Physical Sciences and Mathematics Commons^™

Provenance, Sorting, And Secular Variation In Late Cambrian And Early Ordovician Carbonate Flat-Pebble Conglomerates In West-Central Utah, Rachel Nyznyk, Benjamin Dattilo, Kevin Evans

Benjamin F. Dattilo

Flat-pebble conglomerates (FPCs) are deposits that include tabular clasts of carbonate facies in shallow marine successions. They are common features in Cambrian and Ordovician successions and are more rarely preserved in post-Ordovician strata. Traditional interpretations suggest they are storm deposits, but more recently, they have interpreted as cycle caps and products of sea-level change. Examining FPCs in detail may further our understand of possible origins, including major Earth events such as meteorite impacts, seismic events, superstorms, slope failures, and mass wasting events. This study, which is in its initial phase, examines FPCs based on intrinsic features and seeks to document …

Stop Clinging! –How The Ordovician Brachiopod (Fka Platystrophia) Vinlandostrophia Ponderosa Outgrew Its Mid-Life Attachment Crisis, Benjamin Dattilo, Sadye Howald

Benjamin F. Dattilo

The high-energy nearshore environment and muddy shifting shell gravels recorded in Maysvillian strata of the Cincinnati Ordovician might seem particularly inhospitable to brachiopods, which generally require solid surfaces for attachment. Nevertheless, Vinlandostrophia ponderosa thrived and even characterizes these facies. A preliminary study of growth series suggests that, like the full-grown stages of related species, smaller V. ponderosa were attached by pedicle. Smaller specimens have a large pedicle opening, a nearly flat shape, thin shell, and a shallow sinus/sulcus, leaving the commissure nearly flat. These characteristics are consistent with strong, erect pedicle attachment, even stronger than found in related species, whose …

The Mollusk-Rich Ordovician Miamitown Shale Mapped From Cincinnati To The Bluegrass: Probing Contemporaneous Peritidal Deposits To Decipher The Paleobathymetric Problem Of A Puzzling Pelite., Benjamin Dattilo, Thomas Schramm, Sasha Mosser, Lydia Mark, William Ward

Benjamin F. Dattilo

While most Upper Ordovician (Katian stage) strata in the Cincinnati region can be characterized as mixed carbonates and mudstones, there are a few carbonate-poor silty mudstone units including the Maysvillian Miamitown Shale and the Richmondian Waynesville Formation. These are characterized by molluscan faunas that contrast with the typical brachiopod-bryozoan fauna of the Cincinnatian, or, for that matter, of the Lower Paleozoic in general. The paucity of more widespread common taxa makes it difficult to use such assemblages in determining paleoenvironmental conditions, particularly water depth. Thus, combined with the lack of distinctive sedimentological indicators, it is difficult to say if these …

Sedimentology And Microstratigraphy Of A Cincinnatian Edrioasteroid Obrution Deposit., Aaron Morse, Benjamin Dattilo, David Meyer, Lydia Mark, Michael Harrison

Benjamin F. Dattilo

The Manchester edrioasteroid pavement is a shell layer in mudrock from the Corryville Formation (U. Ordovician, Maysvillain). No previous studies have examined sediments that buried Cincinnatian edrioasteroid pavements. To address this problem, a 16 cm thick stratigraphic sample measuring 90 cm by 30 cm was collected with a plaster jacket, dried for 2 years, then encased in fiberglass for dry cutting into slabs 2-4 cm thick. These were hardened with epoxy and polished dry with sandpaper. A prepared slab was sent to Bruker AXS for analysis using the M4 Tornado µ-XRF.

