Sedimentary Rocks and the Rock Cycle Designed to meet South Carolina Department of Education 2005...

Sedimentary Sedimentary Rocks and the Rocks and the

Rock CycleRock CycleDesigned to meet South Carolina Designed to meet South Carolina

Department of Education Department of Education

2005 Science Academic Standards2005 Science Academic Standards

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Table of ContentsTable of Contents What are Rocks? (What are Rocks? (slide 3)) Major Rock Types (Major Rock Types (slide 4) () (standard 3-3.1)) The Rock Cycle (The Rock Cycle (slide 5) ) Sedimentary Rocks (Sedimentary Rocks (slide 6))

Diagenesis (Diagenesis (slide 7)) Naming and Classifying Sedimentary Rocks (Naming and Classifying Sedimentary Rocks (slide 8)) Texture: Grain Size (Texture: Grain Size (slide 9), Sorting (), Sorting (slide 10) , and Rounding () , and Rounding (slide 11) ) Texture and Weathering (Texture and Weathering (slide 12)) Field Identification (Field Identification (slide 13)) Classifying Sedimentary Rocks (Classifying Sedimentary Rocks (slide 14)) Sedimentary Rocks: (Sedimentary Rocks: (slide 15) )

Clastic Sedimentary Rocks: Sandstone (Clastic Sedimentary Rocks: Sandstone (16) , Siltstone () , Siltstone (17), Shale (), Shale (18), Mudstone (), Mudstone (19) , Conglomerate () , Conglomerate (20), Breccia (), Breccia (21) , and Kaolin () , and Kaolin (22))

Chemical Inorganic Sedimentary Rocks : Dolostone (Chemical Inorganic Sedimentary Rocks : Dolostone (23) and Evaporites () and Evaporites (24)) Chemical / Biochemical Sedimentary Rocks: Limestone (Chemical / Biochemical Sedimentary Rocks: Limestone (25) , Coral Reefs () , Coral Reefs (26), Coquina ), Coquina

and Chalk (and Chalk (27), Travertine (), Travertine (28) and Oolite () and Oolite (29)) Chemical Organic Sedimentary Rocks : Coal (Chemical Organic Sedimentary Rocks : Coal (30), Chert (), Chert (31): Flint, Jasper and Agate (): Flint, Jasper and Agate (

32)) Stratigraphy (Stratigraphy (slide 33) and Sedimentary Structures () and Sedimentary Structures (slide 34 ))

Sedimentary Rocks in South Carolina (Sedimentary Rocks in South Carolina (slide 35)) Sedimentary Rocks in the Landscape (Sedimentary Rocks in the Landscape (slide 36)) South Carolina Science Standards (South Carolina Science Standards (slide 37)) Resources and References (Resources and References (slide 38)

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What are Rocks?What are Rocks? Most rocks are an aggregate of one or more Most rocks are an aggregate of one or more

minerals and a few rocks are composed of non-minerals and a few rocks are composed of non-mineral matter.mineral matter.

There are three major rock types: There are three major rock types:

1. Igneous1. Igneous 2. Metamorphic2. Metamorphic 3. Sedimentary3. Sedimentary

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Major Rock TypesMajor Rock Types IgneousIgneous rocks are formed by the cooling of rocks are formed by the cooling of

molten magma or lava near, at, or below the molten magma or lava near, at, or below the Earth’s surface.Earth’s surface.

SedimentarySedimentary rocks are formed by the lithification rocks are formed by the lithification of inorganic and organic sediments deposited at of inorganic and organic sediments deposited at or near the Earth’s surface.or near the Earth’s surface.

MetamorphicMetamorphic rocks are formed when preexisting rocks are formed when preexisting rocks are transformed into new rocks by rocks are transformed into new rocks by elevated heat and pressure below the Earth’s elevated heat and pressure below the Earth’s surface.surface.

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The Rock CycleThe Rock Cycle

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The Rock Cycle graphic is available from the SCGS website: http://www.dnr.sc.gov/geology/images/Rockcycle-pg.pdf

Sedimentary rocks are formed by the lithification of inorganic Sedimentary rocks are formed by the lithification of inorganic and/or organic sediments, or as chemical precipitates.and/or organic sediments, or as chemical precipitates.

There are two types of sedimentary rocks: There are two types of sedimentary rocks: Clastic Clastic and and ChemicalChemical

ClasticClastic sedimentary rocks formsedimentary rocks form when existing parent rock when existing parent rock material is weathered, fragmented, transported, and deposited material is weathered, fragmented, transported, and deposited in layers that compact, cement, and lithify to form sedimentary in layers that compact, cement, and lithify to form sedimentary rocks.rocks.

Chemical Chemical sedimentary rocks are formed by a variety of sedimentary rocks are formed by a variety of processes and are divided into sub-categories including processes and are divided into sub-categories including inorganic, inorganic, and and biochemical or organic chemical biochemical or organic chemical sedimentary sedimentary rocks.rocks.

Inorganic Inorganic chemical rocks form from chemicals that are chemical rocks form from chemicals that are dissolved in a solution, transported, and chemically dissolved in a solution, transported, and chemically precipitated out of solution.precipitated out of solution.

