Author Question: How do stalagmites enter into the debate on global warming? What will be an ideal ... (Read 48 times)

joesmith1212 · **on:** Jul 15, 2018

How do stalagmites enter into the debate on global warming? What will be an ideal response?

Question 2

What is the importance of a marker bed? What will be an ideal response?

pallen55 · **Reply #1 on:** Jul 15, 2018

Answer to Question 1

Stalagmites are calcium carbonate precipitated from evaporating water in caves, and each new layer of
rock is younger than the previously precipitated layer. Using uranium 234 to thorium 230, geologists
can date stalagmites back to 500,000 years. Crevice Cave in Missouri reveals climate and vegetation
75,000 to 25,000 years ago, and these dates are then correlated with other data to create a detailed
picture of climate change in this period. It is important to be able to reconstruct past climate accurately
to see how Earth's climate system has responded to changes in the past.

Answer to Question 2

Marker beds are important because they can be used for correlation. Ashfalls provided good marker
beds that connect marine and nonmarine sequences, and they often spread far. Lava flows are also
good marker beds because they spread far and are distinctive