https://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&feed=atom&action=historyBedrock Geology UK North: Mesoproterozoic and Neoproterozoic - Revision history2024-03-28T10:02:33ZRevision history for this page on the wikiMediaWiki 1.41.0https://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=6677&oldid=prevDbk at 14:19, 29 January 20152015-01-29T14:19:34Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''The Grampian terrane extends south-westward across Jura and Islay'''. On Islay, the enigmatic Colonsay and Bowmore Sandstone groups may have affinity with the Grampian Group or may be older and more appropriately viewed as part of the Moine Supergroup. Farther south-west, in Northern Ireland, Dalradian rocks form the high ground of the Sperrin Mountains and their continuation into north-east County Antrim. Only the higher part of the Dalradian Supergroup is preserved there, the succession correlating lithologically with the upper part of the Argyll Group and much of the Southern Highlands Group ('''Plate P225420''').</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''The Grampian terrane extends south-westward across Jura and Islay'''. On Islay, the enigmatic Colonsay and Bowmore Sandstone groups may have affinity with the Grampian Group or may be older and more appropriately viewed as part of the Moine Supergroup. Farther south-west, in Northern Ireland, Dalradian rocks form the high ground of the Sperrin Mountains and their continuation into north-east County Antrim. Only the higher part of the Dalradian Supergroup is preserved there, the succession correlating lithologically with the upper part of the Argyll Group and much of the Southern Highlands Group ('''Plate P225420''').</div></td></tr>
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<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">==Bedrock Geology UK North - contents==</ins></div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Bedrock Geology UK North| 02]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Bedrock Geology UK North| 02]]</div></td></tr>
</table>Dbkhttps://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=5316&oldid=prevDbk at 08:04, 19 June 20142014-06-19T08:04:02Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==1600 to 542 million years ago==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==1600 to 542 million years ago==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma ([[File:P785799.jpg|'''Figure P785799a''']). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma ([[<ins style="font-weight: bold; text-decoration: none;">:</ins>File:P785799.jpg|'''Figure P785799a'''<ins style="font-weight: bold; text-decoration: none;">]</ins>]). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td></tr>
</table>Dbkhttps://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=5315&oldid=prevDbk at 08:03, 19 June 20142014-06-19T08:03:44Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma ([[File:P785799.jpg|'''Figure P785799a'''<del style="font-weight: bold; text-decoration: none;">]</del>]). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma ([[File:P785799.jpg|'''Figure P785799a''']). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td></tr>
</table>Dbkhttps://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=5314&oldid=prevDbk at 08:03, 19 June 20142014-06-19T08:03:10Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma ([['''Figure P785799a'''<del style="font-weight: bold; text-decoration: none;">|File:P785799.jpg</del>]]). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma ([[<ins style="font-weight: bold; text-decoration: none;">File:P785799.jpg|</ins>'''Figure P785799a''']]). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td></tr>
</table>Dbkhttps://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=5313&oldid=prevDbk at 08:02, 19 June 20142014-06-19T08:02:50Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==1600 to 542 million years ago==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==1600 to 542 million years ago==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma ('''Figure P785799a'''). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma (<ins style="font-weight: bold; text-decoration: none;">[[</ins>'''Figure P785799a'''<ins style="font-weight: bold; text-decoration: none;">|File:P785799.jpg]]</ins>). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td></tr>
</table>Dbkhttps://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=5312&oldid=prevDbk at 08:01, 19 June 20142014-06-19T08:01:25Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{BedN}}</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{BedN}}</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P785806.jpg|thumb|200px|P785806.]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P785806.jpg|thumb|200px|P785806.]]</div></td></tr>
