{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/41784"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/41784","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"High pressure acadian metamorphism of the Straits Schist, Western Connecticut","abstract":"A detailed petrologic study of the maximum assemblage, minimum variance pelitic units contained within The Straits Schist in western Connecticut was undertaken to provide data on the Acadian Orogeny in the northern half of the western highlands of Connecticut. The Straits Schist, contained within the Connecticut Valley synclinorium, is structurally involved in portions of both the Hartland and Gneiss Dome belts, outlining isoclinally refolded nappes plunging off the Waterbury Dome. The Straits Schist is believed to be of Silurian—Devonian age, based on proposed correlations with the Goshen and the Waits River Formations of Massachusetts and Vermont, respectively. Furthermore, the age of metamorphism is interpreted as being Acadian based on the proposed age and stratigraphy, simple metamorphic textures, and uniform grain sizes. Quantitative estimates of the pressure and temperature conditions under which the mineral assemblages of The Straits Schist equilibrated were calculated using calibrated mineral reactions and ion exchange equilibria. Temperatures range from 607° — 747°C, and pressures range from 6.4 — 8.9 kbar across the study area. Estimates of P<sub>H₂0</sub>/P<sub>total</sub> were obtained and range between 0.21 and 0.57. Although exchange mechanisms have not (or could not have) been determined exactly, biotite and muscovite do show deviation from ideal tri- and di-octahedral stoichiometry, up to 13.7% di-octahedral character and 2.2% tri-octahedral character, respectively. Compositional X-ray maps indicate that The Straits Schist underwent rapid cooling. Therefore, the Acadian Orogeny in western Connecticut is characterized as a high-pressure event that underwent rapid postmetamorphic uplift and cooling.","abstract_html":"A detailed petrologic study of the maximum assemblage, minimum variance pelitic units contained within The Straits Schist in western Connecticut was undertaken to provide data on the Acadian Orogeny in the northern half of the western highlands of Connecticut. The Straits Schist, contained within the Connecticut Valley synclinorium, is structurally involved in portions of both the Hartland and Gneiss Dome belts, outlining isoclinally refolded nappes plunging off the Waterbury Dome. The Straits Schist is believed to be of Silurian—Devonian age, based on proposed correlations with the Goshen and the Waits River Formations of Massachusetts and Vermont, respectively. Furthermore, the age of metamorphism is interpreted as being Acadian based on the proposed age and stratigraphy, simple metamorphic textures, and uniform grain sizes. Quantitative estimates of the pressure and temperature conditions under which the mineral assemblages of The Straits Schist equilibrated were calculated using calibrated mineral reactions and ion exchange equilibria. Temperatures range from 607° — 747°C, and pressures range from 6.4 — 8.9 kbar across the study area. Estimates of P&lt;sub&gt;H₂0&lt;/sub&gt;/P&lt;sub&gt;total&lt;/sub&gt; were obtained and range between 0.21 and 0.57. Although exchange mechanisms have not (or could not have) been determined exactly, biotite and muscovite do show deviation from ideal tri- and di-octahedral stoichiometry, up to 13.7% di-octahedral character and 2.2% tri-octahedral character, respectively. Compositional X-ray maps indicate that The Straits Schist underwent rapid cooling. Therefore, the Acadian Orogeny in western Connecticut is characterized as a high-pressure event that underwent rapid postmetamorphic uplift and cooling.","abstract_has_math":false,"creators":["Miller, Stephen John"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Geological Sciences","degree_department":"Geological Sciences","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1990,"date_issued":"1990","date_published":"1990","updated_at":"2026-07-22T22:19:32Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-03242009-040839"],"render_values":[{"text":"etd-03242009-040839","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/41784","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Geological Sciences"]},{"key":"dc:creator","label":"Author","values":["Miller, Stephen