Which rock layer is the oldest?
The law of superposition is an axiom that forms one of the bases of the sciences of geology, archaeology, and other fields dealing with geological stratigraphy. In its plainest form, it states that in undeformed stratigraphic sequences, the oldest strata will be at the bottom of the sequence.
More Info:
en.wikipedia.org
What are your thoughts on this subject?
67 Comments
Sonny Beaudoin
In the picture D goes below C so D is the deepest. Therefore the oldest .
Stevie G
Poor question and answer. Also the explanation does not give a good enough detailed answer.
Hernando Villegas
It seems layer D is the oldest because it goes under layer C. Explanation is not too convincing.
Arno Janssen
The principle of cross-cutting relationships states that a fault or intrusion is younger than the rocks that it cuts through. The fault cuts through all three sedimentary rock layers (A, B, and C) and also the intrusion (D). So the fault must be the youngest feature. The intrusion (D) cuts through the three sedimentary rock layers, so it must be younger than those layers. By the law of superposition, C is the oldest sedimentary rock, B is younger and A is still younger.
Marina da Conceicao
Poor question and wrong answer. By the author's own explanation it should be D
Gary Chadwick
No A B C or D on Pic. so only logical that we can assuem it goes top to bottom. This would make D the answer.
Could it be that when the question was written there were only 3 options? Then when the 4th option was added, nobody corrected the answer?
Gary Chadwick
No A B C or D on the pic so it is only reasonable to assume that they are in order and from top to bottom. this according to the answer would make D the oldest
When the question was origially written, was it only A B or C and whenthe 4th option was added noone adjusted the answer?
George Trist
I couldn't see the labels on my cell.
Nodmirt
Where does the question setter think A,B,C etc are as it might have been nice to let tge rest of us know
Gillian Heritage
Where were the letters?
bina sarmah
The answer is wrong, what it means A, B, C, D. LAYERS should have name. It is undefinable that so far 101 people like the question.
Wendy Williams
Giselle Tamayo, I didn't either. Makes it very difficult to answer correctly.
Wendy Williams
I can't see the letters at all in the picture, so assumed D was at the bottom.
Giselle Tamayo
I got no letters.
Cora Jeske
I had no letters on my picture either. 😑
Patricia Fraser
I didn't see any letters on the picture.
melvinevans
A B C D not any technical answer
Mena Mitchell
Poorly presented question.
bleonard
No letters on mine either. With D the bottom letter, that would make D the oldest layer.