During the 1951 field season, U. S. Geological Survey Navy Oil Unit party 1 conducted stratigraphic and structural studies of the rocks in the area between the westernmost fork of the Shaviovik River and the East Kuparuk River. This area is drained by the Sagavanirktok River and its major tributaries; the Echooka River, the Ivishak River, and Lupine River. Owing to the nature of the investigation, the studies were confined to a relatively narrow geographic strip, rarely exceeding a distance of 20 miles north of the northernmost occurrence of the Lisburne limestone of the Brooks Range province. The work was thus conducted in an area of approximately 2,000 square miles, which lies wholly within the Brooks and Arctic Foothill provinces; within this area approximately 1,000 square miles was mapped geologically.

The party consisted of six men: A. S. Keller and R. L. Detterman, geologists; I. W. Marine and D. E. Reed, field assistants; L. G. Barbin, cook-field assistant; and T. F. Derrington, weasel mechanic. The party utilized 3 weasels for transportation of equipment and personnel during the season, during which time 15 camps ware established. Work was initiated on the Shaviovik River on May 24, 1951, and the party concluded its investigations on the Kuparuk River drainage on August 24, 1951.

In 1947, G. Gryc and E. H. Lathram conducted reconnaissance studies of the rocks in the vicinity of camps 12-15 (pl. 1); and during the same year, G. Gryn visited outcrops on the Ivishak River in the vicinity of camps 6-7 (pl. 1). These studies were made by the Navy Oil Unit of the U. S. Geological Survey in conjunction with the investigations of NPR-4. No other work of a geologic nature had been done in the area in the past.

The primary objective of the 1951 party was the correlation of the Mesozoic and upper Paleozoic strata of the foothills province west of the Itkillik River, with that of the Shaviovik and Canning Rivers region. A secondary objective was to determine the cause of the pronounced northeasterly swing in the trend of the Brooks Range front in the Sagavanirktok drainage and to determine the structural implications of this swing.

The area was mapped at a scale of 1:20,000 on vertical photographs and transferred to trimetrogon drainage maps at a scale of 1:48,000 and 1:96, 00. An altimeter traverse was carried concurrently with the geologic mapping.