National Geographic : 1892 Mar 21
74 II. F. Reid-Studies of Muir Glacier. The other three of Mr Cushing's diabase specimens are quite typical representatives of this rock, although they are all con siderably altered. They differ mostly in the coarseness of their structure. One contains a little basaltic hornblende and one is slightly amygdaloidal. PETROGRAPHICAL LABORATORY, JOHNS HOPKINS UNIVERSITY, April, 1891.
1892 May 15
1892 Feb 19