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Articles 301 - 330 of 1428

Full-Text Articles in Geology

Pennsylvanian Subsurface Sequence Stratigraphy Based On 3d Seismic And Wireline Data In Western Osage County, Oklahoma, Alexander West May 2015

Pennsylvanian Subsurface Sequence Stratigraphy Based On 3d Seismic And Wireline Data In Western Osage County, Oklahoma, Alexander West

Graduate Theses and Dissertations

The Pennsylvanian System in the Mid-Continent United States has been studied for nearly a century. In north central Oklahoma, the Pennsylvanian is primarily composed of cyclothems. These cyclothems are sequences of alternating carbonate, clastic, and shale members. Because of this, these zones can be difficult to differentiate. This project provides valuable insight into better understanding the Pennsylvanian System in western Osage County, Oklahoma. The scope of this project is to perform a subsurface study to produce a detailed interpretation of the depositional history and stratigraphy of Pennsylvanian sequences in western Osage County.

This study features 3D seismic and well log …


Basic Guide For Description Of Cuttings From Boreholes In Nebraska, Dana P. Divine, R. M. Joeckel, Jesse T. Korus May 2015

Basic Guide For Description Of Cuttings From Boreholes In Nebraska, Dana P. Divine, R. M. Joeckel, Jesse T. Korus

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Geologic Controls On Oil And Gas Accumulation And Production From Missourian Stage Granite Wash Reservoirs In The Western Anadarko Basin, Wheeler County, Texas, Derrell Mathis May 2015

Geologic Controls On Oil And Gas Accumulation And Production From Missourian Stage Granite Wash Reservoirs In The Western Anadarko Basin, Wheeler County, Texas, Derrell Mathis

Graduate Theses and Dissertations

Up-to-date regional and local Granite Wash data of any form is either too scarce to reference or highly privatized by exploration and production companies operating in the region. The objective of this research is to correlate horizontal production data with mapped depositional trends from Upper Pennsylvanian (Missourian Stage) Granite Wash reservoirs in the Western Anadarko Basin in northeastern Wheeler County, Texas. The correlation of raster logs to define various trap type and geometries in Missourian Granite Wash reservoirs of Wheeler County, Texas is used to understand the geologic controls on oil and gas accumulation and production. The analysis includes detailed …


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 Apr 2015

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

ANDRILL Research and Publications

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 …


The Groundwater Atlas Of Saunders County, Nebraska, Dana Divine Jan 2015

The Groundwater Atlas Of Saunders County, Nebraska, Dana Divine

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Schoenophyllum Aggregatum Zone: Stratigraphic Marker For Investigations Of Mississippian Limestones In Western Kentucky, Garland R. Dever Jr., Preston Mcgrain Jan 2015

Schoenophyllum Aggregatum Zone: Stratigraphic Marker For Investigations Of Mississippian Limestones In Western Kentucky, Garland R. Dever Jr., Preston Mcgrain

Report of Investigations--KGS

Schoenophyllum aggregatum, a Mississippian colonial rugose coral, has a widespread geographic distribution and narrow stratigraphic range in the upper Ste. Genevieve Limestone of western Kentucky. This coral zone serves as a useful stratigraphic marker for commercial and geologic investigations of the extensive limestone deposits formed by the Ste. Genevieve and enclosing limestone units in the region. S. aggregatum is also present in rocks correlative with the Ste, Genevieve that occur in the Monteagle Limestone Slade Formation of south-central Kentucky and the Newman Limestone of southeastern Kentucky.


North-Central Nebraska Geology: Niobrara River Valley In Brown, Cherry, And Keya Paha Counties, R. M. Joeckel, L. M. Howard, S T. Tucker Jan 2015

North-Central Nebraska Geology: Niobrara River Valley In Brown, Cherry, And Keya Paha Counties, R. M. Joeckel, L. M. Howard, S T. Tucker

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Nebraska Statewide Groundwater-Level Monitoring Report 2015, A. R. Young, M. E. Burbach, L. M. Howard Jan 2015

Nebraska Statewide Groundwater-Level Monitoring Report 2015, A. R. Young, M. E. Burbach, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Katian Gssp And Carbonates Of The Simpson And Arbuckle Groups In Oklahoma, Jesse R. Carlucci, Daniel Goldman, Carlton E. Brett, Stephen R. Westrop, Stephen A. Leslie Jan 2015

Katian Gssp And Carbonates Of The Simpson And Arbuckle Groups In Oklahoma, Jesse R. Carlucci, Daniel Goldman, Carlton E. Brett, Stephen R. Westrop, Stephen A. Leslie

