FIFTY YEARS' PROGRESS IN GEOLOGY—1876-1926 CONTENTS PAGE Progress in Ore Genesis Studies, by Benjamin Le Roy Miller.... 121 * Manuscripts not available at the time of publication. CONTRIBUTIONS OF HOPKINS TO GEOLOGY By W. S. BAYLEY In order to appreciate fully the part that the Department of Geology at the Johns Hopkins University has taken in the development of Geology in America and to understand why the early graduates of the Department attracted the attention of the geological world so soon after their graduation, one must consider the conditions that prevailed when the Department was established. It must be remembered that when geological study was initiated at the University the work began in that branch of the science that had hitherto been neglected in America. There was an almost boundless opportunity for discoveries by those who adopted it as their specialty. The field was wide open, and Hopkins graduates occupied it. When the Geological Department was established the "Taconic Controversy" was drawing to a close, but it had not been proven that the schists involved among the Taconic rocks were not all sediments. When, however, Williams 1 traced the massive gabbro near Baltimore into hornblende schists, it became clear that some of the members of the schist series are igneous, and that they had intruded an older series of schists that might include not only sediments but also other igneous rocks. It was shown, moreover, that the Archean schists were cut by pegmatites and that at least some of these are igneous. These conclusions which were far reaching were the consequence of the use of the petrographic microscope, which, up to that time had not been employed to any great extent on this side of the Atlantic as an aid in geological investigations. 'Williams, G. H., The gabbros and associated hornblende rocks occurring in the neighborhood of Baltimore, Md.: U. S. Geol. Surv. Bull. 28, 1886. The Hopkins introduced the instrument to American geologists and offered them a new tool with which to attack the more difficult problems that faced them in their attempts to decipher the life histories of the crystalline rocks and to interpret the geological significance of their existence. It is true that there were already a few geologists in this country who, having studied in Germany, were using the microscope in their work. But these were connected with official surveys, and were, therefore, not in positions to impart their knowledge of microscopic methods to other students of geology who had not been fortunate enough to be able to study abroad. There was no place in America where geologists might learn the uses of the new instrument, until the Hopkins offered them the opportunity to enter its laboratories. The young students, who were attracted to Baltimore by the knowledge that they might learn something of the most modern methods of studying geology, soon discovered that they were enabled by the use of these methods to gain a more accurate insight into the composition and origin of crystalline rocks than they had ever supposed possible. They enthusiastically embraced what to them seemed an entirely new science and soon began to employ its methods in solving the baffling problems furnished by the schists, and forthwith announced the discovery of facts that threw much desired light on many geological puzzles. The decision of the Hopkins to avoid competition with the strong departments of geology in other American universities, and, instead, to develop a branch of the science that had been neglected by them was a fortunate one which soon justified itself. Almost immediately important additions were made to the store of knowledge concerning the schistose crystalline rocks in the Piedmont Plateau and elsewhere and as a consequence the most skeptical were soon convinced that the microscope is a geological tool with most promising prospects of usefulness. The impetus given to geological investi gations by the use of the new tool resulted in a great revival of interest in Geology, and America soon became one of the leaders in the Science. The introduction of the microscope to American geologists is one of the outstanding contributions of the Hopkins to American Geology. Not only did the courses in the use of the microscope at the Hopkins make it possible for students to acquire the training that Eureopean geologists had been receiving, without the necessity of going abroad, and thus placed them on a competitive equality with their foreign colleagues, but they also furnished training in what were then the most efficient methods of attacking geological problems to men who soon after their graduation entered other universities and began to train other men in the same methods in which they themselves had been trained. After a comparatively short interval the microscope became a familiar instrument in many geology laboratories and many young men became expert in its use. Whereas the older generation of Hopkins graduates had few competitors in their chosen field of study, the younger graduates found many among the graduates of other universities. In recent years the contest for recognition among young American geologists has been largely between men trained by the Hopkins in Baltimore and those trained by Hopkins men elsewhere. Even where the guiding minds of the geological courses in other universities are not those of Hopkins men they have nevertheless been indirectly influenced by the Hopkins and some of the success that has attended their work unquestionably is due to their adoption of Hopkins methods in their classes. The furnishing of teachers trained in the new methods was another one of the contributions of this University to American Geology. There have been about 30 graduates of the Hopkins occupying chairs of Geology in the universities of America and all of them have been active in investigations as well as busy with teaching. They have been training students pretty much as they, themselves, were trained and are sending out into the world an unbroken |