Dbk at 14:32, 5 May 2016

2016-05-05T14:32:42Z

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	\| valign="top" \| Regional uplift and erosion of Skiddaw Group. Local evidence of fluvial and ?marine deposition		\| valign="top" \| Regional uplift and erosion of Skiddaw Group. Local evidence of fluvial and ?marine deposition
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Dbk at 14:32, 5 May 2016

2016-05-05T14:32:19Z

← Older revision		Revision as of 15:32, 5 May 2016
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	\| valign="top" \| Regional uplift and erosion of Skiddaw Group. Local evidence of fluvial and ?marine deposition		\| valign="top" \| Regional uplift and erosion of Skiddaw Group. Local evidence of fluvial and ?marine deposition
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2016-05-05T14:30:48Z

Created page with "{| class="wikitable" style="width: 700px;" |+ '''P916111''' Summary of the principal phases in the development of the Borrowdale Volcanic Group. | valign="top" colspan="2" | '..."

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{| class="wikitable" style="width: 700px;"
|+ '''P916111''' Summary of the principal phases in the development of the Borrowdale Volcanic Group.
| valign="top" colspan="2" | '''Development phase'''
| valign="top" | '''Location, lithofacies and thickness'''
| valign="top" | '''Main events'''
|-
| valign="top" | 11
| valign="top" | Marine transgression
| valign="top" | Post-BVG<br>Marginal to Lake District in late Caradoc times; S Lake District in Ashgill
| valign="top" | Thermal contraction of granites on cooling allowed progressive marine transgression on to Lake District block
|-
| valign="top" | 10
| valign="top" | Batholith emplacement
| valign="top" | Beneath Scafell and Haweswater calderas. Granite, microgranite and granodiorite
| valign="top" | Injection of thick tabular granite sheets resulting in uplift and erosion of volcanic field
|-
| valign="top" | 9b
| valign="top" | Cross Fell
| valign="top" | Cross Fell Inlier. Volcaniclastic sedimentary and pyroclastic rocks, one major sheet of silicic lapilli-tuff; >1100 m
| valign="top" | Volcaniclastic sedimentation interspersed with sporadic pyroclastic eruptions
|-
| valign="top" | 9a
| valign="top" | Gosforth succession
| 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
|-
| valign="top" | 8
| valign="top" | Helvellyn Basin succession
| valign="top" | Central Fells, Helvellyn Basin. Stratiform units of volcaniclastic sandstone and breccia; subordinate pyroclastic units and a silicic lava; >1600 m
| 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
|-
| valign="top" | 7
| valign="top" | Lincomb Tarns ignimbrite
| 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
|-
| valign="top" | 6
| valign="top" | Ambleside Basin succession
| valign="top" | Central south Lake District. Oversteps 5a, b, 4a; bedded volcaniclastic sandstone and breccia; >1100 m
| valign="top" | Fluviolacustrine sedimentation dominated by catastrophic influx of eruption generated sediment-gravity flows.<br>?Associated with emplacement of many sills
|-
| valign="top" | 5b
| valign="top" | Kentmere Basin succession
| valign="top" | SE Lake District. Bedded units of volcaniclastic sedimentary rocks, intercalated with sheets of pyroclastic rocks, some lavas; <2800 m
| valign="top" | Intermediate to silicic ignimbrites; andesitic tuff-cone and lava-shield; fluviolacustrine sedimentation at base; major centre for sill emplacement
|-
| valign="top" | 5a
| valign="top" | Duddon Basin succession
| valign="top" | SW Lake District. Stratified sequence of volcaniclastic sedimentary rocks, andesitic and rhyolitic pyroclastic rocks and andesite lavas
| 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?
|-
| valign="top" | 4b
| valign="top" | Haweswater Caldera succession
| valign="top" | Ullswater, Haweswater. Stratified sheets of dacitic and rhyolitic pyroclastic rocks; garnetiferous; <650 m
| valign="top" | Large magnitude silicic pyroclastic activity; large-volume ignimbrites associated with caldera collapse
|-
| valign="top" | 4a
| valign="top" | Scafell Caldera succession
| 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
|-
| valign="top" | 3
| valign="top" | Monogenetic andesite volcanoes
| 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
|-
| valign="top" | 2
| valign="top" | Initial phreato- magmatism
| 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)
|-
| valign="top" | 1
| valign="top" | Pre-volcanic
| valign="top" | Latterbarrow Sandstone and Overwater Siltstone locally preserved; 0–400 m
| valign="top" | Regional uplift and erosion of Skiddaw Group. Local evidence of fluvial and ?marine deposition
|}

Template:P916111 - Revision history

Dbk at 14:32, 5 May 2016

Dbk at 14:32, 5 May 2016

Dbk: Created page with "{| class="wikitable" style="width: 700px;" |+ '''P916111''' Summary of the principal phases in the development of the Borrowdale Volcanic Group. | valign="top" colspan="2" | '..."