Geology THIRD EDITION by Stanley Chernicoff University of Washington, Seattle Donna L. Whitney University of Minnesota

1
EGYPT Civilization Geology Geosciences 2020
MINERALS IGNEOUS ROCKS
2
MINERAL DEFINITION
IT MUST BE (1) Naturally Occurring (2)
Inorganic (3) Definite Chemical Composition (4)
Orderly Internal Arrangement (5) Solid
3
WOULD AN INDUSTRIAL DIAMONDMADE BY GENERAL
ELECTRICBE CONSIDERED A MINERAL ?

• YES
• NO

4
ARE PEARLS CONSIDERED TO BE A MINERAL ?

• YES
• NO

5

NATURAL DIAMONDS vs. GRAPHITE
POLYMORPHS (Poly Many, Morph Form) Same
Chemical Composition - Different Atomic
Arrangement
6
MINERAL PROPERTIES
CRYSTAL FORM
7
MINERAL PROPERTIES
COLOR INHERENT (Always the Same) Sulfur
Always Yellow Malachite Always Green
Sulfur
Malachite
8
MINERAL PROPERTIES
EXOTIC COLOR (Different Colors)
Quartz

• White (Milky)
• Purple (Amethyst)
• Yellow (Citrine)
• Pink (Rose)
• Clear (Crystal)
• Grey (Smokey)
• Green

9
MINERAL PROPERTIES

• STREAK
• (color of minerals - with metallic luster - in
  crushed form)
• - Magnetite Black
• - Hematite Red/Brown
• - Sulfur - Yellow

10
MINERAL PROPERTIES
LUSTER
Non-Metallic
Earthy Looks like a brick
Galena
Metallic
Shinny Looks like Newly Machined Metal
11
MINERAL PROPERTIES
LUSTER - Non Metallic
Galena
Sphalerite - Resinous Like Dried Tree Resin
Quartz
Quartz - Vitreous Like Glass
Talc - Pearly Like Mother-of-Pearl
12
MINERAL PROPERTIES
Biotite
CLEAVAGE
Muscovite Biotite
Orthoclase
Hornblende
Halite
Calcite
Fluorite
Halite
Fluorite
Calcite
13
MINERAL PROPERTIES
FRACTURE TYPES - Conchoidal (a concentric ring
pattern similar to broken glass) -
Even (smooth pattern) - Uneven (rough
pattern)
14
MINERAL PROPERTIES

• HARDNESS
• The Resistance of a Mineral to Being Scratched -
  Not Breaking
• Any Harder Material Will Scratch Any Softer
  Material

Mohs Hardness Scale
15
THE MINERAL QUARTZ HAS A HARDNESS OF _________
ACCORDING TO THE MOHS HARDNESS SCALE

1. 5
2. 9
3. 7
4. 3

16
MINERAL AND ROCK RESOURCES Gneiss Statuary
Granodiorite Statuary, Sarcophagus Peridotie Sta
tuary Flint Tools Malachite Ornaments,
Jewelry Turquoise Ornaments, Jewelry Emeralds Or
naments, Jewelry Galena Lead, Pigments Copper To
ols, Pots, Ornaments, Jewelry Gold Ornaments,
Jewelry Iron Tools Coal Fuel,
Pigments Phosphates Fertilizer Gypsum Plaster,
Cement Manganese Pigments, Steel
Making Sulfur Pigments Oil and Gas Energy
17
DEFINITION OF A ROCK
AN AGGREGATE OF MINERALS
GRANITE
18
IGNEOUS ROCKS - The Rock Cycle
19
IGNEOUS ROCKS Rocks That Form from the Cooling
and Crystallization of Molten-Rock (Melt) Magma
Molten Rock within the Earth (Deep and Slow to
Crystallize) Lava Molten Rock on the Earths
Surface (Crystallizes Fast, Looses Gas
Volitiles - CO2, SO2, H2O)
20
Classification of Igneous Rocks

• Texture
• Size and shape of the minerals controlled by the
  rate of cooling
• Composition
• Chemical make-up of the melt

21
IGNEOUS ROCKS ARE CLASSIFIED BY

1. NUMBER OF MINERALS PRESENT
2. TEXTURE (CRYSTAL SIZE)
3. CHEMICAL COMPOSITION
4. ALL OF THE ABOVE
5. BOTH B and C
6. NONE OF THE ABOVE

22
(No Transcript)
23
Granite
Phaneritic (Coarse) Texture

• Crystals Are Large Enough to be Seen by the
  Naked Eye
• Cooled Slowly - Intrusive
• Termed Pegmatite when Very Large

24
(No Transcript)
25
Aphanetic (Fine) Texture
Rhyolite
Crystals Are Difficult or Impossible to be Seen
by the Naked Eye Cooled Rapidly Extrusive
26
(No Transcript)
27
PORPHRITIC TEXTURE

• Both Coarse- and Fine-Grained Minerals Present
• Dual Genesis

Andesite Porphyry with Phenocrysts of Calcium
Plagioclase

GROUNDMASS Fine-grained Matrix PHENOCRYSTS
Coarse-grained Inclusions
28
PORPHYRY
Pliny described the rock as redwith white
spots

• Term originated in Roman Egypt
• Gebel Dokhan - Eastern Desert Quarry 400 50 BCE

