glaciogenic sedimentary rocks in southern Africa: a compilation with definitions and correlations Bulletin of the Geological Society of Finland |
| title | Late Precambrian glaciogenic sedimentary rocks in southern Africa: a compilation with definitions and correlations |
| title_full | Late Precambrian glaciogenic sedimentary rocks in southern Africa: a compilation with definitions and correlations |
| title_fullStr | Late Precambrian glaciogenic sedimentary rocks in southern Africa: a compilation with definitions and correlations |
| title_full_unstemmed | Late Precambrian glaciogenic sedimentary rocks in southern Africa: a compilation with definitions and correlations |
| title_short | Late Precambrian glaciogenic sedimentary rocks in southern Africa: a compilation with definitions and correlations |
| title_sort | late precambrian glaciogenic sedimentary rocks in southern africa a compilation with definitions and correlations |
| url | http://www.geologinenseura.fi/bulletin/Volume45/sgs_bt_045_1_pages_079_102.pdf |
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