Download GLG101online_09B_MountainsoftheWorld_MCC_Leighty

Mountains of the World
GLG 101 - Physical Geology
Bob Leighty
These notes and web links are your primary “lecture” content in this class.
Additionally, various articles are assigned each week to supplement this “lecture”
information. I believe you’ll have enough information to reference without having
to purchase a costly textbook.
These lecture notes are very similar to the ones I use in my traditional classes.
You’ll find they are loaded with imagery and streamlined text that highlight the
most essential terms and concepts. The notes provide a framework for learning
and, by themselves, are not meant to be a comprehensive source of information.
To take advantage of the global knowledge base known as the Internet, I have
included numerous hyperlinks to external web sites (like the Wikipedia, USGS,
NASA, etc.). Follow the links and scan them for relevant info. The information
from linked web sites is meant to supplement and reinforce the lecture notes –
you won’t be responsible for knowing everything contained in them.
As a distance learning student, you need to explore and understand the content
more independently than in a traditional class. As always, I will help guide you
through this learning adventure. Remember, email Dr. Bob if you have any
questions about today’s lecture ([email protected]).
Leave no questions behind!
Explore and have fun!
Mountains
of the World
Orogenic Basics
 Orogenic (not a dirty word): mountain-building
 Orogeny: mountain-building event (e.g., Himalayan Orogeny)
 Orogenic belt: mountain belt (e.g., Himalaya)
Mountains
of the World
Orogenic Basics
 Isostasy = gravitational balance
>
Crust is buoyant & “floats” on top of the mantle
>
The thicker the crust, the higher it “floats”
 Elevation is related to crustal (continental or oceanic) thickness
>
Thick crust = high elevations = mountains
>
Thin crust = low elevations = sedimentary basins
Mountains
of the World
Orogenic Basics
 Continental crust averages ~35 km thick
 Oceanic crust averages ~7 km thick
Mountains
of the World
Orogenic Basics
Ways To Make Mountains
1) Thicken the crust by tectonic compression
2) Thicken the crust by magmatism
Mountains
of the World
Orogenic Basics
Ways To Make Mountains
3) Thermal uplift by magmatism
Mountains
of the World
Orogenic Basics
Ways To Thin the Crust
 Extension (pull & stretch)
 Erosion (off the top)
Mountains
of the World
Mountains of the World
 Mountains can form anywhere, but mainly at tectonic plate
boundaries
Mountains
of the World
Mountains of the World
Continent-Continent Convergent Margins
Appalachians, Urals (mostly Paleozoic)
Himalayas & Alps
(mostly Cenozoic)
Mountains
of the World
Mountains of the World
Continent-Continent Convergent Margins
Himalayas
Mountains
of the World
Mountains of the World
Continent-Continent Convergent Margins
Appalachians
Mountains
of the World
Mountains of the World
Ocean-Continent Convergent Margins
Andes, Cascades (mostly Cenozoic)
Rocky Mountains
(Late Mesozoic-Early Cenozoic)
Mountains
of the World
Mountains of the World
Ocean-Continent Convergent Margins
Andes, Cascades
“Continental arcs”
Mountains
of the World
Mountains of the World
Ocean-Continent Convergent Margins
Rocky Mountains
Mountains
of the World
Mountains of the World
Ocean-Ocean Convergent Margins
Aleutians, Japan
(Cenozoic)
“Island arcs”
Mountains
of the World
Mountains of the World
Oceanic Divergent Margins
“Mid-ocean Ridges”
Mid-Atlantic Ridge, East Pacific Rise (Cenozoic)
Mountains
of the World
Mountains of the World
Continental Divergent Margins
“Continental Rift”
East Africa Rift, Basin & Range, Sierra Nevada
(Cenozoic)
Mountains
of the World
Mountains of the World
Continental Divergent Margins
Basin & Range
Mountains
of the World
Mountains of the World
Continental Divergent Margins
Sierra Nevada
Mountains
of the World
Mountains of the World
Intraplate “Hotspots”
Hawaiian Islands - Emperor Seamounts
(largely Cenozoic)
Mountains
of the World
WWW Links in this Lecture
> Orogeny - http://en.wikipedia.org/wiki/Orogeny
> Isostasy - http://en.wikipedia.org/wiki/Isostasy
> Buoyancy - http://en.wikipedia.org/wiki/Buoyancy
> Crust - http://en.wikipedia.org/wiki/Crust_%28geology%29
> Mantle - http://en.wikipedia.org/wiki/Mantle_%28geology%29
> Continental crust - http://en.wikipedia.org/wiki/Continental_crust
> Oceanic crust - http://en.wikipedia.org/wiki/Oceanic_crust
> Mountains - http://en.wikipedia.org/wiki/Mountains
> Tectonic plate boundaries - http://en.wikipedia.org/wiki/Plate_tectonics#Types_of_plate_boundaries
> Appalachian Mountains - http://en.wikipedia.org/wiki/Appalachian_Mountains
> Ural Mountains - http://en.wikipedia.org/wiki/Ural_Mountains
> Himalayas - http://en.wikipedia.org/wiki/Himalayas
> Alps - http://en.wikipedia.org/wiki/Alps
> Andes - http://en.wikipedia.org/wiki/Andes
> Cascades - http://en.wikipedia.org/wiki/Cascade_Range
> Rocky Mountains - http://en.wikipedia.org/wiki/Rocky_Mountains
> Volcanic arc - http://en.wikipedia.org/wiki/Volcanic_arc
Mountains
of the World
WWW Links in this Lecture
> Aleutian Islands - http://en.wikipedia.org/wiki/Aleutian_Islands
> Japanese Islands - http://en.wikipedia.org/wiki/Geography_of_Japan
> Mid-ocean ridge - http://en.wikipedia.org/wiki/Mid-ocean_ridge
> Mid-Atlantic ridge - http://en.wikipedia.org/wiki/Mid-Atlantic_Ridge
> East Pacific Rise - http://en.wikipedia.org/wiki/East_Pacific_Rise
> Continental rift - http://en.wikipedia.org/wiki/Rift_valley
> East African Rift - http://en.wikipedia.org/wiki/Great_Rift_Valley
> Basin and Range - http://en.wikipedia.org/wiki/Basin_and_Range_Province
> Sierra Nevada - http://en.wikipedia.org/wiki/Sierra_Nevada_%28U.S.%29
> Hawaiian Islands - http://en.wikipedia.org/wiki/Hawaiian_Islands
> Emperor Seamounts - http://en.wikipedia.org/wiki/Hawaiian-Emperor_seamount_chain