Table 2: Difference between revisions
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{| class="wikitable" style="width: 700px;" | |||
| valign="top" colspan="2" | '''Development phase''' | |||
{| class="wikitable" | | valign="top" | '''Location, lithofacies and thickness''' | ||
| colspan="2" | '''Development phase''' | | valign="top" | '''Main events''' | ||
| '''Location, lithofacies and thickness''' | |||
| '''Main events''' | |||
|- | |- | ||
| valign="top" | 11 | | valign="top" | 11 | ||
| Marine transgression | | valign="top" | Marine transgression | ||
| Post-BVG<br>Marginal to Lake District in late Caradoc times; S Lake District in Ashgill | | valign="top" | Post-BVG<br>Marginal to Lake District in late Caradoc times; S Lake District in Ashgill | ||
| Thermal contraction of granites on cooling allowed progressive marine transgression on to Lake District block | | valign="top" | Thermal contraction of granites on cooling allowed progressive marine transgression on to Lake District block | ||
|- | |- | ||
| 10 | | valign="top" | 10 | ||
| Batholith emplacement | | valign="top" | Batholith emplacement | ||
| Beneath Scafell and Haweswater calderas. Granite, microgranite and granodiorite | | valign="top" | Beneath Scafell and Haweswater calderas. Granite, microgranite and granodiorite | ||
| Injection of thick tabular granite sheets resulting in uplift and erosion of volcanic field | | valign="top" | Injection of thick tabular granite sheets resulting in uplift and erosion of volcanic field | ||
|- | |- | ||
| 9b | | valign="top" | 9b | ||
| Cross Fell | | valign="top" | Cross Fell | ||
| Cross Fell Inlier. Volcaniclastic sedimentary and pyroclastic rocks, one major sheet of silicic lapilli-tuff; >1100 m | | valign="top" | Cross Fell Inlier. Volcaniclastic sedimentary and pyroclastic rocks, one major sheet of silicic lapilli-tuff; >1100 m | ||
| Volcaniclastic sedimentation interspersed with sporadic pyroclastic eruptions | | valign="top" | Volcaniclastic sedimentation interspersed with sporadic pyroclastic eruptions | ||
|- | |- | ||
| 9a | | valign="top" | 9a | ||
| Gosforth succession | | valign="top" | Gosforth succession | ||
| West Cumbria: stratiform sequence of andesitic and dacitic lapilli-tuff with | | valign="top" | West Cumbria: stratiform sequence of andesitic and dacitic lapilli-tuff with subordinate volcaniclastic sedimentary rocks and andesite sills; >2500 m | ||
| valign="top" | Dominantly explosive intermediate and silicic pyroclastic activity producing many densely welded ignimbrites; ?caldera related | |||
subordinate volcaniclastic sedimentary rocks and andesite sills; >2500 m | |||
| Dominantly explosive intermediate and silicic pyroclastic activity producing many densely welded ignimbrites; ?caldera related | |||
|- | |- | ||
| 8 | | valign="top" | 8 | ||
| Helvellyn Basin succession | | valign="top" | Helvellyn Basin succession | ||
| Central Fells, Helvellyn Basin. Stratiform units of volcaniclastic sandstone and breccia; subordinate pyroclastic units and a silicic lava; >1600 m | | valign="top" | Central Fells, Helvellyn Basin. Stratiform units of volcaniclastic sandstone and breccia; subordinate pyroclastic units and a silicic lava; >1600 m | ||
| Fluviolacustrine sedimentation within extensional basin with episodic catastrophic influx of eruption-generated sediment-gravity flows; interrupted by small andesite lava shields and ignimbrite emplacement | | valign="top" | Fluviolacustrine sedimentation within extensional basin with episodic catastrophic influx of eruption-generated sediment-gravity flows; interrupted by small andesite lava shields and ignimbrite emplacement | ||