GROUNDMASS Conspicuous Purplish Red Andesite to
Dacite PHENOCRYSTS Small White to Pale Pink
Plagioclase
Gebel Dokhan

Andesite Porphyry with Phenocrysts of Calcium
Plagioclase
Latin Porphyrites derived from Greek
Porphyra Means Purple
Rock Identified with Roman Emperors - Purple
became the sign of Royalty
29
PORPHRITIC TEXTURE INDICATES THE ROCK FORMED IN

1. EXTRUSIVE IGNEOUS ENVIRONMENTS
2. INTRUSIVE IGNEOUS ENVIROMENTS
3. MARINE ENVIRONMENTS
4. DESERT ENVIRONMENTS
5. BOTH A and B
6. NONE OF THE ABOVE

30
(No Transcript)
31
OBSIDIAN

• GLASSY (Ultra-fine-grained)
• Cooled Ultra-rapidly
• Lacks Orderly Structure
• Conchoidal Fracture
• Serrated Knife Edge
• Sharper than Surgical Steel

Obsidian Flow - Mono Lake, California
32
PUMICE

• GLASSY (Ultra-fine-grained)
• Cooled Ultra-rapidly
• Lacks Orderly Structure
• Web of glass Less matter than void space Due
  to Gas Escape
• Light Less Dense than Water - Floats

33
(No Transcript)
34

• Composition
• FEROMAGNESIANS
• (Iron and Magnesium)
• Dark Colored
• Olivine, Pyroxenes, Amphiboles, Biotite
• NON-FEROMAGNESIANS
• (Minor Iron and Magnesium)
• Light Colored
• Felsic Minerals - K, Na, Ca, Quartz, Muscovite,
  Feldspars

35
Ferromagnesians
Non-Ferromagnesians
36
(No Transcript)
37
IGNEOUS ROCK CLASSIFICATION Ultramafic Rocks
Peridotite Olivine and Pyroxene
38
(No Transcript)
39
IGNEOUS ROCK CLASSIFICATION Mafic Rocks
40

• Building Stone BASALT
• Poor Pavement Stone (Not Durable)
• Symbolic of Black Nile River Mud (Life Force)

Basalt source for Pavement in Khafres Mortuary
Temple
Upper Nile Basalt Source
41
IGNEOUS ROCK CLASSIFICATION BASALT
Originally Bekhen-Stone Slightly
Metamorphosed, fine-grained graywacke Sandstone
to siltstone with abundant secondary Chlorite and
epidote
Originally Quarried at Wadi Hammamat
Currently Basanite Feldspathoid and Olivine
Bearing Basalt Basalt Volcanic Rock with the
Composition of Gabbro
42
IGNEOUS ROCK CLASSIFICATION BASALT
43
OPHIOLITES
Pillow Basalts
44
OPHIOLITES - Dense, Mineral-rich Assemblages -
Named for Serpent-like Shape
Troodos Massif sulfide mine (dark material at
bottom of pit)
45
EGYPT BEDROCK
46
OPHIOLITES a suite of ultramafic and mafic
igneous rocks rich in serpentine and other
metamorphic minerals

• Pliney Introduced Ophites to a series of rocks
  in the Eastern Desert with markingswhich
  resembled snakes
• Ophites is derived from ophis Greek for snakes
• Pliney describes Augustean ophites (gabbro -
  Roman Quarry at Wadi Semna) as having markings
  thatcurl over like waves so as to form coils
  and
• Tiberian ophites as scattered grayish-white
  spots which are rolled into coils (quartz
  diorite Roman Quarry at
• Wadi Barud

Wadi Barud
Wadi Semna
Serpentine Agricolas serpentaria (serpens -
Latin equivalent to Greek ophis)
Original Augustean ophites now recognized As part
of ophiolite melange
47
(No Transcript)
48
IGNEOUS ROCK CLASSIFICATION Intermediate Rocks
Andesite
Diorite
49
Khafre 4th Dynasty 2558 2532 BCE Giza Statue
Carved from Diorite
50
(No Transcript)
51
IGNEOUS ROCK CLASSIFICATION Felsic Rocks
52
EGYPT BEDROCK
ASWAN
53
(No Transcript)
54
IGNEOUS ROCK CLASSIFICATION SYENITE
(Quartz-poor Granite)

• Aswan
• Known as Swnt (Swenet) as early as 20th
  Dynasty
• (New Kingdom)
• (1100 1200 BCE)
• Means Commerce
• Ptolemaic Period (330 30 BCE)
• Known as Syene
• Coptic Evolved into Sawan
• Arabic Aswan

• Pliny introduced Syenites to refer to granite
  quarried at Aswan -
• described as red spotted (large pink red
  microcline crystals)
• Geologist first described Aswan Black
  Granodiorite as Syenites
• Reality True Syenite is rare at Aswan and
  was
• not worked in ancient times

55
POST AND BEAM CONSTRUCTION The Need for Granite
Copper Source
Giza
Granite Source
56
The Great Pyramid - The Grand Galley
Grand Gallery Finally Enclosed with Corbelled
Ceiling
57
Kufu's Pyramid - Campbell's Chamber
Cracked Granite Beam
58
THE GREAT PYRAMID KUFU 4th Dynasty Granite
Sarcophagus
59
EGYPT Civilization Geology Geosciences 2020
MINERALS IGNEOUS ROCKS