An Introduction to physical geology
- 1. Introduction to Physical Geology Presented by Tahsin Islam
- 2. Table of Contents Introduction Scientific Method Geology as a science Why Geology? Practical Aspects of Geology Career in Geology Branches of Geology Physical Geology Earth Systems
- 3. Introduction Geology uses the scientific method to explain natural aspects of the Earth such as Solar system Earth’s Interior Volcanism Mountain Building Weathering Transportation Erosion Plate tectonics Earthquake
- 4. Scientific Method Way of finding truth in the word Geology is a science and it requires- • Observations • Measurements • Interpretations
- 6. Geology as a science Names came from Greek goddess “GAEA”, daughter of Chaos. Geology derives from Greek word “Geo” means Earth and “Logos” means discourse/study. The scientific study of the Earth- How earth was formed What earth is made of How earth changes
- 7. Why Geology? Protecting Environment Supply things we need Avoiding Geo-hazards
- 9. Practical Aspects of Geology • Natural Resources All manufactured objects depend on Earth’s resources Localized concentrations of useful geological resources are mined or extracted If it can’t be grown, it must be mined Most resources are limited in quantity and non-renewable
- 10. Career in Geology Petroleum geologist Mining geologist Environmental geologist Marine geologist Hydrogeologist Glaciologist Volcanologist Sedimentologist Geophysicists Engineering geologist Teaching
- 11. Branches of Geology Physical Geology Historical Geology Mineralogy Petrology Geochemistry Volcanology Stratigraphy Sedimentology Palaeontology Geomorphology Hydrogeology Structural Geology
- 12. Physical Geology Concerned with Earth materials as well as The Processes that operate on those materials, either at or beneath the surface of the Earth. Earth materials: elements, minerals, rocks, water
- 13. Physical Geology Cont. Processes: plate tectonics, volcanic eruptions, earthquakes, mountain building, actions of glaciers, oceans, wind, weathering erosion.
- 14. Earth Systems Planet earth has some components which is termed as earth systems/spheres Atmosphere- gases that envelop Earth Hydrosphere- water on or near Earth’s surface Biosphere- all living or once-living materials Geosphere- rock and other inorganic materials
- 15. Earth Systems • Earth’s Heat Engines - External (energy from the Sun) • Primary driver of atmospheric (weather) and hydrospheric (ocean currents) circulation • Controls weathering of rocks at Earth’s surface - Internal (heat moving from hot interior to cooler exterior) • Primary driver of most geospheric phenomena (volcanism, magmatism, tectonism)
- 16. The Solar System
- 17. Earth’s Interior • Compositional Layers – Crust (~3-70 km thick) -Very thin outer rocky shell of Earth Continental crust - thicker and less dense Oceanic crust - thinner and more dense – Mantle (~2900 km thick) • Hot solid that flows slowly over time; • Fe-, Mg-, Si-rich minerals – Core (~3400 km radius) • Outer core - metallic liquid; mostly iron • Inner core - metallic solid; mostly iron
- 18. Volcanism
- 19. India SE Asia HimalayaTibetan Plateau 60 million years ago 30 million years ago Today Continent-Continent Convergence Mountain Building
- 20. Weathering
- 21. Weathering
- 22. Erosion
- 23. Transportation Transported by geologic agents like- Wind Water Glacier
- 24. Wind
- 25. Water
- 26. Glacier
- 27. Earthquakes
- 28. Plate Tectonics
- 29. Tectonic Plate Boundaries • Divergent boundaries – Plates move apart – Magma rises, cools and forms new lithosphere – Typically expressed as mid-oceanic ridges • Transform boundaries – Plates slide past one another – Fault zones, earthquakes mark boundary – San Andreas fault in California • Convergent boundaries – Plates move toward each other – Mountain belts and volcanoes common – Oceanic plates may sink into mantle along a subduction zone, typically marked by a deep ocean trench
- 30. Tectonic Plate Boundaries Transform Divergent Convergent boundary boundary boundary
- 31. Theory of Plate Tectonics • Continental Drift Hypothesis – Originally proposed in early 20th century to explain the “fit of continents”, matching rock types and fossils across ocean basins, etc. • Plate Tectonics Theory – Originally proposed in the late 1960s – Included new understanding of the seafloor and explanation of driving force – Describes lithosphere as being broken into plates that are in motion – Explains origin and distribution of volcanoes, fault zones and mountain belts
- 32. Creating Geo Hazard by Plate Tectonics
- 37. Geologic Time
- 38. Thank You All.
Editor's Notes
- #22: Tapolca lake cave (Bakony Balaton), Hungary