12: Ocean Sediments
After reading this chapter you should:
- know how sediments are classified based on physical characteristics (size, sorting etc.)
- identify the four main sources of marine sediments
- differentiate between organisms that produce different biogenous sediments
- understand the factors that determine the distribution of sediment types in the ocean
- know the different ways sediment samples can be obtained
- understand how biogenous sediments can be used to reconstruct past climate change
Let’s be honest; for the majority of people with an interest in the oceans and oceanography it is not the allure of the sediments that first grabs their attention. At first glance the muddy seafloor may not seem that interesting, but the sediments play a vital role in marine ecosystems and our understanding of ocean and geological processes. The sediments provide habitat for a multitude of marine organisms, and they contain information about past climates, plate tectonics, ocean circulation patterns, and the timing of major extinctions, just to name a few. In this chapter we will examine the major types of sediments, and their distribution on the ocean floor.
Thumbnail: A “black smoker” hydrothermal vent. The “smoke” consists of dissolved particles that precipitate into solids when exposed to colder water (NOAA, http://www.photolib.noaa.gov/htmls/nur04506.htm ).