John"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:32:23Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:32:23Z","2009-03-24"]},{"key":"dc:date.issued","label":"Date","values":["1990"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geological Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-03242009-040839"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/41784"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A detailed petrologic study of the maximum assemblage, minimum variance pelitic units contained within The Straits Schist in western Connecticut was undertaken to provide data on the Acadian Orogeny in the northern half of the western highlands of Connecticut. The Straits Schist, contained within the Connecticut Valley synclinorium, is structurally involved in portions of both the Hartland and Gneiss Dome belts, outlining isoclinally refolded nappes plunging off the Waterbury Dome. The Straits Schist is believed to be of Silurian—Devonian age, based on proposed correlations with the Goshen and the Waits River Formations of Massachusetts and Vermont, respectively. Furthermore, the age of metamorphism is interpreted as being Acadian based on the proposed age and stratigraphy, simple metamorphic textures, and uniform grain sizes. Quantitative estimates of the pressure and temperature conditions under which the mineral assemblages of The Straits Schist equilibrated were calculated using calibrated mineral reactions and ion exchange equilibria. Temperatures range from 607° — 747°C, and pressures range from 6.4 — 8.9 kbar across the study area. Estimates of P<sub>H₂0</sub>/P<sub>total</sub> were obtained and range between 0.21 and 0.57. Although exchange mechanisms have not (or could not have) been determined exactly, biotite and muscovite do show deviation from ideal tri- and di-octahedral stoichiometry, up to 13.7% di-octahedral character and 2.2% tri-octahedral character, respectively. Compositional X-ray maps indicate that The Straits Schist underwent rapid cooling. Therefore, the Acadian Orogeny in western Connecticut is characterized as a high-pressure event that underwent rapid postmetamorphic uplift and cooling."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["High pressure acadian metamorphism of the Straits Schist, Western Connecticut"]}]}],"canonical_facts":{"dc:contributor.department":["Geological Sciences"],"dc:creator":["Miller, Stephen John"],"dc:date.accessioned":["2014-03-14T21:32:23Z"],"dc:date.available":["2014-03-14T21:32:23Z","2009-03-24"],"dc:date.issued":["1990"],"dc:description.abstract":["A detailed petrologic study of the maximum assemblage, minimum variance pelitic units contained within The Straits Schist in western Connecticut was undertaken to provide data on the Acadian Orogeny in the northern half of the western highlands of Connecticut. The Straits Schist, contained within the Connecticut Valley synclinorium, is structurally involved in portions of both the Hartland and Gneiss Dome belts, outlining isoclinally refolded nappes plunging off the Waterbury Dome. The Straits Schist is believed to be of Silurian—Devonian age, based on proposed correlations with the Goshen and the Waits River Formations of Massachusetts and Vermont, respectively. Furthermore, the age of metamorphism is interpreted as being Acadian based on the proposed age and stratigraphy, simple metamorphic textures, and uniform grain sizes. Quantitative estimates of the pressure and temperature conditions under which the mineral assemblages of The Straits Schist equilibrated were calculated using calibrated mineral reactions and ion exchange equilibria. Temperatures range from 607° — 747°C, and pressures range from 6.4 — 8.9 kbar across the study area. Estimates of P<sub>H₂0</sub>/P<sub>total</sub> were obtained and range between 0.21 and 0.57. Although exchange mechanisms have not (or could not have) been determined exactly, biotite and muscovite do show deviation from ideal tri- and di-octahedral stoichiometry, up to 13.7% di-octahedral character and 2.2% tri-octahedral character, respectively. Compositional X-ray maps indicate that The Straits Schist underwent rapid cooling. Therefore, the Acadian Orogeny in western Connecticut is characterized as a high-pressure event that underwent rapid postmetamorphic uplift and cooling."],"dc:description.degree":["Master of Science"],"dc:format.medium":["BTD"],"dc:format.mimetype":["application/pdf"],"dc:identifier.other":["etd-03242009-040839"],"dc:identifier.uri":["http://hdl.handle.net/10919/41784"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["High pressure acadian metamorphism of the Straits Schist, Western Connecticut"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Geological Sciences"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:32Z"}