View
235
Download
0
Category
Preview:
Citation preview
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 1/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 2/91
A NATURALLY OCCURRING,INORGANIC, SOLID, WITH DEFINITE
CHEMICAL STRUCTURE & CRYSTALSTRUCTURE
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 3/91
A Naturally Occurring Solid Made of
One or More Minerals or Other Solid Substances
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 4/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 5/91
MINERALCOMPOSITION
TEXTURES
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 6/91
IGNEOUSMelting Of Rocksin Hot Deep
Crust & Upper
Mantle
MAGMA
(LIQUID & GASES)
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 7/91
SEDIMENTARYWeathering &
erosion of rocksexposed atsurface
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 8/91
METAMORPHICRocks Under HighTemperatures &
Pressures in
Deep Crust &Upper Mantle
SOLID STAGE
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 9/91
IGNEOUSCrystallization
(Differentiation &Solidification ofMagma)
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 10/91
Deposition, burial& lihtification
SEDIMENTARY
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 11/91
Recrystallization insolid state ofnew minerals
METAMORPHIC
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 12/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 13/91
Igneous (ig nee us) isthe term applied to the
rocks that form by thecrystallization of theirconstituent mineralsout of magma (molten
materials below thesurface) or from lava on the earth's surface
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 14/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 15/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 16/91
BATHOLITH
PYROCLASTIC ASH
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 17/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 18/91
AT LEAST PARTLY SMALL CRYSTALS AND/OR GLASS
- produced by relatively fast cooling, usually at or near the
earth’s surface
- typical of extrusive (volcanic) rocks
- sometimes in intrusive rocks (small, shallow intrusions)
glassy texture - no crystals
APHANITIC TEXTURE - very small crystalsPORPHYRITIC TEXTURE - mixed sizes
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 19/91
OTHER TEXTURESBUBBLES: vesicular texture
Gas bubbles trapped in an igneous rock are called vesicles.
Examples: vesicular basalt and pumice
BROKEN FRAGMENTS: pyroclastic texture
If there is enough gas, expanding bubbles may cause lava
to explosively break into fragments.Examples: volcanic ash and pumice
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 20/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 21/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 22/91
AQP CLASSIFICATION (Feldspathic Rocks)
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 23/91
QAP CLASSIFICATION (Volcanic Rocks)
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 24/91
AQP CLASSIFICATION (Plutonic Rocks)
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 25/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 26/91
BASALTIC CLASSIFICATION
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 27/91
CLASSIFICATION PYROCLASTIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 28/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 29/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 30/91
Sedimentary rocks arerocks that are formed
from unconsolidatedcollections of rocks,mineral grains and
organic materials that
have been moved anddeposited by the actionof water, wind, or ice.
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 31/91
rock fragments collect
consolidated
coherent sediment mass
become lithified (convertedinto a truly cohesive solid)
LITHIFICATION PROCESS (LOW T)
As sedimentary rock show
signs of change
to be undergoing
DIAGENESIS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 32/91
LITHIFICATION PROCESS (LOW T)
COMPACTION AND RECRYSTALLIZATION - As sediments pile up, the ones on the
bottom are placed under pressure. The result of this pressure is a compaction of the
sediment; it is squeezed together causing a reduction in pore space and a sticking together
of the grains. Under pressure, some chemical sediments, like halite, may recrystallize into a
solid state.
CEMENTATION- Most sediments are deposited in water. This water, containing dissolved
minerals, flows through the sediment and some of these minerals precipitate on the grain
surfaces. With enough time, this intergranular material effectively glues the sediment
together into a cohesive solid- a sedimentary rock.
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 33/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 34/91
CLASTIC SEDIMENTARY ROCK
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 35/91
CLASTIC SEDIMENTARY ROCK
THE ULTIMATE SOURCE of sediment is FROM OLDER ROCKS that
are exposed to the surface and are weathered and broken intosmaller pieces. These pieces may be CARRIED AWAY A STREAM,
bulldozed by a GLACIER, or picked up by the WIND as their
SEDIMENT LOAD. Ultimately these sediments are DEPOSITED and
may CONSOLIDATE into A COHESIVE MASS that we callCLASTIC or fragmental sedimentary rock. These rocks DO NOT
HAVE THE INTERLOCKING CRYSTAL CHARACTERISTICS of
igneous rocks. Clastic rocks are COMPOSED OF BROKEN UP
PIECES OF PREEXISTING ROCKS AND MINERALS. We can
further IDENTIFY these rocks based on THE SIZE OF THE
FRAGMENTS THAT THEY ARE COMPOSED.