Department of Earth, Environment and Sustainability Faculty Publications

This guidebook was written for the 2015 International Symposium on the Ordovician System (ISOS) as a synopsis of the recent work (e.g., Goldman et al. 2007; Carlucci et al. 2014, forthcoming work for the ISOS meeting) on Ordovician-Silurian rocks of south-central and south-eastern Oklahoma. This new research and past studies (e.g., Harris 1957; Longman 1976; Longman 1982a, b; Fay et al. 1982a; Fay et al. 1982b) underscore the scientific importance of this region. The global stratotype section and point for the Katian Stage of the Upper Ordovician Series is examined on this trip. The first appearances of important graptolites, conodonts …


Geologic Map Of The Welcome Quadrangle And An Adjacent Part Of The Wells Quadrangle, Elko County, Nevada, Allen J. Mcgrew, Arthur W. Snoke Jan 2015

Geologic Map Of The Welcome Quadrangle And An Adjacent Part Of The Wells Quadrangle, Elko County, Nevada, Allen J. Mcgrew, Arthur W. Snoke

Department of Earth, Environment and Sustainability Faculty Publications

Located in central Elko County, the Welcome and adjacent part of the Wells quadrangles expose a remarkable array of critical relationships for understanding the geologic history of the State of Nevada and the interior of the southwestern U.S. Cordillera. Covering the northern end of the East Humboldt Range and adjacent Clover Valley and Clover Hill, this map includes the northern terminus of the Ruby Mountains-East Humboldt Range metamorphic core complex. The oldest rocks in the State of Nevada (the gneiss complex of Angel Lake), and Nevada’s only exposures of Archean rock, form the core of a multikilometer scale, southward-closing recumbent …


Hydrophobic Organic Contaminant Transport Property Heterogeneity In The Borden Aquifer, Richelle M. Allen-King, Indra Kalinovich, David F. Dominic, Guohui Wang, Reid Polmanteer, Dana Divine Jan 2015

Hydrophobic Organic Contaminant Transport Property Heterogeneity In The Borden Aquifer, Richelle M. Allen-King, Indra Kalinovich, David F. Dominic, Guohui Wang, Reid Polmanteer, Dana Divine

Conservation and Survey Division: Faculty and Staff Publications

We determined that the spatial heterogeneity in aquifer properties governing the reactive transport of volatile organic contaminants is defined by the arrangement of lithofacies. We measured permeability (k) and perchloroethene sorption distribution coefficient (Kd) for lithofacies that we delineated for samples from the Canadian Forces Base Borden Aquifer. We compiled existing data and collected 57 new cores to characterize a 30 m section of the aquifer near the test location of Mackay et al. (1986). The k and Kd were measured for samples taken at six elevations from all cores to create a data set consisting of …


Hydrophobic Organic Contaminant Transport Property Heterogeneity In The Borden Aquifer, Richelle M. Allen-King, Indra Kalinovich, David F. Dominic, Guohui Wang, Reid Polmanteer, Dana Divine Jan 2015

Hydrophobic Organic Contaminant Transport Property Heterogeneity In The Borden Aquifer, Richelle M. Allen-King, Indra Kalinovich, David F. Dominic, Guohui Wang, Reid Polmanteer, Dana Divine

Conservation and Survey Division: Faculty and Staff Publications

We determined that the spatial heterogeneity in aquifer properties governing the reactive transport of volatile organic contaminants is defined by the arrangement of lithofacies. We measured permeability (k) and perchloroethene sorption distribution coefficient (Kd) for lithofacies that we delineated for samples from the Canadian Forces Base Borden Aquifer. We compiled existing data and collected 57 new cores to characterize a 30 m section of the aquifer near the test location of Mackay et al. (1986). The k and Kd were measured for samples taken at six elevations from all cores to create a data …


Field Trip Guidebook For The Nebraska Well Drillers Association, Duane A. Eversoll, Matt Joeckel, Lee Orton Sep 2014

Field Trip Guidebook For The Nebraska Well Drillers Association, Duane A. Eversoll, Matt Joeckel, Lee Orton

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


The Significance Of Dolomitized Hunton Strata In The Kinta And Bonanza Fields Of The Arkoma Basin, Christopher William Trotter Aug 2014

The Significance Of Dolomitized Hunton Strata In The Kinta And Bonanza Fields Of The Arkoma Basin, Christopher William Trotter

Graduate Theses and Dissertations

The Hunton Group has been a prolific hydrocarbon-producing reservoir across much of Oklahoma and western Arkansas. The group is a Silurian-Devonian aged interval that is comprised of sequences of limestone, dolomite, and calcareous shale. The group is divided into several formations. The subdivisions include the Chimneyhill Subgroup, Henryhouse, Haragan and Bois d'Arc Formations. Reservoir quality in the Hunton Group is significantly dependent upon the diagenetic events and depositional environments of the sediments. Most hydrocarbon production, from within the Hunton Group, comes from members that have undergone dolomite replacement of the parent limestone.