Delicate colonies of bryozoans, embedded in mudrock were found …

High-Resolution Correlation And Sedimentology Of Carbonate-Shale Cycles In The Type Cincinnatian (Upper Ordovician; Katian): Implications For A Revived "Layer Cake Stratigraphy", Carlton Brett, Benjamin Dattilo, Patrick Mclaughlin, Thomas Schramm

Benjamin F. Dattilo

Strata of the type Cincinnatian Series form an exemplar of the denigrated notion of “layer cake stratigraphy”; Edward Oscar Ulrich, founder of the “Cincinnati School” of paleontology (ca. 1910s), argued that the stratigraphic record is composed of stacks of continuous, far-traceable layers. This view was fostered by observations of limestone-shale strata, then-exposed on the hillsides and riverbanks of Cincinnati. Subsequently, most geologists rejected this notion and favored a “mosaic” view of strata as local patches, based on studies of modern marine environments. Cincinnati reference sections such as those of Eden and Fairview Parks are now largely overgrown or under concrete. …

The Orientation Of Strophomenid Brachiopods On Soft Substrates, Roy Plotnick, Benjamin Dattilo, Daniel Piquard, Jennifer Bauer, Joshua Corrie

Benjamin F. Dattilo

Strophomenid brachiopods have long been interpreted as ‘‘snowshoe’’ strategists, with their flattened concavoconvex valves providing resistance to foundering in very soft sediments. There has been a sharp difference of opinion in whether the shells were oriented with their convex or their concave surface in contact with the sediment. This study, along with independent evidence from sedimentology, ichnology, and morphology, indicates that the strophomenids lived with their shells concave down (convex up). Experiments indicate the force required to push shells into soft cohesive muds is much greater for the convex up than for the convex down orientation. Forces also increase with …

An Enigmatic Lobate Mat-Like Fossil(?) In The Kope Formation (Upper Ordovician), Kenton County, Kentucky, Ron Fine, Carlton Brett, Benjamin Dattilo, David Meyer

Benjamin F. Dattilo

A new, enigmatic, large fossil(?) object from a thin silty mudstone bed (up to 3 cm thick) underlain by siltstone was excavated from the lower Kope Formation (Economy Member, basal Pioneer Valley submember) near Covington, KY. The excavated object is roughly elliptical in outline, over 2 m long, with a parallel-fluted structure at one end that terminates in a complex of conjoined, flattened, ellipsoidal or spatulate concretion-like lobes at the other end. The lobes are about 10 cm and range to 45 cm long. Internally, some lobes show lamination, sometimes convoluted. The most perplexing feature of the lobe-like structures is …

Upper Ordovician Strata Of Southern Ohio-Indiana: Shales, Shell Beds, Storms, Sediment Starvation, And Cycles, Carlton Brett, Thomas Schramm, Benjamin Dattilo, Nathan Marshall

Benjamin F. Dattilo

The Cincinnatian Series (ca. 450 to 442 Ma) of the Cincinnati Arch features some of the most spectacular Ordovician fossils in the world. The rich faunas of bryozoans, brachiopods, molluscs, echinoderms, and trilobites are preserved as discrete shell-rich limestones, cyclically interbedded with sparsely fossiliferous shales and mudstones that may yield exceptionally preserved trilobites and crinoids. Similar successions of shell beds interbedded with mudstones are common components of Paleozoic successions. In such successions, the genesis of the highly concentrated shell beds is often attributed to storm-winnowing, but is this the whole story? This trip will offer an overview of the classic …

Integrating Bio-, Chemo-, Chrono-, Gamma-Ray, Litho-, And Sequence Stratigraphy In The Upper Cambrian And Lower Ordovician: Progress Toward A Comprehensive Stratigraphic Framework, James Miller, Benjamin Dattilo, Raymond Ethington, Kevin Evans, Rebecca Freeman, James Loch, John Repetski, Robert Ripperdan, Anthony Runkel, John Taylor

Benjamin F. Dattilo

Chronostratigraphic classification of the Laurentian Upper Cambrian and Lower Ordovician is based on strata in Utah, Nevada, Missouri, Minnesota, Wisconsin, and Alberta. Biozonations are based on strata there as well as in Texas and Oklahoma. Regional trilobite zonations vary somewhat because of facies influence and periods of regional endemism; the zonation is quite different in slope deposits. Conodont zonation begins in the middle Upper Cambrian; many taxa occur in a variety of facies and are cosmopolitan, so zones can be correlated across Laurentia and globally. Calcitic brachiopod zones established in Oklahoma have been identified in other areas where faunas have …

