GEOG 101 1st Edition Lecture 19Outline of Last Lecture I. Natural Hazardsi. Earthquakesii. TsunamisII. The Rock Cyclei. Igneous ii. Sedimentary iii. MetamorphicOutline of Current LectureI. Tectonic Platesi. Types of crustal stressII. VolcanoesLectureI. Tectonic Plates -Many landforms on the Earth’s surface are produced by the movement of tectonic plates.-What happens around plate boundaries?i. 3 Types of crustal stress1-Tension Stress can form a normal fault: when bedrock is stretched, this can cause horst-and-graben mountains to form. An example is the Great Basin, especially in Nevada. Tension stress can also produce rift valleys. There is a rift valley in New Mexico. The Albuquerque graben is filled with sediment from the river. New Mexico has many volcanoes associated with the rift valley. The moon has a tectonic past because we can observe a graben on it.2-Compression is associated with convergent plate boundaries. Compression stress can produce fold mountains. 3-Shear: Strike-slip faults, such as the San Andreas fault. II. Volcanoes2 different types of lava-Effusive Lava- Mafic/Basaltic lava. It is really hot and low in silica. It can flow easily and long distances.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.-Eruptive Lava- Felsic/andesite lava. It doesn’t flow very well. It has explosive eruptions because the lava builds up.-Shield volcanoes: massive eruptions of effusive lava around a volcanic vent.-Composite volcanoes: come from a mix of effusive and explosive volcanoes. -Cinder cones form when liquid lava is thrown into the air.-Caldera volcanoes form when the crust collapses into a magma chamber. They are usually formed by explosive