</table>Dbkhttps://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=5184&oldid=prevJeth1 at 10:46, 12 June 20142014-06-12T10:46:08Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P219662.jpg|thumb|200px|Folded metapsammite and metapelite of the Glenfinnan Group, Moine Supergroup, north side of Loch Quoich, Lochaber. [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=27681&index=0&total=1&view=viewSearchItem P219662.]]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P219662.jpg|thumb|200px|Folded metapsammite and metapelite of the Glenfinnan Group, Moine Supergroup, north side of Loch Quoich, Lochaber. [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=27681&index=0&total=1&view=viewSearchItem P219662.]]]</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P008633.jpg|thumb|200px|Deformed micaceous metapsammite within the Dava-Glen Banchor succession (formerly known as the Central Highland Migmatite Complex) at Auchterteang, Inverness. [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=7347&index=0&total=1&view=viewSearchItem P008633.]]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P008633.jpg|thumb|200px|Deformed micaceous metapsammite within the Dava-Glen Banchor succession (formerly known as the Central Highland Migmatite Complex) at Auchterteang, Inverness. [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=7347&index=0&total=1&view=viewSearchItem P008633.]]]</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>'''The uniform, siliciclastic sequence''' contains few distinctive horizons that can be readily correlated over long distances, but three lithostratigraphical groups are recognised. The oldest of these, the Morar Group (X1) comprises a 5000 m-thick tripartite metapsammite-metapelite-metapsammite succession. The Glenfinnan Group (X2) is characterised by striped units of thinly interbanded metapsammites, metapelites and quartzites together with thick metapelite formations. The rocks show spectacular fold patterns at all scales ('''</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>'''The uniform, siliciclastic sequence''' contains few distinctive horizons that can be readily correlated over long distances, but three lithostratigraphical groups are recognised. The oldest of these, the Morar Group (X1) comprises a 5000 m-thick tripartite metapsammite-metapelite-metapsammite succession. The Glenfinnan Group (X2) is characterised by striped units of thinly interbanded metapsammites, metapelites and quartzites together with thick metapelite formations. The rocks show spectacular fold patterns at all scales ('''P219662''') but this high level of deformation means that estimates of original sedimentary thickness vary from 1000 to 4000 m. The youngest and largely psammitic Loch Eil Group (X3) may be up to 5000 m thick. A separate sequence of metapsammites and metapelites occurs in the south of Skye where the strata are sliced within the Moine Thrust Zone. This sequence forms the Tarskavaig Group (Y2) and it appears in some respects to be intermediate in character between the Torridonian and the Moine rocks of the mainland; it is also less metamorphosed than the latter.</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"> </del>P219662''') but this high level of deformation means that estimates of original sedimentary thickness vary from 1000 to 4000 m. The youngest and largely psammitic Loch Eil Group (X3) may be up to 5000 m thick. A separate sequence of metapsammites and metapelites occurs in the south of Skye where the strata are sliced within the Moine Thrust Zone. This sequence forms the Tarskavaig Group (Y2) and it appears in some respects to be intermediate in character between the Torridonian and the Moine rocks of the mainland; it is also less metamorphosed than the latter.</div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''South-east of the Great Glen Fault''', psammitic rocks lithologically similar to those of the Moine form a basement to the younger Dalradian Supergroup and are exposed in several inliers. In mainland Scotland, the inliers comprise the Dava–Glen Banchor succession (X1–3) of mainly gneissose metapsammite and some metapelite with quartzite ('''Plate P008633'''). On Colonsay and Islay, two enigmatic but Moine-like metasedimentary sequences (X) are inferred to overlie the Palaeoproterozoic Rhinns Complex: the Colonsay Group seen on both islands comprises up to 6000 m of siliciclastic strata with minor limestone, whilst on Islay (east of Loch Indaal) the arkosic and coarse-grained Bowmore Sandstone Group may exceed 4000 m in thickness. The stratigraphical correlation of both of these units is highly uncertain and whilst they are similar to some Moine lithologies there is also similarity with parts of the Dalradian sequence, notably the Grampian Group. An equally ambiguous and lithologically comparable sequence forms the Iona Group (X), but although Iona is only about 30 km north-north-west of Colonsay it lies to the north-west of the Great Glen Fault close to the Moine Thrust Zone.