Zeolite deposits of possible economic significance on the northern Alaska Peninsula

Abstract

Clinoptilolite, mordenite, haulandite and laumontite have been identified in possible economic concentrations on the Alaska Peninsula. Most important are 1) a haulandite bearing water-laid tuff on Agate Island, 2) a thick sequence of terrestrial volcanics containing mordenite and clinoptilolite located between Squirrel Point and Tommy Creek, 3) water-laid tuffs containing high concentrations of clinoptilolite near Dennis Creek and 4) a haulandite bearing siltstone at Chinitna Bay. Zeolite formation in the Iliamna Lake area was produced in "open" systems of fresh water lakes and ground water systems which have transformed vitric volcanic material into zeolites. Burial diagenesis is responsible for alteration of early formed, low temperature-pressure zeolites into high temperature-pressure varieties. The formation of laumontite in a tuffaceous sandstone at Chinitna Bay was the result of low grade burial metamorphism. The mode of formation of haulandite in a welded tuff and siltstone unit, also located at Chinitna Bay, appears to have resulted from diagensis alteration of terrestrial sediments. Transportation of zeolite ore from Iliamna Lake would be by lake to Pile Bay Village then by road to Iliamna Bay and, finally, by ship to the consumer. In the Chinitna Bay area ore can be loaded directly onto ships for transportation to the consumer.