The higher amounts of porosity and permeability are …


The University Of Nebraska State Museum, Robert F. Diffendal Jr. Jun 2014

The University Of Nebraska State Museum, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

I first walked through the doors of Morrill Hall on the main or City Campus of the University of Nebraska on a day late in August of 1962 and thought that I had entered paleontology heaven. Morrill Hall then housed the University of Nebraska State Museum (UNSM). most of the Geology Department, and some other parts of university units. I was a new graduate student hoping to pursue research in invertebrate paleontology in the Department of Geology and was on my way to see the department chairman for the first time. When I entered the building I walked through a …


Sedimentological And Stratigraphic Study Of A Falling-Stage Delta Complex In The Upper Cretaceous (Turonian) Ferron Sandstone Member Of The Mancos Shale, South-Central Utah, Usa, Fares Alaboud Jun 2014

Sedimentological And Stratigraphic Study Of A Falling-Stage Delta Complex In The Upper Cretaceous (Turonian) Ferron Sandstone Member Of The Mancos Shale, South-Central Utah, Usa, Fares Alaboud

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The character and distribution of lithofacies in falling-stage deltas are incompletely documented. This paper presents a sedimentological and stratigraphic evaluation of a superbly-exposed interval of Cretaceous deltaic strata that are believed to be of falling stage origin. The studied interval forms part of the Upper Cretaceous (Turonian) Ferron Sandstone Member of the Mancos Shale in the southernmost Henry Mountains Basin of south-central Utah, USA. The interval of interest is exposed in three dimensions over a 20 km2 area in a series of canyon walls. Observed facies include fine-grained mudrocks (offshore basin), mudrocks with thinly interlaminated sandstone (prodelta), thinly interbedded …


Origin And Distribution Of The Mississippian–Pennsylvanian Boundary Unconformity In Marine Carbonate Successions With A Case Study Of The Karst Development Atop The Madison Formation In The Bighorn Basin, Wyoming, Lucien Nana Yobo Jun 2014

Origin And Distribution Of The Mississippian–Pennsylvanian Boundary Unconformity In Marine Carbonate Successions With A Case Study Of The Karst Development Atop The Madison Formation In The Bighorn Basin, Wyoming, Lucien Nana Yobo

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The causal mechanism of the widespread unconformity that encompasses the Mississippian – Pennsylvanian boundary remains poorly understood. This unconformity, first thought to be restricted to North America, is now known to be present in other regions of the globe. Possible causes for the unconformity include (1) sea level draw down from the onset of glaciation at start of the late Paleozoic ice age and (2) increased tectonic activity from the formation of the supercontinent of Pangea. Thus the origin of the unconformity is still poorly constrained.

This study examines possible causal mechanisms for the widespread unconformity that encompasses the Mississippian …


An Analysis Of The Green Knoll Salt Dome, Located In The Southeast Green Canyon, Deep Water Gulf Of Mexico, Randal J. Broussard May 2014

An Analysis Of The Green Knoll Salt Dome, Located In The Southeast Green Canyon, Deep Water Gulf Of Mexico, Randal J. Broussard

LSU New Orleans Theses and Dissertations

The western portion of the Mississippi/Atwater fold belt in the Gulf of Mexico contains what is known as The Green Knoll Salt Dome. The creation and growth of this salt diapir is punctuated by salt deposition, salt migration, sediment loading, and is linked to the “Frampton” fold belt. An indicator of these growth periods is exhibited in an angular unconformity (halo-kinetic sequence boundary) that flanks the diapir. This unconformity developed during the Miocene-Pliocene chronostratigraphic boundary. The “Redwood” (Green Canyon 1001) prospect was drilled after the discovery of middle Miocene sands containing hydrocarbons in the Mad Dog field (GC 826). The …


Combining Quantitative Eye-Tracking And Gis Techniques With Qualitative Research Methods To Evaluate The Effectiveness Of 2d And Static, 3d Karst Visualizations: Seeing Through The Complexities Of Karst Environments, Elizabeth Katharyn Tyrie May 2014

Combining Quantitative Eye-Tracking And Gis Techniques With Qualitative Research Methods To Evaluate The Effectiveness Of 2d And Static, 3d Karst Visualizations: Seeing Through The Complexities Of Karst Environments, Elizabeth Katharyn Tyrie