|- | |- | ||
| 7 | | valign="top" | 7 | ||
| Lincomb Tarns ignimbrite | | valign="top" | Lincomb Tarns ignimbrite | ||
| Throughout BVG. | | valign="top" | Throughout BVG.<br>Eutaxitic and parataxitic dacitic lapilli-tuff; columnar jointed; >800 m | ||
| valign="top" | Most widespread and voluminous ignimbrite within BVG. Large magnitude silicic pyroclastic eruptions forming ignimbrite shield | |||
Eutaxitic and parataxitic dacitic lapilli-tuff; columnar jointed; >800 m | |||
| Most widespread and voluminous ignimbrite within BVG. Large magnitude silicic pyroclastic eruptions forming ignimbrite shield | |||
|- | |- | ||
| 6 | | valign="top" | 6 | ||
| Ambleside Basin succession | | valign="top" | Ambleside Basin succession | ||
| Central south Lake District. Oversteps 5a, b, 4a; bedded volcaniclastic sandstone and breccia; >1100 m | | valign="top" | Central south Lake District. Oversteps 5a, b, 4a; bedded volcaniclastic sandstone and breccia; >1100 m | ||
| Fluviolacustrine sedimentation dominated by catastrophic influx of eruption generated sediment-gravity flows. | | valign="top" | Fluviolacustrine sedimentation dominated by catastrophic influx of eruption generated sediment-gravity flows.<br>?Associated with emplacement of many sills | ||
?Associated with emplacement of many sills | |||
|- | |- | ||
| 5b | | valign="top" | 5b | ||
| Kentmere Basin succession | | valign="top" | Kentmere Basin succession | ||
| SE Lake District. Bedded units of volcaniclastic sedimentary rocks, intercalated with sheets of pyroclastic rocks, some lavas; <2800 m | | valign="top" | SE Lake District. Bedded units of volcaniclastic sedimentary rocks, intercalated with sheets of pyroclastic rocks, some lavas; <2800 m | ||
| Intermediate to silicic ignimbrites; andesitic tuff-cone and lava-shield; fluviolacustrine sedimentation at base; major centre for sill emplacement | | valign="top" | Intermediate to silicic ignimbrites; andesitic tuff-cone and lava-shield; fluviolacustrine sedimentation at base; major centre for sill emplacement | ||
|- | |- | ||
| 5a | | valign="top" | 5a | ||
| Duddon Basin succession | | valign="top" | Duddon Basin succession | ||
| SW Lake District. Stratified sequence of volcaniclastic sedimentary rocks, andesitic and rhyolitic pyroclastic rocks and andesite lavas | | valign="top" | SW Lake District. Stratified sequence of volcaniclastic sedimentary rocks, andesitic and rhyolitic pyroclastic rocks and andesite lavas | ||
| Explosive intermediate ?caldera-related pyroclastic eruptions; succeeded | | valign="top" | Explosive intermediate ?caldera-related pyroclastic eruptions; succeeded by catastrophic eruption-generated sedimentation in extensional basin, episodically interrupted by emplacement of silicic ignimbrites. Many sills emplaced? | ||
by catastrophic eruption-generated sedimentation in extensional basin, episodically interrupted by emplacement of silicic ignimbrites. Many sills emplaced? | |||
|- | |- | ||
| 4b | | valign="top" | 4b | ||
| Haweswater Caldera succession | | valign="top" | Haweswater Caldera succession | ||
| Ullswater, Haweswater. Stratified sheets of dacitic and rhyolitic pyroclastic rocks; garnetiferous; <650 m | | valign="top" | Ullswater, Haweswater. Stratified sheets of dacitic and rhyolitic pyroclastic rocks; garnetiferous; <650 m | ||
| Large magnitude silicic pyroclastic activity; large-volume ignimbrites associated with caldera collapse | | valign="top" | Large magnitude silicic pyroclastic activity; large-volume ignimbrites associated with caldera collapse | ||
