Author Question: What evidence from volcanic rocks indicates that Earth was much hotter in the past? What will be ... (Read 45 times)

LCritchfi · **on:** Jul 16, 2018

What evidence from volcanic rocks indicates that Earth was much hotter in the past?

What will be an ideal response?

Question 2

Write a short paragraph in which you use the analogies of a bottle of salad dressing and hand clapping to explain planetary differentiation to a friend or family member who is unfamiliar with the concept.

What will be an ideal response?

Sierray · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

Ultramafic lava flows require mantle temperatures several hundred degrees hotter than our estimates of the present day mantle temperatures. These ultramafic lava flows are all greater than 3 billion years old.

Answer to Question 2

A bottle of salad dressing contains oil and vinegar, which do not mix unless they are shaken together. Over time, the oil and vinegar separate, with the denser vinegar on the bottom. This is analogous to how molten metal would separate from molten silicate.