Biochemical or Organic Biochemical or Organic sedimentary rocks form when plant sedimentary rocks form when plant or animal material is deposited and lithified. Those or animal material is deposited and lithified. Those classified as biochemical chemical generally involve some classified as biochemical chemical generally involve some form of fossilization or the accumulation of fossilized form of fossilization or the accumulation of fossilized organism or organism remains, such as shell fragments. organism or organism remains, such as shell fragments. Organic rocks that are classified as clastic, involve the Organic rocks that are classified as clastic, involve the deposition of plant material and formation of peat and coal deposition of plant material and formation of peat and coal deposits. deposits.

The physical, chemical, or biological changes that occur during the The physical, chemical, or biological changes that occur during the lithification of sedimentary rocks are described by process lithification of sedimentary rocks are described by process collectively referred to as collectively referred to as diagenesisdiagenesis. .

Sedimentary RocksSedimentary Rocks

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DiagenesisDiagenesis Diagenesis collectively refers to the physical, Diagenesis collectively refers to the physical,

chemical, and biological changes which may occur chemical, and biological changes which may occur during the formation of sedimentary rocks. during the formation of sedimentary rocks. Recrystallization, compaction, cementation, and Recrystallization, compaction, cementation, and lithification,lithification, are all examples of diagenetic changes. are all examples of diagenetic changes.

RecrystallizationRecrystallization occurs whenoccurs when unstable minerals recrystallize to unstable minerals recrystallize to form more stable minerals. Recrystallization most often occurs form more stable minerals. Recrystallization most often occurs during the formation of chemical sedimentary limestone rocks during the formation of chemical sedimentary limestone rocks that previously contained aragonite a chemically unstable form that previously contained aragonite a chemically unstable form of calcium carbonate (CaCOof calcium carbonate (CaCO33). ).

Compaction Compaction occurs when sediments are progressively deposited occurs when sediments are progressively deposited on top of one another, and over time the weight of the on top of one another, and over time the weight of the accumulated sediments increases and compresses the buried accumulated sediments increases and compresses the buried sediments. Continued compression of buried sediments reduces sediments. Continued compression of buried sediments reduces pore-spaces and removes excess water, as a result the closely pore-spaces and removes excess water, as a result the closely packed individual grains begin to slowly compact into a solid packed individual grains begin to slowly compact into a solid rock.rock.

CementationCementation involves a chemical change whereby individual involves a chemical change whereby individual grains are cemented together as minerals are precipitated out grains are cemented together as minerals are precipitated out of saturated solution that is percolating as a matrix between of saturated solution that is percolating as a matrix between individual sediments. The accumulation of the precipitated individual sediments. The accumulation of the precipitated minerals causes the grains to cement together. Cementation minerals causes the grains to cement together. Cementation can occur in combination with the presence of other minerals, can occur in combination with the presence of other minerals, rock fragments, or organic constituents such as fossilized rock fragments, or organic constituents such as fossilized organisms.organisms.

Lithification Lithification occurs when unconsolidated sediments are occurs when unconsolidated sediments are cohesively bound to form a solid sedimentary rock. Compaction cohesively bound to form a solid sedimentary rock. Compaction and/or cementation are generally the precursor to the and/or cementation are generally the precursor to the lithification process.lithification process.

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Naming and Classifying Naming and Classifying Sedimentary RocksSedimentary Rocks

Geologists name and classify sedimentary rocks based on their Geologists name and classify sedimentary rocks based on their mineral composition and texture mineral composition and texture

Mineral composition Mineral composition refers to the specific minerals in the rock. refers to the specific minerals in the rock. For example sandstone will contain predominantly quartz, For example sandstone will contain predominantly quartz, while limestone will contain mainly calcite (calcium while limestone will contain mainly calcite (calcium carbonate). carbonate).

TextureTexture includes the grain size and shape, sorting, and includes the grain size and shape, sorting, and rounding of the sediments that form the rock.rounding of the sediments that form the rock.

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Texture: Grain SizeTexture: Grain Size Grain size is used to describe the size of the individual mineral Grain size is used to describe the size of the individual mineral

grains, rock fragments, or organic material that are cemented grains, rock fragments, or organic material that are cemented together to form a clastic or chemical sedimentary rocktogether to form a clastic or chemical sedimentary rock

Grain Size Categories

Grain Size Divisions

very coarse-grained > 16 mm

coarse grained > 2 mm < 16 mm

medium grained > 0.25 mm < 2 mm

fine grained > 0.032 mm < 0.25 mm

very fine-grained > 0.0004 mm < 0.032 mm

cryptocrystalline < 0.0004 mm (4 μm )

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Texture: SortingTexture: Sorting Sorting Sorting is used to describe the grain size distribution or is used to describe the grain size distribution or

range of grain sizes in a rock.range of grain sizes in a rock.

Poorly sorted Poorly sorted rocks contain a variety of different sized rocks contain a variety of different sized grains. Poorly sorted rocks contain a wide range of grain grains. Poorly sorted rocks contain a wide range of grain sizes including fine, medium, and coarse.sizes including fine, medium, and coarse.

