CHARACTERIZATION AND INTERPRETATION OF THE CEPHALOPOD MARKER BED, OAKES QUARRY PARK, FAIRBORN, OHIO

Bibliographic Details
Main Author: McDonough, Jessica Nicole
Language:English
Published: Wright State University / OhioLINK 2006
Subjects:
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=wright1164641557
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-wright11646415572021-08-03T06:16:30Z CHARACTERIZATION AND INTERPRETATION OF THE CEPHALOPOD MARKER BED, OAKES QUARRY PARK, FAIRBORN, OHIO McDonough, Jessica Nicole Geology Brassfield Formation Silurian Microbial sediments calcifying microbes Microbial micrite cephalopods microbial dolomite dolomitization A distinct sequence of orange-brown, fossiliferous grainstones with interbedded blue mudstones exists in the upper portion of the Silurian-aged (Llandoverian) Brassfield Formation exposure at Oakes Quarry Park, Fairborn, Ohio. The unit is locally referred to as the cephalopod marker bed as it can be easily identified and is continuous throughout the quarry. The unit varies considerably in thickness (0.3m-0.9m) and contains a variety of sedimentary structures and fossils indicative of a warm, shallow marine environment subject to wave action. Dominant fossils within the unit include echinoderms, cephalopods, bryozoans, abraded mollusks, gastropods, brachiopods, and trilobites. Less-common fossil organisms within the unit include ostracodes, foraminifera, algae, and stromatoporoids. Mollusk chambers are commonly filled with micrite that contain traces of microbial life, including cement in the shape of bacterial filaments and micropeloids. Samples of the cephalopod marker bed were taken in a vertical sequence at two locations and from several locations along a north-south transect. Thin-sections were created from the samples; these were then point-counted using 300 counts to attain a quantitative analysis of the rock composition. Fossil abundance and diversity increases from the bottom to the top of the sequence and lateral variations within the top two, most-fossiliferous layers were also observed. Petrographic analysis of the cephalopod marker bed revealed that on average, bioclasts represent ~75% of the rock volume, cement is the next most-abundant constituent, and dolomite composes ~9% of the the rock volume. Dolomitization is preferential: it occurs most often in micrite within mollusk shells and might be driven by microbial processes; skeletal grain replacement occurs most easily within bryozoans. 2006-12-11 English text Wright State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=wright1164641557 http://rave.ohiolink.edu/etdc/view?acc_num=wright1164641557 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Geology
Brassfield Formation
Silurian
Microbial sediments
calcifying microbes
Microbial micrite
cephalopods
microbial dolomite
dolomitization
spellingShingle Geology
Brassfield Formation
Silurian
Microbial sediments
calcifying microbes
Microbial micrite
cephalopods
microbial dolomite
dolomitization
McDonough, Jessica Nicole
CHARACTERIZATION AND INTERPRETATION OF THE CEPHALOPOD MARKER BED, OAKES QUARRY PARK, FAIRBORN, OHIO
author McDonough, Jessica Nicole
author_facet McDonough, Jessica Nicole
author_sort McDonough, Jessica Nicole
title CHARACTERIZATION AND INTERPRETATION OF THE CEPHALOPOD MARKER BED, OAKES QUARRY PARK, FAIRBORN, OHIO
title_short CHARACTERIZATION AND INTERPRETATION OF THE CEPHALOPOD MARKER BED, OAKES QUARRY PARK, FAIRBORN, OHIO
title_full CHARACTERIZATION AND INTERPRETATION OF THE CEPHALOPOD MARKER BED, OAKES QUARRY PARK, FAIRBORN, OHIO
title_fullStr CHARACTERIZATION AND INTERPRETATION OF THE CEPHALOPOD MARKER BED, OAKES QUARRY PARK, FAIRBORN, OHIO
title_full_unstemmed CHARACTERIZATION AND INTERPRETATION OF THE CEPHALOPOD MARKER BED, OAKES QUARRY PARK, FAIRBORN, OHIO
title_sort characterization and interpretation of the cephalopod marker bed, oakes quarry park, fairborn, ohio
publisher Wright State University / OhioLINK
publishDate 2006
url http://rave.ohiolink.edu/etdc/view?acc_num=wright1164641557
work_keys_str_mv AT mcdonoughjessicanicole characterizationandinterpretationofthecephalopodmarkerbedoakesquarryparkfairbornohio
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