"Thin sills and dykes of pitchstone and felsite and dykes o crinanite, olivine-dolerite, tholeiites of different types, quartz-dolerite, andesite, craignurite-pitchstone, felsite and porphyry are described and the importance of contact and deep-seated hybridization of two magmas of contrasting basic and acid composition in their formation established. Among the dykes, the sequence of intrusion is surmised to be as follows: basic, sub-basic, intermediate, acidic, and, again, basic."

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