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

Carbonic Column of Rio Grande Region

The character of the later Paleozoic succession in southwestern United States has radically modified our general ideas regarding carbonic history in America. As directly bearing upon this subject the Carbonic rocks of the New Mexican region are of exceptional interest. The Rio Grande section, if it may be so designated, is serially the most complete in the country. It is of great thickness. It contains many elements wholly unknown elsewhere on the continent. It furnishes full data with which to close the already prolix debate on the exact age and stratigraphic position of the uppermost Paleozoic beds of Kansas and other parts of the country. It is particularly important at this time as connecting the succession of the Mississippi province with that of the Far West. By contrast it emphasizes the insignificance of our eastern Carbonic representatives

Physiographic Significance of the Mesa de Maya

The Mesa de Maya is a small elevated tableland lying on the borders of Colorado and New Mexico, between Trinidad and Raton. It has an elevation of over 9,000 feet above sea-level and about 3,600 feet above the valleys on either side