Location: - This report describes sections of the Lisburne limestone studied in the foothills and northern mountains of the Brooks Range, Alaska. The area covered extends along the front of the range from Sagavanirktok Lake (68°28' N. - 149°25' W.) west to the head of the Kukpowruk River (68°25' N. - 162°40' W.). The southernmost point in the area is at the head of Alapah Creek (68°11' N. - 150°40' W.) and the northernmost point is on Lisburne Ridge just west of the Etivluk River (68°36' N. - 156°40' W.).
Field work was done by the authors at Sagavanirktok Lake, Kanayut Lake, Alapah Creek, the Anaktuvuk and Tiglukpuk Creek, and Chandler Lake. Brief visits were made to the Lisburne Ridge just north and west of the junction of the Nigu and Etivluk Rivers and to outcrops of Lisburne limestone along the Kiligwa River (68°30' N. - 158°35' W.). Data from other areas included in this report were collected by other field parties of the U. S. Geological Survey. A. L. Bowsher, Sr. .and J. T. Dutro, Jr. studied the Lisburne limestone at Kanayut Lake, Nanushuk Lake, and Itkillik Lake in 19491/ .W. W. Patton, Jr. and Irving L. Tailleur described the Lisburne limestone exposed in the northern Brooks Range along the Kiruktagiak River 2/ and the Okokmilage River 3/ in1949, and I. L. Tailleur and Bion H. Kent have supplied data on the Etivluk-Kiligwa Rivers area from their field work of 1950 4/. R. M. Chapman, G. D. Eberlein, and C. D. Reynolds measured sections of Lisburne limestone at Kurupa Lake and on the east fork of the Etivluk River in 1950 5/. E. G. Sable and M. D. Mangus measured the section on Iligluruk Creek near the head of the Kokolik River in 1950 6/,, and Chapman end Sable measured the section at the head of the Kukpowrok River in 1949 7/.
