Edited by James E. Palmer and Russell R. Dutcher - University of ...

south rim of Eagle Valley Syncline traversingthe Abbott and Caseyville Formations andChesterian Series strata (upper Mississippian).The strike of these units is subparallel to fieldtrip route.Enter Shawnee National Forest. Evergreenforest on both sides of road.Entrance to Pounds Hollow Recreation Areaon right. Continue straight. Trip will returnhere for lunch following stop at Garden of theGods Recreation Area.Contact between Abbott and Caseyville Formations;Pounds Sandstone Member crops outat right side of road.Concealed scissors fault, about 100 feet(30 m) northwest (right), parallels road here.Downthrown to northwest.Road on right to Indian Wall and RimTrail. Continue straight.Crest of Caseyville escarpment. Elevation isabout 700 feet (213 m) above sea level. Thisarea is typical of high escarpments formed onthe Caseyville Formation at the southernmargin of the Illinois Basin.Country store on left; elevation 735 feet(224 m) above sea level. Lowlands to southformed on Mississippian strata. Route descendshere from Caseyville strata southwestwardacross upper units of Chesterian Series.Russel Cemetery on right. Concealed scissorsfault of mileage '17.1 trends northeastward,underlies area of cemetery. Vertical displacementis about 50 feet (1 5 m), downthrown tonorthwest.Tar Springs Sandstone exposed on both sidesof a fault zone. Scissors fault of mileages 17.1and 18.7; vertical displacement about 50 feet(1 5 m) downthrown southeast.Karbers Ridge School. Hardinsburg Sandstonecrops out on right. View of Caseyville escarpmentto right (north).Dogwood Campground and Gift Shop on left.Large valley south of road is eroded in softshale of the Golconda Group.United States Post Office, Karbers Ridge, left.Karbers Ridge, a thriving community atthe time of the American Civil War(1862-1 865), supported four general stores, ablacksmith shop, funeral parlor, feed mill, andtwo churches.Hardin County and this region of southernIllinois was much more densely populatedabout 100 years ago than at present. Earlysettlers, equipped only with wooden plows,were unable to break the thick prairie sodfarther north in lllinois and chose this rocky,but more easily cultivated soil. As cultivationof rich, glacially-derived soil to the northdeveloped through introduction of the steelplowshare, this land became subeconomic andwas abandoned.Road intersection; continue straight. HighKnob to right (north). Roadbed here is onHardinsburg Sandstone; deeper valleys onroute reach the underlying Golconda Group.Prominent escarpment on the right (north)formed by Caseyville Sandstone along southlimb of Eagle Valley Syncline.Turn right (north) toward Garden of the GodsRecreation Area. Field trip route crossesformations of the upper part of the ChesterianSeries. These units dip northward at about 7".The northward-facing slopes observed adjacentto route here are dip slopes.Bar Springs Sandstone caps hill. CaseyvilleSandstone bluffs (Buzzard's Point) may beseen ahead.Menard Limestone in valley of Rose Creek.Well exposed section at right past bridge.Limestone is bluish gray, general1 y finelycrystalline, medium to thick bedded, veryfossiliferous; fossils include Archimedes sp.(abundant), horn corals, crinoids, blastoids,pelecypods, and brachiopods.Archimedes sp. is restricted to Mississippianand older rocks in the midcontinent ofthe United States. An interesting early use ofthe science of paleontology was made byDavid Dale Owen of the New Harmony ScientificCommunity; he advised farmers of theregion that if the easily identified Archimedessp. was present in rocks cropping out on afarm, no coal could be expected. While certainexceptions did occur due to other geologicalfactors, this fossil was important in the earlydetermination of the extent of coal-bearingstrata in the midcontinent.Palestine Sandstone on right. Ten feet (3 m) isexposed in roadcut; dip about 7" N.Clore Formation (shale) is exposed in deepgully on right in front of house. The CaseyvilleFormation (Pennsylvanian) here directlyoverlies Clore (Mississippian). Two additionalChesterian (upper Mississippian) formations,Kinkaid Limestone and Degonia Sandstone,are absent due to erosion of the lnman Valley(Bristol and Howard, 1971) prior to depositionof the Pennsylvanian System.Contact between Clore Formation (Mississippian)and Caseyville Formation (Pennsylvanian)concealed by slump blocks of thecliff-forming Battery Rock Sandstone Member.Basal tusk Shale Member crops out onright in curve.Garden of the Gods access road.The sub-Pennsylvanian unconformity in the IllinoisBasin contains a linear drainage pattern of valleyseroded into the upper Mississippian Chesterian Seriesand older strata. These paleovalleys, which have cut asmuch as 450 feet (1 37 m) into Chesterian strata, trendgenerally southwesterly (Bristol and Howard, 1971 ;Potter and Desborough, 1965; Siever, 1951). The