The Area discussed.—The following pages refer chiefly to what is known as the coal region of Arkansas. This is in an area situated in the western part of the state, tributary to the Arkansas river. It extends from the Boston mountains on the north to beyond the Poteau and Petit Jean mountains on the south, thus covering an area about 100 miles long in an east-and-west direction by 50 miles broad in a north-and-south direction.
Historical Sketch.—The geotectonic geology of western Arkansas received little or no attention prior to the inauguration of the geological survey of the state now in progress. Shumard, in the report of Marcy’s Red river expedition, made in 1854, makes no reference to the subject. In a paper, published in 1854, by Professor J. A. Warder, of Cincinnati, on a Geological Reconnoissance of the Arkansas River, an attempt is made to locate axes . . .