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 36/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 37/91
MAXIMUM GRAIN SIZE: fine, medium, coarse
GRAIN SHAPE: angular, rounded
SORTING: well-sorted, poorly-sortedWell-sorted,
angular
Poorly sorted
Mixture of sand
& gravel with
Rounded fragments
MAXIMUM GRAIN SIZE fi di
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 38/91
MAXIMUM GRAIN SIZE: fine, medium, coarse
MAXIMUM GRAIN SIZE fi di
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 39/91
MAXIMUM GRAIN SIZE: fine, medium, coarse
GRAIN SHAPE R d d A l
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 40/91
GRAIN SHAPE: Rounded, Angular
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 41/91
SORTING W ll S t d P l S t d
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 42/91
SORTING: Well Sorted, Poorly Sorted
SORTING W ll S t d P l S t d
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 43/91
SORTING: Well Sorted, Poorly Sorted
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 44/91
EXAMPLES
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 45/91
EXAMPLES
EXAMPLES
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 46/91
EXAMPLES
EXAMPLES
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 47/91
EXAMPLES
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 48/91
CLASTIC SEDIMENTARY ROCK
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 49/91
CLASSIFICATION OF CLASTIC SEDIMENTARY
ROCKS BY TEXTURE
TEXTURE ROCK TYPE
coarse, rounded Conglomerate
coarse, angular Breccia
medium Sandstone
fine Siltstone, Mudstone,
Claystone, or Shale
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 50/91
CLASSIFICATION OF CLASTIC SEDIMENTARY
ROCKS BY TEXTURE
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 51/91
CLASSIFICATION OF CLASTIC SEDIMENTARY
ROCKS BY TEXTURE
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 52/91
CLASSIFICATION OF CLASTIC SEDIMENTARY
ROCKS BY TEXTURE
CLASSIFICATION OF CLASTIC SEDIMENTARY
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 53/91
CLASSIFICATION OF CLASTIC SEDIMENTARY
ROCKS BY TEXTURE
Classification of Sandstones by Composition
COMPOSITION ROCK TYPE
Pure Quartz Sand quartz sandstone
Sand Which Includes at arkosic sandstone
Least 20% Feldspar
Sand Which Includes at lithic sandstone
Least 20% Rock Fragments
Sand and Fine Matrix graywacke sandstone
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 54/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 55/91
CLASSIFICATION OF BIOLOGIC & CHEMICAL
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 56/91
CLASSIFICATION OF BIOLOGIC & CHEMICAL
SEDIMENTARY ROCKS BY TEXTURE
COMPOSITION ROCK TYPE
calcite (may also contain some mud) limestone
plant remains coal or peat
silica chert
halite rock salt
gypsum rock gypsum
CLASSIFICATION OF BIOLOGIC & CHEMICAL
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 57/91
CLASSIFICATION OF BIOLOGIC & CHEMICAL
SEDIMENTARY ROCKS BY TEXTURE
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 58/91
CLASSIFICATION OF BIOLOGIC & CHEMICAL
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 59/91
CLASSIFICATION OF BIOLOGIC & CHEMICAL
SEDIMENTARY ROCKS BY TEXTURE
CLASSIFICATION OF BIOLOGIC & CHEMICAL
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 60/91
CLASSIFICATION OF BIOLOGIC & CHEMICAL
SEDIMENTARY ROCKS BY TEXTURE
CLASSIFICATION OF BIOLOGIC & CHEMICAL
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 61/91
CLASSIFICATION OF BIOLOGIC & CHEMICAL
SEDIMENTARY ROCKS BY TEXTURE
CLASSIFICATION OF BIOLOGIC & CHEMICAL
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 62/91
CLASSIFICATION OF BIOLOGIC & CHEMICAL
SEDIMENTARY ROCKS BY TEXTURE
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 63/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 64/91
METAMORPHISM
• includes processes which
change the minerals and
texture of rock withoutmelting it
• caused by changes inpressure, changes in
temperature, and/or fluids
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 65/91
THE TERM METAMORPHIC is derived from the Latin term
meaning, "CHANGE OF FORM". These rocks have been
ALTERED while in THEIR SOLID STATE as a response to
the environment. Extreme circumstances of PRESSUREAND TEMPERATURE, or an introduction of certain
chemicals, can cause the existing rocks minerals to
RECRYSTALLIZE, and they may even become different
minerals all together. It is important that you realize thatthe ROCK REMAINS IN ITS SOLID STATE. Once a rocks
minerals are melted, and then recrystallize, the new
material will be igneous.