|- | |- | ||
| 4a | | valign="top" | 4a | ||
| Scafell Caldera succession | | valign="top" | Scafell Caldera succession | ||
| Central Fells. Stratified sheets of andesitic, dacitic and rhyolitic pyroclastic rocks; dacite and rhyolite lavas; garnetiferous. Overlain by bedded volcaniclastic sandstone and breccia; | | valign="top" | Central Fells. Stratified sheets of andesitic, dacitic and rhyolitic pyroclastic rocks; dacite and rhyolite lavas; garnetiferous. Overlain by bedded volcaniclastic sandstone and breccia; >700 m | ||
| valign="top" | Andesitic phreatoplinian eruption followed by sequence of large volume silicic ignimbrites with associated development of piecemeal hydrovolcanic caldera; postcaldera silicic lavas and caldera basin sedimentary infill | |||
>700 m | |||
| Andesitic phreatoplinian eruption followed by sequence of large volume silicic ignimbrites with associated development of piecemeal hydrovolcanic caldera; postcaldera silicic lavas and caldera basin sedimentary infill | |||
|- | |- | ||
| 3 | | valign="top" | 3 | ||
| Monogenetic andesite volcanoes | | valign="top" | Monogenetic andesite volcanoes | ||
| Throughout BVG. Andesite lavas and sills, some of basalt, basaltic andesite and dacite; subordinate tuff, lapilli-tuff and sandstone; some units garnetiferous; | | valign="top" | Throughout BVG. Andesite lavas and sills, some of basalt, basaltic andesite and dacite; subordinate tuff, lapilli-tuff and sandstone; some units garnetiferous; <2700 m | ||
| valign="top" | Construction of subaerial, multiple-vent, low-profile andesite volcanoes; some high volume basalt lava-fields; episodic silicic volcanism including possible caldera formation | |||
< 2700 m | |||
| Construction of subaerial, multiple-vent, low-profile andesite volcanoes; some high volume basalt lava-fields; episodic silicic volcanism including possible caldera formation | |||
|- | |- | ||
| 2 | | valign="top" | 2 | ||
| Initial phreato- magmatism | | valign="top" | Initial phreato- magmatism | ||
| Devoke Water, Calder Bridge, Millom Park, Ullswater. Mafic lapilli-tuff and | | valign="top" | Devoke Water, Calder Bridge, Millom Park, Ullswater. Mafic lapilli-tuff and tuff-breccia; contains much mudstone and sandstone from Skiddaw Group; <600 m | ||
| valign="top" | Hydrovolcanism, construction of tuff-cone field(s) | |||
tuff-breccia; contains much mudstone and sandstone from Skiddaw Group; <600 m | |||
| Hydrovolcanism, construction of tuff-cone field(s) | |||
|- | |- | ||
| 1 | | valign="top" | 1 | ||
| Pre-volcanic | | valign="top" | Pre-volcanic | ||
| Latterbarrow Sandstone and Overwater Siltstone locally preserved; 0–400 m | | valign="top" | Latterbarrow Sandstone and Overwater Siltstone locally preserved; 0–400 m | ||
| Regional uplift and erosion of Skiddaw Group. Local evidence of fluvial and | | valign="top" | Regional uplift and erosion of Skiddaw Group. Local evidence of fluvial and ?marine deposition | ||
?marine deposition | |||
|} | |} |
Latest revision as of 15:28, 5 May 2016
Development phase | Location, lithofacies and thickness | Main events | |
11 | Marine transgression | Post-BVG Marginal to Lake District in late Caradoc times; S Lake District in Ashgill |
Thermal contraction of granites on cooling allowed progressive marine transgression on to Lake District block |
10 | Batholith emplacement | Beneath Scafell and Haweswater calderas. Granite, microgranite and granodiorite | Injection of thick tabular granite sheets resulting in uplift and erosion of volcanic field |
