Geology Commons^™

Morphodynamic Modeling Of Fluvial Channel Fill And Avulsion Time Scales During Early Holocene Transgression, As Substantiated By The Incised Valley Stratigraphy Of The Trinity River, Texas, Kaitlin Moran, Jeffrey Nittrouer, Mauricio Perillo, Jorge Lorenzo Trueba, John Anderson

Jorge Lorenzo-Trueba

The Trinity River system provides a natural laboratory for linking fluvial morphodynamics to stratigraphy produced by sea-level rise, because the sediments occupying the Trinity incised valley are well constrained in terms of timing of deposition and facies distribution. Herein, the Trinity River is modeled for a range of base-level rise rates, avulsion thresholds, and water discharges to explore the effects of backwater-induced in-channel sedimentation on channel avulsion. The findings are compared to observed sediment facies to evaluate the capability of a morphodynamic model to reproduce sediment deposition patterns. Base-level rise produces mobile locations of in-channel sedimentation and deltaic channel avulsions. …

Exploring The Role Of Organic Matter Accumulation On Delta Evolution, Jorge Lorenzo Trueba, Vaughan Voller, Chris Paola, Robert Twilley, Azure Bevington

Jorge Lorenzo-Trueba

We explore the role of plant matter accumulation in the sediment column in determining the response of fluvial-deltas to base-level rise and simple subsidence profiles. Making the assumption that delta building processes operate to preserve the geometry of the delta plain, we model organic sedimentation in terms of the plant matter accumulation and accommodation (space made for sediment deposition) rates. A spatial integration of the organic sedimentation, added to the known river sediment input, leads to a model of delta evolution that estimates the fraction of organic sediments preserved in the delta. The model predicts that the maximum organic fraction …

Effectiveness Of Four Water-Bearing Zones Of The Glacierized Basin In Meltwater Runoff Modeling, Umesh K. Haritashya

Umesh K. Haritashya

Meltwater runoff modeling from glacierized basins needs several input data, including total meltwater contributing area. This study utilizes optical remote sensing data to assess glacierized basins in the central Himalayas where snow and glaciers contribute substantially to the water resources. Result shows that there are four main water-bearing zones in the basin: (a) dry snow, (b) wet snow, (c) exposed glacial ice, and (d) debris-covered glacial ice, and it is possible to differentiate and map these zones and their spatio-temporal variations from satellite sensor data. These zones can then be incorporated in meltwater runoff modeling as separate entities because they …

Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier

Sandra Passchier

The present study deals with heavy mineral analysis of late Early Miocene marine sediments recovered in the McMurdo Sound region (Ross Sea, Antarctica) during the ANDRILL— SMS Project in 2007. The main objective is to investigate how heavy mineral assemblages reflect different source rocks and hence different provenance areas. These data contribute to a better understanding of East Antarctica ice dynamics in the Ross Sea sector during the Early Miocene (17.6–20.2 Ma), a time of long-term global warming and sea level rise. The AND-2A drill core recovered several stratigraphic intervals that span from Early Miocene to Pleistocene and it collected …

Three-Dimensional Geological Model Of Quaternary Sediments In Walworth County, Wisconsin, Usa, Jodi Jau, Jason F. Thomason, David H. Malone, Eric Wade Peterson

Eric Wade Peterson

Modeling The Sediment Fill Of The Uppertroy Pre-Glacial Bedrock Valley,Mchenry County, Llinois, Usa, Jodi Lau, Jason F. Thomason, David H. Malone, Eric Wade Peterson

Eric Wade Peterson

Effects Of Changes In Moisture Source And The Upstream Rainout On Stable Isotopes In Precipitation – A Case Study In Nanjing, Eastern China, Y. Tang, H. Pang, W. Zhang, Y. Li, Shuang-Ye Wu, S. Hou

Shuang-ye Wu

In the Asian monsoon region, variations in the stable isotopic composition of speleothems have often been attributed to the "amount effect". However, an increasing number of studies suggest that the "amount effect" in local precipitation is insignificant or even non-existent. To explore this issue further, we examined the variability of daily stable isotopic composition (δ18O) in precipitation from September 2011 to November 2014 in Nanjing, eastern China. We found that intra-seasonal variations of δ18O during summer were not significantly correlated with local rainfall amount but could be linked to changes in the moisture source location and rainout processes in the …

Reconstruction Of The Hirnantian (Late Ordovician) Palaeotopography In The Upper Yangtze Region, Linna Zhang, Junxuan Fan, Qing Chen, Shuang-Ye Wu

