Sandstone Ridge Trust

Hydrogeology Workshops

(3rd & 10th November 2014)

Gordon Coombs

Hydrogeology WorkshopIntroduction

1) Aims of the Workshop

2) Introduction to Geology

3) Introduction to Hydrogeology

4) What’s on your Door-step?

Hydrogeology Workshop

Part 1

Introduction to Geology

Hydrogeology WorkshopIntroduction to Geology (1)

1. The Rocks

• Igneous (granite, basalt etc)

• Sedimentary

• Metamorphic (marble, quartzite, schist, gneiss etc)

2. Sedimentary Rocks/Deposits

– Solid/Bedrock

– Drift and superficial (unconsolidated)

– Bedding

Examples:

Hydrogeology WorkshopIntroduction to Geology (2)

Sedimentary deposits of particular relevance to Sandstone Ridge area (green/underlined).

Solid or Bedrock Drift (glacial) and superficial (recent)

Mudstone; shale; marl; clay Clay; Boulder Clay, Glacial Till,

Siltstone Glacial Silts

Sandstone Glacial Sands and Gravel

Conglomerate/breccias Blown Sands

Limestone, Dolomite, Chalk River Terrace Deposits (sand and gravel)

Evaporites (halite, gypsum, anhydrite) Peat

Coal Alluvium

Hydrogeology WorkshopIntroduction to Geology (3)

3. Deposition and Bedding

• Sediment accumulates mainly from:– Settlement; or

– Precipitation; or

– Evaporation

• Laid down in water or air as ‘beds’, separated by:– Interruptions to sediment influx; or

– Sudden influxes of sediment.

• In various environments:– Marine/Estuarine/Beach;

– Fluvial/Rivers;

– Lakes;

– Desert/wind-blown;

– Glacial.

Hydrogeology WorkshopIntroduction to Geology (4)

4. Structure

– Dip (angle of inclination of strata/beds)

– Folds and folding• Anticline

• Syncline

– Faults and faulting• Normal (extension)

• Reverse/Thrust (compression)

• Tear/Wrench/Transverse (lateral) -

A

B

C

C

B

A

D

E

F

F

E

D

Hydrogeology WorkshopGeological History (1)

Where to begin?

Let’s start with the formation of.........

PANGAEA!

Hydrogeology WorkshopGeological History (2)

Higher ground develops as continents come

together