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''South-east of the Great Glen Fault''', psammitic rocks lithologically similar to those of the Moine form a basement to the younger Dalradian Supergroup and are exposed in several inliers. In mainland Scotland, the inliers comprise the Dava–Glen Banchor succession (X1–3) of mainly gneissose metapsammite and some metapelite with quartzite ('''Plate P008633'''). On Colonsay and Islay, two enigmatic but Moine-like metasedimentary sequences (X) are inferred to overlie the Palaeoproterozoic Rhinns Complex: the Colonsay Group seen on both islands comprises up to 6000 m of siliciclastic strata with minor limestone, whilst on Islay (east of Loch Indaal) the arkosic and coarse-grained Bowmore Sandstone Group may exceed 4000 m in thickness. The stratigraphical correlation of both of these units is highly uncertain and whilst they are similar to some Moine lithologies there is also similarity with parts of the Dalradian sequence, notably the Grampian Group. An equally ambiguous and lithologically comparable sequence forms the Iona Group (X), but although Iona is only about 30 km north-north-west of Colonsay it lies to the north-west of the Great Glen Fault close to the Moine Thrust Zone.</div></td></tr>
</table>Jeth1https://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=5183&oldid=prevJeth1 at 10:41, 12 June 20142014-06-12T10:41:47Z<p></p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Farther north, in Shetland''', probable Dalradian sequences are mostly separated from Moine-like rocks by the Boundary Zone Complex (X4), a tectonic intercalation of gneisses, schists and metapsammites of uncertain affinity. The Dalradian strata crop out on both sides of the Walls Boundary Fault. Those to the west, forming the Queyfirth Group (X), are metasedimentary and metavolcanic schists in a highly disrupted sequence that has been thrust westward over possible Moine rocks. To the east of the fault a more coherent sequence has a lower (Scatsta) division of quartzites, pelitic schists and gneisses and has probable affinity with the lower part of the Appin Group and with part of the Grampian Group. A middle (Whiteness) division of thick limestone units separated by mainly metapsammitic sequences probably correlates with the upper part of the Appin Group and lower part of the Argyll Group. The upper (Clift Hills) division of the Shetland Dalradian comprises the infill of a major extensional basin: mafic volcanic breccia and pillow lava are interbedded with phyllite and metapsammite, whilst the highest preserved strata are apparently interbedded with serpentinised ultramafic rock that may have originated as a lava. A general correlation with the upper part of the Argyll Group and the Southern Highland Group seems likely.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Farther north, in Shetland''', probable Dalradian sequences are mostly separated from Moine-like rocks by the Boundary Zone Complex (X4), a tectonic intercalation of gneisses, schists and metapsammites of uncertain affinity. The Dalradian strata crop out on both sides of the Walls Boundary Fault. Those to the west, forming the Queyfirth Group (X), are metasedimentary and metavolcanic schists in a highly disrupted sequence that has been thrust westward over possible Moine rocks. To the east of the fault a more coherent sequence has a lower (Scatsta) division of quartzites, pelitic schists and gneisses and has probable affinity with the lower part of the Appin Group and with part of the Grampian Group. A middle (Whiteness) division of thick limestone units separated by mainly metapsammitic sequences probably correlates with the upper part of the Appin Group and lower part of the Argyll Group. The upper (Clift Hills) division of the Shetland Dalradian comprises the infill of a major extensional basin: mafic volcanic breccia and pillow lava are interbedded with phyllite and metapsammite, whilst the highest preserved strata are apparently interbedded with serpentinised ultramafic rock that may have originated as a lava. A general correlation with the upper part of the Argyll Group and the Southern Highland Group seems likely.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>'''The Grampian terrane extends south-westward across Jura and Islay'''. On Islay, the enigmatic Colonsay and Bowmore Sandstone groups may have affinity with the Grampian Group or may be older and more appropriately viewed as part of the Moine Supergroup. Farther south-west, in Northern Ireland, Dalradian rocks form the high ground of the Sperrin Mountains and their continuation into north-east County Antrim. Only the higher part of the Dalradian Supergroup is preserved there, the succession correlating lithologically with the upper part of the Argyll Group and much of the Southern Highlands Group ('''Plate <del style="font-weight: bold; text-decoration: none;">P001560</del>''').</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>'''The Grampian terrane extends south-westward across Jura and Islay'''. On Islay, the enigmatic Colonsay and Bowmore Sandstone groups may have affinity with the Grampian Group or may be older and more appropriately viewed as part of the Moine Supergroup. Farther south-west, in Northern Ireland, Dalradian rocks form the high ground of the Sperrin Mountains and their continuation into north-east County Antrim. Only the higher part of the Dalradian Supergroup is preserved there, the succession correlating lithologically with the upper part of the Argyll Group and much of the Southern Highlands Group ('''Plate <ins style="font-weight: bold; text-decoration: none;">P225420</ins>''').</div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Bedrock Geology UK North| 02]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Bedrock Geology UK North| 02]]</div></td></tr>