Shuang-ye Wu

Reconstruction of the Hirnantian (Late Ordovician) palaeotopography in South China is important for understanding the distribution pattern of the Hirnantian marine depositional environment. In this study, we reconstructed the Hirnantian palaeotopography in the Upper Yangtze region based on the rankings of the palaeo-water depths, which were inferred according to the lithofacies and biofacies characteristics of the sections. Data from 374 Hirnantian sections were collected and standardized through the online Geobiodiversity Database. The Ordinary Kriging interpolation method in the ArcGIS software was applied to create the continuous surface of the palaeo-water depths, i.e. the Hirnantian palaeotopography. Meanwhile, the line transect analysis …

Transition From Contraction To Extension In The Northeastern Basin And Range: New Evidence From The Copper Mountains, Nevada, Jeffrey M. Rahl, Allen J. Mcgrew, Kenneth A. Foland

Allen J. McGrew

New mapping, structural analysis, and 40Ar/39Ar dating reveal an unusually well‐constrained history of Late Eocene extension in the Copper Mountains of the northern Basin and Range province. In this area, the northeast‐trending Copper Creek normal fault juxtaposes a distinctive sequence of metacarbonate and granitoid rocks against a footwall of Upper Precambrian to Lower Cambrian quartzite and phyllite. Correlation of the hanging wall with footwall rocks to the northwest provides an approximate piercing point that requires 8–12 km displacement in an ESE direction. This displaced fault slice is itself bounded above by another normal fault (the Meadow Fork Fault), which brings …

Prevailing Weather Conditions During Summer Seasons Around Gangotri Glacier, Pratap Singh, Umesh K. Haritashya, K. S. Ramasastri, Naresh Kumar

Umesh K. Haritashya

Meteorological data collected near the snout of the Gangotri Glacier suggest that the study area receives less rainfall. The average seasonal rainfall is observed to be about 260 mm. The rainfall distribution does not show any monsoon impact. Amount of seasonal rainfall is highly variable (131.4-368.8 mm) from year to year, but, in general, August had the maximum rainfall. A verage daily maximum and minimum temperatures were 14.7 and 4.1°C respectively, whereas average mean temperature was 9.4°C. July was recorded as the warmest month. During daytime, wind speed was four times higher than that at night-time. The average daytime and …

Multispectral Image Analysis Of Glaciers And Glacier Lakes In The Chugach Mountains, Alaska, Jeffrey Kargel, Matthew Beedle, Andrew Bush, Francisco Carreño, Elena Castellanos, Umesh Haritashya, Gregory Leonard, Javier Lillo, Ivan Lopez, Mark Pleasants, Edward Pollock, David Wolfe

Umesh Haritashya

The Chugach Mountains contain the largest nonpolar alpine glaciers in the world and include a wide variety of glacier types: some are land terminating; some calve variously into tidewater, lakes, and rivers; some are heavily debris covered; some are surge-type, whereas others are neither debris covered nor surge type. Nearly all are retreating, thinning, or both, though some rare ones are advancing, and some are thickening at high elevations. To assist the further documentation of changes, we establish an inventory of glaciers in the eastern Chugach Mountains. Several case studies of diverse glacier types showcase remotesensing applications and are used …

Encyclopedia Of Snow, Ice And Glaciers, Vijay P. Singh, Pratap Singh, Umesh K. Haritashya

Umesh K. Haritashya

The objective of this encyclopedia is to present the current state of scientific understanding of various aspects of earth’s cryosphere – snow, glaciers, ice caps, ice sheets, ice shelves, sea ice, river and lake ice, and permafrost – and their related interdisciplinary connections under one umbrella. Therefore, every effort has been made to provide a comprehensive coverage of cryosphere by including a broad array of topics, such as the atmospheric processes responsible for snow formation; snowfall observations; snow cover and snow surveys; transformation of snow to ice and changes in their properties; classification of ice and glaciers and their worldwide …

Porosity Controls On Secondary Recovery At The Loudon Field, South-Central Illinois, John S. Wagle, David H. Malone, Eric Wade Peterson

Eric Wade Peterson

Stratigraphy And Extent Of The Pearl-Ashmore Aquifer, Mchenry County, Il, Usa, Drew C. Carlock, David H. Malone, Jason F. Thomason, Eric Wade Peterson

Eric Wade Peterson

Jurassic Eolian Oolite On A Paleohigh In The Sundance Sea, Bighorn Basin, Wyoming, Zoran Kilibarda, David Loope

David B. Loope

Aeolian limestones are widespread in the Quaternary record and have been identified in outcrops and cores of late Palaeozoic strata. These rocks have been interpreted as a low latitude signal of glacio-eustatic sea level fluctuations and have not been previously reported from the Mesozoic or from other episodes of earth history generally believed to have been non-glacial. Numerous lenticular bodies of cross-stratified oolite lie near the contact between the lower and upper members of the mudstone-dominated lower Sundance Formation (Middle and Upper Jurassic) in the Bighorn Basin of north-central Wyoming, USA. The lenses, up to 12 m thick, contain sedimentary …

