3Butler, B. S., Loughlin, G. F., Heikes, V. C., and others, The ore deposits of Utah: Prof. Paper 111, U. S. Geol. Survey, 1920, p. 201.4Leith, C. K., and Mead, W. J., Metamorphic Geology, Pt. 2, Henry Holt and Company, New York, 1915.5Butler, B. S., Loughlin, G. F., Heikes, V. C., and others, The ore deposits of Utah: Prof. Paper 111, U. S. Geol. Survey, 1920, pp. 152-158.6Van Hise, C. R., and Leith, C. K., Geology of the Lake Superior region. Mon. 52, U. S. Geol. Survey, 1911, pp. 506-518; and references there given.