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Full-Text Articles in Earth Sciences

Paleoecology Of Foraminifera From The Late Miocene - Early Pliocene Pullen And Saint George Formations, Northwestern California, Trenton J. Ryan Jan 2017

Paleoecology Of Foraminifera From The Late Miocene - Early Pliocene Pullen And Saint George Formations, Northwestern California, Trenton J. Ryan

Cal Poly Humboldt theses and projects

The Pullen and Saint George formations are coeval late Miocene-early Pliocene sedimentary formations in northwestern California. The type localities of both formations were studied from a micropaleontologic perspective that focused primarily on Foraminifera, but with additional observations of other fossil groups to reconstruct their past depositional environments. The results obtained in this study provided a photomicrographic inventory of the microfossils from both formations, aided in investigating changes in paleobathymetry of the formations during the late Miocene and early Pliocene based on Foraminifera, and allowed for interpretation of paleoecological signals from the foraminiferan associations. Foraminifera have not been previously described in …


Iron Concretions In The Cretaceous Dakota Formation, Anthony Kohtz, Richard Kettler, David Loope Apr 2016

Iron Concretions In The Cretaceous Dakota Formation, Anthony Kohtz, Richard Kettler, David Loope

UCARE Research Products

The Cretaceous Dakota Formation contains abundant iron oxide concretions. The precursors to the iron concretions are siderite (FeCO3) nodules that formed in a reducing floodplain environment. A variety of concretion morphologies formed when the precursor siderite nodules were dissolved by oxidizing groundwater in a paleoaquifer. Iron-oxidizing bacteria are able to oxidize aqueous Fe(II) to Fe(III) oxy-hydroxide at microaerophilic and neutrophilic conditions. This study investigated these concretions to determine if there was a microbial element in their formation and to characterize the concretion morphologies present in the Dakota. This is important for complete paleoenvironment interpretations and astrobiology pursuits.


Geological Controls On Stratigraphy And Sedimentation Of The Mississippian Marshall Formation, Michigan Basin, U.S.A., Joseph G. Adducci Aug 2015

Geological Controls On Stratigraphy And Sedimentation Of The Mississippian Marshall Formation, Michigan Basin, U.S.A., Joseph G. Adducci

Masters Theses

An understanding of regional orogenic, climatic, and eustatic processes is critical to the interbasinal correlation of Paleozoic strata in eastern North America. Tectonic activity associated with the culmination of Appalachian Orogenic events has been shown to have regional influence on paleostructure and sediment dispersal in the Appalachian foreland basin and adjacent intracratonic Illinois and Michigan basins. The culmination of the Acadian Orogeny at the end of the Devonian represents the beginning of a period of general tectonic quiescence extending throughout the early and middle Mississippian in eastern North America. Early Mississippian strata in the Michigan basin is distinctive and marks …


Stratigraphic Column Of The Kope And Fairview Formations, Kentucky 445, Brent, Kentucky, Steven M. Holland, Arnold I. Miller, David L. Meyer, Benjamin F. Dattilo, Sharon C. St. Louis Diekmeyer Jan 2006

Stratigraphic Column Of The Kope And Fairview Formations, Kentucky 445, Brent, Kentucky, Steven M. Holland, Arnold I. Miller, David L. Meyer, Benjamin F. Dattilo, Sharon C. St. Louis Diekmeyer

Map and Chart--KGS

The Upper Ordovician Kope Formation is exposed over a broad area of southwestern Ohio, southeastern Indiana, and northern Kentucky (Weir and others, 1984). Roadcuts along Ky. 445 near Brent (Figs. 2-3) and adjacent roadcuts along Interstate 275 expose a nearly complete section of the Kope Formation as well as the overlying Fairview Formation.


Evaluation Of Chela Formation In Kambala-Livuite Area, Southern Block 0, Cabinda, Angola, Alba B. Bias Dos Santos May 2003

Evaluation Of Chela Formation In Kambala-Livuite Area, Southern Block 0, Cabinda, Angola, Alba B. Bias Dos Santos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The abundance of good reservoir and source rocks offshore Cabinda, Angola, makes the area an attractive and successful hydrocarbon province. Block 0, offshore Cabinda, lies in the Lower Congo basin along the western coast of Africa. The stratigraphy of Block 0 consists of two major oil-rich sequences: the rift sequence (primarily lacustrine) and the post-rift sequence (primarily marine). These are separated by a thick section of evaporites, and thus are referred to as the pre-salt sequence and post-salt sequence, respectively.

