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Marine Geology Overview

Jul 2, 2025

Overview

This lecture introduces the key concepts of marine geology, focusing on the structure, processes, and importance of the ocean floor in marine biology.

Introduction to Marine Geology

  • Marine geology studies the structure, history, and processes shaping the ocean floor.
  • It links biological, chemical, and physical aspects of marine environments.

Ocean Floor Structure

  • The ocean floor consists of continental shelves, slopes, rises, and the deep-sea basin.
  • Mid-ocean ridges are underwater mountain ranges formed by plate tectonics.
  • Deep-sea trenches are the deepest parts of the ocean, often linked to subduction zones.

Geological Processes

  • Plate tectonics cause the movement of Earth's crust, forming ocean basins and features.
  • Volcanic activity under the sea creates islands and hydrothermal vents.
  • Sedimentation refers to the accumulation of particles like sand, silt, and organic matter on the seafloor.

Importance for Marine Life

  • Geological features provide habitats and influence marine biodiversity.
  • Hydrothermal vents support unique biological communities despite extreme conditions.
  • Sediments affect nutrient availability and water chemistry, impacting marine ecosystems.

Key Terms & Definitions

  • Marine geology — study of the ocean floor's origins, structure, and processes.
  • Continental shelf — submerged extension of continents, rich in marine life.
  • Plate tectonics — movement of Earth's lithospheric plates, shaping ocean basins.
  • Mid-ocean ridge — underwater mountain range formed by diverging tectonic plates.
  • Trench — deep, narrow depression in the ocean floor, often at subduction zones.

Action Items / Next Steps

  • Review diagrams of ocean floor structures.
  • Read textbook section on plate tectonics and marine geology basics.