The Rapitan Group: Relevance To The Global Association Of Late Proterozoic Glaciation And Iron-formation
The Rapitan Group (770-600 Ma) is a glacio-marine sedimentary sequence cropping out in Mackenzie and Wernecke Mountains. A marked basal unconformity marks the culmination of a regional extensional event, the Hayhook Orogeny. The lowest unit, the Mount Berg Formation, is a grey-green mixtite seen onl...
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ftunivwestonta:oai:ir.lib.uwo.ca:digitizedtheses-2385 2023-10-01T03:57:19+02:00 The Rapitan Group: Relevance To The Global Association Of Late Proterozoic Glaciation And Iron-formation Yeo, Gary Matthew 1984-01-01T08:00:00Z application/pdf https://ir.lib.uwo.ca/digitizedtheses/1386 https://ir.lib.uwo.ca/context/digitizedtheses/article/2385/viewcontent/NK61753.PDF unknown Scholarship@Western https://ir.lib.uwo.ca/digitizedtheses/1386 https://ir.lib.uwo.ca/context/digitizedtheses/article/2385/viewcontent/NK61753.PDF Digitized Theses Geology text 1984 ftunivwestonta 2023-09-03T07:19:30Z The Rapitan Group (770-600 Ma) is a glacio-marine sedimentary sequence cropping out in Mackenzie and Wernecke Mountains. A marked basal unconformity marks the culmination of a regional extensional event, the Hayhook Orogeny. The lowest unit, the Mount Berg Formation, is a grey-green mixtite seen only in the southern Mackenzies. Conformably above this, the Sayunei Formation is dominated by maroon, silty rhythmites with abundant dropstones. Conformably overlying this, the Shezal Formation successively comprises maroon and greenish-grey mixtites. The Sayunei and Shezal Formations crop out nearly continuously throughout the southern and central Mackenzie Mountains. An homologous succession of rhythmites and mixtites is seen in the Upper Tindir Group of eastern Alaska. In the northern Mackenzies, however, only red and greenish-grey mixtites occur. Jasper-hematite iron-formulation of probable rift-related, hydrothermal origin is found in the red mixtites of the northern Mackenzies as well as in the upper Sayunei and Upper Tindir rhythmites. In Mackenzie Mountains the stratigraphic sequence is interpreted to represent an earlier, local(?) glacial advance (Mount Berg) separated from a later, more extensive one (Shezal) by an interstadial period (Sayunei). Submarine hydrothermal activity and possible volcanism are inferred to have taken place at the same time as the iron-formation was deposited.;On nearly every continent late Proterozoic glacial and glacio-marine sequences, commonly bearing iron-formation of hydrothermal origin, were deposited following major episodes of faulting and extensional tectonism. Diachroneity of these sequences over some 400 Ma suggests that widespread glaciations accompanied a global episode of continental disintegration. The development of new seaways in combination with extensive continental uplift resulted in global(?) climatic changes, including glaciation. Rift related hydrothermal activity resulted in local deposition of iron-formation. Hence, both glacial deposits and iron-formation in ... Text Mackenzie mountains Alaska The University of Western Ontario: Scholarship@Western Mount Berg ENVELOPE(-126.303,-126.303,62.533,62.533) Wernecke ENVELOPE(-135.271,-135.271,63.952,63.952) Wernecke Mountains ENVELOPE(-134.254,-134.254,64.833,64.833) |
institution |
Open Polar |
collection |
The University of Western Ontario: Scholarship@Western |
op_collection_id |
ftunivwestonta |
language |
unknown |
topic |
Geology |
spellingShingle |
Geology Yeo, Gary Matthew The Rapitan Group: Relevance To The Global Association Of Late Proterozoic Glaciation And Iron-formation |
topic_facet |
Geology |
description |
The Rapitan Group (770-600 Ma) is a glacio-marine sedimentary sequence cropping out in Mackenzie and Wernecke Mountains. A marked basal unconformity marks the culmination of a regional extensional event, the Hayhook Orogeny. The lowest unit, the Mount Berg Formation, is a grey-green mixtite seen only in the southern Mackenzies. Conformably above this, the Sayunei Formation is dominated by maroon, silty rhythmites with abundant dropstones. Conformably overlying this, the Shezal Formation successively comprises maroon and greenish-grey mixtites. The Sayunei and Shezal Formations crop out nearly continuously throughout the southern and central Mackenzie Mountains. An homologous succession of rhythmites and mixtites is seen in the Upper Tindir Group of eastern Alaska. In the northern Mackenzies, however, only red and greenish-grey mixtites occur. Jasper-hematite iron-formulation of probable rift-related, hydrothermal origin is found in the red mixtites of the northern Mackenzies as well as in the upper Sayunei and Upper Tindir rhythmites. In Mackenzie Mountains the stratigraphic sequence is interpreted to represent an earlier, local(?) glacial advance (Mount Berg) separated from a later, more extensive one (Shezal) by an interstadial period (Sayunei). Submarine hydrothermal activity and possible volcanism are inferred to have taken place at the same time as the iron-formation was deposited.;On nearly every continent late Proterozoic glacial and glacio-marine sequences, commonly bearing iron-formation of hydrothermal origin, were deposited following major episodes of faulting and extensional tectonism. Diachroneity of these sequences over some 400 Ma suggests that widespread glaciations accompanied a global episode of continental disintegration. The development of new seaways in combination with extensive continental uplift resulted in global(?) climatic changes, including glaciation. Rift related hydrothermal activity resulted in local deposition of iron-formation. Hence, both glacial deposits and iron-formation in ... |
format |
Text |
author |
Yeo, Gary Matthew |
author_facet |
Yeo, Gary Matthew |
author_sort |
Yeo, Gary Matthew |
title |
The Rapitan Group: Relevance To The Global Association Of Late Proterozoic Glaciation And Iron-formation |
title_short |
The Rapitan Group: Relevance To The Global Association Of Late Proterozoic Glaciation And Iron-formation |
title_full |
The Rapitan Group: Relevance To The Global Association Of Late Proterozoic Glaciation And Iron-formation |
title_fullStr |
The Rapitan Group: Relevance To The Global Association Of Late Proterozoic Glaciation And Iron-formation |
title_full_unstemmed |
The Rapitan Group: Relevance To The Global Association Of Late Proterozoic Glaciation And Iron-formation |
title_sort |
rapitan group: relevance to the global association of late proterozoic glaciation and iron-formation |
publisher |
Scholarship@Western |
publishDate |
1984 |
url |
https://ir.lib.uwo.ca/digitizedtheses/1386 https://ir.lib.uwo.ca/context/digitizedtheses/article/2385/viewcontent/NK61753.PDF |
long_lat |
ENVELOPE(-126.303,-126.303,62.533,62.533) ENVELOPE(-135.271,-135.271,63.952,63.952) ENVELOPE(-134.254,-134.254,64.833,64.833) |
geographic |
Mount Berg Wernecke Wernecke Mountains |
geographic_facet |
Mount Berg Wernecke Wernecke Mountains |
genre |
Mackenzie mountains Alaska |
genre_facet |
Mackenzie mountains Alaska |
op_source |
Digitized Theses |
op_relation |
https://ir.lib.uwo.ca/digitizedtheses/1386 https://ir.lib.uwo.ca/context/digitizedtheses/article/2385/viewcontent/NK61753.PDF |
_version_ |
1778528496973250560 |