Mesozoic geology of UK

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Mesozoic geology of UK 1. Overview 2.
Global tectonics 3. Sea level changes 4.
Triassic geology 5. Jurassic geology 6.
Cretaceous geology 7. Overview
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1. Overview
Breakup of Pangaea
Mass extinctions
High sea levels
65 Ma
Cretaceous
144 Ma
Jurassic
Mesozoic
213 Ma
Triassic
248 Ma
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2. Global tectonics
North Sea rift
Cretaceous Jurassic Triassic
Tethys Ocean
North Atlantic
North Sea rift
Laurentia
Tethys Ocean
Central Atlantic
Gondwana
Tethys Ocean
Variscan mountains
Pangaea
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3. Sea level changes
Global sea level rise to 300m
Thermal dome
Hot aesthenosphere
North Atlantic
Local isostatic (tectonic) sea level falls
North Sea
Spreading ridge
Fast spread
Slow spread
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4. Triassic geology
Late Triassic Rhaetic Tea Green
Marls Middle Triassic Keuper Marl Whiff
of the Sea Early Triassic Bunter
Sandstone Arid, terrestrial, coarse.
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5. Jurassic geology
Late Jurassic Shelf seas cover UK. No coarse
clastic supply High sea levels high marine
productivity oil Middle Jurassic Thermal
doming in North Sea. Deltas develop
oil reservoirs. Isostatic sea level fall Early
Jurassic Liassic clay and lime Low clastic
supply, tectonically quiet.
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6. Cretaceous geology
Late Cretaceous Chalk - highest sea level in
Phanerozoic. No clastic input Phytoplankton
blooms provide lime and silica Middle
Cretaceous Greensand - major eustatic marine
transgression North Sea and Atlantic
connect Early Cretaceous Wealden - thermal
doming in Atlantic Isostatic fall in sea
level Deltas and swamps in S. England
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7. Overview
A. Pangaea breaks up via Central and North
Atlantic Tethys Ocean North Sea (failed
rift) B. Eustatic sea level rise from fast
rates of ridge spreading Isostatic sea
level fall from thermal doming close to UK C.
Clastic supply wanes, Calcareous
sedimentation increases D. Begins and ends
with mass extinction