Well sorted Well sorted rocks contain almost all grains of the same size.rocks contain almost all grains of the same size.

Moderately sorted Moderately sorted rocks contain particles of relatively rocks contain particles of relatively similar grain sizes. Moderately sorted rocks may contain fine similar grain sizes. Moderately sorted rocks may contain fine and medium grains, or medium and coarse grains.and medium grains, or medium and coarse grains.

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Poorly SortedPoorly Sorted Well SortedWell Sorted

Texture: RoundingTexture: Rounding RoundingRounding is used to describe the relative shape of the grains. is used to describe the relative shape of the grains.

Classifications are describe as deviations from rounded or Classifications are describe as deviations from rounded or spheroidal grain shapes. spheroidal grain shapes.

Well rounded Well rounded grains are smooth with rounded edges..grains are smooth with rounded edges..

Moderately rounded Moderately rounded grains are in-between the sharp, grains are in-between the sharp, angular edges of a poorly rounded grain and the smooth, angular edges of a poorly rounded grain and the smooth, roundness of a well-rounded grain.roundness of a well-rounded grain.

Poorly rounded Poorly rounded grains may be sharp or angular.grains may be sharp or angular.


Well-rounded, Well-rounded, spheroidal grainsspheroidal grains

Poorly–rounded,Poorly–rounded, angular grainsangular grains

Texture and WeatheringTexture and Weathering The texture of a sedimentary rock can provide a lot of information The texture of a sedimentary rock can provide a lot of information

about the types of environments that the sediments were weathered about the types of environments that the sediments were weathered in, transported by, and deposited in prior to their lithification into in, transported by, and deposited in prior to their lithification into sedimentary rocks.sedimentary rocks.

Most sedimentary rocks consist of grains that weathered from a Most sedimentary rocks consist of grains that weathered from a parent rock and were transported by water, wind, or ice before being parent rock and were transported by water, wind, or ice before being deposited. deposited.

Grain size is a good indicator of the energy or force required to Grain size is a good indicator of the energy or force required to move a grain of a given size. Large sediments such as gravel, move a grain of a given size. Large sediments such as gravel, cobbles, and boulders require more energy to move than smaller cobbles, and boulders require more energy to move than smaller sand, silt, and clay sized sediments. Grain size is also an indicator sand, silt, and clay sized sediments. Grain size is also an indicator of the distance or length of time the sediments may have traveled. of the distance or length of time the sediments may have traveled. Smaller grain sizes generally indicate greater transport distances Smaller grain sizes generally indicate greater transport distances and duration than larger grains. and duration than larger grains.

Sorting will generally improve with the constant or persistent Sorting will generally improve with the constant or persistent moving of particles, and thus can indicate if particles were moving of particles, and thus can indicate if particles were transported over a long distance or for a long time period. Sorting transported over a long distance or for a long time period. Sorting can also indicate selective transport of a particular grain size.can also indicate selective transport of a particular grain size.

Rounding is a good indicator for the amount of abrasion Rounding is a good indicator for the amount of abrasion experienced by sediments. In general, sediments that have been experienced by sediments. In general, sediments that have been transported longer distances will be more rounded than those transported longer distances will be more rounded than those which have traveled shorter distances.which have traveled shorter distances.

An example based on these principles, is that sediments deposited by An example based on these principles, is that sediments deposited by rapid mass wasting events, such as landlsides are expected to be rapid mass wasting events, such as landlsides are expected to be coarse grained, poorly sorted, and poorly rounded; and sediments coarse grained, poorly sorted, and poorly rounded; and sediments deposited by slower, more gradual processes, such as dune deposited by slower, more gradual processes, such as dune formation, are expected to be fine grained, well sorted, and well formation, are expected to be fine grained, well sorted, and well rounded. rounded.


Field IdentificationField Identification Geologists often use reference guides to identify and Geologists often use reference guides to identify and

measure textural characteristics of the sediments. This measure textural characteristics of the sediments. This is an example of a card used to aid in the identification is an example of a card used to aid in the identification textural characteristics. A card like this may be carried textural characteristics. A card like this may be carried in a geologist’s pocket or around their neck.in a geologist’s pocket or around their neck.

Front of cardFront of card

Back of cardBack of card


Classifying Sedimentary Classifying Sedimentary RocksRocks


Sedimentary RocksSedimentary Rocks ClasticClastic

SandstoneSandstone SiltstoneSiltstone ShaleShale MudstoneMudstone ConglomerateConglomerate BrecciaBreccia KaolinKaolin

Chemical Inorganic Chemical Inorganic Sedimentary RocksSedimentary Rocks

DolostoneDolostone EvaporitesEvaporites

Chemical / BiochemicalChemical / Biochemical Sedimentary RocksSedimentary Rocks

LimestoneLimestone Coral ReefsCoral Reefs Coquina and ChalkCoquina and Chalk

Inorganic LimestoneInorganic Limestone TravertineTravertine OoliticOolitic

ChertChert Flint, Jasper, AgateFlint, Jasper, Agate


Sedimentary Rocks in North AmericaSedimentary Rocks in North America

Source: USGS http://pubs.usgs.gov/imap

SandstoneSandstone Sandstone rocks are composed almost entirely of sand-Sandstone rocks are composed almost entirely of sand-

sized quartz grains (0.063 – 2 mm) cemented together sized quartz grains (0.063 – 2 mm) cemented together through lithification.through lithification.

