Schroyer, C. R.

The Ohio Journal of Science

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BURIED STREAM CHANNELS AT THE BASE OF THE PENN-SYLVANIAN SYSTEM IN SOUTHEASTERN OHIO.1C. R. SCHROYER.Contents:Introduction,Description of the contact at the north,Description of channels,Channel south of Logan,Channel south of Beyer,Evidences of a continuous system.Numerous and marked irregularities are present at the topof the Mississippian strata in Ohio. Professor C. F. Lamb findsthe surface a series of north-south ridges with alternating depres-sions in northeastern Ohio.2 Dr. J. J. Stevenson, collecting thescattered evidence for a wider area has interpreted this surface asthe effect of a wide spread subaerial erosion.3It seems worth while to add some observations made in south-eastern Ohio. Over wide areas the contact is very regular; somuch so that, were it not for the general difference of the strataabove from that below, it might be taken for a bedding plane.Minor irregularities do occur but only by careful search and com-parison of elevations can evidence be found of a time break aslong as this one appears to have been.THE CONTACT A LEVEL PLANE AT THE NORTH.The contact between these two systems is almost a level planefrom Newark to Logan, crossing Licking, Perry, and FairfieldCounties. The regularity may be inferred from the fact that inan east-west section of twenty-two miles extending west from WhiteCottage past Mt. Perry, the base of the Pennsylvanian stratalowers 420 feet to the east and in the twenty-two exposures studiednot a single one shows a counter dip. Another section along theNational Road from Amsterdam on the west to Gratiot at the eastshows a regular eastward inclination of about 19 feet to the mile.If this be extended eastward to where the Waverly goes underin the Licking River at Dillon, it gives a relief of 400 feet in 18>^miles or 21.6 feet to the mile. This inclination approaches thereported dip of the bed rock.1. Published by permission of the Director of the Ohio GeologicalSurvey.Partial abstract of the material offered as a Master's thesis atOhio State University.2. lour, of Geol., Vol. 19, p. 104, 1911.3. Bull. Geol. Soc. of America. Papers in Vol's. 14, 15, 17, and 18.51952O The Ohio Naturalist. [Vol. XV, No. 7,A- SECTION AT HEAD of BIG RUNB- SECTION IN HAY HOLLOW ONEMILE NORTH.May, 1915.] Buried Stream Channels. 521THE CHANNEL SOUTH OF LOGAN.South of Logan the regularity is broken by the scar of a buriedchannel. It extends in an east and southeast direction across thesouth central part of Falls Township, Hocking County and canbe first distinctly seen along a west tributary to Dry Run. Aftermeeting that stream farther east it turns south past the junctionwith Scott Creek finally burying itself under a continuous blanketof Pennsylvanian rocks one mile north of the village of Ewing.This channel is clearly marked by the filling—a coarse quartzsandstone usually stained a reddish brown by the weathering ofthe iron cement. Occasional well-rounded quartz pebbles maybe found. The depression extends as a distinct channel for adistance of four miles, its width changing from place to place,due both to variations in the original channel and the depth towhich the filling has been removed by recent erosion. At oneplace it is 400 yards; where Scott Creek has cut well down into thefilling it is but little over 150 yards wide.The exact depth was not obtained but from the general levelof the basal sandstone beyond the borders of the channel to thelowest exposed rock of the same character is a vertical distance ofover 100 feet. At the north a small tributary to Dry Run has cutdown to the Waverly almost half way across the channel. Judgingfrom this the bottom is not far below. The elevation is near779 feet above sea level, while the lowest exposure to the south isbelow 755 feet, indicating a southward gradient. Just above thejunction of Dry Run with Scott Creek buff colored Waverly shaleswere found in grave diggings; across the road to the west coarseiron-stained sandstone forms the bed of the present stream,giving a relief of 55 feet in little over twice that distance hori-zontally.The abrupt curve in its course, the depth of the depression andthe steepness of the slopes at the sides are strong evidences of theaction of meteoric waters.THE CHANNEL SOUTH OF BYER.Another buried valley may be found one mile south of Byer,the station at the junction of the Baltimore and Ohio Southwesternand the Cincinnati, Hamilton and Dayton Railroads. It crossesthe present valley of