Chapter 5 Oceanography

What is the age of the oldest marine sediments?

• Over 500 million years

• Rarely older than 180 million years

• Approximately 1 billion years

• Around 50 million years

What is the significance of the depth and composition of marine sediments?

• They indicate future climate changes

• They reveal recent events in the ocean basin

• They show the age of the Earth

• They predict volcanic eruptions

What is the typical thickness of sediment on the deep seafloor?

• A few centimeters to a few meters

• Several kilometers

• Only a few millimeters

• Over 10 meters

What is the main characteristic of the sediment in Figure 5.3?

• Ripples caused by bottom currents

• Completely smooth

• Covered in algae

• Full of shells

What can dissolve material on the seafloor as it settles?

• Cold water

• Hot water percolating upward

• Acidic rain

• Salty water

Which sediment type is associated with the accumulation of hard parts of marine organisms?

• Terrigenous

• Biogenous

• Hydrogenous

• Cosmogenous

What is the primary method of transport for terrigenous sediments to the sea?

• Wind and water

• Volcanic eruptions

• Meteorite impacts

• Dissolution

What are biogenous sediments primarily formed from?

• Rocks

• Marine organisms

• Volcanic ash

• River deposits

What natural event in April 2010 caused ash to be transported across Europe?

• Earthquake

• Volcanic eruption

• Tsunami

• Hurricane

What is the main component of siliceous biogenous sediments?

• Calcium carbonate

• Silicon

• Iron

• Magnesium