GIS-based identification of areas that have resource potential for sediment-hosted Pb-Zn deposits in Alaska

Abstract

A state-wide Geographic Information System (GIS) analysis was conducted to assess prospectivity for lead (Pb) and zinc (Zn) in sediment-hosted deposits in Alaska. The datasets that were utilized include publicly available geospatial datasets of lithologic, geochemical, and mineral occurrence data. Key characteristics of Pb-Zn deposits were identified in avail able datasets and scored with respect to relative importance. To evaluate resource potential, drainage basins of the smallest size were chosen, each of which covers approximately 100 square kilometers (km 2 ). Drainage basins are the most logical and efficient unit for evaluation because the most regionally robust dataset comes from stream sediment geochemistry. CD CD is deposits include the (1) western and central Brooks Range, referred to in this report as the Brooks Range zinc belt; (2) Seward Peninsula (and adjacent St. Lawrence Island); (3) Farewell terrane in Interior Alaska; (4) two spatially distinct belts in east-central Alaska; and (5) the central Alaska Range. All areas contain some known deposits, and that provides credibility to the scoring process. describe localities where minerals of the commodity have no reported inventory. Mineral deposit “types” are recognized styles of mineralization described in published deposit models. A list of keyword search terms that are unique to sediment-hosted Pb-Zn deposits was developed to distinguish these deposits from other Zn-Pb bearing deposit types. and