Desert varnish: potential for age dating via uranium-series isotopes

Journal Article · Tue Jan 01 00:00:00 EST 1980 · J. Geol.; (United States)

DOI:https://doi.org/10.1086/628476· OSTI ID:6353928

Knauss, K G; Ku, T L

Trace metals and natural radioisotopes are measured in an unusually thick and presumed ancient desert varnish from the Colorado Plateau in Utah. Uranium and thorium concentrations in the sequence: varnish--altered rind--heartrock (Shinarump formation sandstone) indicate that uranium with little accompanying thorium is derived from external sources. The varnish forms a closed system for /sup 230/Th and /sup 231/Pa with equilibrium values for both /sup 230/Th//sup 234/U and /sup 231/Pa//sup 235/U. Selective leaching of the ferromanganese oxides followed by analysis of both the leachate and silicate residue is proposed to allow age determinations.

• Research Organization: Lawrence Livermore National Lab., CA
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6353928
• Journal Information: J. Geol.; (United States), Vol. 88:1
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
COATINGS
ISOTOPE DATING
ROCKS
ARID LANDS
DEPOSITS
ISOTOPE RATIO
METALS
PROTACTINIUM 231
THORIUM 230
TRACE AMOUNTS
URANIUM 234
URANIUM 235
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
AGE ESTIMATION
ALPHA DECAY RADIOISOTOPES
ELEMENTS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-EVEN NUCLEI
PROTACTINIUM ISOTOPES
RADIOISOTOPES
THORIUM ISOTOPES
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES
580100* - Geology & Hydrology- (-1989)