slide1 n.
Skip this Video
Loading SlideShow in 5 Seconds..
WJEC A2 Geology PowerPoint Presentation
Download Presentation
WJEC A2 Geology

Loading in 2 Seconds...

play fullscreen
1 / 19

WJEC A2 Geology - PowerPoint PPT Presentation

  • Uploaded on

WJEC A2 Geology. BGS Mapwork. I.G.Kenyon . BGS 1:50.000 scale maps. 1mm on the map represents 50m on the ground Grid squares are 1 km ² and have sides of 2cm on the map. BGS 1:25,000 scale maps. 1mm on the map represents 25m on the ground

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

WJEC A2 Geology

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

WJEC A2 Geology




BGS 1:50.000 scale maps

1mm on the map represents 50m on the ground

Grid squares are 1 km² and have sides of 2cm on the map


BGS 1:25,000 scale maps

1mm on the map represents 25m on the ground

Grid squares are 1 km² and have sides of 4cm on the map


BGS Maps are produced in solid and solid and drift editions

Solid maps show only the fully lithified rocks

Solid and drift maps show the lithified rocks plus any recent sediments deposited on top


Solid Geology – Cockermouth Sheet 23 1:50.000

Permo-Triassic Rocks

Carboniferous rocks

Recent drift deposits such as alluvium and boulder clay not shown


Solid and Drift Geology – Clitheroe Sheet 68 1:50,000

River Terrace Deposits


Solid Geology


Structures to Identify on BGS Maps 1

Beds – direction of dip/angle of dip

Beds – strike direction/orientation


Fold axes/axial plane of folds


Symmetrical/asymmetrical folds

Plunging folds

Open/tight/recumbent/overturned folds


Structures to Identify on BGS Maps 2

Normal faults/reverse faults/thrust faults

Tear faults – sinistral/dextral/step faults

Graben/rift valley/Horst/block mountain



Lava flow/sill/dyke/pluton/mineral veins

Metamorphic aureole

Inverted relief


Generalized vertical sections are given on BGS Maps

This is a vertical log of all the rock types present in chronological order with the oldest at the base and the youngest at the top

On 1:50,000 maps the scale is often 1:10,000

On 1:25,000 maps the scale is often 1:4,000

However scales can vary-check carefully on each map that you are studying


Part of the generalized vertical section from Hawes Solid and Drift 1:50,000

Note that rock types and ages of beds are given

Unconformities are clearly indicated in the section

It is vital that the vertical section is studied carefully in conjunction with the map in order to interpret all of the geological structures


Cross sections are also included on BGS maps and should be studied carefully along with the vertical section and map

From Hawes Solid and Drift 1:50,000

You do not have to construct cross sections from BGS maps at A2!


In addition to geological structures, you will be asked questions with a GL3 bias

These could include evaluating the suitability of certain locations for the construction of roads, landfill sites, housing estates, reservoirs, power stations, dams or tunnels

Questions relating to the causes of landslips are also a possibility


Sometimes additional maps are included on the BGS geology maps

These may include magnetic, gravity, radon, isostatic or mineralogical data

Questions related to this additional data may be asked in relation to the geological map


Okehampton/Dartmoor Map Geology and Gravity Anomalies

Gravity anomalies (contoured in milligals). The negative gravity anomaly is due to the granite being of lower density than the surrounding rocks


Okehampton/Dartmoor Map Geology and Magnetic Anomalies

Aeromagnetic anomalies (contoured in nanoteslas) Magnetic disturbances skirting the granite are due to mineralisation in the Lower Carboniferous rocks and basic intrusions at depth


The End

Ash deposits of the Las Canadas Volcano, Tenerife, Canary Islands