Fine-Scale Lithologic Variations In Late Ordovician (Katian) Pertidal Depositions Of The Kentucky Bluegrass Suggest Sea-Level Fluctuations As The Primary Mechanism For Type Cincinnatian Meter-Scale Cycles., Sasha Mosser, Thomas Schramm, Benjamin Dattilo, Carlton Brett, Rebecca Freeman, Michael Blair

Benjamin F. Dattilo

Late Ordovician peritidal facies of central Kentucky are laterally equivalent to cyclic subtidal facies of the Cincinnati region but correlation details, and causes of cyclicity are poorly understood. If type Cincinnatian shale-limestone (meter scale) cycles were driven by sea-level fluctuations then equivalent peritidal facies should be cyclic. Likewise, the same magnitude of base level change should result in greater environmental variability in these shallow facies. If cycles are of Milankovitch origin, it should be reflected in cycle duration. We attempt to test these predictions by examining litho, sequence, and macro-biostratigraphic evidence at Point Leavell, KY and other localities. Exposures at …

The Great American Carbonate Bank In The Miogeocline Of Western Central Utah: Tectonic Influences On Sedimentation., James Miller, Kevin Evans, Benjamin Dattilo

Benjamin F. Dattilo

No abstract provided.

Tempestites In A Teapot? Condensation-Generated Shell Beds In The Upper Ordovician, Cincinnati Arch, Usa., Benjamin F. Dattilo, Carlton E. Brett, Thomas J. Schramm

Benjamin F. Dattilo

Skeletal concentrations in mudstones may represent local facies produced by storm winnowing in shallow water, or time-specific deposits related to intervals of diminished sediment supply. Upper Ordovician (Katian) of the Cincinnati region is a mixed siliciclastic-carbonate succession including meter-scale cycles containing a shelly limestone-dominated phase and a mudstone-dominated phase. The “tempestite proximality model” asserts that shell-rich intervals originated by winnowing of mud from undifferentiated fair-weather deposits. Thus shell beds are construed as tempestites, while interbedded mudstones represent either fair-weather or bypassed mud. Meter-scale cycles are attributed to sea-level fluctuation or varying storm intensity. Alternatively, the “episodic starvation model” argues, on …

The Brachiopod Trap: What Their Oldest (Upper Ordovician, Ohio) Failed Escape Burrows Tell Us About The Evolution Of Burrowing In Lingulids, Rebecca Freeman, Benjamin Dattilo, Aaron Morse, Michael Blair, Bryan Utesch, Steve Felton, John Pojeta

Benjamin F. Dattilo

Infaunal organisms living in shallow marine settings are vulnerable to exhumation during storms or entombment by storm-deposited sediments. Cambrian­–Early Ordovician lingulids included epifaunal as well as possible infaunal forms. However, many epifaunal forms became extinct during the Middle Ordovician, and Late Ordovician lingulids were similar in their infaunal habits and marginal habitats. Modern infaunal lingulids are able to reorient themselves after burial in sediments, but it is unclear when this ability evolved. Initial burrowing of juvenile lingulids, as well as re-burrowing of exhumed modern lingulids involves digging downwards and then back up in a u-shape, but successful escape burrowing involves …

Temporal And Spatial Evolution Of Wave-Induced Ripple Geometry: Regular Versus Irregular Ripples, Timothy Nelson, George Voulgaris

George Voulgaris

Concurrent observations of inner shelf near bed hydrodynamics and acoustic imagery of the seabed are used to relate wave-induced ripple geometry (wavelength and orientation) to near bed directional wave velocities. The observations were collected on the continental shelf of the South Atlantic Bight at water depths of 9.5 and 30 m off the coasts of South Carolina (median size 177 mm) and Georgia (388 mm), respectively. 2-D spectral analysis techniques are performed on the imagery to automate detection of ripple wavelength, orientation, and irregularity. Our analysis shows that ripple irregularity is a time-dependent process dependent on magnitude, direction, and duration …

