Mineral or not?

2. Mineral or not? • Which of these is a mineral? Why or why not? Gene Simmons Princess Penny Garnet Rose Quartz

3. Eggs are to cake… • Eggs are to cake… • What minerals are to rocks.

4. 3 Main Rock Groups • Igneous • Sedimentary • Metamorphic

5. Igneous Rocks

6. Igneous Rocks • Igneous comes from the Greek word for Fire. • Igneous rocks are formed when hot molten rock crystallizes and solidifies.

7. Igneous Rocks • Forms from molten material • magma

8. Magma is molten rock What is magma?

9. Magma is molten rock • What is magma? • Mostly oxygen, silicon, aluminum, iron, magnesium, calcium, sodium, potassium, titanium, and manganese. • As well as melted rock, crystals, bits of unmelted parent rock and dissolved gases.

10. Igneous Rocks • If magma cools quickly: • There is less time for crystals to form • Crystals will be small

11. Igneous Rocks • If magma cools slowly: • There is more time for crystals to grow • Crystals will be larger

12. 2 Types of Igneous Rocks • Based on where they form: • Intrusive / Plutonic • Magma that cools and hardens below the surface. • Extrusive • Magma that cools and hardens above the surface (lava).

13. Intrusive Igneous Rocks • Intrusive or Plutonic rocks form when molten rock, or magma, is trapped deep within the earth where it slowly cools and solidifies. • The cooling may take thousands or even millions of years. • Since it takes so long to cool, the crystals within the rock may grow relatively large. • Slow cooling, and large crystals create a coarse grained texture. • Ex: granite, gabbro, diorite

14. Igneous Rocks • Intrusive or Plutonic • Batholith- large igneous intrusion • Sills – an igneous intrusion parallel to the layers • Lacolith– an igneous intrusion into sedimentary layers

15. Intrusive Igneous Rocks

16. Extrusive Igneous Rocks • Extrusive rocks are formed by magma that exits the earth(lava). • Ex: From volcanoes, and fissures. • As magma erupts from the earth it cools very rapidly. There is little time to form large crystals. • Extrusive rocks are fine grained or even glassy texture. • Ex: basalt, rhyolite, obsidian.

18. Extrusive Igneous Rocks

19. Igneous Rocks

20. Igneous Rock groups • 2 main groups based on their chemical composition; • Mafic • Felsic

21. Mafic • Mafic magmas have relatively low silica (Si) and high Fe and Mg contents. • The high Fe and Mg content makes these rocks heavier & darker than felsic types. • Mafic magma will cool and crystallize to produce the volcanic rock basalt and gabbro.

22. Mafic • Very Hot lava, rich in iron and magnesium, low in silica, is fluid and flows like hot tar (highly viscous). • Mafic Magnesium + Iron • Mg + Fe

23. Mafic rocks • Magnesium + Iron (Fe) • More easily weathered than felsic-types • Highly dense/heavy • Dark colored • Ex: basalt, gabbro

24. Felsic • Felsic magmas, have relatively high silica and low Fe and Mg contents. • Lighter in weight and color than mafic. • Felsic magma will cool and crystallize to produce dacite and rhyolite. • Intermediate-composition magmas will crystallize to produce the rock andesite.

25. Felsic • Cooler, gas-poor lava high in silicon, sodium, and potassium can be either pasty, blocky or flows very slowly (not viscous). • Felsic Feldspar + Silicon • Fe + Si

26. Felsic Rocks • Feldspar + Si • Harder • Weather last • Low density • Lighter color • Ex: quartz, muscovite, orthoclase

27. Igneous Rocks • If lava is felsic and contains a high percentage of gases it will be explosive. • If thick the lava will explode in blocks or bombs.

28. Igneous Rocks • If lavas are thin and contain few gases, the flow will be very viscous. • Smooth, liquidy

29. How Igneous Rocks are formed

31. Extrusive Igneous Rocks

32. What type of igneous rocks are formed here?

33. What types of igneous rocks would be formed here? http://hvo.wr.usgs.gov/gallery/kilauea/volcanomovies/