Present Status of Geological Studies in the Alaska Range: ABSTRACT

Abstract

After more than one-half century of geological study in Alaska, the geology of the Alaska Range remains imperfectly known. This has resulted from emphasis on areas of greater economic potential, such as north of the Brooks Range and Cook Inlet. However, recent geological studies in the eastern Alaska Range by faculty and graduate students at the University of Alaska are now adding substantially to our knowledge of this region. End_Page 356------------------------------ Some initial results of these studies are as follows: (1) a pre-Devonian polymetamorphic basement complex, including Precambrian granulite facies gneisses, has been located south of the Denali fault; (2) a stratigraphic interval containing approximately 12,000 feet of grey-wackes, thin limestones, and associated andesitic volcanics has been mapped and dated paleontologically as upper Mississippian and lower Pennsylvanian in age; and (3) a preliminary study of rugose and tabulate corals representative of the Lonsdaleiidae, Cyathopsidae, Hapsiphyllidae, Favositidae, and Auloporidae has been made and indicates that many forms are as closely related to Asiatic species as to described North American species. Heretofore, rocks of Pennsylvanian age were believed to be rare or absent in the Alaska Range. Their presence in geosynclinal accumulations will require modification of existing concepts of the depositional history of this region. Additional paleontological study of these northern faunas may further modify and expand our present poor understanding of the paleogeography and faunal realms of the Carboniferous. End_of_Article - Last_Page 357------------