Sandstone rocks are generally classified as quartz Sandstone rocks are generally classified as quartz sandstone, arkose (quartz with feldspars), or graywacke sandstone, arkose (quartz with feldspars), or graywacke (quartz with feldspar, clay, and other coarse-grained (quartz with feldspar, clay, and other coarse-grained mineral fragments).mineral fragments).

Sandstones comprise about 20% of all sedimentary rocks Sandstones comprise about 20% of all sedimentary rocks and are formed in a variety of different environments and are formed in a variety of different environments including fluvial (rivers), marine, coastal (oceans and including fluvial (rivers), marine, coastal (oceans and beaches), aeolian (wind blown), and glacial (ice).beaches), aeolian (wind blown), and glacial (ice).

The differences in texture, sorting, and rounding help The differences in texture, sorting, and rounding help geologists decipher the environmental conditions that geologists decipher the environmental conditions that formed the sandstone.formed the sandstone.


Courtesy: Florida Department of Environmental Protection

ShaleShale Shale is a fine-grained, moderately to well-sorted rock Shale is a fine-grained, moderately to well-sorted rock

formed by the compaction of well rounded silt-and clay-formed by the compaction of well rounded silt-and clay-sized grains.sized grains.

Shales often contain fine laminations which helps impart Shales often contain fine laminations which helps impart fissility to the rock. Fissility is a term used to describe fissility to the rock. Fissility is a term used to describe layered laminations formed by compression forces exerted layered laminations formed by compression forces exerted over long-time periods.over long-time periods.

Shale usually contains about 50% silt, 35% clay, and 15% Shale usually contains about 50% silt, 35% clay, and 15% chemical materials, many shales may also contain organic chemical materials, many shales may also contain organic plant materials and fossils.plant materials and fossils.

Shale is characterized by thinly, laminated layers, Shale is characterized by thinly, laminated layers, representing successive deposition of sediments.representing successive deposition of sediments.

Shale accounts for about 50% of all sedimentary rocks Shale accounts for about 50% of all sedimentary rocks deposited on the Earth’s surface.deposited on the Earth’s surface.

The sediments that form shale are most likely deposited The sediments that form shale are most likely deposited very gradually in non-turbulent, environments such as a very gradually in non-turbulent, environments such as a lakes, lagoons, flood plains, and deep-ocean basins.lakes, lagoons, flood plains, and deep-ocean basins.

1717Table of ContentsCopyright ©Andrew Alden

SiltstoneSiltstone Siltstone is finer grained than sandstone, but coarser Siltstone is finer grained than sandstone, but coarser

grained than mudstone, and it consists primarily of well-grained than mudstone, and it consists primarily of well-sorted, rounded grains ranging between 3.9 - 62.5sorted, rounded grains ranging between 3.9 - 62.5 μ μm.m.

Siltstone is similar to shale except that it lacks fissility. Siltstone is similar to shale except that it lacks fissility.


Copyright ©Andrew Alden

MudstoneMudstone Mudstone consists of very silt-sized and clay-sized Mudstone consists of very silt-sized and clay-sized

grains grains ( <0.0625 mm) and are often well consolidated with ( <0.0625 mm) and are often well consolidated with little pore space. little pore space.

Mudstones do not contain laminations or fissility, but Mudstones do not contain laminations or fissility, but they may contain bedding-plane features such as they may contain bedding-plane features such as mud cracks or ripples. Mud cracks are formed by mud cracks or ripples. Mud cracks are formed by subaerial drying conditions. Ripples suggest gentle subaerial drying conditions. Ripples suggest gentle wave activity or water movement during deposition. wave activity or water movement during deposition.


http://www.auckland.ac.nz/

ConglomerateConglomerate Conglomerates are poorly-sorted composites of a Conglomerates are poorly-sorted composites of a

wide range of rounded grain sizes ranging from sand wide range of rounded grain sizes ranging from sand to cobbles (< 0.062 to > 2 mm). to cobbles (< 0.062 to > 2 mm).

Conglomerates usually contain a framework of large Conglomerates usually contain a framework of large grains held together by a matrix of sands, silt, and grains held together by a matrix of sands, silt, and clay-sized particles. clay-sized particles.

The combination of poorly-sorted, predominantly The combination of poorly-sorted, predominantly coarse, rounded grains suggests that conglomerates coarse, rounded grains suggests that conglomerates form in high-energy environments such as steep-form in high-energy environments such as steep-gradient streams.gradient streams.

