The pyroclastic dikes of the Tertiary San Luis Potosí volcanic field: Implications on the emplacement of Panalillo ignimbrite

Abstract

Pyroclastic dikes emplaced along regional NW-SE faults in the Tertiary San Luis Potosí Volcanic Field consist of vitric pumice shards, rhyolite lithics, and broken crystals of quartz, sanidine, and biotite. These clasts display a parallel orientation inside the dikes and have developed devitrification structures after emplacement.The presence of these pyroclastic dikes associated to normal faults and their relation to the Oligocene pyroclastic sequences of the San Luis Potosí Volcanic Field suggests that they may represent the feeding conduits from which the Panalillo ignimbrite was erupted.

Keywords

• Pyroclastic dike
• Panalillo ignimbrite
• tectonics
• volcanism
• San Luis Potosí
• Tertiary
• Mexico