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It was not originally directed to the Findlay gas rock, but it was simply drilled to test the ordinary range of rocks of this region. After the Berea grit, which was struck at 1,028 feet, had proved unproductive, the bold plan was formed of drilling the well to the Trenton limestone, this last horizon having become prominent at this time. The record is as follows:

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13. Blue shale, with occasionally thin courses of sandstone...

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24. Trenton limestone counted as beginning here............

25. Drilling suspended at........

The interpretation of this long record is for the most part obvious and unmistakable.

The Coal Measure Conglomerate and the Logan Conglomerate appear to be blended in one great series, No. 10. In No. 13 the Cuyahoga shale is distinctly shown in normal measure and character. In No. 14 the Berea shale appears in its usual place, overlying the Berea grit, No. 15. In No. 18 we find the red Bedford shale overlying 700 feet of the Ohio shale series. The limestone series that comes next consists of the Waterlime, Niagara and Clinton limestones. Possibly the Corniferous is also present here. The section has just half the thickness that the same strata show in the northern counties of the state. In No. 22 we find the Clint n and Medina, and probably the beginning of the Hudson River shales. The Utica is not distinguished in the drilling. This

part of the well was drilled wet, it having been found impracticable to exclude the deepest lying salt-water. The Trenton limestone, as identified here, agrees in physical characters with the known samples of this rock from other counties of southern Ohio. It is a whitish, flaky limestone, quite silicious in composition, and altogether lacking in the characteristics of an oil or gas-rock. The determination of the Trenton limestone is not confidently made. Black shale was struck below 3,440 feet, and it is quite possible that the stratum counted Trenton is one of the limestone belts enclosed in the Utica shale. These Utica limestones are of the same character as the Trenton. In any case, the Trenton is not far from the bottom of this well. It is nearly 3,000 feet below tide. The record can be condensed as follows:

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This is decidedly the deepest well ever drilled in Ohio, and it is a matter of great interest and importance to find as we do that under this deepest cover, the various divisions retain the same characteristics as in their several outcrops.

This well was altogether experimental in its character. When it was decided by the company to push a well down to the Findlay horizon, while there was not a single fact from all the experience then in hand to warrant any expectation of success, neither was there anything to condemn the scheme as sure to result in failure. At the present time the facts have taken the latter complexion, and it can be positively asserted that the Trenton limestone of the Ohio Valley is not a reservoir of petroleum to any such extent as to justify the drilling of deep wells to reach it.

SUMMARY.

The leading facts in a remarkable history have now been stated. Within the last three years a new horizon of petroleum and the gas that originates from it has been brought to light, a horizon which bids fair to be the most prolific single source of gas and oil that has yet been discovered in this country. The discovery comes from an unexpected quarter, viz., from the "black swamp" of old time of northwestern Ohio. Under its broad and level expanses, a few hundred square miles have been found, distributed through portions of five counties, within which are contained fountains of oil and reservoirs of gas of infinitely more value than any like accumulations hitherto discovered in the state, and fully deserving a place among the most valued repositories of these substances in any quarter of the world.

The good fortune of Findlay and Lima has had a wonderful effect, not only upon the towns directly surrounding them, but upon all adjacent regions, and even upon entire states. Many hundreds of thousands of dollars have been already spent in drilling wells to the Findlay gas-rock throughout Ohio, Indiana, Kentucky and Michigan, and even far beyond the limits of these states. Indiana has developed a gas-field in this horizon, which is in reality a bodily extension of the Ohio field, but which greatly exceeds the latter in area and perhaps also in intrinsic value. Beyond the districts already indicated in Ohio and the one now named in Indiana, however, there has been no adequate return for the large amount of money spent in exploration. In fact, the productive areas make but a small and almost an insignificant fraction of the entire territory that has been tested.

How are these invaluable accumulations, so limited and apparently so capricious in their distribution, to be explained? The answer to this question, so far as it can now be given, is to be found in the preceling pages of this chapter. The facts that are gathered there will be found to make an important contribution to our knowledge of the modes of accumulation of oil and gas. There is a simplicity of structure in the new field that is not paralleled in any of the productive areas hitherto reported upon. The conditions of accumulation are so obvious that he who runs may read them. For missing the true interpretation, there would scarcely be excuse.

The leading facts pertaining to the field can be summarized as follows:

1. In fourteen of the northwestern counties of Ohio (and like conditions prevail in contiguous territory in Indiana), the upper beds of the Trenton limestone, which lie from 1,000 to 2,000 feet below the surface, have a chemical composition different from that which generally characterizes this great stratum. They are here found as dolomite or magnesian limestone instead of being, as usual, true carbonate of lime. Their percentage of lime, in other words, ranges between 50 and 60 per cent. instead of between 80 and 90 per cent., as in the formation at large. These dolomites of northwestern Ohio are mainly quite free from silicious impurities. The dolomitic composition seems to have resulted from an alteration of a true limestone. At least the occasional masses of true limestones charged with fossils, that are found on the

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