The Rocky Mountains

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The Rocky Mountains

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Geologic events

• The Rockies are composed exclusively of layered
  sedimentary rocks.
• These include limestone, dolomite, sandstone and
  shale, among others.
• Sedimentary rocks cover approximately 75 of the
  worlds surface.
• Regular sedimentation has been shattered, older
  rocks lie on top of younger rocks.
• SOURCE Mountainnature.com. http//www.mountainnat
  ure.com/geology/Deposition.htm. Accessed 11/10/09.

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Mountain Types

• The Rockies include Matterhorn mountains.
• Glaciers have scoured the peak.
• Other types of mountains are dogtooth, sawtooth,
  castellate, anticlinal, synclinal, and complex
• SOURCE Mountainnature.com. http//www.mountainnat
  ure.com/geology/platetectonics.htm. Accessed
  11/10/09.

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Geologic Forces

• In some places the formation of the mountains
  ripped through to the magma, which pushed through
  the older rocks
• This is called an igneous intrusion of dacite
  porphyry.
• This one is called Tooth of Time in Northern New
  Mexico and was formed in the Tertiary Period of
  the Cenozoic era some 22-40 million years ago
• SOURCE Tooth of Time. http//www.absoluteastronom
  y.com/topics/Tooth_of_Timeencyclopedia. Accessed
  11/10/09.

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Extent of the Rockies
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• The orogony that caused the Rockies moved from
  the ocean inland
• This mountain belt protects the craton which is
  called The Great Plains
• It affects the weather and helps much of the
  United States in its ability to produce large
  amounts of food
• It is formed by the tectonic plates thrusting
  the continental shelf inward toward the
  continental interior, producing giant thrust
  faults hundreds of miles long, as if one block of
  continental crust was simply pushed over the top
  of another
• SOURCE Google Answers. Plate Tectonics-Rocky
  Mountains. http//answers.google.com/answers/threa
  dview/id/181294.html. Updated 3/26/03. Accessed
  11/10/09.

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The mountains themselves have unpredictable
weather. Snowfalls end in June at the mountain
peaks and start again in August.
But the peaks also provide many valleys with good
grazing land for horses and cattle and ensure
water for the growth of plants and animals.
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Limestone is a very common sedimentary rock of
biochemical origin. It is composed mostly of the
mineral calcite. (SourceLimestone.
http//www.galleries.com/Rocks/limestone.htm.
Updated 2009, accessed 11/10/09.)
Dolomite rock is one of the sedimentary rocks
that undergoes a significant mineralogical change
after it is deposited. The process is not
metamorphism, but something just short of
that. (SOURCEDOLOMITE. http//www.galleries.com/m
inerals/carbonat/dolomite/dolomite.htm. Updated
2009. Accessed 11/10/09)
Sandstone is sand cemented together into rock. It
is a clastic sedimentary rock. It is composed
mostly of medium-grain sand .(SOURCE About
Sandstone. http//geology.about.com/od/more_sedroc
ks/a/aboutsandstone.htm. Accessed 11/10/09.)
Shale is a claystone that is fissile, splitting
in layers. Shale is usually soft and does not
crop out unless harder rock protects it.
(Source Shale. http//geology.about.com/od/rocks/
ig/sedrockindex/rocpicshale.htm. Accessed
11/10/09.)
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ABOUT MY GEOLOGIC FEATURE
The Tooth rises from the valley floor creating a
sheer vertical face unable to support substantial
plant life. Both its pinkish-gray color and its
unusual shape make it a particularly notable
geological landmark. It was well-known among the
overland traders on the Santa Fe Trail.
The Tooth was formed when magma from the Earth's
mantle rose through older rock layers via
convection and slowly cooled. Over thousands of
years, the older sedimentary rock eroded and left
the harder igneous formation. The sedimentary
rock acted as a mold for the intrusive magma,
causing it to harden and cool where the
sedimentary rock was strongest.
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HOW DO WE KNOW THE AGE OF THE ROCKIES?

• The formation of the Rocky Mountain structures in
  late Cretaceous through Eocene time is that plate
  of oceanic lithosphere was underthrust
  horizontally along the base of the North American
  lithosphere.
• The horizontal components of the motion of this
  plate are known from paleomagnetism
• The edge of the region of flat slab can be
  estimated from reconstructed patterns of
  volcanism.
• (SOURCE Peter Bird. Formation of the Rocky
  Mountains, Western United States A Continuum
  Computer Model. http//www.sciencemag.org/cgi/cont
  ent/abstract/239/4847/1501. 3/25/88. Accessed
  11/10/09)

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ROCKY MOUNTAIN CLIMATE VARIANCES
From the Alpine Tundra (SOURCE
http//www.terragalleria.com/parks/np.rocky-mounta
ins.3.html)
To high mountain lakes (SOURCE
http//www.terragalleria.com/parks/np.rocky-mounta
ins.3.html)
And tree lines that go from pines to aspens
(SOURCE http//www.terragalleria.com/parks/np.roc
ky-mountains.3.html)
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Rocky Mountain Surprises
To rivers flowing with water that was ice just
hours before (SOURCE http//www.terragalleria.com
/parks/np.rocky-mountains.3.html)
And hidden cantons hiding Native American
history. (Source http//dori-stories.com/places/n
m/slides/More20Philmont20Indian20Writings20Pet
roglyphs.html
The Rockies provide some of the most interesting
and exciting areas in the United States.