CAUSES OF METAMORPHISM
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 66/91
CAUSES OF METAMORPHISM
PRESSURE
- different minerals are stable at different pressures
- changing the pressure can cause the types of minerals
present in a rock to change
CONFINING PRESSURE (LITHOSTATIC PRESSURE)- equal pressure in all directions
- increased confining pressure can cause minerals with
more compact (denser) structures to form
DIRECTED PRESSURE- pressure which is greater in a specific direction
- may cause folding or cause mineral to grow with a
specific orientation
CAUSES OF METAMORPHISM
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 67/91
CAUSES OF METAMORPHISM
TEMPERATURE
- different minerals are stable at different temperatures
- changing the temperature can cause the types of minerals
present in a rock to change
HYDROTHERMAL FLUIDS
(mostly water and/or carbon dioxide plus dissolved material)
- can change the overall chemical composition of a rock by
adding or removing material- many important ore deposits have been formed by this
metamorphic process
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 68/91
TYPE OF METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 69/91
TYPE OF METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 70/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 71/91
CLASSIFICATION OF METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 72/91
A FOLIATED :This is determined by the presence of
minerals that are aligned parallel to each other. This
results in a layered appearance.
A NONFOLIATED metamorphic rock generally consists of
equaldimensional grains.
A rock can also be IDENTIFIED BY ITS METAMORPHICGRADE.
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 73/91
FOLIATED METAMORPHIC ROCKS
- foliation refers to a preferred orientation of mineral grains
found in some metamorphic rocks
- metamorphic rocks which have a preferred orientation of mineral grains are called foliated metamorphic rocks
- the preferred orientation is the result of directed
pressure
NON-FOLIATED METAMORPHIC ROCKS
- lack a preferred orientation of mineral grains
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 74/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 75/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 76/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 77/91
SEDIMENTARY TO METAMORPHIC
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 78/91
SEDIMENTARY TO METAMORPHIC
The following is a very general progression from
sedimentary rock to metamorphic rock based primarily on
pressure
SURFACE MUD5 km DEEP SHALE (sedimentary)
10 km DEEP SLATE (low grade metamorphic)
15 km DEEP SCHIST (Garnet appears)
20 km DEEP GNEISS (high grade metamorphic)25 km DEEP HORNFELS (Cordierite appears)
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 79/91
Shale Slate PhylliteSchist
Gneis
Sandstone
Quarzite
Limestone
Marble
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 80/91
TYPES OF FOLIATED METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 81/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 82/91
TYPES OF FOLIATED METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 83/91
TEMPERATURE
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 84/91
TEMPERATURE
MAGMA
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 85/91
TYPES OF NON- FOLIATED METAMORPHIC ROCKS
QUARTZITE - composed primarily of quartz (REGIONAL)
MARBLE - composed mostly of calcite and/or dolomite
HORNFELS - variable composition
SKARN - contains mostly calcite and/or dolomite with garnet
TYPES OF NON FOLIATED METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 86/91
TYPES OF NON- FOLIATED METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 87/91
OTHERS METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 88/91
MYLONITE- formed in the deepest parts of fault zones
MIGMATITE
- formed when a rock begins to partially melt- represents the transition between metamorphic and
igneous rock
OTHERS METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 89/91
OTHERS METAMORPHIC ROCKS
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 90/91
8/3/2019 Present Lect1
http://slidepdf.com/reader/full/present-lect1 91/91
Recommended