Thin Gravel Deposits on Wave-Eroded Cliffs Near Barrow, Alaska

Аннотация

The beach southwest of Barrow, Alaska, is limited to a foreshore which is backed by wave-eroded cliffs of the Quaternary Gubick Formation. These cliffs, which have an approximate elevation of 20 to 35 feet above mean sea level, are covered with a thin layer of coarse sand and gravel. This gravel unit ranges in thickness from a few inches to an intermittent covering of gravel. The unit extends inland about 10 feet in some places to about 300 feet in others. A gravel deposit of these dimensions is of little or no importance to most scientific disciplines. However, its presence and method of formation are of extreme importance to the unravelling of the archaeological sequence along the coast of Northern Alaska. The gravel units were first observed during the archaeological excavation of an Eskimo site at Walakpa, which is approximately 12 miles southwest of Barrow. At this location there is a sequence of gravel units interspersed throughout the stratigraphic column of the site. These gravel units were formed at the surface after a period of Eskimo occupation and then covered by a subsequent period of occupation, thus they served as a basis for separating one period of occupation from another either older or younger occupation level. ... The presence and method of deposition of the sand and gravel units at the Walakpa site give further evidence that vertical sorting has not occurred. This in turn suggests that the artifacts found in an occupation level belong only to that occupation level; i.e., the tool assemblages found can be attributed to a single period of cultural deposition. The observations are of extreme importance to the unravelling of the archaeological sequence along the arctic coast of Alaska. Owing to the uncommon occurrence of this phenomenon the author has only pieced together the sequence of events necessary for the deposition of these gravel units. However, they have been observed by Silas Negovanna who is a native of the area (personal communication).