Clay mineralogical variations and evolutions in sandstone sequences near a coal seam and shales in the Westphalian of the Campine Basin (NE Belgium)
| Autor: | I. Van Keer, Philippe Muchez, Willy Viaene |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Mineralogy
020101 civil engineering 02 engineering and technology Authigenic engineering.material 010502 geochemistry & geophysics 01 natural sciences 0201 civil engineering Diagenesis Geochemistry and Petrology Clastic rock Meteoric water engineering Kaolinite Sedimentary rock Clay minerals Dickite Geology 0105 earth and related environmental sciences |
| Zdroj: | Clay Minerals. 33:159-169 |
| ISSN: | 1471-8030 0009-8558 |
| Popis: | Mineralogical trends have been investigated on a detailed scale in two Westphalian fluvial sandstone sequences in contact with either a coal seam or shales. The evolution in an authigenic clay mineral assemblage can be related to changes in the pH of the pore-water. Firstly, kaolinite formed early in diagenesis, mainly as a result of K-feldspar dissolution and alteration. This process, which took place under acidic conditions, consumed protons. Subsequently the pH of the pore-water increased and after compaction, illitization of kaolinite occurred under near neutral conditions. Deep burial is marked by dickite formation, which again reflects acidic conditions. Distribution of clay minerals is related to meteoric water flux through the sediments and the release of organic acids and CO2 from coalification of organic matter in the underlying strata. |
| Databáze: | OpenAIRE |
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