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

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EGYPT Civilization Geology
GEOS 2020
SEDIMENTARY ROCKS
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SEDIMENTARY ROCKS - The Rock Cycle
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Sediments andSedimentary Rocks

• Sediments - Loose Fragments of Solid Materials
• (pre-existing rocks remains of organisms, and
  minerals that have precipitated)
• Sedimentary Rocks Make up 75 of Earths Surface
• Contain Valuable Natural Resources (oil, gas,
  coal, water, minerals)
• Window into the Geologic Past (climate,
  geography)
• Two Main Categories
• Detrital (Clastic) from pre-existing igneous,
  sedimentary, or metamorphic rocks
• Chemical (Non-Clastic) - either inorganic or
  organic/biogenic direct ppt. or taken out of
  solution by organisms

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SEDIMENTS AND SEDIMENTARY ROCKS
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Lithification(Turning Sediment to Rock)

• Lithification
• - Result of diagenesis
• Diagenesis
• Compaction (dewatering and close packing)
• Cementation (calcite and silica, iron)
• Recrystallization (aragonite to calcite
  dolomite)

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Sediments and Detrital Sedimentary Rocks

• Sediment Textures
• Size, Shape, and Arrangement
• Determined by Transportation and Depositional
  Processes and Parent Rock
• Sorting
• Particles Sorted, or Separated by Size, Shape
  and Density
• Wind (very effective), Water (environmental
  indicators)
• Shape
• Angular or Irregular Grains Become Rounded
• Longer Transport Distance Leads to More Rounding
  of Grains (But Also a Function of Mineral
  Hardness and Resistance to Weathering)

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Detrital Sediments and Rocks Size The Wentworth
Scale
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TRUE or FALSE

• COBBLES ARE LARGER THAN PEBBLES AND INDICATE A
  HIGHER ENERGY ENVIRONMENT OF DEPOSITION

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Eolian (well sorted)
SEDIMENTARY ROCKS Sediment Sorting
Glacial (poorly sorted)
Beach (well sorted)
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SEDIMENTARY ROCKS Sediment Shape
Increased surface area!
FROST WEDGING
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SEDIMENTARY ROCKSStream Action Length of
Transport
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TRUE or FALSE

• SEDIMENTS WITH MORE CLAY, A GREATER MIX OF
  PARTICLE SIZES AND MORE ANGULAR FRAGMENTS IS
  TYPICAL OF MATURE SEDIMENTS

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(Based Upon Grain Size)
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SEDIMENTARY ROCKSBRECCIA
Gravel Size - Angular Fragments, Poorly Sorted
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SEDIMENTARY ROCKSCONGLOMERATE
Gravel Size - Moderate to Well Rounded Pebbles,
Poorly Sorted
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TRUE or FALSE

• "CONGLOMERATES" WOULD BE CONSIDERED MODERATELY
  MATURE BECAUSE THE PEBBLE SIZE FRACTION CONSISTS
  OF ROUNDED FRAGMENTS (DESPITE POOR SORTING)

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Quartz Arenite
Arkosic Sandstone
Graywacke
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Navajo Sandstone, Zion National Park, Utah
Aeolian Sandstone - Clean Quartz-rich - Well
Sorted - Rounded Grains - Frosted Grains
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The Middle Kingdom 2055 1650 BC Dynasties
11 - 14
Adequate flooding returns - Normal agriculture
resumes
Montuhotep II (2055 2004 during 11th Dynasty)
ruling from Thebes conquers northern Egypt
reuniting country
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Nubian Sandstone exposed in southern Egypt (1/3
of country) and in northern Nubia (Sudan)
EGYPT BEDROCK
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Entrance to Luxor Temple
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Luxor Karnak Temple to Amun
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UPPER NILE SANDSTONE TEMPLES Construction Methods
STEP ONE
STEP TWO
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UPPER NILE SANDSTONE TEMPLES Construction Methods
STEP THREE
STEP FOUR
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UPPER NILE SANDSTONE TEMPLES Construction Methods
STEP FIVE
STEP SIX
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Gebel el-Silsila River Edge Nubian
Sandstone Rock-cut Tombs and Temples Horemheb -
Dynasty XVIII
SANDSTONE Characterizes Tombs and Temples of the
Upper Nile
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ABU SIMBEL
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Abu Simbel Temple
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(50 of all Detrital Rocks)
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SEDIMENTARY ROCKSShale
Laminated Shale Near Drummond, Montana
Shale Containing Plant Remains
Side View
Top View
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TRUE or FALSE
THE TERM "ARKOSE" MEANS THERE IS A LOT OF
FELDSPAR IN THE SEDIMENTARY ROCK
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SEDIMENTARY ROCKSChemical Rocks

