Jacky_Ye
Badges: 10
Rep:
?
#1
Report Thread starter 3 years ago
#1
Name:  98A796EB-96E5-4818-A4E7-506BF926550F.jpg.jpeg
Views: 75
Size:  22.5 KB Please help me with my Geography h/w. The task is to write how A, B and C are formed and a geological history about them. Thanks
0
reply
username2088165
Badges: 20
Rep:
?
#2
Report 3 years ago
#2
(Original post by Jacky_Ye)
Name:  98A796EB-96E5-4818-A4E7-506BF926550F.jpg.jpeg
Views: 75
Size:  22.5 KB Please help me with my Geography h/w. The task is to write how A, B and C are formed and a geological history about them. Thanks
A - all sedimentary layers are deposited more or less horizontally, so here you should list the order in which the rock types were deposited, then describe the process which caused them to deform (i.e. fold).

B - the rocks here aren't folded, however they have been eroded. Again, write about the order in which the rocks were deposited, and how erosion has affected them.

C - in this cross section, the concept of 'cross-cutting relationships' is an important tool to use to figure out what's going on. Structures such as faults and igneous intrusions 'cross-cut' the rocks which are already there, so are therefore younger than the rocks they cut through. The oldest rock is the clay, followed by the sandstone and limestone, which lie in horizontal beds. A fault has displaced these beds upwards, and the basalt intrusion has intruded into them. Both the fault and the intrusion stop at the sandstone, meaning that a period of erosion must have occurred, followed by the deposition of the sandstone.

I hope that helps
0
reply
Jacky_Ye
Badges: 10
Rep:
?
#3
Report Thread starter 3 years ago
#3
(Original post by Leviathan1741)
A - all sedimentary layers are deposited more or less horizontally, so here you should list the order in which the rock types were deposited, then describe the process which caused them to deform (i.e. fold).

B - the rocks here aren't folded, however they have been eroded. Again, write about the order in which the rocks were deposited, and how erosion has affected them.

C - in this cross section, the concept of 'cross-cutting relationships' is an important tool to use to figure out what's going on. Structures such as faults and igneous intrusions 'cross-cut' the rocks which are already there, so are therefore younger than the rocks they cut through. The oldest rock is the clay, followed by the sandstone and limestone, which lie in horizontal beds. A fault has displaced these beds upwards, and the basalt intrusion has intruded into them. Both the fault and the intrusion stop at the sandstone, meaning that a period of erosion must have occurred, followed by the deposition of the sandstone.

I hope that helps
Alright, thanks!
1
reply
Jacky_Ye
Badges: 10
Rep:
?
#4
Report Thread starter 3 years ago
#4
(Original post by Jacky_Ye)
Alright, thanks!
(Original post by Leviathan1741)
A - all sedimentary layers are deposited more or less horizontally, so here you should list the order in which the rock types were deposited, then describe the process which caused them to deform (i.e. fold).

B - the rocks here aren't folded, however they have been eroded. Again, write about the order in which the rocks were deposited, and how erosion has affected them.

C - in this cross section, the concept of 'cross-cutting relationships' is an important tool to use to figure out what's going on. Structures such as faults and igneous intrusions 'cross-cut' the rocks which are already there, so are therefore younger than the rocks they cut through. The oldest rock is the clay, followed by the sandstone and limestone, which lie in horizontal beds. A fault has displaced these beds upwards, and the basalt intrusion has intruded into them. Both the fault and the intrusion stop at the sandstone, meaning that a period of erosion must have occurred, followed by the deposition of the sandstone.

I hope that helps
Hey Levi! Please can you do part A for me as an example because I really don’t get it :/ Thank you
0
reply
username2088165
Badges: 20
Rep:
?
#5
Report 3 years ago
#5
(Original post by Jacky_Ye)
Hey Levi! Please can you do part A for me as an example because I really don’t get it :/ Thank you
Okay, I'll just go through A

Point 1 says that rocks get younger from the bottom up, which just means that the rocks at the bottom are the oldest, and the rocks at the top are the youngest. In this case, the sandstone is the oldest rock, the limestone is younger, and the clay is the youngest rock type. Point 2 tells you that layers can be assumed to have been originally horizontal, and the rocks in the image are wavy, not horizontal, meaning they have been folded.

In summary, the sandstone, then limestone, then clay were deposited horizontally, and later they were folded
0
reply
Jacky_Ye
Badges: 10
Rep:
?
#6
Report Thread starter 3 years ago
#6
(Original post by Leviathan1741)
Okay, I'll just go through A

Point 1 says that rocks get younger from the bottom up, which just means that the rocks at the bottom are the oldest, and the rocks at the top are the youngest. In this case, the sandstone is the oldest rock, the limestone is younger, and the clay is the youngest rock type. Point 2 tells you that layers can be assumed to have been originally horizontal, and the rocks in the image are wavy, not horizontal, meaning they have been folded.

In summary, the sandstone, then limestone, then clay were deposited horizontally, and later they were folded
Thank you very much
0
reply
username2088165
Badges: 20
Rep:
?
#7
Report 3 years ago
#7
(Original post by Jacky_Ye)
Thank you very much
No problem
0
reply
Jacky_Ye
Badges: 10
Rep:
?
#8
Report Thread starter 3 years ago
#8
(Original post by Leviathan1741)
No problem
Levi, did I do it right?Name:  185208D1-1899-4694-AD6F-A7E134249B9D.jpg.jpeg
Views: 62
Size:  23.9 KB
0
reply
username2088165
Badges: 20
Rep:
?
#9
Report 3 years ago
#9
(Original post by Jacky_Ye)
Levi, did I do it right?Name:  185208D1-1899-4694-AD6F-A7E134249B9D.jpg.jpeg
Views: 62
Size:  23.9 KB
It looks like you've got a bit confused :yes:

For B, the rocks haven't been folded, and I can't see any faults on there. I would say that the sandstone, limestone and clay were deposited horizontally, then eroded (you can see that there are gaps in the the clay, and some of the limestone is missing where it has been removed by erosion).

C is a bit trickier. Remember to always start with the deposition of the rocks - clay, sandstone, and then limestone. The three rocks have been faulted and moved upwards, and the basalt has intruded into them. The rocks, including the basalt, were then eroded (shown by the wavy, smooth surface), and lastly, sandstone was deposited on top of everything.

Does that make sense? I do geology as my degree, and I know these can be hard to understand at first
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

If you haven't confirmed your firm and insurance choices yet, why is that?

I don't want to decide until I've received all my offers (44)
40.74%
I am waiting until the deadline in case anything in my life changes (21)
19.44%
I am waiting until the deadline in case something in the world changes (ie. pandemic-related) (6)
5.56%
I am waiting until I can see the unis in person (9)
8.33%
I still have more questions before I made my decision (9)
8.33%
No reason, just haven't entered it yet (8)
7.41%
Something else (let us know in the thread!) (11)
10.19%

Watched Threads

View All