Silurian Formations and Reef Sturctures of Northern Indiana

Abstract

In response to popular demand, the Silurian formations and associated reef structures of northern Indiana were chosen as the subject for the 1949 Field Conference. The numerous quaquaversal structures in the Niagaran of northern Indiana were long the subject of controversies and objects of mystery until, in 1927, Cumings and Shrock showed conclusively that they are ancient coral and stromatoporoid reefs. In the past few years, interest in reefs, recent and ancient, has been revived. The vast number of soundings taken in coral reef lagoons during the war and recent studies in connection with the Bikini atom bomb tests have shed much new light on present day reefs, and recent oil field discoveries associated with reef structures have stimulated much interest and study of the Paleozoic reefs. The conference has been planned to provide group observation and to promote group discussion of Niagaran reefs. Silurian stratigraphy is emphasized and special attention is given to lithology of reef core, reef flank, and inter-reef strata, as well as to the effect of reef structure on the overlying Devonian rocks. We hope that discussion combined with actual field examples will be of mutual benefit. This opportunity to become better acquainted and to exchange ideas is the most important part of the program.