Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: guest47296 on 03/10/2018 00:23:28

Title: What are the principles of stratigraphy?
Post by: guest47296 on 03/10/2018 00:23:28

Could someone tell me if this info from my textbook is correct?
(https://cdn.pbrd.co/images/HGEBlkY.png)
I thought the bottom layers are the oldest and the top are the youngest, or am I misunderstanding something?

Title: Re: What are the principles of stratigraphy?
Post by: chiralSPO on 03/10/2018 03:21:40

I believe there is a mistake in the book, and your understanding is correct: the oldest layers should be the furthest down, and the youngest closer to the surface. (Unless I am also very mistaken)

Title: Re: What are the principles of stratigraphy?
Post by: Colin2B on 03/10/2018 09:11:20

As @chiralSPO says, it looks like a typo. If you look at the top right of your screenshot you can see words ‘youngest on top’.

There are some places where the folding is so extreme that the layers are inverted in an area, but this is unusual.

Title: Re: What are the principles of stratigraphy?
Post by: chris on 03/10/2018 09:20:06

You should write to the publisher and tell them; a) they'll be grateful for the careful proof-reading and opportunity to fix a glaring error; and b) they might send you a free copy of something else!

Title: Re: What are the principles of stratigraphy?
Post by: Bill S on 03/10/2018 11:58:25

Hi Minerals, welcome.

You are, as Chiral and Chris point out, absolutely right.

https://www.nps.gov/badl/learn/nature/geologicformations.htm 

Quote

The oldest formations are at the bottom and the youngest are at the top, illustrating the principle of superposition.

Are you just starting in geology?  If so, I wish you years of joy with it.