Economic Geology

9. Mines & Yours

“If you can't grow it,it has to be mined”

Our rocky economy

Economic stones

AggregatesUK - 200-250 million tonnes/yrRailway ballast, iron and steel, agriculture

Road building (~50%)

Concrete (~50%)

Economic graniteVery high

compressive strength

Dimension / armour stone

Hard to carve

Feldspar decomposes

The only geological sport

Economic dolerite

Very strong

Roadstone/aggregate

Slating the economyWales: 15,000 men

employed in 1890s

Economic sandstone

Common, fairly strong

Dimension / paving stone

Weathers

Economic limestone

Dimension stone

Cement

Aggregate

Dudley limestoneDudley limestone

Fossil-fuelled furnacesFossil-fuelled furnaces

Yorkshire's Industrial Coast

Ironstones

Cleveland Ironstone Mines

Why Are The Ironstones There?Why Are The Ironstones There?

Fossilized Ropes?

Fossil shrimp burrows!

Shrimpy miners = human miners

Sediment-hosted minerals

Bronze Age copper mine

Great Orme, Llandudno

The origins of ores

Magmatism– Fractionation / Immiscibility

The origins of oresHydrothermal processes:– Brines– Metamorphic fluids

Metamorphic shearing

Sedimentary placers

Rare earths and renewables

Rare earth elements

Not that rare

Soft, malleable, metallic

Conductive, magnetic

Shifting sourcesGlobal product

Fossil fuelsOil and gas

North Sea oil & gas

UK energy balance

(Figure from DECC report)

Conventional / Unconventional

Britain for shale?

CarboniferousNW England

JurassicSE England

The impact of power

Vidal et al. - Nature Geoscience (2013)

The trajectory of demand

Vidal et al. - Nature Geoscience (2013)

Next week: The FuturePredictive Geology

- Earthquakes

- Tectonics

- Climate

• + A Final Review