Meteoric 10Be, FeD, And Clay In Critical Zone Soils, Front Range, Colorado, Cianna Wyshnytzky, James Mccarthy

Cianna E Wyshnytzky

The critical zone is the zone within which meteoric water, atmospheric gases, soil, and bedrock interact, encompassing the zone of soil formation (Anderson et al., 2007). The concentrations of various pedogenic compounds at a given location indicate the degree of weathering that has taken place in the Critical Zone. Among the products of chemical weathering are secondary phyllosilicate minerals (clays) and iron (Birkeland, 1999). At stable sites, chronosequence studies have shown that the amount of pedogenic iron oxide and clay increase as soils become older (McFadden and Hendricks, 1985).

Meteoric ¹⁰Be is a cosmogenic nuclide produced from oxygen and nitrogen …

Updated Glacial Chronology Of The South Fork Hoh River Valley, Olympic Peninsula, Washington Through Detailed Stratigraphy And Osl Dating, Cianna E. Wyshnytzky, Tammy M. Rittenour, Glenn D. Thackray

Cianna E Wyshnytzky

Four glacial advances are preserved and exposed in the stratigraphy of the South Fork Hoh River valley. The oldest of these advances extended beyond the South Fork valley into the Hoh River valley. The three younger advances are preserved in the stratigraphy cut bank exposures in the valley and geomorphically by moraines and outwash plains. One of these advances represents a re-advance to the same terminal position of the previous advance and has not previously been recognized in this valley or other glaciated valleys in the western Olympic Mountains. This finding advocates for a detailed sedimentologic and stratigraphic approach to …

Holocene Sediment Distribution On The Inner Continental Shelf Of Northeastern South Carolina: Implications For The Regional Sediment Budget And Long-Term Shoreline Response, Jenny Denny, William Schwab, Wayne Baldwain, Walter Barnhadt, Paul Gayes, Robert Morton, John Warner, Neil Driscoll, George Voulgaris

George Voulgaris

High-resolution geophysical and sediment sampling surveys were conducted offshore of the Grand Strand, South Carolina to define the shallow geologic framework of the inner shelf. Results are used to identify and map Holocene sediment deposits, infer sediment transport pathways, and discuss implications for the regional coastal sediment budget.

The thickest deposits of Holocene sediment observed on the inner shelf form shoal complexes composed of moderately sorted fine sand, which are primarily located offshore of modern tidal inlets. These shoal deposits contain ∼67 M m3 of sediment, approximately 96% of Holocene sediment stored on the inner shelf. Due to the lack …

Evaluation Of Beach Nourishment Evolution Models Using Data From Two South Carolina Beaches: Folly Beach And Hunting Island, Sc, Usa, Harry Weathers, George Voulgaris

George Voulgaris

Beach nourishment is a common method used for mitigating coastal erosion. However, it is also a costly undertaking and requires an appropriate cost-to-benefit analysis. Although the costs can be estimated relatively easily, the benefits are directly related to the life expectancy of the proposed project. With this in mind, three existing beach replenishment time-evolution models (the Linear Erosion, the Verhagen, and the One-Line models) were compared for their ability to represent data from two beach nourishment projects that have taken place in South Carolina, USA, at Folly Beach and Hunting Island. Another newly introduced model that combines the One-Line model …

The “Curse Of Rafinesquina:” Negative Taphonomic Feedback Exerted By Strophomenid Shells On Storm-Buried Lingulids In The Cincinnatian Series (Katian, Ordovician) Of Ohio, Rebecca Freeman, Benjamin Dattilo, Aaron Morse, Michael Blair, Steve Felton, John Pojeta

Benjamin F. Dattilo

Taphonomic feedback is the idea that accumulation of organic remains either enhances the habitat for some organisms (positive taphonomic feedback), and/or degrades the habitat for others (negative taphonomic feedback). Examples of epibionts living on skeletal remains are direct evidence of positive taphonomic feedback. Disruption of infaunal burrowing activities by skeletal fragments is an example of negative taphonomic feedback; direct fossil evidence of this phenomenon has not been documented previously. Infaunal organisms are vulnerable to exhumation or entombment during storms, but organisms that burrow can also re-establish viable life positions subsequently. For example, when modern lingulids re-burrow after exhumation, they first …

Introduction And Tribute, George Voulgaris, Timothy Kana, Jacqueline Mitchell

George Voulgaris

No abstract provided.

