Geology of the Lantern property near Scossa mining district, Pershing County, Nevada

Abstract

The Lantern property and Scossa mining district o-f northern Pershing County, Nevada, exhibit gold-silver mineralization characteristic o-f epithermal systems. Mineralized boulders deposited as clasts in a mid-Tertiary fanglomerate bed and "in-place" mineralization of Tertiary- Quaternary sediments indicate that two separate hydrothermal systems have operated. Alteration, texture, and grade of mineralized rock that occur in three separate areas were influenced by the physical characteristics of the host rock-type: 1) Mineralization and alteration in a thick metamorphic sequence of phyllite, quartsite, sandstone, and carbonate is restricted to fault zones. The confined alteration and mineralization reflects the impermeable and nonreactive nature of the metamorphic sequence; 2) A near-surface "hot-springs" system operated in a permeable fanglomerate during the late Tertiary to early Quaternary resulting in widespread sericitic, argillic, and propylitic (?) alteration. Erratic mineralization was concentrated into veins below a silicified seal or cap; and 3). A hydrothermal system operated in interbedded fine to coarse grained sediments during the mid-Tertiary. This event produced relatively high grade mineralization which indicates that precious metals can be effectively concentrated in heterogeneous sediments.