South Carolina Geological South Carolina Geological SurveySurvey


BrecciaBreccia Breccia is a poorly-sorted composite of a wide Breccia is a poorly-sorted composite of a wide

range of grain sizes ranging from clays to gravels (< range of grain sizes ranging from clays to gravels (< 0.062 to > 2 mm). 0.062 to > 2 mm).

Breccias usually contain a framework of gravel-sized Breccias usually contain a framework of gravel-sized grains held together by a matrix of sands, silts, and grains held together by a matrix of sands, silts, and clay. clay.

Breccia is similar to a conglomerate except that it Breccia is similar to a conglomerate except that it consists of angular grains, as opposed to rounded consists of angular grains, as opposed to rounded grains.grains.

The combination of poorly-sorted, predominantly The combination of poorly-sorted, predominantly coarse, angular grains suggests that breccias form coarse, angular grains suggests that breccias form from rapid deposition in high energy environments from rapid deposition in high energy environments such as steep-gradient streams, glacial flood such as steep-gradient streams, glacial flood deposits, landslides, talus, alluvial fans, or in deposits, landslides, talus, alluvial fans, or in association with faulting.association with faulting.

South Carolina Geological SurveySouth Carolina Geological Survey 2121Table of Contents

KaolinKaolin Kaolin consists of very fine-grained kaolinite clay weathered from Kaolin consists of very fine-grained kaolinite clay weathered from

feldspar minerals in metamorphic and igneous rocks. feldspar minerals in metamorphic and igneous rocks. Kaolin is generally very light colored to off-white. Kaolin is generally very light colored to off-white. Kaolin is mined in several counties of South Carolina, including Kaolin is mined in several counties of South Carolina, including

Aiken, Lexington, Richland, Kershaw, and Chesterfield Counties.Aiken, Lexington, Richland, Kershaw, and Chesterfield Counties.

Florida Department of Environmental Protection, Florida Geological SurveyFlorida Department of Environmental Protection, Florida Geological Survey2222

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GallmanK

Moved text box just a little.

DolostoneDolostone Dolostone is composed of Dolomite, a calcium-magnesium Dolostone is composed of Dolomite, a calcium-magnesium

carbonate mineral.carbonate mineral. Dolostone forms when magnesium in pore water replaces Dolostone forms when magnesium in pore water replaces

some of the calcium present in limestone. For this reason, some of the calcium present in limestone. For this reason, dolostone is often preceded by the formation of limestone dolostone is often preceded by the formation of limestone deposits. Dolostone forms very slowly and is rarely observed deposits. Dolostone forms very slowly and is rarely observed forming in modern environments. forming in modern environments.

Dolostone abundance increases with age. There are more Dolostone abundance increases with age. There are more older than younger dolostones.older than younger dolostones.

Copyright © Roger Slatt 2323Table of Contents

EvaporitesEvaporites Evaporites are chemical deposits formed when restricted Evaporites are chemical deposits formed when restricted

bodies of saline water evaporate, precipitating out a range of bodies of saline water evaporate, precipitating out a range of minerals.minerals.

Evaporite deposits do not involve a single chemical Evaporite deposits do not involve a single chemical precipitate, instead they consist of chlorides, sulfides, precipitate, instead they consist of chlorides, sulfides, carbonates, and borates. carbonates, and borates.

Halite and gypsum are two common examples of mineral Halite and gypsum are two common examples of mineral precipitates. precipitates.

Utah’s Bonneville Salt FlatsUtah’s Bonneville Salt Flats

Copyright © Bruce Molnia, USGS


LimestoneLimestone Limestone consists almost entirely of the mineral calcite Limestone consists almost entirely of the mineral calcite

(CaCO(CaCO33) and can form by either inorganic or biochemical ) and can form by either inorganic or biochemical processes. processes.

Limestones form under a variety of environmental Limestones form under a variety of environmental conditions and for this reason several types of limestone conditions and for this reason several types of limestone exist.exist.

Limestone accounts for about 10% of all sedimentary rocks, Limestone accounts for about 10% of all sedimentary rocks, and of those, limestones with marine biochemical origin and of those, limestones with marine biochemical origin are the most common.are the most common.


Copyright © Glen J. Kuban

This example of limestone This example of limestone formed in a shallow, marine formed in a shallow, marine

environment where dinosaurs environment where dinosaurs once roamed the Earth. This set once roamed the Earth. This set

of tracks is from an of tracks is from an Arancanthosaurus Arancanthosaurus track in the track in the Paluxy River in Dinosaur Valley Paluxy River in Dinosaur Valley State Park in Glen Rose, Texas.State Park in Glen Rose, Texas.

Coral ReefsCoral Reefs Coral Reefs are limestone formations created by marine Coral Reefs are limestone formations created by marine

organisms.organisms. Corals are invertebrate animals which secrete a calcareous Corals are invertebrate animals which secrete a calcareous

(calcite-rich) external skeleton . Over long periods of time coral (calcite-rich) external skeleton . Over long periods of time coral colonies form massive reef formations. Some of which surround colonies form massive reef formations. Some of which surround entire islands or extend along the shoreline for 100’s of miles.entire islands or extend along the shoreline for 100’s of miles.

