National Geographic : 1892 Mar 21
Fossils of ancient Aspect. marble occurring on some of the moraines have had such a source. Two large calcite seams of this character show beautifully on the eastern face of Pyramid peak, looking, to an observer in Dying glacier valley, like rills of water on the mountain side. In the vicinity of the eruptives these fissures are often metalliferous, and occasional quartz veins occur. Careful search for fossils was made in these argillites at many points, but no discovery rewarded the search. It is very possi ble that the series comprises rocks of more than one age. The whole is so homogeneous in appearance that its dissection, if dissection is possible, will be a matter of vast and painstaking labor. The Limestone.-The mountains forming both shores of the larger part of Glacier bay, and all the islands in the bay except the two in Muir inlet and the Beardslee islands, are made up of metamorphic limestone. This first appears on the eastern side of the bay, form ing the mountain peak just south of the peak of mount Wright, follows along the mountain summits for some little distance with slight dip and then abruptly plunges down to the shore with a very steep southerly dip. Near its contact with the slates it con tains considerable argillaceous admixture; otherwise it is an ex tremely pure dolomitic limestone, containing only a trace of insoluble matter. More commonly it is of a dark purplish tint, though some portions are drab. It is cut by the same fissure systems as the argillites, but is bound into a more compact mass by the calcite which everywhere completely fills the fissures, so that it disintegrates with less rapidity. Search for fossils in the limestone was rewarded at only one locality, on the island in Glacier bay nearly due south of Headland island. Here but a handful were found. The only recognizable forms were shells of Leperditia. Sections of large gasteropods showed beautifully on the highly polished limestone surface, but it was impossible to break out specimens which would give any indication of external form. I sent the collection to Professor H. S. Williams for ex amination. He replied that Leperditia was recognizable, while the others would scarcely repay careful examination; that the age was probably Paleozoic, but that the collection would war rant no more decisive statement. The superior limit of the lime stone was not seen, but it has a thickness of several thousand feet. It appears conformable with the argillites below, indicating their probable Paleozoic age. 9-NAT. GEOG. MAG , VOL. IV, 1892.
1892 May 15
1892 Feb 19