Geologic Mapping C

UTF-8 U+6211 U+662F
Exalted Member
Posts: 1463
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA

Re: Geologic Mapping C

Snayhill wrote:Hello Everyone!

I was just wondering if anyone here know what lines that are not faults in a relative dating/strata diagram are. Here's a link https://d2vlcm61l7u1fs.cloudfront.net/media%2Fd3f%2Fd3f1e735-faac-4704-aa99-61fcf269b020%2FphpIiQrsg.png. I'm specifically talking about "G" in this picture.

Thanks!

What does line G represent? It's not a fault because there isn't any relative motion across it as you can see in line K

fabishkf
Member
Posts: 13
Joined: February 17th, 2018, 10:41 am
Division: C
State: WI

Re: Geologic Mapping C

joint
Hamilton Middle School '17
Madison West High School '21
National tournaments: 2016 Stout, 2017 Wright State division B, 2018 CSU, 2019 Cornell division C
2019 SONT at Cornell: 2nd Geologic Mapping, 6th Fossils

bluesm0ke
Member
Posts: 1
Joined: January 21st, 2019, 8:07 pm

Re: Geologic Mapping C

Unome wrote:
UTF-8 U+6211 U+662F wrote:
poonicle wrote:On one test, the formula for true thickness was given as T = Wsin(d) + Hcos(d) where T = true thickness, W = width, H = height, d = dip, whereas on another test, the formula for true thickness was given as T = Wsin(d) where T = true thickness, W = width, d = dip. Which one is the correct formula? I am very confused.

What is height?

(Note that a formula for true thickness can be derived using basic trig in emergencies!)

I would strongly recommend deriving the formula yourself, so you understand how it works. There are several standard formulas for true thickness that cover various situations.

Do you think you could post those formulas here? I'm having a hard time grappling more complex true thickness problems that don't just use the basic formula. thanks

Unome
Moderator
Posts: 4030
Joined: January 26th, 2014, 12:48 pm
State: GA
Location: somewhere in the sciolyverse

Re: Geologic Mapping C

bluesm0ke wrote:
Unome wrote:
UTF-8 U+6211 U+662F wrote:What is height?

(Note that a formula for true thickness can be derived using basic trig in emergencies!)

I would strongly recommend deriving the formula yourself, so you understand how it works. There are several standard formulas for true thickness that cover various situations.

Do you think you could post those formulas here? I'm having a hard time grappling more complex true thickness problems that don't just use the basic formula. thanks

I don't have the third one memorized, and can't seem to find it, but I'm pretty sure it's on one of the test exchange tests.
Userpage
Chattahoochee High School Class of 2018
Georgia Tech Class of 2022

Opinions expressed on this site are not official; the only place for official rules changes and FAQs is soinc.org.

poonicle
Member
Posts: 18
Joined: September 22nd, 2017, 3:11 pm
Division: C
State: -

Re: Geologic Mapping C

bluesm0ke wrote:
Unome wrote:
UTF-8 U+6211 U+662F wrote:What is height?

(Note that a formula for true thickness can be derived using basic trig in emergencies!)

I would strongly recommend deriving the formula yourself, so you understand how it works. There are several standard formulas for true thickness that cover various situations.

Do you think you could post those formulas here? I'm having a hard time grappling more complex true thickness problems that don't just use the basic formula. thanks

yeah, i'm not gonna lie, i asked that question before TSTs when i didn't know that much about the event. my accuracy improved a lot when i started drawing stuff out then applying trig as opposed to formulas--i'm not very good at identifying which formula applies to which situation yet, but drawing a picture really, really helps imo

that being said, i found T = w*sin(D - S) where D = dip, S = slope, T = true thickness on one practice test. hope that's helpful
messed up your nats predicts and what abt it TT____TT

fleicol1
Member
Posts: 5
Joined: January 9th, 2018, 12:57 pm
State: -

Re: Geologic Mapping C

What would be a good website for information on all of the fault. I haven't had much luck finding a good one.

UTF-8 U+6211 U+662F
Exalted Member
Posts: 1463
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA

Re: Geologic Mapping C

fleicol1 wrote:What would be a good website for information on all of the fault. I haven't had much luck finding a good one.

There's not just one website with all the info, but here's a start

https://www.usgs.gov/faqs/what-a-fault- ... e_products
https://en.wikipedia.org/wiki/Fault_(geology)
https://www.thoughtco.com/fault-types-w ... ms-3879102

l0lit
Member
Posts: 16
Joined: July 30th, 2018, 12:20 pm
Division: C
State: IN

Re: Geologic Mapping C

I've seen that there is some discussion on the concept of bed thickness. The only scenario I've seen so far is where T = V cos d where T is true thickness, V is vertical thickness, and d is the angle of dip (as found in this scenario. Are there any other scenarios where the other equations (such as T = V cos d - H sin d ) come into play?
List of compiled Science Olympiad tests here
* Others coming soon...

