Abstract
THE age of the Nain anorthosite1,2 on the coast of Newfoundland–Labrador is probably the same as that of the Michikamau anorthosite (1,400 ± 80 m.y.) recently reported by Emslie3. The Nain anorthosite is flanked on the north side by the Kiglapait layered intrusion4,5, which shows no chill against anorthosite and is therefore thought to be barely younger than the anorthosite. The Kiglapait intrusion is invaded on its north margin by a granodiorite, possibly rheomorpbic, the biotite of which gives a potassium-argon age6 of 1,480 ± 50.m.y. This is therefore a minimum age for the Kiglapait intrusion, and also for the anorthosite.
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References
Kranck, E. H., C.R. Soc. Geol. Finlande, 33, 299 (1961).
Wheeler, jun., E. P., Geol. Soc. Amer. Bull., 71, 1755 (1960).
Emslie, R. F., Nature, 202, 172 (1964).
Morse, S. A., Geol. Soc. Amer. Spec. Paper, 73, 208 (1963) (abst).
Morse, S. A., unpublished Ph.D. thesis McGill Univ. (1962).
Beall, G. H., Hurley, P. M., Fairbairn, H. W., Pinson, jun., W. H., Amer. J. Sci., 261, 580 (1963). The correct locations of these samples are: B 4016: 57°–08′.2 N, 61°–42′.4 W.; B 4023: 56°–59′.2 N, 61°–21′.1 W. For “Cape Manvers” read “Port Manvers”.
Wheeler, jun., E. P., Geol. Soc. Amer. Bull., 66, 1021 (1955).
Leech, G. B., Lowden, J. A., Stockwell, C. H., and Wanless, R. K., Geol. Surv. Canada Paper, 63–17 (1963).
Walton, Matt, and De Waard, Dirk, Geol. Soc. Amer. Spec. Paper, 73, 258 (1963) (abst.).
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MORSE, S. Age of Labrador Anorthosites. Nature 203, 509–510 (1964). https://doi.org/10.1038/203509a0
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DOI: https://doi.org/10.1038/203509a0
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