Pigeon Creek where that stream receivesthe second tributary from the west. The direction is a little southof west or north of east but only along the sides of this valleyis the depression distinctly visible. In these outcrops it is across-bedded quartz conglomerate enclosed on each side by drabto gray argillaceous shales and sandstones. Surface weatheringhas worn away the less resistent material thus exposing the coarseconlomerate filling on the east bank of Pigeon Creek. There, in522 The Ohio Naturalist [Vol. XV, No. 7,a small ravine, a wall of conglomerate may be found oppositeslopes covered by weathered Waverly. At the head of the ravinethe highest Waverly is almost 100 feet above the level of PigeonCreek where the conglomerate forms the bed of that stream.Across from this ravine layer after layer of horizontal argillaceousshales and sandstones end abruptly against the filling of cross-bedded conglomerate and sandstone. Usually the outer edgesof the beds show a slight slumping or bowing downward as if theoverlying filling had compressed them after they had been exposedto erosion. The south boundary is less definitely marked butthe width is about 200 yards. But a very thin coating and inmany places no trace of pebbles may be found outside this channel.EVIDENCES POINTING TO A CONTINUOUS STREAM SYSTEM.Such sections seem to imply that the pebbles of the conglom-erate were borne largely by strong surging currents restricted with-in the channels themselves. These currents would most likelybe found in a continuous system of channels and although hiddenin many places by the overlying Pennsylvanian strata, traces ofsuch a system can be found. At Richland Furnace two milesnortheast of the conglomerate outcrops last mentioned the coarsesandstone and basal conglomerate lowers from 812 feet above sealevel on the west and 762 on the east to below the 700 feet contour.Pebbly beds may be found below the Baltimore and Ohio South-western Railroad at that place, while on either side they rise tothe heights mentioned.West and south traces of this line of conglomerate filling areexposed along Glade Run, and at Canter's Cave three and a halfmiles soutwest it forms vertical cliffs from which large cavernshave been worn by weathering. Such conglomerate walls con-tinue south to Jackson where they form the well-known JacksonConglomerate area. The conglomerate there becomes moregeneral but its, thickness still varies.Tributaries join this system from the west. A definite andwell marked line of conglomerate ledges extends northwest fora distance of over seven miles. The present elevation of the bedof this channel above sea level is as follows:890 feet at the exposure south of Hay Hollow840 feet at the head of Hay Hollow807 feet in the first large hollow west of Big Rock742 feet at the base of Big Rock690 feet at the head of Pigeon Creek where the base of theconglomerate goes under.In all, this gives a relief of 200 feet in less than 6 miles. Afterallowing for the gentle southeast dip of about 25 feet to the milea gradient of 30 to 50 feet still remains. This conglomerate isMay, 1915.] Meeting of Biological Club. 523bounded on the north by a ridge of Waverly which rises as muchas 100 feet above the bed of the channel. On the south at LinnPost Office the contact is at an elevation of about 1000 feet abovesea level; at the Pike-Jackson County boundary line, 900 feeton the north and 950 feet on the south. The structure sectionsshow the relation and comparative elevation of the contact atLinn and in Hay Hollow one mile north. The whole depressionis filled with a quartz conglomerate over a thin bed of chertybreccia in some of the deeper places. This filling rises over thesides of the valley but may form only a thin coating. Withinthe channel the thickness ranges from 160 feet at the west to 250feet at the east.Another tributary is outlined by a line of conglomerate cappedhills extending west across Marion, Union and into Scioto Town-ship of Pike County. After turning south across the pre-glacialvalley of the Teays River conglomerate ledges rise 80 feet abovethe valley of Dry Run and 67 feet at the White Gravel Church.Beyond that place the conglomerate thins, a result evidently of awidening of the channel and a lowering of its gradient.

Buried Stream Channels at the Base of the Pennsylvanian System in Southeastern Ohio

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Buried Stream Channels at the Base of the Pennsylvanian System in Southeastern Ohio

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