Rare earths, thorium, and other minor elements in sphene from some plutonic rocks in West-Central Alaska

Journal Article · Sat Jan 01 00:00:00 EST 1977 · J. Res. U.S. Geol. Surv.; (United States)

OSTI ID:5277469

Staatz, M H; Conklin, N M; Brownfield, I K

Sphene is an abundant accessory mineral in some abnormally radioactive plutonic rocks in west-central Alaska. Seven samples of sphene from four different areas in west-central Alaska contained from 20,350 to 39,180 parts per million total rare earths and 390 to 2000 ppM thorium. The lanthanide content in six of the seven sphenes is chiefly the light rare earths and is similar to that of crystal abundance; a seventh sphene from the Darby Mountains, however, contains above average amounts of the heavy rare earths. A comparison of the lanthanide distribution in sphene from several areas indicates that the structure of sphene will accommodate whatever lanthanides are available when the mineral crystallizes. The amount of thorium and rare earths in sphene is also affected by the presence of other accessory minerals. Sphene in rocks containing either allanite or zircon has a lower thorium content than in rocks that do not contain allanite or zircon. Sphene, because of its abundance, may contain the greater part of the rare earths and thorium in some of the plutonic rocks of west-central Alaska.

• OSTI ID: 5277469
• Journal Information: J. Res. U.S. Geol. Surv.; (United States), Vol. 5:5
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BARIUM
DISTRIBUTION
IGNEOUS ROCKS
CHEMICAL COMPOSITION
MANGANESE
NIOBIUM
RARE EARTHS
STRONTIUM
THORIUM
TIN
URANIUM
VANADIUM
ZIRCONIUM
ALASKA
MINERALS
ACTINIDES
ALKALINE EARTH METALS
ELEMENTS
METALS
NORTH AMERICA
REFRACTORY METALS
ROCKS
TRANSITION ELEMENTS
USA
500400* - Environment
Atmospheric- Thermal Effluents Monitoring & Transport- (-1989)