Thursday, March 4th, 1999
Announcements: There was a 5 pt. attendance quiz given in today's lecture.

Lecture notes:

I. Preview
    A. "Surface Processes" (same as notes on Tuesday's lecture)

    B. Deposition--transfer of seidmentary materials through moving water into a stable area

II. "The Rock Cycle"

III. Terms
    A. Uniformitarionism--uniform, slow processes that occur everyday; rivers carrying sediments; plate tectonism is
        uniformitarion

    B. Catastrophism--every once in awhile there is a huge earthquake, volcano, etc. that causes a huge change in
        geography and topography; in the later part of the 18th century, this was the principle way of thinking

    C. Mass wasting--Gros Ventre landslide (Grand Tetons, NW Wyoming)
            1. Gros Ventre (summary of events)
                    a. River eroded the stable toe (river event)
 
                    b. Major landslide/debris flow (land event)

                    c. Debris dammed river, formed lake (river event)

                    d. Debris dam eroded after 2 years (land event)

                    e. Down--river flooding destroyed town (river event)

            2. Debris flow was triggered by wet conditions over the entire season

IV. Water/Rivers (fresh water)
    A. Dominant agent of chemical weathering; hydrolysis, breakdown of parts; water is a polarized molecule therefore it
        can "suck" other molecules from the clay

    B. Rivers are an agent of transport; lubricant in slides of rocks (unconsolidated materials)

    C. Rivers are agents of erosion

V. Rivers
    A. Meandering or braided

    B.Different life cycles
            1. "Young" rivers
                        a. Braided--many channels

                        b. Many channels for flow

                        c. Steep, rocky, "flashy" (respond really fast to rain)

                        d. Usually the beginning of a river

            2. "Mature" rivers
                        a. Meandering

                        b. One main sinuous channel

 
                        c. Low gradient (not steep)

                        d. Typically not "flashy"

                3. "Young" and "mature" really mean how old the terrain is that the river is flowing through

                4. New River and Kanawha River have head waters in the Appalachian Mountains but they empty into the
                Gulf of Mexico because the rivers still are working as if Pangea were still in tact (the rivers don't know that
                it is possible to flow into the Atlantic Ocean)