Rock Classification Scheme (BGS).pdf - The Water, Sanitation and ...
Rock Classification Scheme (BGS).pdf - The Water, Sanitation and ...
Rock Classification Scheme (BGS).pdf - The Water, Sanitation and ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
level 5 level 6 level 7 level 8HIERARCHICAL LEVELFIELDCLASSIFICATIONrhyolitic-rockdacitic-rockQAPF CLASSIFICATIONalkali-feldspar-rhyoliterhyolitedacitequartz-alkali-feldspar-trachyteQAPFFIELD234,56*felsitealkali-feldspar-trachyte6Note that the terms felsite<strong>and</strong> mafite are intended tobe used in the fieldclassification of generallylight <strong>and</strong> generally darkaphanitic rocks, respectively.However, the compositionof such rocks may notalways correspond to one ofthe rock types at level 7 or 8to which they are attachedon this diagram.trachytic-rockfoid-bearingalkali-feldspar-trachytequartz-trachytetrachytefoid-bearing-trachytequartz-latite6'7*77'8*latite8FINE-GRAINEDNORMALCRYSTALLINEROCKS<strong>and</strong>esitic-rockbasaltic-rockfoid-bearing-latite<strong>and</strong>esitebasalt8'9, 109, 10Where the name of agroup of minerals appearsin a root name, it may bereplaced by a moredefinitive mineral name,where appropriate. Forexample sanidine-rhyoliteinstead of alkali-feldsparrhyolite,<strong>and</strong> nephelinebearing-latiteinstead offoid-bearing-latite.phonolitic-rocktephritic-rockphonolitetephritic-phonolitephonolitic-basanitephonolitic-tephritebasanite1112131314mafitetephritephonolitic-foidite1415afoiditic-rockbasanitic-foiditetephritic-foidite15b15bfoidite15cultramafitite16Figure 17a Hierarchical classification of fine-grained normal crystalline rocks with QAPFclassification at level 8.40
Change language