Roots of white ash have a better configuration than roots of sugar maple for anchoring shallow colluvium against landsliding on hillslopes along the Ohio River and its tributaries in southwestern Ohio. The landslides are in a shallow layer of colluvium, about one meter thick, overlying shale and limestone bedrock. The sliding hillsides range in slope angle from 16 to 36 degrees and the roots which penetrate shear surfaces are anchored in the weathered bedrock and help to hold landmasses in place. The hillsides are covered by a mesophytic forest, locally known as a ravine community, dominated by white ash, sugar maple and sweet buckeye. Sugar maple is the most common species on the landslides; its roots do not penetrate the soil as deeply as the roots of the white ash.
A stratigraphic and paleontological analysis of 303 samples of Paleocene sediments of the eastern Gulf Coastal Plain of Mississippi, Alabama, and Georgia provided the basis for a geochronologic, quantitative paleoecologic, and paleoceanographic model.
The present work is a stratigraphic, reservoir, and environmental analysis of the Itarare Group (Permo-Carboniferous) using the well data of the Parana Basin which covers about 1,000,000 Km$\sp{2}$ in Brazil alone. More than three thousand kilometers of cross sections were analysed, over 100 wells were studied, nearly 400 meters of cores were described, and 95 thin sections were analysed.
"The Molango manganese deposit is the only known large Mn deposit in North America. Mineralization involves Mn-carbonate exclusively in a finely laminated bed about 10 meters thick with a strike length $>$50 kilometers. The ore bed is the basal unit of the Chipoco facies (Taman Fm., Kimmeridgian) and underlain by laminated black shales of the Santiago formation (Oxfordian)."
A 3rd order theory of folding of viscous multilayers indicates that forms of folds are controlled by the behavior of layer contacts or interbeds, the relative stiffnesses of the multilayer and confining media, and the scale of the folding. A 2nd order analysis shows that asymmetry of folds is determined largely by the behavior of layer contacts and the sense of layer-parallel shear during folding.
I solve boundary-value problems for an idealized thrust block moving over a detachment surface and ramp, and produce theoretical bed-duplication folds in the thrust block that closely resemble the Powell Valley anticline in the southern Appalachian Mountains. The anticline is narrow and rounded if the translation is small, and broad and flat-topped if the translation is large. The limbs of the anticline are symmetric if drag is zero. Drag along the ramp part of the detachment surface can explain the asymmetry of dips of the two limbs of the Powell Valley anticline, particularly if drag between relatively competent rocks in opposition at the ramp causes an initial anticline to form as the thrust block begins to move, and then drag reduces markedly as relatively soft shales at the base of the block were thrust over competent rocks in the ramp.
The taxonomy, phylogeny, biostratigraphy, functional morphology, and paleoecology of Middle and Upper Ordovician (Blackriveran-Richmondian) Monoplacophora and bellerophontacean Gastropoda of the Cincinnati Arch region are discussed. Six genera and 29 species of monoplacophorans, and 13 genera and 56 species of bellerophontaceans are evaluated. The study is centered around new U.S. Geological Survey silicified collections.
It is recognized that the ecology of planktonic foraminiferal assemblages provides information about the chemical and physical properties of the water in which they live. Their areal and vertical distributions in the water column and in deep-sea sediments may be used to derive oceanographic and climatic models of Recent and past oceans.
The principal objective of this study was to develop a battery of methodologies for the analysis of texture, grain packing and pore geometry in sands and sandstones. The methodologies developed include: (1) the 'roller micrometer', a machine which sizes grains by their smallest dimension, S; (2) plots of the joint I:S size and S/I form distributions (I is the intermediate grain dimension determined by sieving); (3) a sorting comparator for the visual estimation of sorting in thin sections; (4) 'packing efficiency', the ratio of minimum compactional to depositional porosity; (5) 'floating index', the proportion of grains lacking intergranular contacts; (6) correction of measurement errors in standard thin section packing analyses; (7) transformation, via digitization, of plain sections of samples into matrices of binary (rock vs pore) numbers; and (8) computer processing of the rock-pore matrices using the Fortran IV program PORESTAT which measures numerous parameters including porosity, specific pore surface area, pore size distribution, pore tortuosity, pore orientation, and periodic repetitions in the pore pattern.