The Chela Formation, mid-Aptian in age, was deposited before the salt. It consists of sandstones and conglomerates locally interbedded with …


Stratigraphy And Paleoecology Of The Morrison Formation, Como Bluff, Wyoming, Melissa V. Connely May 2002

Stratigraphy And Paleoecology Of The Morrison Formation, Como Bluff, Wyoming, Melissa V. Connely

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Morrison Formation at Como Bluff, Wyoming, has been historically known for containing a rich source of Late Jurassic vertebrate fossils. However, when collected, most of these fossils were not positioned into a stratigraphic or sedimentologic framework. Research shows that the Morrison Formation at Como Bluff can be divided into three members. These members can be identified by lithologic and paleontological characteristics. The lower Morrison members include the Windy Hill Member and the recently described Lake Como Member. The Windy Hill Member primarily contains near-shore marine sandstone. Megavertebrate fauna is lacking. The Lake Como Member contains illitic clay in red …


Petrology Of Passive Margin-Epeiric Sea Sediments: The Garden City Formation, North-Central Utah, Susan K. Morgan May 1988

Petrology Of Passive Margin-Epeiric Sea Sediments: The Garden City Formation, North-Central Utah, Susan K. Morgan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Lower Ordovician Garden City Formation is part of the thick sequence of Lower Paleozoic limestones, dolostones, and minor siliciclastic sedimentary rocks of the western United States. The carbonate rocks were formed predominantly by shallow water deposition in tropical, passive-margin epeiric seas.

The Garden City Formation is composed of nine lithotypes which represent the various environments. The formation is a storm-influenced transgressive sequence which may be divided into innershelf shallow subtidal and outer-shelf deep subtidal environments separated by a skeletal accumulation. The skeletal accumulation, formed by storm initiation, was a submerged topographic high, below normal wave base. The inner shelf …


Growth, Morphology, Habit And Habitat Of Selected Brachiopod And Mollusc Species From The Meade Peak Member Of The Phosphoria Formation, Permian, Northeastern Utah - Southeastern Idaho - Southwestern Wyoming, Scott Lewis Russell May 1980

Growth, Morphology, Habit And Habitat Of Selected Brachiopod And Mollusc Species From The Meade Peak Member Of The Phosphoria Formation, Permian, Northeastern Utah - Southeastern Idaho - Southwestern Wyoming, Scott Lewis Russell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Permian Meade Peak Member of the Phosphoria Formation was examined at four localities in this investigation. Fossils were collected at each locality. The four collecting localities visited in this investigation are: Brazier Canyon, Utah, Montpelier Canyon, Idaho, Coal Canyon, Wyoming, and Cokeville, Wyoming.

The environment of deposition of the Meade Peak Member in the study area is inferred to have been an outer shelf or basin characterized by moderately deep and quiet water. This has aided reconstruction of life habits, population dynamics, and growth characteristics of the examined species.

The articulate brachiopod Leiorhynchoidea weeksi is inferred to have attached …


Environmental Analysis Of The Swan Peak Formation In The Bear River Range, North-Central Utah And Southeastern Idaho, Philip L. Vandorston May 1969

Environmental Analysis Of The Swan Peak Formation In The Bear River Range, North-Central Utah And Southeastern Idaho, Philip L. Vandorston

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Swan Peak Formation in the Bear River Range of northern Utah and southeastern Idaho varies in thickness from 0 feet to over 400 feet. It consists of three units: (1) a lower unit of interbedded quartzites, shales, and limestones; (2) A middle unit of interbedded quartzites and shales; (3) An upper unit of nearly homogeneous quartzites. The different sedimentary structures, ichnofossils, body fossils, and mineral compositions of each unit represent different environments of deposition. The lower unit probably was deposited in a shallow-shelf environment, and its sediments grade upward into probably shoreface-, tidal-flat-, and lagoonal deposits of the middle …


New Members Of The Gering Formation (Miocene) In Western Nebraska, Including A Geological Map Of Wildcat Ridge And Related Outliers, Carl F. Vondra, C. Bertrand Schultz, Thompson M. Stout Jan 1969

New Members Of The Gering Formation (Miocene) In Western Nebraska, Including A Geological Map Of Wildcat Ridge And Related Outliers, Carl F. Vondra, C. Bertrand Schultz, Thompson M. Stout

Conservation and Survey Division

No abstract provided.


Cambrian Stratigraphy In The Northern Wasatch Region, George Burke Maxey May 1941

Cambrian Stratigraphy In The Northern Wasatch Region, George Burke Maxey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An exhaustive field study of the Cambrian stratigraphy of the northern Wasatch region indicates that in addition to the Blacksmith Fork section there are two complete and better exposed middle and upper sections. Several other good exposures of the lower Middle Cambrian section have been studied in detail. The Spence shale is found to be a member low in the Langston, not the basal member of the Ute. Relative ages of the Spence shale and Ptarmigania faunas have been determined. Other Cambrian faunal zones have been discovered and are discussed. Paleontologic evidence suggests that the Nounan formation is of Upper …


The Grenola Formation, G. E. Condra, C. E. Busby Jan 1933

The Grenola Formation, G. E. Condra, C. E. Busby

Conservation and Survey Division

No abstract provided.