Continental Drift Alfred Wegener 1915 Continental Jigsaw Puzzle

Continental Drift • Alfred Wegener – 1915 • Continental Jigsaw Puzzle – Fossils Matched across the sea – Common rock types (Africa and Appalachian) – Ancient Climates

Fossil and Rock Evidence

Rejected • There was no credible mechanism for the movement of continents

Theory of Plate Tectonics • WWII oceanographers – large picture of the ocean floor. Ocean ridges • Ocean drilling – established the age of the ocean floor • Paleomagnetism

Age of Ocean Floor

paleomagnetism

Plate boundaries

Divergent boundaries

Rift zone

Convergent boundaries •

Volcanic formation

Transform boundary

How is sediment formed • Weathering • Mass wasting • Erosion

Weathering • Rocks are broken down to sediment through the process of either – Mechanical weathering – Chemical weathering

Mechanical Weathering – Physical breaking up of rock - disintegration – Rock is broken into smaller pieces • Frost Wedging • Sheeting • Biological activity

Frost Wedging

Sheeting

Biological weathering

Chemical Weathering • Alters internal structure of the mineral by removing and/or adding elements – Oxidation – Carbonic Acid

Oxidation • Water is the agent of chemical weathering. • Oxygen dissolved in water will oxidize iron-rich minerals

Carbonic acid • Carbon dioxide dissolved in water forms a weak acid. This weak acid will react with mineral elements; breaking the rock down.

Mass Wasting • The transfer of rock and soil downslope, under the influence of gravity. – Mudslide – Rockslide – Earthflow – slump

Triggers of Mass Wasting Over saturation of land Over steepened slopes Loss of vegetation Earthquakes

Erosion • The physical removal of material by a mobile agent such as flowing water, waves, wind or ice • Water • Wind

Soil • Combination of sediment and organic matter