• Inorganic
• Direct precipitation from water (limestone,
  chert)
• Ooids environmental indicator
• Evaporation of saline waters (halite, gypsum)
• Environmental indicator
• Organic/Biogenic derived from living organisms
• Limestone and chert composed of skeletal
  remains of animals
• Reefs environmental indicator
• Coal carbon-rich remains of terrestrial plants
• Environmental indicator

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SEDIMENTARY ROCKSChemical Rocks
Limestone Micrite (Mud) Lithographic Limestone
Trenton Limestone
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SEDIMENTARY ROCKS OOLITIC LIMESTONE Indicators of
Shallow Marine Environments
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Great Bahama Bank
CaCO3 Limestone Tropics
Ooids chemical ppt.
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Alexandria, Egypt Oolitic Beach Sand
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NILE DELTA Oolites vs Silisiclastics
Abuqir Bay
Mud Dominated

• Oolites only form in clean, warm, carbonate-rich
  water
• Muddy water shuts down the formation of oolites

Carbonate Dominated
Abuqir Bay
Littoral Drift
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THE PRESENCE OF OOLITES INDICATES DEPOSITION

1. IN SHALLOW MARINE WATERS
2. FROM WARM WATER
3. FROM WATER SATURATED IN CALCIUM CARBONATE
4. IN AN ENVIRONMENT AGGITATED BY WAVE ACTION
5. ALL OF THE ABOVE

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SEDIMENTARY ROCKS
Calcedony
Agate
Flint
Travertine
Chemical (Inorganic) Precipitation of CaCO3
(Travertine)
Jasper
Precipitation of SiO2 Calcedony
CaCO3
Grey/white CHERT
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ALABASTER
Massive crystalline form of Gypsum (CaSO4 . 2H2O)
Forms as salt precipitate in restricted basins or
associated with Travertine (CaCO3) in Hot Springs
Pliny Alabastritisis found at the town of
Alabastrum in Egypt
Large deposits of travertine found a few miles
east of the Nile River in the Eastern Desert (Red
Sea Mountains) just north of Luxor (between
Assiut El-Minya - Numerous Ancient Quarries)

• Used for
• Statuary
• Conopic Jars
• Roman Era Jars and Vessels

Mammoth Hot Springs Yellowstone National Park
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Halite (Rock Salt)
Least Soluable Minerals Precipitate First 63
75 Water Evaporated GYPSUM 90 of Water
Evaporated HALITE Final Stage Salts Rich in
Potassium (K)
EVAPORITES
Nonclastic Texture Evaporites Form as Masses of
Intergrown Crystals NOT as Accumulations of
Individual Crystals
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Evaporites Bonneville Salt Flats, Utah
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Gulf of SUEZ
Mid Miocene

• Aqaba Fault begins 18 mya
• Fault blocks rise
• Red Sea/Suez Basin nearly cut off from
  Mediterranean
• Restricted basin forms
• Evaporite rocks deposited
• Halite and gypsum deposits around the Gulf are
  several km thick. This event precedes the
  Miocene Desiccation of the Mediterranean Sea

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SEDIMENTARY ROCKS Chemical - Organic Fossiliferous
Limestone
Natural Casts of Shelled Invertebrates
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The Pyramid Builders
SAQQARA - MASTABAS SAQQARA - STEP PYRAMID OF
DJOSER MEIDUM - SNEFERUS FIRST
PYRAMID DAHSHUR - BENT PYRAMID OF
SNEFERU DAHSHUR - RED PYRAMID OF SNEFERU GIZA
- KUFU, DJEFRE, KAHFRE,
MENKAURE DAHSHUR - AHMENEMHET III MUD BRICK
CORE
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EGYPT BEDROCK
Eocene Limestone exposed in central Egypt north
to Cairo
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Eocene Limestone (with Numilites)
GIZA PLATEAU
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CORE STONE
CASING STONE
GIZA PYRAMIDS
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EGYPT Civilization Geology Geosciences 2020
METAMORPHISM AND METAMORPHIC ROCKS
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METAMORPHIC ROCKS - The Rock Cycle
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METAMORPHIC ROCKS Types of Metamorphism

• Contact
• Hydrothermal
• Regional

(4) Burial
(5) Faulting
(6) Shock
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(1) Contact Metamorphism
METAMORPHIC ROCKS

• - Local in Scope
• - Temperature Driven
• Caused by Contact with a Pluton
• Pressure not a Major Factor

Pre-existing Rock
Metamorphic Zone
Intrusive Rock
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METAMORPHIC ROCKS(2) Hydrothermal Metamorphism
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METAMORPHIC ROCKS (3) Regional Metamorphism

• - Temperature and Pressure Related
• 1,000s 10,000s km2
• Associated with the Boundaries of Tectonic
  Plates

