PHYSICAL n STRUCTURAL GEOLOGY_FINAL

Page 1: Course Introduction

• Course Title: Physical and Structural Geology (MN/MR 161)

• Institution: University of Mines and Technology, Tarkwa

• Lecturer: Ing. Dr. M.L.Y Ankah

• Date: 26 January 2025

Page 2: Course Overview

• Objectives:

  • Introduce geology fundamentals including major rock types.

  • Explore physical structures shaping Earth’s surface and their origins.

  • Understand geological processes and evolution.

Page 3: Course Logistics

• Contact Hours: 3 hours/week

• Evaluation:

  • Attendance: 10%

  • In-class Activities (IAs): 30% (Assignments & Quizzes)

  • Final Examination: 60%

Page 4: Course Outline

1. General Geology

2. Internal Processes

3. Geologic Time

4. Plate Tectonics

5. Weathering and Soils

6. Mass Wasting

7. Groundwater

8. Streams and Drainage

9. Wind Action and Deserts

10. Volcanism

11. Overview of Geological Structures

Page 6: Introduction to Geology

• Derived from Greek: geo (Earth) + logos (discourse).

• Definition: Study of Earth's materials, physical and chemical changes, and planetary history, including life forms.

Page 7: Earth's Composition

• Radius: Approximately 6370 km, primarily composed of rocks.

• Rock outcrops create diverse terrains like cliffs and arches.

• Rocks consist of minerals; over 3500 known minerals exist, but only a few are common.

Page 8: Reasons to Study the Earth

• To satisfy human curiosity and link to our environment.

• To understand energy & mineral resources, geological hazards, and environmental impacts.

Page 9: Natural Resources and Environmental Impact

• Manufactured Objects: Depend on Earth’s resources.

• If it cannot be grown, it must be mined (non-renewable resource consideration).

Page 10: Resource Extraction Impacts

• Coal Mining: Careless methods may poison groundwater.

• Petroleum: Extraction processes can harm the environment.

Page 11: Geologic Hazards

• Earthquakes: Can damage infrastructure.

• Volcanoes: Ashflows can devastate populated areas.

• Landslides and Floods: Can lead to catastrophic events.

Page 13: Branches of Geology

1. Physical Geology: Studies Earth's materials and processes.

   • Includes mineralogy, petrology, geomorphology, etc.

2. Historical Geology: Examines Earth's history via rock analysis, including paleontology and stratigraphy.

Page 14: Historical Perspective on Earth's Age

• Archbishop Usher's Calculation: Earth created in 4004 BC (circa 6000 years old).

• James Hutton (Father of Geology) challenged this idea via observations of Earth processes.

Page 15: Principle of Uniformitarianism

• Concept: Present-day processes shaped the Earth in the past ("the present is the key to the past").

Page 16: Principle of Catastrophism

• States Earth's history is shaped by sudden events rather than gradual processes.

Page 17: Age Determination Advances

• Advances in radiometric dating revealed the Earth is approximately 4.54 billion years old.

Page 19: Understanding the Universe

• The universe encompasses all space, matter, energy, and time including Earth and other celestial bodies.

Page 20: Big Bang Theory

• The universe began as a hot, dense singularity around 13.6 billion years ago, leading to the formation of light elements.

Page 22: Nebular Hypothesis

• Suggests solar systems formed from a large rotating cloud of gas and dust (nebula) approximately 5 billion years ago.

Page 24: Formation of the Earth

• Earth formed through gravitational accretion from a nebula, eventually leading to the development of the Moon and oceans.

Page 28: Earth's Spheres

1. Atmosphere: Gases enveloping Earth.

2. Hydrosphere: All water on Earth’s surface.

3. Biosphere: Regions inhabiting life.

4. Geosphere: The solid rocky Earth.

Page 32: The Geosphere

• Extends about 6400 km, consists of solid, semi-solid, and liquid layers, characterized by physical and chemical diversity.

Page 33: The Earth System

• Components interrelate; powered by solar energy and Earth’s internal heat (radioactive decay).

Page 34: Geological Processes

• Processes can be slow (e.g., erosion) or fast (e.g., landslides).

Page 37: The Rock Cycle

• Rocks classified into three categories based on their formation:

  • Igneous: Formed from solidified magma.

  • Sedimentary: Formed from deposited sediments.

  • Metamorphic: Formed from alteration of existing rocks due to heat and pressure.

Page 41: Metamorphic Rock Formation

• Formed when existing rocks undergo changes due to increased heat, pressure, or deformation.

Page 49: Internal Processes

• Compositional Layers:

  • Crust: Thin layer above Mantle.

  • Mantle: Thick solid layer.

  • Core: Iron-nickel solid center and molten outer layer.

Page 60: Internal Processes Dynamics

• Originating mechanisms: radioactive decay and thermal processes.

Page 61: Sources of Geological Processes Heat

• Earth's internal heat due to extra-terrestrial impacts, gravitational contraction, and radioactive decay.

Page 73: Geologic Time

• Dating Techniques: Absolute (via radioactive decay) and relative (through stratigraphy and rock layering).

Page 75: Principles of Relative Dating

• Principle of Original Horizontality: Sediments are deposited horizontally.

Page 76: Principle of Lateral Continuity

• Layers extend laterally over a distance; can be affected by geological events.

Page 90: Difference between Fault Types

• Normal Fault: Hanging wall moves down.

• Reverse Fault: Hanging wall moves up.

Page 115: Geological Time Scale

• Eons, eras, and periods defined by life forms and geological events.

Page 126: Plate Tectonics Overview

• Lithosphere divided into tectonic plates; movements cause geological activity such as earthquakes and volcanism.

Page 140: Evidence Supporting Plate Tectonics

• Coastline shapes, faunal similarities, geological formations, and past climatic conditions indicate continental drift and tectonic plate movements.

Page 151: Types of Weathering

• Mechanical: Physical breakdown of rocks.

• Chemical: Changes in rock composition through chemical reactions.

Page 161: What are Soils?

• Composed of minerals mixed with organic matter; vary in texture, consistency, and structure.

Page 173: Importance of Water in Mass Wasting

• Influences slope stability, can decrease friction or enhance soil cohesion.

Page 178: Groundwater Movement

• Groundwater moves through soil; influenced by porosity and permeability of materials.

Page 201: Importance of Streams

• Conduits for water cycling, sediment transport, and habitats for aquatic life.

Page 220: Wind Actions in Deserts

• Wind modifies landscape through erosion and sediment transport, affecting soil and mineral stability.

Page 232: Types of Volcanic Rocks

• Two main types: Volcanic (extrusive) and Plutonic (intrusive); characterized by distinct formation processes.

Page 257: Overview of Geologic Structures

• Types: Primary structures form during rock formation, secondary structures develop post-formation.

Page 282: Overview of Glaciers

• Represent Earth's largest fresh water reservoir; sensitive to climatic changes.