Seismic Refraction and Gravity Surveys of Pilgrim Springs KGRA, Alaska

Abstract

Pilgrim Springs KGRA is located in a major northeast-trending tectonic depression on the Seward Peninsula, Alaska. Refraction has identified a layer which coincides with a hot artesian aquifer in hydrothermally cap rock is possible but not proven. Crystalline bedrock lies to at least 200 m beneath the springs, dropping to possibly 500 m in depth immediately to the southwest in what appear to be a trough bounded by normal faults on the north, south and east. Pilgrim Springs area situated over the intersection of the two faults, at the northeastern corner of this trough, suggesting that one or both faults are acting as conduits to the springs. Pilgrim Springs are associated with extensional tectonics and recent alkalic volcanism suggestive of active rifting in the region.