Wyatt Formation, Metavolcanic Mountains

A 235, Wyatt Formation, Mt. Gardiner, Scott Glacier B F-64-61, Wyatt Formation, Metavolcanic Mountain, Wisconsin Range... 

S.2.2 Wyatt Formation, Metavolcanic Mountain, Wisconsin Range... 

The metavolcanic rocks of the Wyatt Formation occur primarily on Metavolcanic Mountain and on Shapley Ridge of the Cleveland Plateau of the Watson Escarpment west of Reedy Glacier and opposite Metavolcanic Mountain in Figs. 7.4. Murtaugh (1969)... 

The rocks of the Wyatt Formation on Metavolcanic Mountain contain no primary structures and neither their thickness nor their attitude are known. Along Shapley Ridge of the Cleveland Mesa in Fig. 7.4 the rocks of the Wyatt Formation grade into gneissic granite and are cut by dikes of the same granite. 

The Wyatt Formation was initially assigned a Neoproterozoic date of 633 13 Ma (k = 1.39 x 10" year 0 based on the Rb-Sr systematics of four samples from Metavolcanic Mountain (Faure et al. 1968a Montigny and Faure 1969). This date was later restated as 630 14 Ma by Faure et al. (1968b). After analyzing additional samples, Faure et al. (1977) reported a date of 543 48 Ma (Early Cambrian) when the decay constant of Rb is taken to be A. = 1.42 x 10 year"h The analytical data of seven samples of the Wyatt Formation from Metavolcanic Mountain, the Cleveland Mesa, and the Wisconsin Plateau in Appendix 1.9.2.2 constrain a straight line in Fig. 7.12 which defines the time of crystallization of these rocks ... 

Ford and Himmelberg (1976) also pubfished the average chemical composition of 27 specimens of the Thiel Mountains Porphyry, which they classified as a rhyodacite, as well as chemical analyses of the cordierite and the orthopyroxene aU of which are fisted in Appendix 8.5.1. The chemical composition of the Thiel Mountains Porphyry closely resembles the chemical compositions of the metavolcanic rocks of the Wyatt Formation on Mt. Gardiner in the Scott Glacier area and on Metavolcanic Mountain at the head of the Reedy Glacier (Appendix 7.8.1). 

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