Toursit attractions, suppliers and places worth visiting

Geology in the USA and Canada

While a complete study of the geology of the USA and Canada is an immense subject, a little understanding can provide some useful background knowledge during a visit, especially to many of the National Parks, National Monuments and other similar areas.

The geological processes which created the landscape is often mentioned in exhibits and displays at the parks. Many of the parks are of course excellent examples of such processes.

A few very basic definitions may be useful. This is only intended to cover the tip of the tip of the tip of the subject. A book on the subject or the relevant entries in a quality encyclopedia (either traditional or on CD-ROM) will provide much more information for those who are interested.

Erosion

Erosion is the effect of wind, water, frost, ice, temperature changes, plants, etc on rocks.

Examples of erosion include the creation of canyons by the rivers flowing through them (such as the Grand Canyon), the creation of caves by water dripping through them, and the creation of mountain landscapes by the advance and retreat of glaciers (such as in Canadian Rockies and Glacier National Park in Montana.

Igneous Rocks

Igneous rocks are formed when molten rock, called magma, cools and turns solid. The magma may be ejected as lava from a volcano but there are other processes which can bring it to the surface.

Examples of igneous rocks include granite and basalt.

Metamorphic Rocks

Metamorphic rocks are those which have been changed by heat and pressure within the earth's crust.

Examples of metamorphic rocks include slate and marble.

Plate Tectonics

Plate Tectonics, or Continental Drift, is the concept of large areas of the earth's surface moving very slowly over geological time. Earthquakes tend to occur where two of these plates meet - the best known example being the San Andreas Fault in California.

Sedimentary Rocks

Sedimentary rocks are formed from the sediment at the bottom of bodies of water.

Examples of sedimentary rock include sandstone (formed from sand) and limestone (which includes the remains of microscopic organisms which lived in the water).

Canadian Shield