Emplacement of shallow intrusions at Goblin Colony and their impact on paleohydrology and alteration, Southern Jemez Mountains, New Mexico

Abstract—Goblin Colony is a recently described area in the southern Jemez Mountains that contains 0.15 km2 of zeolite-altered Tshirege Member of the Bandelier Tuff. The altered tuff (ignimbrite) fills a southwest-trending paleovalley in which preexisting basal-contained sediments provided water for the alteration of the tuff. The southeast side of the paleovalley is bounded by a prominent trachydacite to trachyandesite dike and plug zone that formed a hydrologic barrier to fluid flow. In this short paper, we describe the intrusions, the results of recent 40Ar/39Ar dates on the intrusions, and their impact on paleohydrology and low-temperature alteration of the tuff in the Goblin Colony.