Masters Theses & Specialist Projects

Karst environments are interconnected landscapes vulnerable to degradation. Many instances of anthropogenic karst disturbance are unintentional, and occur because of the public's lack of understanding or exposure to karst knowledge. When attempts are made to educate the general public about these landscapes, the concepts taught are often too abstract to be fully understood. Thus, karst educational pursuits must use only the most efficient and effective learning materials. A technique useful for assessing educational effectiveness of learning materials is eye-tracking, which allows scientists to quantitatively measure an individual's points of interest and eye movements when viewing a 2D or 3D visualization. …


Subsurface Sequence Stratigraphy And Reservoir Characterization Of The Mississippian Limestone (Kinderhookian To Meramecian), South Central Kansas And North Central Oklahoma, Thomas Cahill May 2014

Subsurface Sequence Stratigraphy And Reservoir Characterization Of The Mississippian Limestone (Kinderhookian To Meramecian), South Central Kansas And North Central Oklahoma, Thomas Cahill

Graduate Theses and Dissertations

Both conventional and unconventional Mississippian reservoirs in the mid-continent are largely comprised of chert-rich carbonates of Osagean and Meramecan age. The conventional reservoir target is the Mississippian "chat," a high porosity, chert residuum interval found immediately beneath the Mississippian-Pennsylvanian unconformity. The unconventional reservoir target occurs in the lower porosity, cherty, mud-rich intervals that occur in the lower portion of the Mississippian succession.

There has been considerable debate surrounding the sequence stratigraphic interpretations, depositional models, and formation names applied to the reservoir intervals within the subsurface. Another major issue with regard to the subsurface is the stratigraphic position and origin of …


Structure And Stratigraphy Of A Complex Anticlinal Feature, Backbone Anticline, Arkoma Basin, Arkansas, Shailyn Marie Abbott May 2014

Structure And Stratigraphy Of A Complex Anticlinal Feature, Backbone Anticline, Arkoma Basin, Arkansas, Shailyn Marie Abbott

Graduate Theses and Dissertations

The Arkoma Basin of Arkansas and Oklahoma formed in the Ouachita foreland during the late Mississippian and Pennsylvanian periods (about 290-to 330 million years ago). The basin developed in response to convergent tectonic boundaries that closed obliquely from west to east associated with Ouachita orogenic event. The Backbone anticline in the northern Arkoma Basin is a prominent product of this convergence, and represents the first major component of this study. The structure is asymmetric with beds on the southern limb dipping steeply to the south. It is also expressed topographically as a prominent ridge that trends eastward from the Oklahoma-Arkansas …


Depositional History And Stratigraphic Framework Of Upper Cretaceous (Campanian To Maastrichtian) Strata In The Minerva-Rockdale Oil Field Of Milam County And Adjacent Counties, Texas., Adam Thomas Martin May 2014

Depositional History And Stratigraphic Framework Of Upper Cretaceous (Campanian To Maastrichtian) Strata In The Minerva-Rockdale Oil Field Of Milam County And Adjacent Counties, Texas., Adam Thomas Martin

Graduate Theses and Dissertations

First discovered in 1921, the Minerva-Rockdale Oil Field (MROF) has experienced a recent resurgence of drilling. The targeted Navarro Group is Upper Cretaceous (Maastrichtian) in age and ranges in depth from approximately 100 to 3000+ ft. (subsea). Several thin elongated sandy zones within the Kemp clay of the Corsicana (Navarro) Formation, are the current targets for oil production. These sandy zones are informally divided into the Navarro `A' and `B' and their depositional morphology is described by the shelf plume model, as proposed by Patterson (1983).

Despite the mature nature of the MROF and surrounding area, only a small number …


Structural And Stratigraphic Transition From The Arkoma Shelf Into The Arkoma Basin During Basin Subsidence; Arkoma Basin, Northwest Arkansas, Elizabeth Whitney Studebaker May 2014

Structural And Stratigraphic Transition From The Arkoma Shelf Into The Arkoma Basin During Basin Subsidence; Arkoma Basin, Northwest Arkansas, Elizabeth Whitney Studebaker

Graduate Theses and Dissertations

The Arkoma basin is an arcuate Paleozoic structural feature in the Ouachita foreland that extends from central Arkansas and westward into southeastern Oklahoma. The Arkoma shelf lies immediately north of the basin and is comprised of Cambrian to Pennsylvanian age sedimentary rocks. In northwestern Arkansas, the stratigraphic and structural transition from the shelf into the northern portion of the Arkoma basin is poorly defined.