The Florida Keys were once an underwater coral reef rich in The Florida Keys were once an underwater coral reef rich in biodiversity of sea life. Today the Keys are lithified limestone biodiversity of sea life. Today the Keys are lithified limestone deposits exposed above modern sea level. Living coral reefs exist deposits exposed above modern sea level. Living coral reefs exist offshore along the Atlantic Coast of the Keys.offshore along the Atlantic Coast of the Keys.

South Carolina Geological Survey

This is an example of a fossilized This is an example of a fossilized brain coral from the Key Largo brain coral from the Key Largo

Limestone formation in the Limestone formation in the Florida Keys. Interestingly Florida Keys. Interestingly

snorkelers and divers can view snorkelers and divers can view living brain coral just 20 miles living brain coral just 20 miles offshore from these fossilized offshore from these fossilized

coral reefs.coral reefs.


Coquina and ChalkCoquina and Chalk Coquina rock formations are poorly cemented, coarse-textured Coquina rock formations are poorly cemented, coarse-textured

masses of shells and shell fragments. masses of shells and shell fragments. The shells and shell fragments are easily discerned, and they The shells and shell fragments are easily discerned, and they

give the rock a rough, sharp texture.give the rock a rough, sharp texture. Chalk is formed from calcareous microscopic marine organisms Chalk is formed from calcareous microscopic marine organisms

(nanofossils). When the organisms die their exoskeletons fall (nanofossils). When the organisms die their exoskeletons fall to the ocean floor creating a sedimentary layer. to the ocean floor creating a sedimentary layer.

Anastasia Formation coquinaAnastasia Formation coquina

Florida Department of Environmental Protection, Florida Geological SurveyFlorida Department of Environmental Protection, Florida Geological Survey 2727Table of Contents

Meitzen Kimberly

http://www.dep.state.fl.us/geology/geologictopics/rocks/anastasia.htmrequested info for use of pictures

TravertineTravertine Travertine is an inorganic limestone that forms when calcium Travertine is an inorganic limestone that forms when calcium

carbonate precipitates out of ground water that discharges carbonate precipitates out of ground water that discharges from seeps, caves, grottos, springs, or along faults.from seeps, caves, grottos, springs, or along faults.

When the ground water becomes exposed to the atmosphere When the ground water becomes exposed to the atmosphere carbon dioxide dissolved in the water escapes, causing calcium carbon dioxide dissolved in the water escapes, causing calcium carbonate to precipitate out of the solution.carbonate to precipitate out of the solution.

Travertine also forms where water emerges from hot springs. Travertine also forms where water emerges from hot springs. The picture below is of a hot spring in Yellowstone National The picture below is of a hot spring in Yellowstone National Park. Park.

Copyright © Bruce Molnia, USGS2828

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OoliteOolite Oolitic limestone is formed by the cementation of tiny spherical Oolitic limestone is formed by the cementation of tiny spherical

grains called ooids.grains called ooids. Ooids form in warm, shallow marine environments. When small Ooids form in warm, shallow marine environments. When small

grains of shell roll back in forth in the current, They are coated grains of shell roll back in forth in the current, They are coated with calcium carbonate precipitating out of the supersaturated with calcium carbonate precipitating out of the supersaturated marine water. marine water.

Ooids exhibit growth rings from the accumulation of the calcium Ooids exhibit growth rings from the accumulation of the calcium carbonate precipitates. The presence of algae and sea-grasses carbonate precipitates. The presence of algae and sea-grasses accelerates and increases the formation of ooids.accelerates and increases the formation of ooids.

Ooid formation and oolitic limestones cover vast areas of the Ooid formation and oolitic limestones cover vast areas of the Bahamas creating shoals and tidal flats. Bahamas creating shoals and tidal flats.


Copyright Marli Miller, University of Oregon

CoalCoal Coal is made almost entirely of plant material and other Coal is made almost entirely of plant material and other

organic deposits that have been buried for millions of years organic deposits that have been buried for millions of years under elevated conditions of heat and pressure.under elevated conditions of heat and pressure.

Although the chemical composition of coal changes from its Although the chemical composition of coal changes from its organic origins, it often retains fossilized imprints of plant organic origins, it often retains fossilized imprints of plant leaves, bark, wood, and organisms that lived during the leaves, bark, wood, and organisms that lived during the time the organic materials were deposited. time the organic materials were deposited.

It requires very specific environmental conditions for plant It requires very specific environmental conditions for plant material to become coal. The organic material must be material to become coal. The organic material must be deposited in an anoxic (oxygen free) environment to deposited in an anoxic (oxygen free) environment to prevent it from decomposing. Most coal beds originated in prevent it from decomposing. Most coal beds originated in swampy, saturated, environments. swampy, saturated, environments.