Biomarker And Sedimentological Investigations Of Mis 8 Through Mis 12 From Lake El'gygytgyn, Ne Arctic Russia, Jeremy H. Wei, Julie Brigham-Grette, David Finkelstein, Isla S. Castañeda

Jeremy H Wei

Multiple proxy analysis of lake sediment records are crucial for understanding changes in environmental and climate conditions over historical and geological time. Most recently, the use of biomarker proxies coupled with sedimentological investigations provides a new approach for gaining insight into the lake processes that capture information about past climate change. This approach is applied here to better understand the paleoclimate record from Lake El’gygytgyn in Western Beringia. Multiple organic geochemical compound concentrations were measure as proxies for both aquatic and terrestrial biological productivity. Measurements of n-alkane (plant leaf waxes) as well as concentrations of the compounds arborinol (marker for …

Tempestites In A Teapot? Condensation-Generated Shell Beds In The Upper Ordovician, Cincinnati Arch, Usa, Benjamin F. Dattilo

Benjamin F. Dattilo

Skeletal concentrations in mudstones may represent local facies produced by storm winnowing in shallow water, or time-specific deposits related to intervals of diminished sediment supply. Upper Ordovician (Katian) of the Cincinnati region is a mixed siliciclastic-carbonate succession including meter-scale cycles containing a shelly limestone-dominated phase and a mudstone-dominated phase.

The “tempestite proximality model” asserts that shell-rich intervals originated by winnowing of mud from undifferentiated fair-weather deposits. Thus shell beds are construed as tempestites, while interbedded mudstones represent either fair-weather or bypassed mud. Meter-scale cycles are attributed to sea-level fluctuation or varying storm intensity.

Alternatively, the “episodic starvation model” argues, on …

Storm Deposited Fish Debris In The Cretaceous Mowry Shale Near Vernal, Utah, Alvin Anderson, Bart Kowallis

Bart J Kowallis

Isolated, lens-shaped accumulations of fi sh bones, scales, teeth, and coprolites in a sandy matrix occur along a few bedding planes within the Cretaceous Mowry Shale in an outcrop along Highway 191 north of Vernal, Utah. These accumulations have previously been interpreted to be large coprolites or regurgitate material, but are actually storm lag deposits in a sediment-starved basin. Accumulations (lenses) vary in size: the largest measured is 15 x 10 cm in plan view and 2 cm thick. Matrix in these lenses consist of fine-grained, well-rounded quartz grains that are absent in the surrounding shale layers. The disarticulated fossil …

Sediment Control At Water Intakes Along Sand Bed Rivers, Fred L. Ogden

Fred L. Ogden

Results from five physical hydraulic model studies of riverside water intakes situated along the Missouri River reach between Sioux City, Iowa, and St. Louis, Missouri, are presented. Movable-bed, undistorted Froude-scale models are used to determine the effectiveness of structural modifications in the vicinity of the intake to limit the influx of bed-load sediments. Solutions developed in each case include a series of submerged flow-turning vanes located on the riverward side of the intake. A sediment-barrier wall between the vanes and intake ...

Miocene Paleogeography Of West-Central California--Offset Along The San Gregorio-Hosgri Fault Zone, Clarence Hall Jr, Mark Sutherland, Raymond Ingersoll

Mark Sutherland

The major faults that occur in the region are described and the amount of lateral offset used to construct palinspastic maps is given. The longest, most controversial, and most critical fault relative to the palinspastic maps is the San Gregorio-San Simeon-Hosgri fault, which is discussed in detail