1. Rock Types
November 21, 2011

2. Todays Class Waiting for email on question for Gordon
Term 2: Grade Breakdown
Test 1: 25%
Test 2: 25%
Term Paper: 25%
Quizzes: 10%
Participation 5%
Test 3: 10% MC

3. Rock Types
A rock is a collection of one or more minerals. Rocks are divided into three major groups.

4. Igneous Rocks
rocks of molten origin

5. Intrusive
magma cooled at depth: often forced into cracks or cavities in a molten condition. Generally coarse-grained. eg granite, quartz, feldspar,

6. Extrusive
 lava cooled on the surface after flowing out of cracks or volcanoes as lava. Generally fine-grained. eg pummice, obsidian

7. SEDIMENTARY ROCKS 
are composed of the products of mechanical and chemical weathering. Sedimentary rocks are deposited usually in near-horizontal layers by the agents of transportation. eg wind, water, and ice. Burial produces lithification or hardening.

8. Sedimentary Sources deserts - aeolian deposits glacial deposits
rivers - deltas
shallow marine areas (fossils)
deep marine areas
reefs

9. Types of Sedimentary Rocks
Conglomerate: composed of large rounded fragments embedded in a fine-grained material (easily eroded because made up of tiny particles and layers). b) Sandstone: composed mainly of sand-sized particles, and these are mainly of quartz.

10. Sandstone

11. Types of Sedimentary Rocks
Arkose: composed mainly of sand-sized particles of quartz and feldspar, the latter making up more than 25% of the total. d) Shale: composed of fine particles predominantly of clay size.

12. Types of Sedimentary Rock
Limestone: composed of calcite either
(1) chemically precipitated in water, or  (2) accumulated through the collection of organic remains such as  shells, or
(3) the result of building up of organic rock through the action of organisms like corals

13. METAMORPHIC ROCKS 
formed by the influence of heat and pressure on other rocks resulting in changes in mineralogy and texture

14. Types of Metamorphic
 Gneiss: has a banded appearance with alternating composition; may be formed by  metamorphism of an igneous or sedimentary rock b) Slate: fine-grained and platy; fissile; formed by the metamorphism of shale.

15. Slate

16. Types of Metamorphic
Schist: rock flaky minerals (eg mica) aligned in a parallel fashion; formed by the metamorphism of shale and slate. d) Quartzite: hard, mainly composed of quartz; formed by the metamorphism of  sandstone. e) Marble: a coarse, but even-grained rock formed by the metamorphism of limestone.

17. Marble

18. Rock Cycle