|Quadrangle map, 1:250,000-scale||PA|
|Quadrangle map, 1:63,360-scale||D-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Several traverses have been made to study the radioactivity in the vicinity of the Goddard Hot Springs (West and Benson, 1955). The springs are at the site of Goddard which is shown on the USGS 1:63,360-scale topographic map. The springs are near the center of the SW1/4 section 17, T. 58 S., R. 63 E. The location is accurate.|
Geologic descriptionThe Goddard Hot Springs have long been known (Knopf, 1912) and there are no known base or precious metal deposits nearby. The rocks in the vicinity are part of a large Tertiary intrusion. Loney and others (1975) call it a hornblende-biotite granodiorite; Reifenstuhl (1986) assigns the rocks to the border phase of the Crawfish Pluton which consists mainly of hornblende-biotite granodiorite and tonalite that has been dated as 48.0 plus/minus 1.4 Ma and 48.3 plus/minus 1.3 Ma. Based on the report of radium in the water of the springs, West and Benson (1955) completed three traverses for up to two miles away from the hot springs to assess the radioactivity of the area. The most radioactive sample was of granite slope wash between the Main Spring and the Magnesia Spring; it contained 0.016 percent equivalent uranium. A sample of beach sand at Goddard contained 0.015 percent equivalent uranium, and a sample of sand and gravel about 0.8 mile north of Goddard contained 0.015 percent equivalent uranium. The other samples were lower. In most of the samples, the radioactive is probably due mainly to thorium in allanite which forms up to 7 percent of some of the mineral concentrates.
|Geologic map unit||(-135.372919384639, 56.8351467089076)|
|Mineral deposit model||Radioactive allanite in granitic rocks.|
|Age of mineralization||Radioactive allanite is an accessory mineral in a Tertiary granitic pluton dated at about 48 Ma.|
|Workings or exploration||Several traverses were carried out in 1949 by the U.S. Geological Survey in the vicinity of the hot springs to determine the radioactivity of the rocks in the area.|
|Indication of production||None|
Additional commentsMAS number: 0021160011.
Bittenbender, P., Still, J.C., Maas, K., and McDonald, M., Jr., 1999, Mineral resources of the Chichagof and Baranof Islands area, southeast Alaska: Bureau of Land Management, BLM-Alaska Technical Report 19, 222 p.
Cobb, E.H., 1972, Metallic mineral resources map of the Port Alexander quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-464, 1 sheet, scale 1:250,000.
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Port Alexander quadrangle: U.S. Geological Survey Open-File Report 78-787, 33 p.
Loney, R.A., Brew, D.A., Muffler, L.J. B., and Pomeroy, J.S., 1975, Reconnaissance geology of Chichagof, Baranof, and Kruzof Islands, southeastern Alaska: U.S. Geological Survey Professional Paper 792, 105 p.
Overstreet, W.C., 1967, The geologic occurrence of monazite: U.S. Geological Survey Professional Paper 530, 327 p.
Reifenstuhl, R.R., 1986, Geology of the Goddard Hot Springs area, Baranof Island, southeastern Alaska: Alaska Division of Geological & Geophysical Surveys Public Data File 86-2, 82 p., 1 sheet, scale 1:40,000.
|Reporters||Donald J. Grybeck (U.S. Geological Survey)|
|Last report date||2-Jan-05|