Unnamed (east of Dundas Bay)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Fe
Ore minerals magnetite

Geographic location

Quadrangle map, 1:250,000-scale MF
Quadrangle map, 1:63,360-scale B-1
Latitude 58.35
Longitude -136.17
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is at or near the north shoreline of Icy Strait and about 5 miles northeast of the mouth of Dundas Bay. It is approximately located within about 0.5 mile. The approximate location was taken from an unpublished map by Darwin Rossman (MacKevett and others, 1971, locality 33). The site is approximately the same as number 60 of Cobb (1972) and number 69 of Kimball and others (1978).

Geologic setting

Geologic description

The occurrence is an inferred iron deposit based on old claim activity (1903), permissive geology, and the existence of a strong magnetic anomaly reported near the locality by MacKevett and others (1971, p. 70).
Geologically, carbonate rocks of Devonian-Silurian age are sandwiched between granite or Cretaceous age to the west and granite of Tertiary age to the east (Brew and others, 1978). The carbonate section is a permissive host for metasomatic iron deposits. Another permissive locality for a contact metasomatic iron occurrence is the southwest contact of Tertiary granite with the carbonate septum about 1/2 mile to the northeast of the first possible locality (MacKevett and others, 1971, pl. I). Iron locality 33 of MacKevett and others is shown within the foliated granite, but the location was from a reported mineral occurrence that was not examined by the U.S. Geological Survey in 1966. Stream-sediment samples anomalous in total heavy metals (THM) were reported near the site.
Geologic map unit (-136.171835213243, 58.349647184399)
Mineral deposit model Contact metasomatic iron deposit.
Age of mineralization Cretaceous or younger.

Production and reserves

Workings or exploration Four claims were staked for iron in the area in 1903; five other claims were staked nearby for unspecified commodities before 1953 (Kimball and others (1978, p. C270).
Indication of production None

Additional comments

MacKevett and others (1971, p. 70) cited a magnetic anomaly on the north side of Icy Strait near their locality 33. The size of the magnetic anomaly suggests that a substantial iron deposit is possible. The magnetic anomaly is on USC & GS Chart No. 8202, 13th edition.
The site is in Glacier Bay National Park and Preserve.

References