Sample Detail of
Sample: Sample No. 71-LG-13 -- USGS No. Cenozoic loc. M5005
Locality: Field No. 71-LG-13
Description: Pelecypod-bearing sand and silt overlying a well-indurated till, Constantine Harbor, Amchitka Island (lat 51o, 23'30" N., long. 179o, 17'05"E.) Alt. about 40 feet. Coll: L. M. Gard, 1971.
Location: Alaska Quadrangle: Rat Islands A-3
Lat.: 51o23'30 " Long.: 179o17'05 "
Reference
Title: Report on Referred Fossils ,  1972 (01/24)
Report by: Warren O. Addicott
Referred by: L. M. Gard
Age: Late Pleistocene-Holocene (Late Pleistocene or Holocene)
Comment:This poorly preserved assemblage is suggestive of a Pleistocene or Holocene age. So far as I can determine, Macoma nasuta has never been recorded from Hopkins’ (1967) Pleistocene Transgressions (neither it, nor M. inquinata, are recorded from the South Bight locality – USGS loc. M4098 and Allison (in press)) and is restricted today to areas east and southeast of the Aleutian Chain. It would seem, therefore, to suggest a very young age, possibly every late Pleistocene or Holocene. The other doubtfully identified species, M. inquinata, is a circum-North Pacific bivalve and ranges northward into the Bering Sea.

This association of Macomas is suggestive of very shallow water conditions – intertidal or upper reaches of the inner sublittoral zone (= neritic zone). Assemblages such as this in which Macomas are the dominant element are often indicative of shallow water bays or marine estuaries.

Occurrence(s)
No. Group Name Qty Notes
1 Bivalves Macoma cf. M. inquinata (Deshayes)
2 Bivalves Macoma cf. M. nasuta (Conrad)
3 Bivalves ?Macoma
4 Bivalves ?Spisula