</table>Jeth1https://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=5182&oldid=prevJeth1 at 10:37, 12 June 20142014-06-12T10:37:05Z<p></p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 10:37, 12 June 2014</td>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==1600 to 542 million years ago==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==1600 to 542 million years ago==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma ('''Figure <del style="font-weight: bold; text-decoration: none;">4a</del>'''). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>'''In Mesoproterozoic times''', by about 1200 million years ago (Ma), the deeply eroded Lewisian Gneiss Complex was becoming buried by a thick fluvial and lacustrine sequence of red, arkosic sandstones, informally referred to as the Torridonian. Despite lithological similarity throughout the sequence, there is little geological connection between its older and younger parts, an orogenic event intervening between their respective depositions. That was the Grenville Orogeny, which was brought about by the series of continental collisions that assembled the Rodinia ‘supercontinent’ between about 1100 and 1000 Ma ('''Figure <ins style="font-weight: bold; text-decoration: none;">P785799a</ins>'''). Its effects are now mainly preserved in Canada but a Scottish relict from this tectonic episode might be the enigmatic Strathy Complex, which now forms part of the north-east coastal region of Sutherland. Though dominantly made up of psammitic gneisses the complex also contains a variety of unusual rock types, including some that have a very high magnetite content, and all have experienced high-grade metamorphism between about 1100 and 1000 Ma.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''At about the same time as the younger''', Neoproterozoic Torridonian was accumulating, a marine, clastic shelf sequence of sandstone and mudstone also built up which now comprises the Moine Supergroup. Thereafter, the acceleration of rifting and the beginning of sea-floor spreading, which would eventually create the Iapetus Ocean, allowed passive margin and oceanic sedimentation accompanied by igneous activity. These events are recorded by the late Neoproterozoic to Cambrian, shallow- to deep-marine strata and volcanic rocks of the Dalradian Supergroup, and the Cambro-Ordovician marine shelf strata of the north-west Highlands.</div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P219662.jpg|thumb|200px|Folded metapsammite and metapelite of the Glenfinnan Group, Moine Supergroup, north side of Loch Quoich, Lochaber. [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=27681&index=0&total=1&view=viewSearchItem P219662.]]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P219662.jpg|thumb|200px|Folded metapsammite and metapelite of the Glenfinnan Group, Moine Supergroup, north side of Loch Quoich, Lochaber. [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=27681&index=0&total=1&view=viewSearchItem P219662.]]]</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P008633.jpg|thumb|200px|Deformed micaceous metapsammite within the Dava-Glen Banchor succession (formerly known as the Central Highland Migmatite Complex) at Auchterteang, Inverness. [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=7347&index=0&total=1&view=viewSearchItem P008633.]]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Image:P008633.jpg|thumb|200px|Deformed micaceous metapsammite within the Dava-Glen Banchor succession (formerly known as the Central Highland Migmatite Complex) at Auchterteang, Inverness. [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=7347&index=0&total=1&view=viewSearchItem P008633.]]]</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>'''The uniform, siliciclastic sequence''' contains few distinctive horizons that can be readily correlated over long distances, but three lithostratigraphical groups are recognised. The oldest of these, the Morar Group (X1) comprises a 5000 m-thick tripartite metapsammite-metapelite-metapsammite succession. The Glenfinnan Group (X2) is characterised by striped units of thinly interbanded metapsammites, metapelites and quartzites together with thick metapelite formations. The rocks show spectacular fold patterns at all scales ('''<del style="font-weight: bold; text-decoration: none;">Plate </del>P219662''') but this high level of deformation means that estimates of original sedimentary thickness vary from 1000 to 4000 m. The youngest and largely psammitic Loch Eil Group (X3) may be up to 5000 m thick. A separate sequence of metapsammites and metapelites occurs in the south of Skye where the strata are sliced within the Moine Thrust Zone. This sequence forms the Tarskavaig Group (Y2) and it appears in some respects to be intermediate in character between the Torridonian and the Moine rocks of the mainland; it is also less metamorphosed than the latter.