geog 2 start Flashcards
Igneous rock ABBREVIATION
CHC
Igneous rock explanation
CHC - Moleten rock (magma) from mantle COOLS down and HARDENS. Then CRYSTALISES (forms crystals) as it cools.
Igneous rocks are usually ahrd eg granite
METAMORPHIC ROCK ABBREVIATION
OCHP
METAMORPHIC ROCK explanation
OCHP
Metamorphic rocks are formed when OTHER ROCKS (igneous, sedimentary or older metamorphic rocks) are CHANGED by HEAT and PRESSURE. The new rocks become harder and more compact
eg shale becomes slate and with further process slate becomes schist
SEDIMENTARY ABBREVIATION
LSCS
SEDIMENTARY EXPLANATION
LAYERS of SEDIMENT are COMPACTED together until they become SOLID rock/.
WHAT ARE THE 2 MAIN TYPES OF SEDIMENTARY ROCK IN THE UK
Carboniferous limestone and chalk
How are the two main types of sedimentary rocks of the UK (carboniferous limestone and chalk) formed
From tiny shells and skeletons of dead sea creatures.
Limestone is quite hard but chalk is softer.
What are the three main ways tectonic processes have shaped the UK landscpae
Through…
ACTIVE VOLCANOES
PLATE COLLISIONS
PLATE MOVEMENTS - UK POSITION
HOW HAVE ACTIVE VOLCANOES SHAPED THE UK LANDSCAPE
520 MILLION YEARS AGO THE LAND OF UK USED TO BE MUCH CLOSER TO A PLATE BOUNDARY THAN IT IS NOW. ACTIVE VOLCANOES FORCES MAGMA THROUGH THE EARTH’S CRUST WHICH COOLED TO FORM IGNEOUS ROCKS eg granite
HOW HAVE PLATE COLLISIONS SHAPED THE UKS LANDSCAPE
PLATE COLLISION CAUSED THE ROCKS TO BE FOLDED AND UPLIFTED, FORMING MOUNTAIN RANGES. MANY OF THESE AREAS REMAIN AS UPLANDS eg Scottish Highlands, the Lake District and north Wales - the igneous granite is hard and more resistant to erosion.
Also, the intense heat and pressure ccaused by plate collisions formed hard metamorphic rocks in the northern Scotland and northern Ireland.
HOW HAVE PLATE MOVEMENTS SHAPED THE UK LANDSCPAE
PLATE MOVEMENTS MEANT THAT MILLIONS OF YEARS AGO BRITAIN WAS IN THE TROPICS AND HIGHER SEA LEVELS MEANT IT WAS PARTLY UNDERWATER - carboniferous limestone formed in the warm shallow seas. THIS CAN BE SEEN IN THE UPLANDS OF PEAK DISTRICT (northern England) , south Wales and south west England.
Also, the youngest rocks. in the UK are the chalks and clays found in the southern England. THEY FORMED SHALLOW SEAS AND SWAMPS.Chalks and clays are softer rocks that are more easily eroded - they form lowland landscapes.
What very heavily influence the type of landscape that forms.
The characteristics of each rock type influences heavily the type of landscape that formss…most of the uK landscape has also been affected by erosion, deposition and caused by glaciers.
The characteristics of different rock types create different landscapes.
Talk about granite.
GRANITE IS A FORM OF IGNEOUS ROCK.
IT IS VERY RESISTENT AND FORMS UPLAND LANDSCAPES.
IT HAS MANY JOINTS (CRACKS) WHCIH ARE NOT EVENLY SPREAD. THE PART OF THE ROCK WHERE THERE ARE MORE JOINTS WEAR DOWN FASTER. AREAS THAT HAVE FEWER JOINTS ARE WEATHERED MORE SLOWLY THAN THE SURROUNDING ROCK AND STICK OUT AT THE SURFACE FORMING TORS.
GRANITE IS ALSO IMPERMEABLE - IT DOES NOT LET WATER THROUGH. THIS CREATES MOORLANDS - large areas of waterlogged land and acidic soil, with low-growing vegetation.
The characteristics of different rock types create different landscapes.
Talk about slate and schist.
ARE METAMORPHIC ROCKS
SLATE FORMS IN LAYERS CREATING WEAK PLANES IN THE ROCK AND IS USUALLY VERY HARD AND RESISTANT TO WEATHERING BUT IT IS EASILY SPLIT INTO THIN SLABS.
SCHIST HAS BIGGER CRYSTALS THAN SLATE AND ALSO SPLITS EASILY INTO SMALL FLAKES
SLATE AND SCHIST OFTEN FORM RUGGED, UPLAND LANDSCAPES. THEY ARE IMPERMEABLE WHICH CAN LEAD TO WATERLOGGED AND ACIDIC SOILS.
The characteristics of different rock types create different landscapes.
Talk about carboniferous limestone.
IS A HARD SEDIMENTARY ROCK.
