Alternation of Fossil Faunas

Several years ago while studying the coal measures of Iowa and the neighboring states, it was suggested in a general way that the so-called Lower Coal Measures and the so-called Upper Coal Measures eventually might prove to be essentially contemporaneous

Volcanic Necks of Piatigorsk, Southern Russia

On the Rostov and Wladikavkas railroad, in southern Russia, there rises out of the flat steppes, a few hours before reaching the last mentioned place, a remarkable group of steep-sided hills, or mountains, each isolated from the others. The principal town of the region is Piatigorsk, which is about ten miles from the railway station of Mineralniya Vody

Certain Basin Features of the High Plateau Region of Southwestern United States

In the Basin region of Western America there exists a remarkable type of intermontane valleys to which the Spanish name Bolson has been given. The geological substructure of these plains has been recently described at some length. In the present connection some additional features are discussed

Notes on the Carboniferous Faunas of Mississippi Valley in the Rocky Mountain Region

Recent critical and extensive comparative studies of the Carboniferous faunas of the Rocky Mountain region have disclosed some facts that are of great interest to those who have become familiar with the Paleozoic fossils of the Mississippi valley. The Carboniferous faunas of the Continental Interior have now been well understood for over half a century. The faunas of the same geological age from the vast region west of the great central valley of the continent have also been well made out, but for the most part by a group of paleontologists entirely different from that group which was most familiar with the fossils of the Mississippi valley. On this account, chiefly, the faunas of the two regions have been treated largely independently and few exact correlative comparisons made

Theory of Meteoritic Agglomeration and the Ultimate Source of the Ores

At the present time unusual interest is taken by mining men in the subject of the origin of the deposits of the metallic ores, the extent of the world\u27s supply, and the means of conserving them, for alarming as it may seem the end is already in sight

Depositional Equivalent of Hiatus at Base of Our Coal Measures; and the Arkansan Series, a New Terrane of the Carboniferous in the Western Interior Basin

For a long time it has been known that in Iowa and the neighboring states to the south a break in sedimentation exists at the base of the coal measures. It has been noted in various places in the reports of the Iowa geological survey and reference has been made to it in various other publications. Of its real significance no hint has ever been given