Transcript No Slide Title

Lower Palaeozoic history of UK
1. Continental motions
2. Cambrian events
3. Ordovician events The Grampian Orogeny
4. Ordovician and Silurian The history of the Iapetus Ocean
5. Silurian - Iapetus closure
6. Devonian - Acadian Orogeny
Development of major
continent
7. Building the UK
1. Continental motions
Late Silurian
Laurentia
Armorica
Avalonia
Ordovician
Baltica
Laurentia
Avalonia
Acadia
Gondwana
Iapetus Ocean
England
and Wales
Late
Precambrian
Scotland
‘Vendian’
supercontinent
South
pole
2. Cambrian events
Laurentia
Passive margin carbonates - Durness Limestone
Passive margin
clastics
Avalonia
Cambrian - Breakup of Vendian supercontinent
- Ocean forms between Laurentia,
Gondwana and Baltica
- volcanic arcs and continental
fragments
within ocean
3. Early Ordovician events
Laurentia
Acadia
Passive margin carbonates
Ballantrae ophiolite
Dalradian
metamorphism
Highland
border ophiolite
The Grampian orogeny
Passive margin
clastics
Avalonia
Ordovician - Arcs and continental fragments
begin to collide
- mixture of marine sediments and
volcanics
4. Ordovician/ early Silurian events
Laurentia
Accretionary prism scraped off subducting
slab. Fault bounded units
young south, but within tracts
rocks young northwards
Midland Valley
Southern Uplands
Iapetus Ocean
Lake District
Avalonia
Avalonia
Spreading ridge
Welsh Basin
Silurian - early marine sedimentation
and subduction related
volcanism
5. Iapetus closure
Moine
thrust
Great Highland Southern
Glen Boundary Uplands
Highlands
Major terrane
boundaries
Midland Southern Lakes Wales
valley
Uplands
Sinistral movements on
major faults
Oblique
collision
Silurian - ends in soft sediment and then
continental collision - Caledonian
orogeny
- this marks the closure of Iapetus
6. Devonian events
Scotland
England
Laurentian margin
Rheic Ocean
Lizard region
Armorica
Devonian
‘Old Red Sandstone’
Diachronous deposits
Local basins
Gondwana
Devonian - Formation of large land mass,
shedding large volumes of terrestrial
material into inland basins
7. Building the UK
Moine thrust
Great Glen fault
Originally Laurentia
Highland Boundary Fault
Southern Uplands
fault
Iapetus suture
Lake District
Originally Avalonia
Welsh basin
Variscan front
Stable
Precambrian
crust
New crust generated in Lower Palaeozoic extends
from Moine thrust to Wales, and to deep crustal
levels between Highland Boundary fault and the
English Midlands