9b | Cross Fell | Cross Fell Inlier. Volcaniclastic sedimentary and pyroclastic rocks, one major sheet of silicic lapilli-tuff; >1100 m | Volcaniclastic sedimentation interspersed with sporadic pyroclastic eruptions |
9a | Gosforth succession | West Cumbria: stratiform sequence of andesitic and dacitic lapilli-tuff with subordinate volcaniclastic sedimentary rocks and andesite sills; >2500 m | Dominantly explosive intermediate and silicic pyroclastic activity producing many densely welded ignimbrites; ?caldera related |
8 | Helvellyn Basin succession | Central Fells, Helvellyn Basin. Stratiform units of volcaniclastic sandstone and breccia; subordinate pyroclastic units and a silicic lava; >1600 m | Fluviolacustrine sedimentation within extensional basin with episodic catastrophic influx of eruption-generated sediment-gravity flows; interrupted by small andesite lava shields and ignimbrite emplacement |
7 | Lincomb Tarns ignimbrite | Throughout BVG. Eutaxitic and parataxitic dacitic lapilli-tuff; columnar jointed; >800 m |
Most widespread and voluminous ignimbrite within BVG. Large magnitude silicic pyroclastic eruptions forming ignimbrite shield |
6 | Ambleside Basin succession | Central south Lake District. Oversteps 5a, b, 4a; bedded volcaniclastic sandstone and breccia; >1100 m | Fluviolacustrine sedimentation dominated by catastrophic influx of eruption generated sediment-gravity flows. ?Associated with emplacement of many sills |
5b | Kentmere Basin succession | SE Lake District. Bedded units of volcaniclastic sedimentary rocks, intercalated with sheets of pyroclastic rocks, some lavas; <2800 m | Intermediate to silicic ignimbrites; andesitic tuff-cone and lava-shield; fluviolacustrine sedimentation at base; major centre for sill emplacement |
5a | Duddon Basin succession | SW Lake District. Stratified sequence of volcaniclastic sedimentary rocks, andesitic and rhyolitic pyroclastic rocks and andesite lavas | Explosive intermediate ?caldera-related pyroclastic eruptions; succeeded by catastrophic eruption-generated sedimentation in extensional basin, episodically interrupted by emplacement of silicic ignimbrites. Many sills emplaced? |
4b | Haweswater Caldera succession | Ullswater, Haweswater. Stratified sheets of dacitic and rhyolitic pyroclastic rocks; garnetiferous; <650 m | Large magnitude silicic pyroclastic activity; large-volume ignimbrites associated with caldera collapse |
4a | Scafell Caldera succession | Central Fells. Stratified sheets of andesitic, dacitic and rhyolitic pyroclastic rocks; dacite and rhyolite lavas; garnetiferous. Overlain by bedded volcaniclastic sandstone and breccia; >700 m | Andesitic phreatoplinian eruption followed by sequence of large volume silicic ignimbrites with associated development of piecemeal hydrovolcanic caldera; postcaldera silicic lavas and caldera basin sedimentary infill |
3 | Monogenetic andesite volcanoes | Throughout BVG. Andesite lavas and sills, some of basalt, basaltic andesite and dacite; subordinate tuff, lapilli-tuff and sandstone; some units garnetiferous; <2700 m | Construction of subaerial, multiple-vent, low-profile andesite volcanoes; some high volume basalt lava-fields; episodic silicic volcanism including possible caldera formation |
2 | Initial phreato- magmatism | Devoke Water, Calder Bridge, Millom Park, Ullswater. Mafic lapilli-tuff and tuff-breccia; contains much mudstone and sandstone from Skiddaw Group; <600 m | Hydrovolcanism, construction of tuff-cone field(s) |
1 | Pre-volcanic | Latterbarrow Sandstone and Overwater Siltstone locally preserved; 0–400 m | Regional uplift and erosion of Skiddaw Group. Local evidence of fluvial and ?marine deposition |