Clearfield County Research Articles

High-alumina clays of Pennsylvania

More than five million tons of high-alumina clays occur in the Curwensville and Morgan Run districts of Clearfield County, Pennsylvania. These clays, associated chiefly with the Mercer member of the Pottsville group (Pennsylvanian), are flint, and diaspore-bearing flint clays. All gradations between flint clay and nearly pure diaspore occur at the Mercer horizon.The stratigraphic position of the nodule (diaspore-bearing) clays is now shown to be only at the base of the Mercer. Consequently a datum plane now exists in the economically important Pottsville rocks where formerly structural mapping depended on the Homewood sandstone, commonly lacking, or the overlying Lower Kittanning coal of the Allegheny group.The northeast-southwest trending Laurel Hill and Chestnut Ridge anticlines are the major structural features of the two districts. Normal faulting occurs in the Morgan Run district.The clay occurs in lenticular masses which have wide ranges of thickness. Both the thickness and sporadic distribution of the clay bodies are apparently influenced by the underlying eroded surface of the Connoquenessing sandstone.From the field relations and the petrographic textures and structures it is shown that the diaspore-clays were formed partly by the leaching of silica from flint clay and partly by addition of alumina to the flint clay.

EPIDEMIOLOGIC AND ETIOLOGIC STUDIES OF ACUTE POLIOMYELITIS IN PENNSYLVANIA

During 1907 some 200 cases of poliomyelitis developed in a district in the northwestern section of Pennsylvania, extending from 78° 55′ to 80° 15′ west longitude and from 41° to 41° 30′ north latitude. The outbreak apparently began the latter part of July in Elk County and in early August in Venango County, appearing first in Elk County at Ridgway and in Venango County at Oil City; later at Du Bois, in Clearfield County and at Eau Claire in Butler County. In this outbreak the height of the epidemic seemed to be reached the latter part of September and by the end of November the disease was practically stamped out. A small outbreak occurred in Adams County during July and August, 1908. Sporadic cases, only, occurred during 1909. During the summer of 1910 an epidemic of considerable proportions developed in widely separated sections of the state, reaching a total of

Analysis of some of the minerals found at Karthaus and three runs, on the West Branch of the Susquehanna River. Clearfield County, Pennsylvania. Accompanied by a section of the mineral ground

Analysis of some of the minerals found at Karthaus and three runs, on the West Branch of the Susquehanna River. Clearfield County, Pennsylvania. Accompanied by a section of the mineral ground