UTF-8 U+6211 U+662F
Exalted Member
Posts: 1463
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA

Re: Geologic Mapping C

l0lit wrote:I've seen that there is some discussion on the concept of bed thickness. The only scenario I've seen so far is where T = V cos d where T is true thickness, V is vertical thickness, and d is the angle of dip (as found in this scenario. Are there any other scenarios where the other equations (such as T = V cos d - H sin d ) come into play?

It's best to just use trig instead of trying to apply an equation in that scenario in my opinion. Other equations would apply if other angles/lengths were given.

Unome
Moderator
Posts: 4030
Joined: January 26th, 2014, 12:48 pm
State: GA
Location: somewhere in the sciolyverse

Re: Geologic Mapping C

UTF-8 U+6211 U+662F wrote:
l0lit wrote:I've seen that there is some discussion on the concept of bed thickness. The only scenario I've seen so far is where T = V cos d where T is true thickness, V is vertical thickness, and d is the angle of dip (as found in this scenario. Are there any other scenarios where the other equations (such as T = V cos d - H sin d ) come into play?

It's best to just use trig instead of trying to apply an equation in that scenario in my opinion. Other equations would apply if other angles/lengths were given.

Heh, that's exactly what I was going to say.
Userpage
Chattahoochee High School Class of 2018
Georgia Tech Class of 2022

Opinions expressed on this site are not official; the only place for official rules changes and FAQs is soinc.org.

freed2003
Member
Posts: 153
Joined: November 3rd, 2015, 3:00 pm
Division: C
State: CA

Re: Geologic Mapping C

whats the difference between brittle and friable? or are they interchangable?
Great Oak/Regionals/state
Thermodynamics2/4
Geologic Mapping2/1
Protein Modeling6/2

UTF-8 U+6211 U+662F
Exalted Member
Posts: 1463
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA

Re: Geologic Mapping C

freed2003 wrote:whats the difference between brittle and friable? or are they interchangable?

Brittle is used more often in structural geology and thus this event. According to Wikipedia, friable is used in soft-rock geology and describes the tendency of a solid substance to break insto smaller pieces under duress or contact, especially by rubbing, e.g. sandstone.

SciHenry2017
Member
Posts: 3
Joined: October 4th, 2018, 9:06 pm
State: -

Re: Geologic Mapping C

I’m new to this forum so I’m not sure if I am supposed to ask questions on here, but I need help. I don’t know how to solve this problem any help would be great. Thank You!!

You notice a horizontal outcrop of an unfolded stratum with a midline 50 meters below the top of a vertical cliff, with a thickness of 3 meters. After climbing to the top of the cliff to investigate further, you find another outcrop of the stratum on the flat clifftop, 2.6 meters wide.
61. What is the true thickness of this stratum in meters? (3)
62. How far is the midline of the second outcrop from the cliff edge in meters? (2)

UTF-8 U+6211 U+662F
Exalted Member
Posts: 1463
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA

Re: Geologic Mapping C

SciHenry2017 wrote:I’m new to this forum so I’m not sure if I am supposed to ask questions on here, but I need help. I don’t know how to solve this problem any help would be great. Thank You!!

You notice a horizontal outcrop of an unfolded stratum with a midline 50 meters below the top of a vertical cliff, with a thickness of 3 meters. After climbing to the top of the cliff to investigate further, you find another outcrop of the stratum on the flat clifftop, 2.6 meters wide.
61. What is the true thickness of this stratum in meters? (3)
62. How far is the midline of the second outcrop from the cliff edge in meters? (2)

The first thing to do when encountering this kind of picture is drawing a picture and labeling relevant angles and lengths. In this case, you would probably only need to draw a cross section. From there, solve for the angles and remaining lengths using some trig calculations. If you need more help, I can attempt to draw a picture. For 62, you would probably use similar triangles.
Last edited by UTF-8 U+6211 U+662F on March 19th, 2019, 5:26 pm, edited 1 time in total.

SciHenry2017
Member
Posts: 3
Joined: October 4th, 2018, 9:06 pm
State: -

Re: Geologic Mapping C

UTF-8 U+6211 U+662F wrote:
SciHenry2017 wrote:I’m new to this forum so I’m not sure if I am supposed to ask questions on here, but I need help. I don’t know how to solve this problem any help would be great. Thank You!!

You notice a horizontal outcrop of an unfolded stratum with a midline 50 meters below the top of a vertical cliff, with a thickness of 3 meters. After climbing to the top of the cliff to investigate further, you find another outcrop of the stratum on the flat clifftop, 2.6 meters wide.
61. What is the true thickness of this stratum in meters? (3)
62. How far is the midline of the second outcrop from the cliff edge in meters? (2)

The first thing to do when encountering this kind of picture is drawing a picture and labeling relevant angles and lengths. In this case, you would probably only need to draw a cross section. From there, solve for the angles and remaining lengths using some trig calculations. If you need more help, I can attempt to draw a picture.

Yes can you draw the picture please? I would really appreciate it. Thank you!
Oh the answers are
61. 1.96-1.97 m
62. 43.3-43.4 m