RAINWATER SLOWLY EATS AWAY AT LIMESTONE THROUGH CARBONATION WEATHERING (a type of chemical weathering that happens in warm and wet conditions)
MOST WEATHERING HAPENS ALONG JOINTS (CRACKS) IN THE ROCK, CREATING SOME SPECTACULAR FEATRUES, eg limestone pavements (flat areas with deep weatehred cracks), caverns. and gorges.
LIMESTONE IS PERMEABLE, SO LIMESTONE AREAS ALSO HAVE DRY VALLEYS AND RESURGENT RIVERS (rivers that pop out at the surface when limestone is on top of impermeable rock.)
The characteristics of different rock types create different landscapes.
Talk about chalk and clay.
ARE SEDIMENTARY ROCKS.
CHALK IS HARDER THAN CLAY.
IT FORMS ESCARPMENTS (hills) IN UK LOWLANDS AND CLIFFS AT THE COAST. ONE SIDE OF THE HILL IS USUALLY STEEP AND THE OTHER SIDE IS MORE GENTLE.
CHALK IS PERMEABLE - WATER FLOWS THROUGH IT AND EMERGES AS A SPRING WHERE IT MEETS IMPERMEABLE ROCK.
CLAY IS VERYS OFT AND EASILY ERODED.
IT FORMS WIDE FLAT VALLEYS IN UK LOWLANDS. IT IS IMPERMEABLE SO WATER FLOWS OVER THE SURFACE - there are lots of streams, rivers and lakes.
Much of UK used to be covered in ice =- explain!
THERE HAVE BEEN LOTS OF GLACIAL (cold) PERIODS IN THE LAST 2.6 MILLION YEARS.
DURING SOME GLACIAL PERIODS PARTS OF THE UK WERE COVERED IN A MASSIVE ICE SHEET
AT ITS MAX, ICE COVERED MOST OF SCOTLAND, IRELAND AND WALES AND CAME AS FAR SOUTH AS THE BRISTOL CHANNEL IN ENGLAND.
ICE IS VERY POWERFUL AND SO WAS ABLE TO ERODE THE LANDSCAPE CARVING OUT LARGE U SHAPED VALLEYS IN UPLAND AREAS SUCH AS THE LAKE DISTRICT.
GLACIERS ALSO DEPOSITED LOTS OF MATERIAL AS THEY MELTED…LANDSCAPES FORMED BY GLACIAL MELTWATER AND DEPOSITS EXTEND SOUTH OF THE ICE SHEETS. eg large parts of eastern England are covered in till (an unsorted mixture of clay, sand and rocks) deposited by melting glaciers.
Physical processes are constantly changing in the UK. What do they consist of
WEATHERING
EROSION
POST-GLACIAL RIVER PROCESSES
SLOPE PROCESSES
HOW WEATHERING IS A PHYSICAL PROCESS CONSTANTLY CHANGING THE LANDSCAPE OF THE UK.
Weathering is the breakdown of rock into smaller pieces.
It can be
mechanical - the breakdown of rock without changing its chemical composition
chemical - the breakdown of rock by changing its chemical composition
biological/ PHysical/disaggregation?
the breakdown of rock by living things eg plant roots break down rocks by growing into cracks on their surface and pushing them apart.
HOW EROSION IS A PHYSICAL PROCESS CONSTANTLY CHANGING THE LANDSCAPE OF THE UK.
EROSION WEARS AWAY ROCK . DURING LAST GLACIAL PERIOD, ICE ERODED THE LANDSCAPE. RIVERS AND THE SEA NOW CONSTANTLY ERODE THE LANDSCAPE.
HOW POST-GLACIAL RIVER PROCESSES ARE A PHYSICAL PROCESS CONSTANTLY CHANGING THE LANDSCAPE OF THE UK.
MELTING ICE AT THE END OF THE GLACIAL PERIODS MADE RIVERS MUCH BIGGER THAN NORMAL WITH MORE POWER TO ERODE LANDSCAPE. THE ICE ALSO LEFT DISTINCTIVE LANDFORMS WHEN IT MELTED, eg hanging valleys (little valleys that are left at a higher level than the main valley.)
HOW SLOPE PROCESS IS A PHYSICAL PROCESS CONSTANTLY CHANGING THE LANDSCAPE OF THE UK.
INCLUDING MASS MOVEMENT eg rockfalls, slides, slumps and soil creep
HOW CLIMATE ALSO AFFECTS PHYSICAL PROCESSES
A COLD CLIMATE INCREASES THE LIKELIHOOD OD FREEZE THAW WEATHERING (freeze thaw is a type of mechanical weathering and hapens when the temperature alternates above and below 0 degrees C - the freezing point of water.
Water gets into the rock that has cracks eg granite. When the water freezes it expands, which puts pressrure on the rock. When the water thaws in contracts which releases the pressure on the rock.
Repeated freezing and thawing widens the cracks and causes the rock to break up.). and a wet climate increases the number of streams and rivers.
