The literature on the subject of the Geology of East Texas is very fragmentary and vague. This might well be said of all parts of the State, yet it is especially true of the eastern part.

The first systematic work of a geological nature done in East Texas, was by Dr. Ferdinand Rœmer, who visited Texas in 1845-47; but even he, as also most succeeding investigators, quickly moved into the Cretaceous and Paleozoic regions lying in the western part of the State. He published two principal works, both in German, entitled:

• 1. "Texas, with Special Reference to German Emigration," etc., with a topographic and geognostic map of Texas. Bonn, 1849.
• 2. "The Cretaceous Formations of Texas and their Organic Remains, with a Description of the Accompanying Paleozoic and Tertiary Strata." Bonn, 1852. Besides these works, Dr. Rœmer also published several articles on Texas, in the American Journal of Science and Arts.

The Report of the Mexican Boundary Survey, of 1848-1855, contains data on the geology of the region, by Arthur Schott; also, papers by James Hall and T. A. Conrad, who, though they did not accompany the Expedition, drew conclusions from the specimens collected. These statements, however, relate only to the region in the immediate vicinity of the Rio Grande, and not to East Texas proper.

The printed reports of the State Geologists, 1858 to 1876—Dr. B. F. Shumard, Francis Moore, S. B. Buckley, and John W. Glenn—contain but little information concerning the eastern part of the State, although some of the iron localities are described, and sections given.

In 1884 Professor Angelo Heilprin published his work entitled "Contributions to the Tertiary Geology and Paleontology of the United States." This