Deposited organic material goes through four main phase Deposited organic material goes through four main phase of coal formation, which are related to increasing heat and of coal formation, which are related to increasing heat and pressure :pressure :

1. Peat 1. Peat 2. Lignite2. Lignite 3. Bituminous3. Bituminous 4. Anthracite4. Anthracite


Copyright ©Dr. Richard Busch

ChertChert Chert represent a group of hard rocks made from micro- and Chert represent a group of hard rocks made from micro- and

cryptocrystalline silica (SiOcryptocrystalline silica (SiO22). Chert can develop as a nodules inside ). Chert can develop as a nodules inside other rocks or as rock layers. other rocks or as rock layers.

Most cherts are hypothesized to originate from silica derived from Most cherts are hypothesized to originate from silica derived from one of three sources: solution in water, biochemical sediments, or one of three sources: solution in water, biochemical sediments, or lava flows and volcanic ash.lava flows and volcanic ash.

Silicate materials can be precipitated out of a solution in marine Silicate materials can be precipitated out of a solution in marine waters, or produced as a byproduct of water dwelling organisms. waters, or produced as a byproduct of water dwelling organisms. Diatoms and radiolarians extract it from their surroundings and Diatoms and radiolarians extract it from their surroundings and use it to grow silica-rich skeletons. When these organisms die use it to grow silica-rich skeletons. When these organisms die and settle to the bottom, their skeletons provide the silica and settle to the bottom, their skeletons provide the silica source for the chert to develop. source for the chert to develop.

Large beds of chert have been found to develop in association Large beds of chert have been found to develop in association with lava flows and volcanic ash. It is thought that the chert is with lava flows and volcanic ash. It is thought that the chert is the produced by the decomposition of volcanic ash. the produced by the decomposition of volcanic ash.

Chert occurs in a variety of forms including flint, jasper, and agate.Chert occurs in a variety of forms including flint, jasper, and agate.

Chert is a very hard rock that generally breaks along conchoidal Chert is a very hard rock that generally breaks along conchoidal fractures, this characteristic makes it possible to carve sharp-fractures, this characteristic makes it possible to carve sharp-pointed edges onto the rock. Native American’s used chert to create pointed edges onto the rock. Native American’s used chert to create arrowheads that were attached to primitive spears, arrows, and arrowheads that were attached to primitive spears, arrows, and knives. knives.


ChertChert

Flint Flint is the most common form of is the most common form of chert. It is often a dark, glassy, chert. It is often a dark, glassy, colored rock that forms as nodules colored rock that forms as nodules embedded in limestone. The dark embedded in limestone. The dark color of the chert comes from the color of the chert comes from the organic matter it contains.organic matter it contains.

Jasper Jasper is a red variety of chert is a red variety of chert that gets its color from iron oxide.that gets its color from iron oxide.

AgateAgate is a banded form of chert is a banded form of chert that may contain several different that may contain several different colors layered throughout the colors layered throughout the rock. rock.

JaspJasp

er er

Agate forming inside a coralAgate forming inside a coral

Florida Department of Florida Department of Environmental Protection, Florida Environmental Protection, Florida

Geological SurveyGeological Survey

Copyright © Dr. Richard Busch, West Copyright © Dr. Richard Busch, West Chester UniversityChester University


GallmanK

Moved picture and text boxes up just a little.

StratigraphyStratigraphy Stratigraphy is the study of rock layering, succession, age, Stratigraphy is the study of rock layering, succession, age,

distribution, form, and composition of sedimentary rocks.distribution, form, and composition of sedimentary rocks.

Sedimentary rocks form as layers of sediment that accumulate one Sedimentary rocks form as layers of sediment that accumulate one on top of the other. The individual layers of sedimentary rock are on top of the other. The individual layers of sedimentary rock are referred to as strata orreferred to as strata or beds (stratum for singular). beds (stratum for singular).

Law of superposition Law of superposition states that younger sedimentary layers are states that younger sedimentary layers are deposited on top of older layers, and, therefore, younger layers are deposited on top of older layers, and, therefore, younger layers are closest to the surface and older layers are buried below the surface.closest to the surface and older layers are buried below the surface.

Original horizontality Original horizontality principle states that layers of sediment are principle states that layers of sediment are originally deposited horizontally. While this applies to most originally deposited horizontally. While this applies to most stratigraphic sequences it does not necessarily apply to all. For stratigraphic sequences it does not necessarily apply to all. For example, sediments deposited at the base of a slope or at the angle example, sediments deposited at the base of a slope or at the angle of repose would not exhibit original horizontality. of repose would not exhibit original horizontality.

Lateral continuity principle states that layers of sediments initially Lateral continuity principle states that layers of sediments initially extend in all directions and are therefore laterally continuous. Rock extend in all directions and are therefore laterally continuous. Rock units dissected by valleys, should occur at relatively the same units dissected by valleys, should occur at relatively the same elevation on either side of the valley. elevation on either side of the valley.

Each individual stratum is unique and will be slightly different from Each individual stratum is unique and will be slightly different from the one above or below it. This is because each stratum was formed the one above or below it. This is because each stratum was formed under slightly different environmental conditions.under slightly different environmental conditions.

