Reference | {Deposit:: MUILENBURG, G.A., 1919, MANGANESE DEPOSITS OF COLORADO: CGS BULLENTIN 15, P. 28-31}{Deposit:: VAN ALSTINE, R.E., 1974, GEOLOGY AND MINERAL DEPOSITS OF THE PONCHA SPRINGS SE QUADRANGLE, CHAFFEE COUNTY, COLORADO: USGS PROFESSIONAL PAPER 829, P. 16-17.}{Production:: MUILENBURG, G.A. (1919)} |