1. HNRS 228 Astrobiology Chap.4 Geology Bennett et al. Lecture Notes for Chapter 4 (mostly from HNRS 227) Prof. Geller

2. The Geological History zReading the Earth’s history in the rocks yRocks and fossils yRelative and absolute dating methods zFormation of the Earth yAccretion, differentiation, Moon, age zThe Hadean Earth zPlate Tectonics zClimate zGeology and life

3. Telling Rocks Apart zHow geologists tell apart different minerals and rocks ycolor, luster, texture yhardness test xscratching one against another diamond is hardest yacid test xusing weak hydrochloric acid to ystreak test xform a streak across a ceramic tile

4. Minerals (see Table 19.1) zCharacteristics ynaturally occurring yinorganic ydefinite crystalline structure zThe natural resources of industry

5. Igneous Rocks z“Rocks formed from hot molten mass of melted rock material”

6. Sedimentary Rocks z“Rocks formed from particles or dissolved materials from previously existing rocks.”

7. Metamorphic Rocks z“Previously existing rocks that have been changed by heat, pressure, or hot solutions into a distinctly different rock.”

8. The Rock Cycle

9. Earth’s Interior and How We Know It

10. Earthquakes Galore

11. Earth’s Inside Story

12. Crustal Rumblings

13. Plate Tectonics z“The theory that the Earth’s crust is made of rigid plates that float on the asthenosphere.” zConsider the scientific evidence for plate tectonics and what forced scientists to accept the theory as fact

14. Fossils across an ocean

15. Boundaries Galore

16. Plates are smashing

17. Surface Building Processes zStress y“stress is a force that tends to compress, pull apart, or deform” ydifferent types of stress xcompressive stress xtensional stress xshear stress zStrain y“the adjustment to stress”

18. Stress and Strain

19. Surface Building Processes zFolds ybends in layered bedrock zAnticline/\ zSyncline \/

20. Surface Building Processes zFaulting yformation of a crack caused by relative movement of rock on either side of a fracture xdifferent types - normal, reverse, thrust

21. Earthquakes zDefined as “quaking, shaking, vibrating, or upheaval of the ground” zEarthquake causes yelastic rebound theory zIntensity measure yRichter Magnitude xnot linear

22. Mountains z“elevated parts of the Earth’s crust that rise abruptly above the surrounding surface” zCauses yfolding, faulting, volcanic activity

23. Volcanoes z“hill or mountain formed by the extrusion of lava or rock fragments from magma below” zDifferent types yshield, cinder cone, composite (composite shown)

24. Tear-Down Processes zWeathering ymechanical weathering ychemical weathering zErosion ymass movement (mass wasting) yrunning water (floodplain, delta) yglacier ywind (deflation and abrasion) yimpact cratering

25. Development of Geologic Time zFossilization z“Reading the Rocks” yprinciple of uniformity yprinciple of original horizontality yprinciple of superposition yprinciple of crosscutting relationships yprinciple of faunal succession yradiometric dating zGeologic Time Scale

26. Geologic Time Scale