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METAMORPHIC ROCKS (4) Burial Metamorphism
BURIAL METAMORPHISM - Sedimentary Basin -
Confining Pressure - Non-Foliated Rocks
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Metamorphic Rocks (5) Fault Plane
Metamorphism
Fault
San Andres Fault, California
Chief Mountain, Glacier National Park, Montana
Titus Canyon, Death Valley, California
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Meteor (Barrington) Crater near Winslow, Arizona
- Impact 50,000 years ago
Manicouagan, Quebec 200 million year old Eroded
Impact Crater Lake Outlines Crater Remnant 70 km
(42 mi) Across Fractures Extend an Additional 30
km
Meteor Found in Arabian Desert
METAMORPHIC ROCKS (6) Shock Metamorphism
Libyan Desert Glass
World Map of Major Impact Structures
(Astroblemes) More Than 100 Have Been Identified
to Date
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LIBYAN DESERT GLASS
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METAMORPHIC ROCKS Non-Foliated v.s. Foliated Rocks
DYNAMOTHERMAL METAMORPHISM - Plate Boundaries -
Directed Pressure - Foliated Rocks
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METAMORPHIC ROCKS Non Foliated No Directed
Pressure
Quartz Sandstone
Quartzite
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METAMORPHIC ROCKSDEVELOPMENT OF FOLIATION DUE
TO DIRECTED PRESSURE
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TRUE or FALSE

• BURIAL METAMORPHISM IS THE PRINCPLE CAUSE OF
  FOLIATION

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Development of Lineation
Needle-like (Elongate) Minerals
METAMORPHIC ROCKS Slaty Cleavage Schistosity Linea
tion
Plane of Foliation
Development of Schistosity
Well Developed Slaty Cleavage
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METAMORPHIC ROCKS Metamorphic Grade Increases
with Depth Shale (Sedimentary Rock) Slate Phyllit
e Mica Schist Garnet Mica Schist Gneiss Migmatite
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Foliated Metamorphic Rocks Slate
Note - Lack of Visible Mineral Grains - Easily
Split Along Cleavage Planes
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Neolithic Agricultural Communities 7-8,000 Years
Ago
Narmer Palette From Hierakonpolis The Scorpion
King End of Pre-Dynastic Dynasty 0 3150 3050
BC Father of Menes (Aha) First Pharaoh and
Founder of Memphis Carving on Metamorphic Slate
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Menkaure 4th Dynasty Giza
Statue from His Valley Temple Flanked by God
Hathor One of his Queens
Carving on Metamorphic Slate
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TRUE or FALSE

• CLEAVAGE SURFACES IN METAMORPHIC SLATE WILL
  ALWAYS MIMMIC THE ORIGINAL BEDDING PLANE SURFACES
  OF THE PARENT SEDIMENTARY SHALE

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Foliated Metamorphic Rocks Phyllite
Note - Lack of Visible Mineral Grains -
Slippery, Glossy Sheen
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Mica Schist
Foliated Metamorphic Rocks
Mica Garnet Schist
Garnet Mica Schist
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METAMORPHIC ROCKS
PORPHYROBLASTS (Porphyroblastic Texture)
Few Large Mineral Crystals Surrounded by
Matrix of Finer - Grained Crystals of Another
Mineral
Garnet Mica Schist
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Foliated Metamorphic Rocks Gneiss
Note Light and Dark Bands
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METAMORPHIC ROCKS Migmatites (Partially
Metamorphic, Partially Melted/Igneous)
Lightest-colored layers igneous rocks of quartz
and feldspar Darker-colored layers metamorphic
origin
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TRUE or FALSE

• MOST MIGMATITES ARE COMPOSED OF MELTED
  METAMORPHIC ROCK (IGNEOUS MELT STAGE) AND
  UNMELTED METAMORPHIC SLATE

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Non-Foliated Metamorphic Rocks Marble
Note - Lacks Any Rock Cleavage, Slatey Cleavage,
Schistocity, Lineation, etc.
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METAMORPHIC ROCKS(1) Contact Metamorphism
Marble Formed
INCREASING HEAT AND CONTACT METAMORPHISM
- Veins Formed - Fe (Magnetite) Concentrated
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Non-Foliated Metamorphic Rocks Quartzite
Note - Lacks Any Rock Cleavage, Slatey
Cleavage, Schistocity, Lineation, etc.
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Building Stone - QUARZTITE
Gebel el-Ahmur Quarry - Cairo
Aswan Several West Bank Quarries
Colossi of Memnon Remains of Mortuary Temple of
Amenhotep III
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Queen Nefertiti Queen of Akhenaten 18th
Dynasty 1352 1336 BCE Unfinished Head Paint on
Quartzite
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METAMORPHIC ROCKS Hornfels
HORNFELS Metamorphic
GRAYWACKE Sedimentary Parent
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MINERAL AND ROCK RESOURCES Gneiss Statuary
Granodiorite Statuary, Sarguhagus Peridotie Stat
uary 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
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EGYPT Civilization Geology Geosciences 2020
METAMORPHISM AND METAMORPHIC ROCKS