E learning geography project by Kurt Muscat, 3.02

E-Learning Geography E-Learning Geography ProjectProject

Name: Kurt MuscatName: Kurt Muscat

Class: Form 3.02Class: Form 3.02

Geology- The Rocks of MaltaGeology- The Rocks of Malta

1.1. There are three categories of rocks;There are three categories of rocks;

• IgneousIgneous: these are rocks that solidified directly from : these are rocks that solidified directly from molten silicates, which geologists call magma. molten silicates, which geologists call magma. Examples are: Granite, Basalt, Pumice and Flint.Examples are: Granite, Basalt, Pumice and Flint.

• SedimentarySedimentary: these are formed when igneous rocks are : these are formed when igneous rocks are eroded as sediment under the sea. Fossils are often found eroded as sediment under the sea. Fossils are often found in this layer. Examples are limestone, chalk and sandstone.in this layer. Examples are limestone, chalk and sandstone.

• MetamorphicMetamorphic: these are made up of igneous and : these are made up of igneous and sedimentary rocks of all ages which have been subjected to sedimentary rocks of all ages which have been subjected to intense heat and or pressure. Examples are: slate, marble intense heat and or pressure. Examples are: slate, marble and quartzite.and quartzite.

2.2. The Maltese Islands are made up of marine sedimentary The Maltese Islands are made up of marine sedimentary rocks which originated on the sea bed where sediment, rocks which originated on the sea bed where sediment, silt and remains of tiny sea creatures were deposited.silt and remains of tiny sea creatures were deposited.

+ + tiny sea + + tiny sea creatures = Marine Sedimentary Rockscreatures = Marine Sedimentary Rocks

3.3. These rock strata were formed over millions of years These rock strata were formed over millions of years through continuous accumulation. These rock strata were through continuous accumulation. These rock strata were uplifted for the first time 10 million years ago. This uplift uplifted for the first time 10 million years ago. This uplift was due to pressure exerted by the African plate crashing was due to pressure exerted by the African plate crashing into the Eurasian plate.into the Eurasian plate.

4.4. The rock layers of the Maltese Islands are:The rock layers of the Maltese Islands are:

NAME OF ROCKNAME OF ROCK

(ENGLISH)(ENGLISH)

NAME OF ROCKNAME OF ROCK

(MALTESE)(MALTESE)

RESISTANCERESISTANCE PERMEABLEPERMEABLE COLOURCOLOUR USESUSES

Upper Coralline Upper Coralline LimestoneLimestone

Qawwi ta’ FuqQawwi ta’ Fuq HardHard PermeablePermeable White to Light White to Light GreyGrey

SpallsSpalls

GreensandGreensand Ramli /Ramli /

Ġebla SafraĠebla Safra

FriableFriable PermeablePermeable OrangeOrange NoneNone

Blue ClayBlue Clay TafalTafal

Very Soft & Very Soft & Malleable Malleable

(when wet)(when wet)ImpermeableImpermeable GreyGrey PotteryPottery

Globigerina Globigerina LimestoneLimestone

FrankaFranka SoftSoft PermeablePermeable White to YellowWhite to Yellow BuildingsBuildings

Lower Coralline Lower Coralline LimestoneLimestone

Qawwi ta’ TaħtQawwi ta’ Taħt

ŻonqorŻonqor

HardHard PermeablePermeable White to Light White to Light GreyGrey

WeatheringWeathering1.1. Weathering is the breakdown and alteration of Weathering is the breakdown and alteration of

rocks and minerals at or near the Earth’s rocks and minerals at or near the Earth’s surface.surface.

2.2. Weathering is divided into 3;Weathering is divided into 3;

• Physical WeatheringPhysical Weathering

• Chemical WeatheringChemical Weathering

• Biological WeatheringBiological Weathering

3.3. Chemical weathering involves the alteration of the Chemical weathering involves the alteration of the chemical composition of the weathered material.chemical composition of the weathered material.

4.4. Limestone Solution Limestone Solution is type of chemical is type of chemical weathering. It occurs when naturally acidic rain weathering. It occurs when naturally acidic rain falls on limestone and causes a reaction with the falls on limestone and causes a reaction with the limestone. As a result of this reaction limestone limestone. As a result of this reaction limestone dissolves.dissolves.

5.5. Physical weathering is the breakdown of mineral Physical weathering is the breakdown of mineral or rock material by entirely mechanical methods or rock material by entirely mechanical methods (forces) brought about by a variety of causes.(forces) brought about by a variety of causes.

6.6. Frost ShatteringFrost Shattering is an example of physical is an example of physical weathering which occurs when water trapped in weathering which occurs when water trapped in the cracks of the rocks freezes and as it freezes the cracks of the rocks freezes and as it freezes it expands and shatters the rock. This occurs it expands and shatters the rock. This occurs mostly in alpine and polar areas.mostly in alpine and polar areas.

7.7. Another type of physical weathering is Another type of physical weathering is exfoliation exfoliation or or onion-skinonion-skin weatheringweathering. . Exfoliation occurs when the surface of the rock Exfoliation occurs when the surface of the rock expands during the heat of the day and contracts expands during the heat of the day and contracts during the cold of the night. This occurs mostly in during the cold of the night. This occurs mostly in deserts.deserts.

8.8. Biological weathering involves the disintegration Biological weathering involves the disintegration of rock and mineral due to the chemical and / or of rock and mineral due to the chemical and / or physical agents of an physical agents of an organismorganism. The types of . The types of organisms that can cause weathering range from organisms that can cause weathering range from bacteria to plants to burrowing animals such as bacteria to plants to burrowing animals such as earthworms and rabbits.earthworms and rabbits.