Geologist use characteristic of the stratum to infer information about Geologist use characteristic of the stratum to infer information about the environmental conditions that were present at the time that the environmental conditions that were present at the time that particular layer was deposited and eventually lithified particular layer was deposited and eventually lithified


Sedimentary StructuresSedimentary Structures

, SCGS, SCGSCross-BeddingCross-Bedding

Copyright @Marli MillerCopyright @Marli Miller

Ripple MarksRipple Marks

Copyright @ Bruce Molnia, Terra Copyright @ Bruce Molnia, Terra PhotographicsPhotographics

Mud CracksMud Cracks

Courtesy NASA Visible EarthCourtesy NASA Visible Earth

Ripples and MudcracksRipples and Mudcracks

Copyright @Michael CollierCopyright @Michael Collier

Copyright @ Bruce Molnia, USGSCopyright @ Bruce Molnia, USGS

Bedding PlanesBedding PlanesLaminationsLaminations

Copyright @ Bruce Molnia, USGSCopyright @ Bruce Molnia, USGS


Sedimentary Rocks in South Sedimentary Rocks in South CarolinaCarolina


Sedimentary Rocks in the Sedimentary Rocks in the LandscapeLandscape


The sedimentary rocks in Arizona’s The sedimentary rocks in Arizona’s Marble Canyon exhibit a “cliff-slope-Marble Canyon exhibit a “cliff-slope-cliff” pattern formed by differential cliff” pattern formed by differential

weathering of the alternating resistant weathering of the alternating resistant sandstone and easily erodible sandstone and easily erodible

siltstone and shale. The Colorado siltstone and shale. The Colorado River, winding through the left side of River, winding through the left side of

the photo has been carving this the photo has been carving this majestic landscape for the last 17 majestic landscape for the last 17

million years. million years.

Copyright ©Michael CollierCopyright ©Michael Collier

The bright white areas of this aerial The bright white areas of this aerial photo is where limestone is being photo is where limestone is being

mined from the Giant Cement Quarry in mined from the Giant Cement Quarry in the Lower Coastal Plain of South the Lower Coastal Plain of South

Carolina. These sub-surface limestone Carolina. These sub-surface limestone deposits were formed 53-36 million deposits were formed 53-36 million

years ago when this area was a deep-years ago when this area was a deep-underwater, marine environment. The underwater, marine environment. The

limestone in the quarry contains limestone in the quarry contains abundant fossilized remains of marine abundant fossilized remains of marine organisms, including sharks teeth that organisms, including sharks teeth that

measure several inches across. measure several inches across.

www.maps.google. comwww.maps.google. com

3737

Table of ContentsTable of Contents

1) Earth’s Materials and Changes:1) Earth’s Materials and Changes:Standard 3-3: Standard 3-3: The student will demonstrate an understanding of Earth’s composition and the changes that The student will demonstrate an understanding of Earth’s composition and the changes that occur to the features of Earth’s surface. (Earth Science).occur to the features of Earth’s surface. (Earth Science).

Indicators:Indicators: 3-3.1: Classify rocks (including sedimentary, igneous, and metamorphic). (slides: 3-36 ) 3-3.1: Classify rocks (including sedimentary, igneous, and metamorphic). (slides: 3-36 )

South Carolina Science South Carolina Science Academic Standards: Grade 3Academic Standards: Grade 3

Resources and ReferencesResources and ReferencesChristopherson, R. W. ,2002, Geosystems (4Christopherson, R. W. ,2002, Geosystems (4thth ed.): Upper Saddle River, New Jersey, Prentice Hall. ed.): Upper Saddle River, New Jersey, Prentice Hall.

Christopherson, R. W., 2004, Elemental Geosystems (4Christopherson, R. W., 2004, Elemental Geosystems (4 thth ed.): Upper Saddle River, New Jersey, Prentice Hall. ed.): Upper Saddle River, New Jersey, Prentice Hall.

Hallsworth, C. R. ,and Knox, R.W.O.B., 1999, BGS Rock Classification Scheme, Volume 3, classification of sediments Hallsworth, C. R. ,and Knox, R.W.O.B., 1999, BGS Rock Classification Scheme, Volume 3, classification of sediments and sedimentary rocks: British Geological Survey Research Report (2and sedimentary rocks: British Geological Survey Research Report (2ndnd Edition), RR 99-03. Edition), RR 99-03.

Keller, E. A., 2000, Environmental Geology (8Keller, E. A., 2000, Environmental Geology (8thth ed.): Upper Saddle River, New Jersey, Prentice Hall. ed.): Upper Saddle River, New Jersey, Prentice Hall.

Lutgens, F. K., and Tarbuck, E. J., 2003, Essentials of Geology (8Lutgens, F. K., and Tarbuck, E. J., 2003, Essentials of Geology (8 thth ed.): Upper Saddle River, New Jersey, Prentice Hall. ed.): Upper Saddle River, New Jersey, Prentice Hall.

Pettijohn, F.J. ,1975, Sedimentary Rocks (3Pettijohn, F.J. ,1975, Sedimentary Rocks (3rdrd Ed.): Baltimore, The Johns Hopkins University, Harper and Row, Ed.): Baltimore, The Johns Hopkins University, Harper and Row,New York, New York. New York, New York.


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