The Rock Cycle in Michigan

Prepared by the Michigan Department of Environmental Quality

Office of Geological Survey

What is the

Rock Cycle ?

The Rock Cycle explains how Rocks and Natural Processes

are related

weathering

Sedimentary Metamorphic

Igneous

is a sequence of events involving the formation, alteration, destruction, and reformation of rocks as a result of natural processes ...

Glossary of Geology, Bates & Jackson, AGI

Rock Cycle

A more traditional definition is:

The

Rock

Cycle

The Rock Cycle

The Rock Cycle

• Mineral - a naturally occuring,

solid, inorganic substance with a

definite chemical composition

and molecular structure.

• Rock Forming Minerals - there

are 2,500 minerals, 90% of all

rocks are made from just 15 of

these minerals.

The Rock Cycle

• Sedimentary Rock - formed from

sediments.

– Characteristics include:

• distinct layers

• fragments/pieces of other rocks

• organic composition (fossils)

• range in particle size -OR- mostly one

sized particles.

The Rock Cycle

• Non-Sedimentary Rock - formed

by heat and pressure. These

rocks are known as igneous and

metamorphic rocks.

• Igneous Rock - visible crystals

• Metamorphic Rock

– “banding” - parallel lines made by

crystals

– bent or folded lines of crystals

– foliation - crystals line up in 1

direction

We will use the graphic seen inthe background to help

represent theRock Cycle.

There are many ways to show the various relationships between the rocks and

the related natural processes.

let’s review some basic information …

Before we look at the

Rock Cyclein detail,

TheRock Cycle involves the recognition of three main classes of rocks. All three types are found in Michigan.

The three rock types are …

CEMETERY METABOLIC

INGENIOUS

SedimentaryRocks

MetamorphicRocks

IgneousRocks Right?

The eminent 18th century lawyer, doctor, gentleman farmer and founder of modern geoscience,

James Hutton,

developed the concept of the Rock Cycle to show how rocks and natural, physical processes are interrelated.

The understanding of the world in the 18th century was different from today …

Hutton knew about solar energyand gravity at the surface. He did not know about radioactiveheating from inside the earth.

As a result, the Rock Cyclewill be self-sustaining for thousands of millions of years.

Solar energy, gravity and radioactive heating are the major forces driving the Rock Cycle.

How does an antique concept like the Rock Cycle hold up in light of contemporary data and scientific thinking?

Of special interest is Plate Tectonics.

The mantle, crust and surface of the earthcan be thought of as a giant recycling machine;rocks are neither created nor destroyed, but redistributed and transformed from one rock type to another.

IM

S

If you were to ask a geologist what the earth is …

What do you think theresponse would be?

Diagram of the Interior of the EarthCrust

0 to 40 km0°C

Upper Mantle40 to 670 km

1,000°C

Lower Mantle670 to 2,890 km

2,000°C

Outer Core2,890 to 5,150 km

3,700°C

Inner Core5,150 to 6,370 km

4,300°C

lets move to some of the smallest components of Geology …

Now that we better understand the largest components of Geology …

.

Minerals make up rocks.

Natural compoundsand elements combineto form minerals.

Elements combine to form the natural compounds.

Rocks make up the Earth.

There is a hierarchy to the elements of Geology

Atoms make up elements.

Elements can be arranged, based on their identifiable properties, into the Periodic Table

Atomic Theory proposes that all matter is composed of the atoms of about 100 different chemical elements. It further proposes that chemical compounds are formed by the combination of the atoms of different chemical elements.

Only eight elements make up over 98%of the earth’s crust!

MgNa

K

O

SiAl

FeCa

.

Minerals make up rocks.

Natural compoundsand elements combineto form minerals.

Elements combine to form the natural compounds.

Rocks make up the Earth.

There is a hierarchy to the elements of Geology

Atoms make up elements.

What are Minerals? How can we tell what they are?

