Classroom presentations to accompany Understanding Earth , 3rd edition

Classroom presentations to accompany Understanding Earth, 3rd edition prepared by Peter Copeland and William Dupré University of Houston Chapter 3 Rocks: Records of Geologic Processes

Rocks:Records of Geologic Processes Rocks:Records of Geologic Processes

Three types of rocks Igneous Sedimentary Metamorphic Igneous rocks make up most of the earth sedimentary rocks make up most of the surface.

Major Rock Groups IGNEOUS SEDIMENTARY METAMORPHIC Fig. 3.1

Igneous Rocks Rocks formed from the cooling and consolidation of magma.

Fig. 3.2

Intrusive Granite Fig. 3.2

Extrusive Basalt Fig. 3.2

Intrusive Granite Fig. 3.2

Extrusive Basalt Fig. 3.2

Sedimentary Rocks Rocks formed by the consolidation of fragments of previously existing rock or chemically precipitated from solution.

From Weathering to Sedimentary Rock Fig. 3.3

Genesis of Sedimentary Rocks • Physical weathering: reduction in size • Chemical weathering: change in composition • Transportation: • Solid particles ... clastics by water, wind, ice • Ions in solution ... chemical

How common are sedimentary rocks? Fig. 3.4

Metamorphic rocks Rocks whose original form has changed in the solid state due to increased temperature and/or pressure.

Where does Metamorphism occur? Regional Metamorphism Fig. 3.5

Where does Metamorphism occur? Regional Metamorphism Contact Metamorphism Fig. 3.5

Where we see rocks • Outcrops • Drilling

Outcrop Fig. 3.6

Fig. 3.7 Fred Hirschmann

Fig. 3.8 Russ Kinne/ Comstock

Fig. 3.9 Carr Clifton

TheRockCycle Fig. 3.10

Plate tectonics and the rock cycle The production and destruction of rocks is ultimately related to plate tectonics.

Subduction at convergent plate boundaries causes partial melting to form magma and resulting igneous rocks. Fig. 3.11a

Magma rises from the mantle at divergent plate boundaries. Fig. 3.11b

Subsidence at rifted plate margin allows for the deposition, burial, and lithification of sediments. Fig. 3.11c

Plate interiors are dominated by sedimentary processes, with some volcanism due to mantle “hot spots.” Fig. 3.11d

Convergence of plates causes deformation, uplift, and regional metamorphism. Fig. 3.11e

Classroom presentations to accompany Understanding Earth , 3rd edition