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>'''The uniform, siliciclastic sequence''' contains few distinctive horizons that can be readily correlated over long distances, but three lithostratigraphical groups are recognised. The oldest of these, the Morar Group (X1) comprises a 5000 m-thick tripartite metapsammite-metapelite-metapsammite succession. The Glenfinnan Group (X2) is characterised by striped units of thinly interbanded metapsammites, metapelites and quartzites together with thick metapelite formations. The rocks show spectacular fold patterns at all scales ('''</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"> </ins>P219662''') but this high level of deformation means that estimates of original sedimentary thickness vary from 1000 to 4000 m. The youngest and largely psammitic Loch Eil Group (X3) may be up to 5000 m thick. A separate sequence of metapsammites and metapelites occurs in the south of Skye where the strata are sliced within the Moine Thrust Zone. This sequence forms the Tarskavaig Group (Y2) and it appears in some respects to be intermediate in character between the Torridonian and the Moine rocks of the mainland; it is also less metamorphosed than the latter.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''South-east of the Great Glen Fault''', psammitic rocks lithologically similar to those of the Moine form a basement to the younger Dalradian Supergroup and are exposed in several inliers. In mainland Scotland, the inliers comprise the Dava–Glen Banchor succession (X1–3) of mainly gneissose metapsammite and some metapelite with quartzite ('''Plate P008633'''). On Colonsay and Islay, two enigmatic but Moine-like metasedimentary sequences (X) are inferred to overlie the Palaeoproterozoic Rhinns Complex: the Colonsay Group seen on both islands comprises up to 6000 m of siliciclastic strata with minor limestone, whilst on Islay (east of Loch Indaal) the arkosic and coarse-grained Bowmore Sandstone Group may exceed 4000 m in thickness. The stratigraphical correlation of both of these units is highly uncertain and whilst they are similar to some Moine lithologies there is also similarity with parts of the Dalradian sequence, notably the Grampian Group. An equally ambiguous and lithologically comparable sequence forms the Iona Group (X), but although Iona is only about 30 km north-north-west of Colonsay it lies to the north-west of the Great Glen Fault close to the Moine Thrust Zone.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''South-east of the Great Glen Fault''', psammitic rocks lithologically similar to those of the Moine form a basement to the younger Dalradian Supergroup and are exposed in several inliers. In mainland Scotland, the inliers comprise the Dava–Glen Banchor succession (X1–3) of mainly gneissose metapsammite and some metapelite with quartzite ('''Plate P008633'''). On Colonsay and Islay, two enigmatic but Moine-like metasedimentary sequences (X) are inferred to overlie the Palaeoproterozoic Rhinns Complex: the Colonsay Group seen on both islands comprises up to 6000 m of siliciclastic strata with minor limestone, whilst on Islay (east of Loch Indaal) the arkosic and coarse-grained Bowmore Sandstone Group may exceed 4000 m in thickness. The stratigraphical correlation of both of these units is highly uncertain and whilst they are similar to some Moine lithologies there is also similarity with parts of the Dalradian sequence, notably the Grampian Group. An equally ambiguous and lithologically comparable sequence forms the Iona Group (X), but although Iona is only about 30 km north-north-west of Colonsay it lies to the north-west of the Great Glen Fault close to the Moine Thrust Zone.</div></td></tr>
</table>Jeth1https://earthwise.bgs.ac.uk/index.php?title=Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic&diff=5089&oldid=prevDbk: Protected "Bedrock Geology UK North: Mesoproterozoic and Neoproterozoic" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite)) [cascading]2014-06-11T12:19:45Z<p>Protected "<a href="/index.php/Bedrock_Geology_UK_North:_Mesoproterozoic_and_Neoproterozoic" title="Bedrock Geology UK North: Mesoproterozoic and Neoproterozoic">Bedrock Geology UK North: Mesoproterozoic and Neoproterozoic</a>" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite)) [cascading]</p>
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<td colspan="1" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 12:19, 11 June 2014</td>
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