Calcite, CaCO 3 - usually white or colourless, can form good‘dog tooth’ crystals, good cleavage, fairly low hardness, reactswith dilute acid, is <strong>the</strong> main mineral in marble and insome sedimentary rocks (limest<strong>on</strong>e) and is found as a ganguemineral in veinsDiam<strong>on</strong>d, C - usually colourless, forms good crystals, extremelyhard, rareFeldspar, silicate - white or pink, can form good rectangularcrystals, good cleavage, hard, comm<strong>on</strong> in igneous and somemetamorphic rocksGarnet, silicate - usually red or pink, <strong>of</strong>ten forms ball-shapedcrystals, no cleavage, hard, found mainly in medium and highgrade metamorphic rocksGold, Au - gold colour, usually irregular shape, feels verydense, low hardness (s<strong>of</strong>t), rare. <str<strong>on</strong>g>The</str<strong>on</strong>g> picture shows a veryunusual example <strong>of</strong> a large gold nugget, rounded because itwas found in stream sediment.Figure 1.14: Some important minerals and <strong>the</strong>ir identificati<strong>on</strong> properties9
Hematite, Fe 2 O 3 - earthy red, metallic lustre, feels dense, redstreak, usually hard, <strong>of</strong>ten found in irregular masses. <str<strong>on</strong>g>The</str<strong>on</strong>g>picture shows its reddish colour and metallic lustreHalite, NaCl - white or pink, cube-shaped crystals, good cleavage,low hardness (very s<strong>of</strong>t), soluble in water, forms rock saltdeposits. <str<strong>on</strong>g>The</str<strong>on</strong>g> picture shows pink halite crystals in a rock saltdeposit.Galena, PbS - silvery grey, metallic lustre, cube-shaped crystals,good cleavage, feels very dense, grey streak, low hardness(s<strong>of</strong>t), found in mineral veins; <strong>the</strong> picture shows silvery-greycubic galena crystals with <strong>the</strong>ir metallic lustre, with a palegangue mineral.Mica, silicate - usually colourless or black, forms platy crystals,good cleavage in <strong>on</strong>e directi<strong>on</strong>, low hardness (s<strong>of</strong>t), comm<strong>on</strong>in igneous and some metamorphic rocksQuartz, SiO 2 - usually grey, white or colourless, can form goodhexag<strong>on</strong>al crystals, no cleavage, hard, comm<strong>on</strong> in sedimentary,igneous and metamorphic rocks and as a gangue mineral inveinsFigure 1.15: Important minerals - 210
- Page 1 and 2: Basic Books in ScienceBook 6<strong
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Figure 2.6: The jo
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Figure 2.25: Dinosaur tracks conser
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Figure 3.23: Map of the major tecto
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Figure 3.26: Global temperature cha
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Figure 3.29: A computer generated p
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Figure 3.31: The
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planet extended th
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Figure 4.1: William Smith’s geolo
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Millionsof yearsago (Ma)01000Some M
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Figure 4.9: The ch
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Figure 4.12: The 4
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Millionsof years Some Major Earth E
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Figure 5.2: Strike-slip movement (r
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Figure 5.4: The So
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Figure 5.6: An ash eruption rising
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Figure 5.10: A hazard zone map of t
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Figure 5.14: A GPS (global satellit
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None of these methods has yet prove
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Figure 5.17: A windfarm in Ireland.
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Figure 5.19: A beautifully preserve
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Another ‘missing link’ find has
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Figure 5.22: A dinosaur reconstruct
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Figure 5.25: A working aggregate-pr
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Chapter 6Understanding what geologi
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Figure 6.2: A drilling rig used for
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When an oil/gas field has been foun
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Figure 6.6: Groundwater flowing out
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Dam disaster in Italy, when the wav
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Figure 6.10: A slab foundation, bui
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An example of this is investigation
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GlossaryAbsolute age The</s
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Carbon capture The
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Crustal shortening This results of
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Evaporite deposits (or evaporites)
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Geophysical survey Using the method
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“Integrated waste management” <
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Metamorphism The r
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Pore spaces (or pores) Gaps bet<str
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Saltation Sediment movement by flui
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Suspension Sediment movement by flu
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AcknowledgementsPermission to repri
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Figure 2.3 A scree slope. Photo ID:
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Figure 1.15a Hematite.Figure 1.15b
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Figure 1.28 Dune cross bedding in s
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Figure 3.18 An island arc volcano,
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Figure 5.21 Excavations at the dino