From abstract: Pt 1. The present work seems to confirm the genetic theory previously published, namely that [Illinois Cave in Rock] deposits were formed by ascending solutions. These solutions probably followed minor fissures that connected below with larger fissures, which in turn probably connected with a major fault zone. It is believed that where such minor fissures extended upward only to the shale or other impervious cap rock, or were greatly reduced in size where they penetrated such beds, the solutions spread laterally along the contact and along the limestone beds beneath it and replaced the limestone. Pt 2. This report is a presentation of the results of an electrical-resistivity survey conducted in the fluorspar-bearing areas of Hardin County, Ill., principally during the field seasons of 1934 and 1935.

A report about applying 40Ar/39Ar dating methods, along with other rock techniques, to determine the age of emplacement and the cooling history of the Grant intrusive breccia at Hicks dome in Illinois.

This following report discusses the study of Lower and Middle Pennsylvanian sandstones of the Illinois Basin examined for evidence of regional diagenetic and fluid-flow patterns.

A report about how topographically driven ground-water flow and other processes that involve dewatering of basins fail to account for the temperatures indicated by fluid inclusion and sulfur isotope studies in the Upper Mississippi Valley zinc-lead district on the northern edge of the Illinois Basin.

From introduction: The subject of this paper is the district of the extreme northwestern portion of Illinois, included in the upper Mississippi Valley containing zinc and lead.