DLESE Teaching Boxes: Global Ups and Downs: Changing Sea Level (6-12)

Concept Map - Text only

Overarching Concept:

All mountains have a history and there are many features of a mountain that provide information about that history.

Shape:
The shapes of mountains vary significantly.
The shape of a mountain provides evidence about its formation and history.
  a. The shape of non-volcanic mountains is determined by their tectonic setting.
     • Where plates collide, compressional forces cause folded and thrust fault mountains.
     • Where plates are pulling apart, tensional forces result in fault block mountains.
  b. The shape of volcanoes is determined by the viscosity of the magma.

Constructive and Destructive Forces:
Geologic forces that form and shape mountains are both constructive and destructive.
Erosion is a destructive force that sculpts and shapes all mountains.
Mountains are usually made up of many types of rock.
Some rock types erode more easily than others, producing differential rates of erosion in neighboring rocks.
Differential erosion of rocky material produces jagged mountains as well as batholiths, mesas and buttes.

Rock Composition:
A rock's environment can modify it or completely transform it into something else.
  a. Erosion changes rocks by breaking them down and moving them to different environments.
Rocks are categorized based on the most recent major change that occurred to them.
  b. Three main categories are igneous, sedimentary, and metamorphic.
Rocks have identifying characteristics that provide evidence of the changes that they have endured.

Location:
Mountains tend to form near plate boundaries in long ranges that parallel the boundaries.
  a. Volcanoes form over subduction zones as continuous arc-shaped chains of volcanoes of different sizes.
     • Mountains composed entirely of volcanic rocks might be, but are not necessarily, volcanoes.
  b. As plates move around over geologic time, plate boundaries change, resulting in modern day mountain belts that are far from present-day plate boundaries.