Departmental Papers (EES)

Document Type

Journal Article

Date of this Version

1994

Publication Source

Radiochimica Acta

Volume

66/67

Start Page

469

Last Page

474

DOI

10.1524/ract.1994.6667.special-issue.469

Abstract

Natural pyrochlore and zirconolite undergo a crystalline-aperi­odic transformation caused by alpha-decay of 232Th and 2380 at dose levels between 2 X 1014 and 3 X 1017 a/mg. The principal effects of the transformation are volume expansion and micro­fracturing, providing potential pathways for fluids. Geochemical alteration of the minerals may occur under hydrothermal conditions or in low temperature, near surface environments, but Th and U usually remain immobile and can be retained for time scales up to 109 years. However, the Th-U isotope systematics of a zirconolite-bearing vein and dolomite host rock may provide evidence for disequilibrium between 230Th, 234U and 238U.

Share

COinS
 

Date Posted: 25 April 2017