Explore the ocean’s sediments

When we see pictures of the earth from space it is easy to appreciate the varied environments on land such as mountains, polar regions, deserts, the tropics and so on. The ocean surface appears as a vast expanse of constant blue but, as you will see, the seafloor itself is as varied in its composition as the land we walk upon.

In the previous step you learned about the four main sources of sediment in the ocean; lithogenous, biogenous, hydrogenous, and cosmogenous. These can be further divided, depending on features of those sediments, such as particle size and more specific origins.

The composition and distribution of these different sediments influences biogeochemical cycles and storage of chemical elements in the ocean. By studying ocean sediments, scientists can increase our understanding of the occurrence of metal deposits; how sediments are transported around the ocean; the behaviour of deep-ocean currents; the reconstruction of past environments; and the response of the deep ocean to global warming.

Your task (optional)

In this task, you will take a closer look at the composition of the seabed around the world using a 3D model and then tell us what you discover in the comments area.

Instructions

Explore this model of a 3D globe from GPlatesPortal. You might find it easier to open the link in a new window so you can see it whilst writing your comments.

For details of the different sediment types, click the legend in the bottom right-hand corner of the map. You will see that various types of biogenous and lithogenous sediment types are shown on the map.

Consider the questions below and share your observations in the comments section.

Can you see any patterns in the distribution of different kinds of sediments? Why might these be?

Why are hydrogenous and cosmogenous sediments not shown?

^{How to control the 3D globe?}

^{– Left click and drag – Rotates the camera around the globe in 3D.}

^{– Right click and drag – Zooms the camera in and out.}

^{– Middle wheel scrolling – Also zooms the camera in and out.}

^{– Middle click and drag – Rotates the camera around the point on the surface of the globe.}