Stratigraphy of the western Lake St. Joseph greenstone terrain, Northwestern Ontario
The western Lake St. Joseph area in Northwestern Ontario is underlain by Archean metavolcanic and metasedimentary rocks. The strata, referred to as the Lake St. Joseph Group comprise three formations representative of mafic to felsic volcanic cyclicity. The Blackstone Formation, stratigraphically th...
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ftlakeheaduniv:oai:knowledgecommons.lakeheadu.ca:2453/2379 2023-05-15T16:03:08+02:00 Stratigraphy of the western Lake St. Joseph greenstone terrain, Northwestern Ontario Berger, B. R. (Ben R.) Shegelski, Roy Kehlenbeck, Manfred 1981 application/pdf http://knowledgecommons.lakeheadu.ca/handle/2453/2379 en_US eng http://knowledgecommons.lakeheadu.ca/handle/2453/2379 Geology Ontario Lake St. Joseph Region Thesis 1981 ftlakeheaduniv 2022-12-04T18:29:56Z The western Lake St. Joseph area in Northwestern Ontario is underlain by Archean metavolcanic and metasedimentary rocks. The strata, referred to as the Lake St. Joseph Group comprise three formations representative of mafic to felsic volcanic cyclicity. The Blackstone Formation, stratigraphically the lowest, contains a lower member composed of predominantly high-Mg, low-K tholeiitic pillowed basalts and an upper member composed of rhyoliticflows and pyroclastic rocks. The overlying Western Lake St. Joseph Formation contains a lower member composed of predominantly calc-alkaline massive and pillowed basalts and an upper member composed of dacitic pyroclastic and epiclastic rocks. The overlying Carling Formation contains a volcanic member and a sedimentary member. The volcanic member is composed predominantly of high-Fe, low-K tholeiitic pillow breccias and dacitic to rhyolitic epiclastic and pyroclastic rocks. The sedimentary member consists of basal greywacke turbidites and laminated iron formation of economic potential overlain by chloritic classical turbidites. These sedimentary rocks are overlain by massive and cross-bedded arkosic greywackes which are in turn overlain by conglomerate and pebbly sandstone. The deformation of the rocks is expressed by isoclinal folding, most evident on Eagle Island, and development of the regional Lake St. Joseph Fault. Contact and regional metamorphism (lower to middle greenschist facies) have also affected the rocks. The primary structures, vertical and lateral variations in the felsic volcanic rocks of the Blackstone and Western Lake St. Joseph Formations indicate deposition on a subaqueous paleoslope. Similarly the felsic volcanic rocks of the Carling Formation indicate subaqueous deposition on a different paleoslope. The lithologies, primary structures, vertical and lateral variations of the units in the sedimentary member of the Carling Formation indicate deposition on a prograding submarine fan. Meyn and Palonen (1980) support this interpretation. Reconstruction of the ... Thesis Eagle Island Lakehead University Knowledge Commons Eagle Island ENVELOPE(-57.489,-57.489,-63.660,-63.660) Western Lake ENVELOPE(-128.106,-128.106,52.663,52.663) |
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Open Polar |
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Lakehead University Knowledge Commons |
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ftlakeheaduniv |
language |
English |
topic |
Geology Ontario Lake St. Joseph Region |
spellingShingle |
Geology Ontario Lake St. Joseph Region Berger, B. R. (Ben R.) Stratigraphy of the western Lake St. Joseph greenstone terrain, Northwestern Ontario |
topic_facet |
Geology Ontario Lake St. Joseph Region |
description |
The western Lake St. Joseph area in Northwestern Ontario is underlain by Archean metavolcanic and metasedimentary rocks. The strata, referred to as the Lake St. Joseph Group comprise three formations representative of mafic to felsic volcanic cyclicity. The Blackstone Formation, stratigraphically the lowest, contains a lower member composed of predominantly high-Mg, low-K tholeiitic pillowed basalts and an upper member composed of rhyoliticflows and pyroclastic rocks. The overlying Western Lake St. Joseph Formation contains a lower member composed of predominantly calc-alkaline massive and pillowed basalts and an upper member composed of dacitic pyroclastic and epiclastic rocks. The overlying Carling Formation contains a volcanic member and a sedimentary member. The volcanic member is composed predominantly of high-Fe, low-K tholeiitic pillow breccias and dacitic to rhyolitic epiclastic and pyroclastic rocks. The sedimentary member consists of basal greywacke turbidites and laminated iron formation of economic potential overlain by chloritic classical turbidites. These sedimentary rocks are overlain by massive and cross-bedded arkosic greywackes which are in turn overlain by conglomerate and pebbly sandstone. The deformation of the rocks is expressed by isoclinal folding, most evident on Eagle Island, and development of the regional Lake St. Joseph Fault. Contact and regional metamorphism (lower to middle greenschist facies) have also affected the rocks. The primary structures, vertical and lateral variations in the felsic volcanic rocks of the Blackstone and Western Lake St. Joseph Formations indicate deposition on a subaqueous paleoslope. Similarly the felsic volcanic rocks of the Carling Formation indicate subaqueous deposition on a different paleoslope. The lithologies, primary structures, vertical and lateral variations of the units in the sedimentary member of the Carling Formation indicate deposition on a prograding submarine fan. Meyn and Palonen (1980) support this interpretation. Reconstruction of the ... |
author2 |
Shegelski, Roy Kehlenbeck, Manfred |
format |
Thesis |
author |
Berger, B. R. (Ben R.) |
author_facet |
Berger, B. R. (Ben R.) |
author_sort |
Berger, B. R. (Ben R.) |
title |
Stratigraphy of the western Lake St. Joseph greenstone terrain, Northwestern Ontario |
title_short |
Stratigraphy of the western Lake St. Joseph greenstone terrain, Northwestern Ontario |
title_full |
Stratigraphy of the western Lake St. Joseph greenstone terrain, Northwestern Ontario |
title_fullStr |
Stratigraphy of the western Lake St. Joseph greenstone terrain, Northwestern Ontario |
title_full_unstemmed |
Stratigraphy of the western Lake St. Joseph greenstone terrain, Northwestern Ontario |
title_sort |
stratigraphy of the western lake st. joseph greenstone terrain, northwestern ontario |
publishDate |
1981 |
url |
http://knowledgecommons.lakeheadu.ca/handle/2453/2379 |
long_lat |
ENVELOPE(-57.489,-57.489,-63.660,-63.660) ENVELOPE(-128.106,-128.106,52.663,52.663) |
geographic |
Eagle Island Western Lake |
geographic_facet |
Eagle Island Western Lake |
genre |
Eagle Island |
genre_facet |
Eagle Island |
op_relation |
http://knowledgecommons.lakeheadu.ca/handle/2453/2379 |
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1766398767517401088 |