The Geognosy of the Appalachians and the Origin of Crystalline Rocks; An Address to the American Association for the Advancement of Science by Thomas Sterry Hunt, LL.D., on Retiring from the Office of President of the Association, Indianapolis, August 16, (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1871 Excerpt: ... lowest of these, succeeding the granite, is a series of crystalline rocks, not described lithologically, with mineral veins, "having some resemblance to the rocks of Cornwall," and including towards the summit, "chiastolite schists and chiastolite rocks." These are followed in ascending order by two great series of slates and grits, succeeded by a fourth division of schists, sometimes carbonaceous, holding in parts fucoids and graptolites, which are apparently overlaid discordantly by sundry trappean conglomerates and chloritic slates. The graptolites of the Skiddaw slates are found to be identical with those of the Levis formation, and it is worthy of notice that although Sedgwick places the micaschists with andalusite (chiastolite) so far below the graptolitic beds, he elsewhere, in comparing the rocks of North Wales and Cumberland, states that the chloritic and micaceous rocks of Anglesea and Caernarvon are not represented in Cumberland, being distinct from the other rocks of North Wales, and much older.f Synopsis of British Paleozoic Rocks, p. lxxxiv, being an introduction to McCoy's Brit. Pal. Fossils (1835). In Victoria, Australia, the position of the chiastolite schists, according to Selwyn, is beneath the graptolitic slates. Boblaye, it is true, asserted in 1838 that the chiastolite schists of Les Salles. near Pontivy in Brittany, include Orthis and Calymene, J but when we remember that even experienced observers in the White Mountains for a time mistook for remains of crustacea and brachiopods, certain obscure forms, which they afterwards found not to be organic, and that Dana, in this connection, has called attention to the deceptive resemblance to fossils presented by some imperfectly developed chiastolite crystals in the sam...