The rock cycle

Question 1

Granite description

Answer 1

Course grained, multicoloured, intrusive forms at convergent boundaries. Silica rich minerals eg. quartz, feldspar, mica => speckled

Question 2

Granite location

Answer 2

Wicklow mountain, Leinster Batholith

Question 3

Granite formation

Answer 3

Forms at convergent boundaries through folding and subduction

Question 4

Granite - folding

Answer 4

2 continental plates collide => sedimentary rock pushed up - fold mountains & magma rises underneath. Sedimentary rock traps heat => large granite crystals + metamorphic cap

Question 5

Granite - subduction

Answer 5

Oceanic sinks + melts, magma seeps into overlying plate through sedimentary rock to slowly cool to granite

Question 6

Granite landscapes

Answer 6

Leinster Batholith: 400 mil years, North American & Eurasian collided - Caledonian folds (Dublin Wicklow), magma rose through fractures in the crust + cooks sedimentary to metamorphic. Weathering - visible

Question 7

Basalt description

Answer 7

Fine grained + smooth. Made of magnesium & iron. Red-brown, rust colour

Question 8

Basalt - Location

Answer 8

Antrim Derry plateau & Giants Causeway

Question 9

Basalt formation

Answer 9

Extrusive + found at divergent boundaries. Basic lava pools from fissures + cools rapidly when exposed to surface. Makes sea floor, still coming out of Mid Atlantic Ridge

Question 10

Basalt landscape

Answer 10

Antrim Derry plateau: 65 mil years ago, North American & Eurasian separated. Basic lava has low viscosity& spread into river valley - cooled rapidly. Basalt contracted

Question 11

Sandstone description

Answer 11

Coarse grained + inorganic, red brown

Question 12

Sandstone location

Answer 12

Macgillycuddys Reeks in Kerry

Question 13

Sandstone formation

Answer 13

Grains of quartz are deposited in thick layers on land/shallow seabed. Sandstone formed in Ireland 380 mil years ago, dessert climate eroded Caledonian mountains+carried to shallow seabed, compacted+lithified

Question 14

Limestone description

Answer 14

Fine grained + organic. Pure = white chalk. Irish “carboniferous limestone” is grey

Question 15

Limestone location

Answer 15

The Burren, Co. Clare

Question 16

Limestone formation

Answer 16

320 yrs old when Ireland was underwater. Fish fossils compressed + water removed from pores + Calcium carbonate in bonds cement them - lithifies. Brittle - joints+ permeable

Question 17

Limestone landscape

Answer 17

Burren, Co. Clare(Karst region) 250km². Submerged under tropicsea until Armorican. African+Eurasian collided + Burren lifted up. Glaciers erode to show limestone. Carbonation

Question 18

Marble description

Answer 18

Coarse grained, non foliated. Pure white Rathlin
, black (carbon) Kilkenny, red (iron) Cork, green (serpentine) Connemara,

Question 19

Marble formation

Answer 19

Regional metamorphism - intense heat as plates collids melts fossils + makes limestone strata melt - non foliated. Limestone heats, calcite minerals expand+ lock - crystals melt + stick

Question 20

Quartzite description

Answer 20

Coarse grained, non foliated, from sandstone, pale pink

Question 21

Quartzite location

Answer 21

Mount Errigal, Co. Donegal

Question 22

Quartzite formation

Answer 22

Contact metamorphism, 400 mil years ago North American+Eurasian collide - magma forces through the crust & came in contact with sandstone. The heat+pressure chemically changes sand to quartz. Silica fills pores, cementing them - unfoliated