The paipa volcano, eastern cordillera of colombia, south america (part ii): petrography and major elements petrology

Paipa volcano products are mainly pyroclastic pumice and ash flow tuffs, lava domes and pyroclastic block and ash flow tuffs. They are classified as alkaline rhyolites and trachytes and high-K calcalkaline rhyolites. Chemical data show SiO2 values between 68 and 72%, and alkalis (Na2O+K2O) content o...