NATURE 



485 



THURSDAY, APRIL 5, 1877 



THE GEOLOGICAL SURVEY OF OHIO 



Rcp07-t of the Geoloi^ical Survey of Ohio, Vols. I. and II. 

 Geology, and I. and II. Palaeontology. (Columbus, 

 Ohio : Nevins and Myers, State Printers, 1873-5.) 



T N the reports of American Scientific Surveys we have 

 become accustomed to find that the results are as new 

 and interesting as the methods of working are original 

 and ingenious. Few of the States are more richly 

 endowed with the elements of prosperity and stability 

 than Ohio, and yet she has but recently come into the 

 field with her contribution to the knowledge of her own 

 geological structure and natural history. It is gratifying 

 to know that this contribution can well afford to be tried 

 by the high standard attained by the reports already 

 issued by many of the neighbouring States. 



The survey just completed is technically the second 

 but practically the first geological survey of Ohio, taking 

 into consideration how long ago the former survey was 

 disbanded, and how short was its term of life. 



In 1836 the legislature appointed a committee con- 

 sisting of Dr. Hildreth, Dr. Locke, Prof. Riddell, and 

 Mr. Lapham, to report on the best method of obtaining 

 a complete geological survey of the State, and to estimate 

 the probable cost. In the summer of that year three of 

 these gentlemen made reconnaissances, while the fourth 

 analysed iron ores and limestones. A year after the 

 appointment of the committee, the legislature, on its 

 recommendation, created a geological corps, comprising 

 a state geologist (Prof. W. W. Mather) and six assistants. 

 During the summer of 1837, the State geologist and three 

 assistants prosecuted geological explorations, two assist- 

 ants being absorbed by zoology and topography. Next 

 summer the survey was continued on a similar footing, 

 but a financial panic having broken out, " the legislature of 

 1838-39 made no appropriation for the continuation of 

 the geological survey, and it was at once suspended." In 

 spite of the disadvantages under which this early survey 

 laboured in being almost entirely without pal^ontological 

 assistance, its two annual reports were much appreciated, 

 and the short-sighted economy that led to its disband- 

 ment was soon regretted by the citizens of the State. 

 Although several attempts were made, what with the de- 

 falcations of a State treasurer, the building of a costly 

 State-house, and the great Civil War, Ohio was not finan- 

 cially in a position to re-establish a geological survey till 

 the year 1869. 



According to its constitution, this new survey was to be 

 begun (and was begun) on June i, 1869, and was to be 

 finished in three years. It was required "to make a 

 complete and thorough geological, agricultural, and 

 mineralogical survey of each and every county in the 

 State." To the chief geologist the act 0/ legislature 

 allowed three assistants, and a number (generally eight 

 or nine) of temporary local assistants were employed and 

 paid from a fund provided for " contingent expenses." 

 One of the assistant geologists was to be a chemist. We 

 can see in the organic law of the survey no provision for 

 a palceontologist, and presume that the appointment of 

 that officer was authorised by one of the subsequent Acts 

 Vol. XV.— No. ^88 



of Appropriation. At any rate, Prof. J. S. Newberry, 

 having been appointed chief geologist, conjoined with 

 himself two assistants, a palaeontologist and a chemist, 

 and it can hardly be disputed that this was the best 

 possible disposition of his forces, however desirable a 

 large increase in the number of assistants might have 

 been. 



Such then is the scale on which a State, having an 

 area of 39,904 square miles, plans its geological survey. 

 Considering the number of working days in a year, the 

 number of the field geologists, and the area of the State, 

 many will not hesitate to decide that the character of a 

 reconnaissance was stamped on the survey by its framers 

 from the beginning. But it should not be forgotten that 

 there are circumstances which render the geological 

 mapping of Ohio exceptionally simple. The Palaeozoic 

 rocks which form its framework are so undisturbed, that 

 over areas of sometimes thousands of square miles, only 

 one formation makes its appearance at the surface, and out- 

 crops are therefore little more than contour lines. We are 

 accustomed in this country to think of " dip " as something 

 visible to the naked eye, and measurable with a pocket 

 clinometer ; and as producing, by its relation to the 

 contour of the ground, endless variety in our geological 

 boundary-lines. In Ohio it appears that themethod of ascer- 

 taining the degree of dip is to set up half a dozen or so of trigo- 

 nometrical stations, several miles apart, and carefully take 

 the levels of the outcrop at the several points. So far as we 

 have noted in reading the Reports, there is not a dip in the 

 whole state that would make an appreciably stiff railway 

 gradient. Then we are informed by Prof. Newberry that 

 " faults in which the displacement amounts to more than 

 one foot are very rare in the Ohio Coal-field," and that the 

 greatest known has a down-throw of 3 feet. In Europe 

 the complications produced by faults frequently add the 

 excitement of a puzzle to the labours of the field-geologist 

 and just as often leave an irritating element of uncertainty 

 to embitter the satisfaction with which he is apt to regard 

 his finished work. Then again there are no igneous rocks 

 in Ohio and no metamorphic rocks in the ordinary sense 

 of the term. Indeed it may almost be said that over 

 large tracts there are no rocks at all. Thus in one county 

 " consisting of twelve towns," i.e. 432 square miles— exactly 

 the area, let us say for comparison's sake, of a whole sheet 

 of the i-inch Ordnance Map of Scotland — the rock is 

 deeply covered with drifc and is never seen, having been 

 reached by boring at one point only, at a depth of 1 10 

 feet. 



On the other hand, the very simplicity of the geology 

 of the State makes it a typical region by which other 

 lands may measure their geological scale, and on this 

 account it becomes necessary to survey it with minute- 

 ness and care. If Ohio renders this service to the neigh- 

 bouring states, each of these has already given an 

 equivalent. As it happened, when the late survey was 

 begun, Ohio was almost surrounded by a belt of states 

 which had got ahead of her in the work, and whose 

 completed labours greatly simplified her task, at the 

 same time that they presented discrepancies which could 

 only be reconciled on her neutral ground. 



Although it was originally intended that the survey 

 should be finished in three years, its field work lasted for 

 five, the average annual cost being 817,355. 



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