Wireline logs were used to construct a series of three north to south cross sections, as well as two along-strike west to east cross sections to examine Morrowan and lower Atokan age strata. In addition to …


Porosity Development Within Lobes To Downslope Ramp Deposits On A Prograding Carbonate Shelf Of The Kinderhookian To Osagean Series In Northwest Arkansas, Elizabeth Marchese May 2014

Porosity Development Within Lobes To Downslope Ramp Deposits On A Prograding Carbonate Shelf Of The Kinderhookian To Osagean Series In Northwest Arkansas, Elizabeth Marchese

Graduate Theses and Dissertations

Carbonate bodies with lobate geometries form a substantial part of the Osagean (early Mississippian) section in northwest Arkansas. The purpose of this study is to isolate and describe a single lobe from three-dimensional exposures in quarry walls to provide criteria by which lobe and lobe porosity can be recognized in the subsurface. Carbonate sediment generated on the Mississippian Burlington shelf moved southward by gravity flows from the shelf margin to positions on a prograding ramp in Arkansas where overlapping deposits with lobate geometries accumulated. These deposits are recognized in outcrops of the Boone Formation. Stratigraphic units within the Boone are …


Some Reflections On Our Experiences At Sun Yat-Sen University Since 1985, Robert F. Diffendal Jr., Anne P. Diffendal Jan 2014

Some Reflections On Our Experiences At Sun Yat-Sen University Since 1985, Robert F. Diffendal Jr., Anne P. Diffendal

Robert F. Diffendal, Jr., Publications

Professor Zhang Ke, Chairman of the Department of Earth Sciences at Sun Yat-sen University, has asked us to write about some of our memories from our several visits to Sun Yat-sen University, as part of the 2014 celebration of the 90th anniversary of the founding of the university and the creation of the department. We are very pleased to do so and to include with our written comments copies of some photographs that we have taken during these visits. We have gone back through our notes, books, tourist maps, photo files, and other information that we have kept as souvenirs …


Nebraska Statewide Groundwater-Level Monitoring Report 2014, A. R. Young, M. E. Burbach, L. M. Howard Jan 2014

Nebraska Statewide Groundwater-Level Monitoring Report 2014, A. R. Young, M. E. Burbach, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Depositional Environment Of The St. Mary River Formation In Western Montana, Stacia M. Martineau Jan 2014

Depositional Environment Of The St. Mary River Formation In Western Montana, Stacia M. Martineau

Undergraduate Theses, Professional Papers, and Capstone Artifacts

In May 2013, the Two Medicine Dinosaur Center (TMDC) began excavation on a dinosaur bonebed in the St. Mary River Formation on Carey Butte, Montana. Since excavation started, four additional bonebeds have been discovered in the surrounding area. They display different depositional environments; two are in sandstone and the other three are in siltstone. The purpose of this study is to provide a depositional setting for the area that links all five sites together comprehensively by examining the sedimentology of the area. A stratigraphic analysis of the St. Mary River Formation of Carey Butte revealed four distinct facies associations. Facies …


The Groundwater Atlas Of Lancaster County, Dana Divine Jan 2014

The Groundwater Atlas Of Lancaster County, Dana Divine

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Reconstruction Of The Hirnantian (Late Ordovician) Palaeotopography In The Upper Yangtze Region, Linna Zhang, Junxuan Fan, Qing Chen, Shuang-Ye Wu Jan 2014

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

Department of Earth, Environment and Sustainability Faculty Publications

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 …


Architecture, Heterogeneity, And Origin Of Late Miocene Fluvial Deposits Hosting The Most Important Aquifer In The Great Plains, Usa, R. Matthew Joeckel, Steve R. Wooden Jr., Jesse T. Korus, Jon Garbisch Jan 2014

Architecture, Heterogeneity, And Origin Of Late Miocene Fluvial Deposits Hosting The Most Important Aquifer In The Great Plains, Usa, R. Matthew Joeckel, Steve R. Wooden Jr., Jesse T. Korus, Jon Garbisch

Department of Earth and Atmospheric Sciences: Faculty Publications

The Ash Hollow Formation (AHF) of the Ogallala Group is an important sedimentary archive of the emergence of the Great Plains and it contains major groundwater resources. Stratal patterns of constituent alluvial lithofacies demonstrate that the AHF is much more heterogeneous than is commonly assumed. Very fine- to fine-grained sandstone dominate overall, chiefly lithofacies Sm (massive to locally stratified sandstone). Stacked, thin sheets of Sm with accretionary macroform surfaces are common, indicating that many sandstone architectural elements originated as compound-bar deposits in dominantly sand-bed streams. Channel forms are difficult to identify and steep cutbanks are absent. Multiple units of lithofacies …