Daniels Range and Wilson Hills

The first age determinations by the whole-rock K-Ar method of gneisses and granites in the Wilson Hills and on several small off-shore islands by Ravich and Krylov (1964) ranged from 564 to 434 Ma. A sample of biotite from Aviation Island (also called Ostrova Polyamoy) at 69°16 S, 158°47 E, yielded an even 

The basement rocks of the Daniels Range were dated by K-Ar, Rb-Sr, and U-Pb methods and the resulting dates are compiled in Appendix 4.8.3 and are visualized by means of the nested histograms in Fig. 4.12. 

Whole-rock Rb-Sr isochron dates indicate that the Rennick Schist of the Daniels Range crystallized at about 532 20 Ma (Early Cambrian lUGS 2002) and that the sandy (psammitic) and clay-rich (pelitic) facies had elevated initial Sr/ Sr ratios of 0.7187 0.0009 and 0.7243 0.0009, respectively (Adams 1986). A Rb-Sr date of a single whole-rock sample reported by Faure and Gair (1970) was recalculated to 548 33 Ma based on initial ratios obtained by Adams (1986) and using the decay constant of Rb recommended by 

Biotite and muscovite of the Granite Harbor Intrusives and biotite of a tonalite dike cooled to about 300°C at about 475 3 Ma based on K-Ar dates measured by Kreuzer et al. (1981). In contrast to the wide range of whole-rock K-Ar dates of gneisses in the Wilson Hills reported by Ravich and Krylov (1964), the K-Ar dates of the basement rocks in the Daniels Range measured by Kreuzer et al. (1981) vary only from 471.5 to 478.5 Ma with a mean of 474.3 2.4 Ma for ten samples of biotite and muscovite. 

Harbor Intrusives of northern Victoria Land contain varying amounts of excess radiogenic Sr of crustal origin (see also Section 3.4.2). The initial ratios of five of the 21 specimens range from 0.510685 (Daniels Range) to 0.510830 (Aviator Glacier) and are all lower than the ratio of the chondritic 

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