The Position and Age of the Sciotoville Bar Locality, Southern Ohio
The Sciotoville Bar was a rock ledge exposed along the northeast bank of the Ohio River between the Little Scioto River and Wolfred Run (NEJ4, sec. 8, T2N, R20W, Scioto County, Ohio). This well-known fossil locality yielded an abundant fauna from concretions in a shale which formed a portion of the ledge. Since 1920, however, the locality has been flooded by the pool created first from construction of Lock and Dam 31, and later by the Captain Anthony Meldahl Locks and Dam. Information assembled from various sources indicates that the main concretionary horizon represents the upper portion of the Portsmouth Member of the Cuyahoga Formation. In addition, a previously unpublished measured section of this locality by Hyde is now available which describes the location of the concretionary fossil-bearing horizon. The combined ammonoid fauna from the upper Cuyahoga and the overlying lower Logan Formation suggests a Kinderhookian rather than Osagean age for the concretionary horizon.
Mississippian (Lower Carboniferous) miospores from the Cuyahoga and Logan formations of northeastern Ohio, USA
Well-preserved Lower Mississippian (Dinantian) miospore assemblages have been recovered from the upper Cuyahoga Formation (type Wooster Member) and overlying lower Logan Formation (Byer Member) at two localities in Wayne County, northeastern Ohio, USA. All six samples were productive and yielded assemblages that represent the middle Tournaisian Spelaeotriletes pretiosus–Raistrickia clavata (PC) Miospore Biozone of Western Europe including a new species of trilete, acamerate miospore, Mooreisporites streelii, described from the Wooster Shale. Significant numbers of latest Devonian and earlier Carboniferous miospores are reworked into all assemblages. The palynological evidence is consistent with a late Kinderhookian age for most of the Cuyahoga Formation, including its well known ammonoid fauna. However, the position of the boundary between the Kinderhookian and Osagean Series remains uncertain.
Evaluation and Control of Collapsible Soils
Some compacted soils wetted under certain conditions of compaction and loading may exhibit additional settlement (collapse). To investigate the effect of the soil type, compaction water content, initial dry unit weight and applied pressure at wetting on collapse potential, 138 single‐oedometer tests were conducted on eight different soils. The results indicate that well‐graded soils tend to collapse more than poorly graded ones under similar conditions. Furthermore, collapse potential decreases with an increase in (1) The difference between the sand and clay percentages; (2) compaction water content; and (3) initial dry unit weight, while it increases with pressure at wetting. A multiple regression analysis was performed on the laboratory results to provide a collapse‐predictive model that was substantiated by data reported by several researchers. A chart is presented to estimate (1) The collapse potential of soils under various conditions; and (2) the critical water content beyond which no collapse is ex...