BGS Rock Classification Scheme - Text search results
220 records found. Please click on a code for a "thumbnail" definition.
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| Description | Code |
|---|---|
| Basalt and rhyolite [composite intrusion] | BARYI |
| Basalt, subalkali - A type of basalt (TAS). In the Rock Classification Scheme, the root name basalt (TAS) may be divided into alkali basalt and subalkali basalt according to the state of silica saturation. If the analysis contains no normative nepheline the rock may be called a subalkali basalt. British Geological Survey Research Report RR/99/06, section 5.2. | BASBA |
| Basalt, schistose | BASCH |
| Tuff, basalt | BASTUF |
| Basalt (TAS) - A type of basaltic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of basalt (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. | BAT |
| Basalt, tholeiitic - A subgroup of subalkali basalt. Tholeiitic describes a variety of basalt which is saturated or slightly oversaturated in silica with respect to alkalis so that hypersthene appears in the CIPW norm and hypersthene or pigeonite amongst the modal pyroxenes. Olivine may be present in widely varying amounts, or absent. The term is also used for a suite of rocks showing marked iron-enrichment on AFM diagrams. British Geological Survey Research Report RR/99/06, section 8.4. | BATHL |
| Basaltic tuff and basaltic lava | BATL |
| Basalt and trachyte [composite intrusion] | BATR |
| Basaltic-trachyandesite - A type of trachytic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of basaltic-trachyandesite is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. | BATRAT |
| Tuff, basaltic-trachyandesitic | BATTUF |
| Tuff, basaltic | BATUF |
| Basalt, variolitic | BAV |
| Volcaniclastic-breccia, basaltic | BAVBR |
| Volcaniclastic-sandstone, basaltic | BAVST |
| Basaltic lava and andesitic lava | BCLACL |
| Lava, basaltic | BCLAVA |
| Basaltic lava and volcaniclastic-breccia | BCLVBR |
| Hawaiite, basaltic | BHAW |
| Basalt lava and andesite lava | BLAL |
| Basaltic lava and mugearite | BLMU |