The identifiable characteristics

of Minerals are

naturally occurring inorganic elements or compounds

having an orderly internal structure

and a characteristic chemical composition,

crystal form and

physical properties of a solid

There are over 300 minerals found in Michigan.

alunite, amethyst, amphibole, analcite, anatase, andalusite, andesine, andradite, anglesite, anhydrite, ankerite,

annabergite, anorthite, anthonyite, anthophyllite, anthraconite, anthraxolite, antigorite, apatite, aphrosiderite, apophyllite,

aragonite, ardennite, argentoalgodonite, arsenopyrite, asbestos, atacamite, attapulgite, augite,awarurite, axinite, azurite,

babingtonite, baddeleyite, barite, bassetite, bastnaesite, beaconite, beryl, biotite, bismuthinite, blomstrandine, bornite,

bowlingite, brannerite, braunite, brochantite, bronzite, brookite, brucite, brunsvigite, buttgenbachite, byssolite, bytownite,

calciovolborthite, calcite, calderite, calumetite, carnallite, carnelian, celadonite, celestite, cerargyrite, chabazite, chalcedony,

chalcocite, chalconatronite, chalcopyrite, chalcotrichite, chamosite, chert, chloanthite, chlorargyrite, chlorastrolite, chlorite,

clinochlore, clino-chrysotile, clinozoisite, collophane, columbite, copiapite, copper, coquimbite, cordierite, corrensite,

corundum, covellite, crocidolite, cubanite, cummingtonite, cuprite, dahllite, datolite, daubreelite, delessite, diabantite,

diallage, diamond, dickite, digenite, dihydrite, diopside, dioptase, djurleite, dolomite, domeykite, forsterite, francolite,

freirinite, fuchsite, fulgurite, galena, garnet, garnierite, gersdorffite, gibbsite, glauconite, goethite, gold, halite, halloysite,

halotrichite, harmotome, heterosite, heulandite, hisingerite, hollandite, hornblende,

hyacinth, hydrocarbon, hydrohausmannite, hydromica, hydromuscovite, hydrotroilite, hypersthene, iddingsite, illite,

ilmenite, isle royale greenstone, jacksonite, jacobsite, jasper, jaspilite, julgoldite, kamacite, kamiokite, kaolinite,

kearsargeite, keweenawite, kinoite, koutekite, kupfferite, kutnahorite, kyanite, labradorite, langite, laumontite, lavendulan,

lead, lechetelierite, ledouxite, leonhardite, lepidocrocite, lepidolite, manganoan siderite, manganocalcite, marcasite,

margarite, marmolite, martite, masonite, maucherite, melaconite, melanochalcite, melanterite, melilite, mercury, mesolite,

meta-autunite, metatorbernite, metatyuyamunite, microcline, millerite, minnesotaite, mirabilite, mohawk-algodonite,

mohawkite, molybdenite, monazite, montmorillonite, muscovite, nacrite, nantokite, natrojarosite, natrolite, neltnerite,

neotocite, niccolite, nontronite, oligoclase, oligonite, olivenite, olivine, orientite, orthoclase, ottrelite, palygorskite,

paragonite, paramelaconite, pararammelsbergite, paratacamite, pargasite, patricianite, paxite, pectolite, pennine,

pentlandite, peristerite, perthite, pharmacolite, phengite, phillipsite, phlogopite, phosphides, phosphorite, picrolite,

picropharmacolite, pigeonite, pistacite, pitchblende, plagioclase, plancheite, plessite, polyhalite, posnjakite, powellite,

prehnite, priorite, prochlorite, protolithionite, pyrolusite, pyrope, pyrophyllite, pyrostilpnite, pyroxene, pyrrhotite, quartz,

rammelsbergite, rauenthalite, rhodochrosite, rhodonite, riebeckite, ripidolite, roscoelite, rubellan, rutherfordine, rutile, salite,

salt, sanidine, saponite, saussurite, scapolite, scheelite, schefferite, schorl, schreibersite, scolectite, seamanite, semi-

whitneyite, sericite, serpentine, siderite, silicon, sillimanite, silver, smaltite, smectite, soapstone, specularite, spessartite,

sphalerite, sphene, spinel, spodumene, staurolite, steatite, stellerite, stibiodomeykite, stilbite, stilpnomelane, stinkstone,

strontianite, sulfur, sussexite, sylvanite, sylvite, synchisite, szaibelyite, taenite, talc, tantalite, tellurium, tenorite, tetrahedrite,

thomsonite, thuringite, tirodite, titanite, titanomagnetite, topaz, tourmaline, tremolite, trichalcite, tridymite, troilite, tyrolite,

uralite, uraninite, uranothorite, uvarovite, vaterite,, vesuvianite, violarite, viridite, vivianite, vladimirite, wairakite, whitneyite,

williamsite, wollastonite, wurtzite, xanthosiderite, xonotlite, zeolite, zircon, zoisite, zonochlorite

Each mineral has its own set of uniquely identifiable

properties or characteristics

Minerals combine to form Rocks

Some Rocks are made up of just one mineral -

like the sedimentary rock salt (made up of the mineral halite) that is mined near Detroit.

