rocks - earth2class.org · non-clastic rocks form by chemical precipitation (settling out from a...
TRANSCRIPT
![Page 1: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/1.jpg)
Rocks
Dr. Michael J. Passow
http://www.beg.utexas.edu/mainweb/publications/graphics/granite.htm
http://en.wikipedia.org/wiki/File:USDA_Mineral_Sandstone_93c3955.jpg
http://www.gccaz.edu/earthsci/imagearchive/gneiss.htm
![Page 2: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/2.jpg)
This slide show is intended to help you
understand important types of rocks.
The diagram in the next slide represents the ROCK CYCLE—a scheme that represents the processes of continuous changes that connect the three major groups of rocks:
SEDIMENTARY
IGNEOUS
METAMORPHIC
It also shows two other important parts of the “Rock Cycle” – SEDIMENTS and molten LAVA and MAGMA
Note about image sources: Many images come from a website (Volcano World) that no longer is supported, so no credit is given. The last slide provides possible sources.
![Page 3: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/3.jpg)
![Page 4: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/4.jpg)
Here is another version of the Rock Cycle
![Page 5: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/5.jpg)
![Page 6: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/6.jpg)
IGNEOUS ROCKS
• Form by solidification (crystallization) of
melted minerals
• At the surface, LAVA hardens to form
EXTRUSIVE rocks with tiny (FINE-
GRAINED) crystals or GLASSY (no
crystal) TEXTURES
• Beneath the surface, MAGMA hardens to
form INTRUSIVE rocks with easily visible
(COARSE-GRAINED) crystal texture.
![Page 7: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/7.jpg)
Granite
• Light-colored, coarse-
grained, no pattern
• Mostly quartz,
feldspar, mica, and
hornblende
• Often used for
buildings and
monuments
![Page 8: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/8.jpg)
Basalt
• Dark-colored, fine-
grained, extrusive
• Formed where lava
erupted onto surface
• Most widespread igneous
rocks
• Found locally in the
Palisades along west
shore of Hudson River,
Connecticut River valley
![Page 9: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/9.jpg)
Gabbro
• Dark-colored, coarse-
grained intrusive
• Similar composition to
basalt—plagioclase
feldspar with some
pyroxene and olivine
![Page 10: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/10.jpg)
Obsidian
• Natural volcanic glass
• Forms when lava cools
very quickly
• Usually dark, but small
pieces may be clear
• Fractures along curved
(conchoidal) surface
• Used as spear and
arrow points, knives
![Page 11: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/11.jpg)
Pumice and other igneous rocks
• Light colored, frothy
(many air spaces)
• Same minerals as in
granite, but finer in
grain size
![Page 12: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/12.jpg)
Sedimentary Rocks
Sedimentary rocks may be made of rock fragments—
sediments—or by chemical reactions. The classification of
sediments is shown below.
![Page 13: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/13.jpg)
Clastic rocks–made of cemented
sediments—are classified by their grain
sizes.
![Page 14: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/14.jpg)
Non-clastic rocks form by chemical precipitation
(settling out from a solution.) Limestone is
made from calcite, chert from quartz, and halite
is rock salt.
![Page 15: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/15.jpg)
Biologic sedimentary rocks come
from the remains of organic matter.
• The most important of these is coal. Anthracite coal results from the greatest pressure and releases the most energy when burned. Other varieties are bituminous and lignite. “Petrified” (permineralized) wood is another organic rock.
![Page 16: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/16.jpg)
More about sedimentary rocks
• Shale is the most
common sedimentary
rock
• Sedimentary rocks
cover about three-
quarters of the land
surface
• For more about
sedimentary rocks:
![Page 17: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/17.jpg)
Metamorphic Rocks
• Formed by heat and pressure changing
existing rocks
• REGIONAL METAMORPHIC affects a
large area and results from plate tectonics
• CONTACT METAMORPHISM affects
rocks on a local scale, such as “baking”
sedimentary rocks next to magma or lava
![Page 18: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/18.jpg)
“Foliated” rocks contain much mica and
other rocks that produce layering or banding
Gneisses and schists are common in New York City and
Westchester.
![Page 19: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/19.jpg)
Non-foliated metamorphic rocks include
marble, which comes from limestone, and
quatzite, which comes from sandstone
![Page 20: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/20.jpg)
Locations, types,
and ages of the
bedrocks are
represented in a
geologic map
http://www.state.nj.us/dep/njgs/
![Page 21: Rocks - earth2class.org · Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt](https://reader033.vdocument.in/reader033/viewer/2022050504/5f95d880902bbe24fb639722/html5/thumbnails/21.jpg)
Additional Resources
There are many web sites that can
provide you with more information about
rocks and images. Here are a few: http://geology.about.com/library/bl/images/blrockindex.htm
http://www.state.nj.us/dep/njgs/
http://www.p12.nysed.gov/assessment/reftable/earthscienc
e-rt/esrt2011-engr.pdf