Question

What method would be the best choice for a climatologist to find out what the ocean temperatures were like during the Pleistocene ice ages 30 million years ago?

A. Analyze the tree rings of petrified wood from the Pleistocene.

B. Analyze alkenones molecules of phytoplankton in rocks of that period.

C. Analyze ice core samples from pleistocene glaciers.

D. Analyze O-18 ratios from Antarctic glaciers.

Answer 1

B

Step-by-step explanation:

Alkenone molecules from phytoplankton are robust enough to survive the effects of weathering and chemical breakdown for 110 million years. Rock layers yield chemical traces of these ancient organisms. Their chemical composition indicates ancient water temperatures.

Answer 2

b

Step-by-step explanation:

Alkenone molecules from phytoplankton are robust enough to survive the effects of weathering and chemical breakdown for 110 million years. Rock layers yield chemical traces of these ancient organisms. Their chemical composition indicates ancient water temperatures.