Others Rocks are made up of many

minerals - like the igneous rock graniteand the metamorphic rock gneiss,found near Marquette.

Now that some of the basicshave been covered, letsconsider some of the

details about the

Rock Cycle

The Rock Cycle

weathering

Sedimentary Metamorphic

Igneous

Rocks are weathered,eroded,transported,deposited,and lithified to formsedimentary rocks

The igneous rock granite canbe physically weathered to produce clay and sand.

Becoming a SEDIMENTARY ROCK …

Sand can become sandstone.

Clay can become shale

These sediments can be transported deposited and lithified to form sedimentary rocks.

The metamorphic rock gneiss can be physically weathered to produce clay and sand.

Becoming a SEDIMENTARY ROCK …

Sand can become sandstone.

Clay can become shale

These sediments can be transported deposited and lithified to form sedimentary rocks.

Sedimentary rocks can be physically weathered to produce sediments that can become other sedimentary rocks.

Becoming a SEDIMENTARY ROCK …

Chemical weathering dissolves the minerals in rocks. The resulting dissolved compounds could form evaporites like rock salt or rock gypsum or chemical precipitates like some kinds of limestones. What forms depends upon composition and depositional environment factors.

H2O + CO2 H2CO3

2KAlSi3O8+ 2H+ + H2O

Al2Si2O5(OH)4+ 2K+ + 4SiO2

Becoming a SEDIMENTARY ROCK …

The Rock Cycle

Sedimentary Metamorphic

Igneous

Igneous Rocksform frommolten rock ormagma in thesubsurface orfrom lavaextruded at the surface

Becoming an IGNEOUS ROCK …

When magma cools to a solid it becomes an igneous rock.

Molten rock is called magma.

Any existing rock – igneous, metamorphic or sedimentary - can be subjected to enough heat and or pressure causing it to melt.

The kind of igneous rock formed depends on what was melted and how it cooled.

Igneous rocks are classified based on their mineral composition and texture.

basaltgranite

granodiorite

rhyolite

pegmatite

Igneous rocks found in Michigan include:

Sedimentary Metamorphic

Igneous

The Rock Cycle

Pressure, heatand fluidscause preexistingrocks or sediments to becomemetamorphic rocks

Becoming a METAMORPHIC ROCK …

When the prefix metais applied to a rock name that means that the original rock has been metamorphosed.

If the igneous rock basalt is exposed to sufficient heat and or pressure it can be transformed into the metamorphic rock call metabasalt

Becoming a METAMORPHIC ROCK …

If the sedimentary rock sandstoneis metamorphosed it can become the metamorphic rock quartzite.

If the sedimentary rock limestone or dolomite is metamorphosed it can become the metamorphic rock marble.

If the sedimentary rock shale is metamorphosed it can become the metamorphic rock slate.

Becoming a METAMORPHIC ROCK …

If the metamorphic rock phyllite is metamorphosed it can become the metamorphic rock schist.

If the metamorphic rock slate is metamorphosed it can become the metamorphic rock phyllite

If the metamorphic rock schist is metamorphosed it can become the metamorphic rock gneiss.

weathering

Sedimentary Metamorphic

Igneous

The Rock Cycle

The Rock Cycledoes not go in just one direction. Any given rock can go through any part of the cycle any number of times.

DEQ GSD - The Rock Cycle in Michigan - February 2001

weathering

Sedimentary Metamorphic

Igneous

The Rock Cycle

I hope you better understand the Rock Cycleand what it means.

DEQ GSD - The Rock Cycle in Michigan - February 2001

Please email any comments about this program to Steve Wilson: wilsonse@Michigan.gov - thanks