Three-Dimensional Geologic Model Of The Pecatonica Gas Storage Field, Winnebago County, Illinois, Nicole Kron, David Malone, Eric Peterson

Eric Wade Peterson

Stratigraphy And Porosity Modeling Of Southern Centeral Illinois Chester (Upper Missisippian) Series Sandstones Usng Petrel, Darren Kimple, Eric Peterson, David Malone

Eric Wade Peterson

Identification Of Potential Vertical Gas Migration Pathways Above Gas Storage Reservoirs, Eric Peterson, Lauren Martin, David Malone

Eric Wade Peterson

Changes In Beach Gravel Lithology Caused By Anthropogenic Activities Along The Southern Coast Of Lake Michigan, Usa, Zoran Kilibarda, Nolan Graves, Melissa Dorton, Richard Dorton

Zoran Kilibarda

The southern coast of Lake Michigan is the most urbanized and most densely populated area in the Great Lakes region. Development of steel mills, harbors, and municipalities in NW Indiana and in NE Illinois in the last century and a half altered the nearshore environment so much that native beach gravel (>8 mm) now exist only in the exhumed paleo-beach remnants from the Nipissing Phase (~4,500 years ago) of Lake Michigan. Native gravel, collected from paleo-beach remnants at Mount Baldy Dune and Beach House Blowout, contain predominantly beach shingle, very platy siltstones (71–78 %), with secondary crystalline pebbles (18 …

Shallow-Water Origin Of A Devonian Black Shale, Cleveland Shale Member (Ohio Shale) Northeastern Ohio, James E. Evans

James E. Evans

No abstract provided.

Forum On The Flood/Post-Flood Boudary, Marcus R. Ross

Marcus R. Ross

The location of the Flood/post-Flood boundary is an important issue for Flood geology because it is the starting point for a host of research questions. Many papers have been published on this topic, but its placement is still controversial. Three main views are advocated: a low Flood boundary in the Paleozoic or below, a boundary at or near the Cretaceous-Tertiary boundary (now the Cretaceous/Paleogene boundary), and a variable boundary towards the upper Cenozoic but with each geographical area to be evaluated on its merits.

In 2012, Marcus Ross, published a biostratigraphic analysis and argued that a Flood/post-Flood boundary at or …

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 …

The Flood/Post-Flood Boundary (Comment And Reply), Marcus R. Ross

Marcus R. Ross

First paragraph: Michael Oard’s recent article on the Flood/post-Flood boundary consists of two parts: the first is response to my earlier paper on utilizing mammalian biostratigraphy in evaluating post-Flood boundary locations, which found placement of this boundary at or near the Pliocene/Pleistocene boundary untenable; the second part is a set of disparate observations placed in support of a high post-Flood boundary placed at variable locations in the “Late Cenozoic”. (comment continues; download for full comment and reply by Michael Oard)

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 …

Selected Drillhole Data (Dogm), Emery County, Ut, David J. Richey

David J Richey

Compiled formation tops data for selected oil and gas exploration drill holes in Emery County, Utah. Data was downloaded from [http://oilgas.ogm.utah.gov/index.htm].

Subsurface Facies Analysis Of The Late Cambrian Mt. Simon Sandstone In Western Ohio (Midcontinent, U.S.A.), James E. Evans

James E. Evans

No abstract provided.

Evaluating Potential Post-Flood Boundaries With Biostratigraphy--The Pliocene/Pleistocene Boundary, Marcus R. Ross

Marcus R. Ross

Here I report a biostratigraphic analysis of 303 genera from 28 North American terrestrial mammalian families, in which all families contain members that are either extant or last appear in Pliocene or Pleistocene deposits. The distribution of these taxa within the Cenozoic rock record is used to evaluate proposed demarcations for the Flood/post-Flood boundary. A pronounced biostratigraphic break is expected at the Flood/post-Flood boundary since the final devastation and burial of pre-Flood nephesh creatures should be stratigraphically overlain by the arrival of post-Flood migrants. It is found that when the Flood/post-Flood boundary is placed at or near the Pliocene/Pleistocene boundary, …

Central New York Varve Chronology: A Suggestion For Quaternary Geologists, Thomas Bradley Walker

Thomas Bradley Walker

Work done to build a chronology of deglaciation using varves has been the focus of a number of researchers in New England for many years. The locations employed to build their timeline have been quite useful to date. However, New England is not the only place in the Northeast conducive to studying the last deglaciation of North America. The discovery of a set of ice proximal varves in an ancient glacial lake, now a swamp, in Oswego County, central New York, has shown that some locations outside of New England would be suitable for similar studies. The land having been …