Page 2 of 9

Re: Geologic Mapping C

Posted: October 18th, 2018, 5:58 pm
by syo_astro
OrigamiPlanet wrote:On 3. c., there's something about "subsurface geometries," but I don't understand what exactly they are. Would somebody mind explaining what these are so I can look into it a little deeper? I just need to know what they are and the gist of it, no need for in-depth explanations. Thank you!
A few ways I used to think about them were (I haven't read the rules recently...so sorry if this is useless):
1) Identifying sub surface geometries in different geologic features and knowing how they "work" (this I think is what UTF is suggesting by looking at folds and faults...there might be others). In general, it's good to visualize each geologic structure as planes, lines, and points. So an example question to think about is: Can you spot the planar, linear, and point like aspects of folds? If you want some ideas for geologic *structures* that can be below the surface (sub surface), maybe look at relative age dating diagrams.
2) But this is also a mapping event! You should also know how to map, read, and understand these geologic structures (whether they are below or above the surface...and everything in between).
-The first way you can do this that I know of is with stereonets, which are all about mapping / noting information about geometric features (planes, lines, and points!).
-Another one would be "outcrop patterns" (the shape a structure makes from looking at a "top view" of the ground...you can maybe spot a fold or fault from a map, but how do we know how they look below the ground? How do you even know there is a fold or fault just from looking at a geologic map? This is how!). Note that "outcropping" I think has something to do with being visible on the surface.
-There are also "structure contours" (these are related to 3 point problems...they are contour lines that you use to usually connect the outcropping points of equal height for a single structure/plane)
-Lastly, cross sections are super common (they can be done with simple old topographic maps to see the shape of a mountain, but you can also use them with structure contours to infer how a structure or say a plane looks below ground).

Re: Geologic Mapping C

Posted: October 21st, 2018, 6:46 pm
by OrigamiPlanet
syo_astro wrote: A few ways I used to think about them were (I haven't read the rules recently...so sorry if this is useless):
1) Identifying sub surface geometries in different geologic features and knowing how they "work" (this I think is what UTF is suggesting by looking at folds and faults...there might be others). In general, it's good to visualize each geologic structure as planes, lines, and points. So an example question to think about is: Can you spot the planar, linear, and point like aspects of folds? If you want some ideas for geologic *structures* that can be below the surface (sub surface), maybe look at relative age dating diagrams.
2) But this is also a mapping event! You should also know how to map, read, and understand these geologic structures (whether they are below or above the surface...and everything in between).
-The first way you can do this that I know of is with stereonets, which are all about mapping / noting information about geometric features (planes, lines, and points!).
-Another one would be "outcrop patterns" (the shape a structure makes from looking at a "top view" of the ground...you can maybe spot a fold or fault from a map, but how do we know how they look below the ground? How do you even know there is a fold or fault just from looking at a geologic map? This is how!). Note that "outcropping" I think has something to do with being visible on the surface.
-There are also "structure contours" (these are related to 3 point problems...they are contour lines that you use to usually connect the outcropping points of equal height for a single structure/plane)
-Lastly, cross sections are super common (they can be done with simple old topographic maps to see the shape of a mountain, but you can also use them with structure contours to infer how a structure or say a plane looks below ground).
That actually helps a lot! Thank you so much syo_astro! :D

Re: Geologic Mapping C

Posted: October 24th, 2018, 11:23 am
by Unome
For those interested, UGA posted their invitational tests, which include the Geomaps test that I wrote.

Link to tests folder

The high score was around 50 points, with the typical quick drop-off near the top.

Re: Geologic Mapping C

Posted: October 27th, 2018, 10:06 am
by UTF-8 U+6211 U+662F
freed2003 wrote:Can someone link me to a good resource on how to solve three-point problems?
If you're still struggling with this, I posted a mathematical solution to a three-point problem in the question marathon.

Re: Geologic Mapping C

Posted: October 27th, 2018, 10:58 am
by syo_astro
UTF-8 U+6211 U+662F wrote:
freed2003 wrote:Can someone link me to a good resource on how to solve three-point problems?
If you're still struggling with this, I posted a mathematical solution to a three-point problem in the question marathon.
That uses matrices? I remember only needing geometry to do it / no equation solving required...(not that your way is bad, I just mean that I suck at matrices:/)

Re: Geologic Mapping C

Posted: October 27th, 2018, 11:00 am
by UTF-8 U+6211 U+662F
syo_astro wrote:
UTF-8 U+6211 U+662F wrote:
freed2003 wrote:Can someone link me to a good resource on how to solve three-point problems?
If you're still struggling with this, I posted a mathematical solution to a three-point problem in the question marathon.
That uses matrices? I remember only needing geometry to do it / no equation solving required...(not that your way is bad, I just mean that I suck at matrices:/)
Nah, it's just a quick way of solving a three-equation system. You can use elimination, substitution, etc.

You can also use geometry, but I like algebra more and suck at drawing :P

Re: Geologic Mapping C

Posted: October 27th, 2018, 2:24 pm
by Unome
UTF-8 U+6211 U+662F wrote:
syo_astro wrote:
UTF-8 U+6211 U+662F wrote: If you're still struggling with this, I posted a mathematical solution to a three-point problem in the question marathon.
That uses matrices? I remember only needing geometry to do it / no equation solving required...(not that your way is bad, I just mean that I suck at matrices:/)
Nah, it's just a quick way of solving a three-equation system. You can use elimination, substitution, etc.

You can also use geometry, but I like algebra more and suck at drawing :P
Drawing isn't necessary anyway, although with a graphing calculator matrices work just fine.

Re: Geologic Mapping C

Posted: October 27th, 2018, 4:48 pm
by l0lit
freed2003 wrote:Can someone link me to a good resource on how to solve three-point problems?
I believe that Youtube is the best resource for this, simply because the powerpoints and textbooks available are very confusing without a professor to explain what they mean. One such video is here. Hope this helps!

Re: Geologic Mapping C

Posted: November 4th, 2018, 7:53 am
by SciolyHarsh
Hey guys, I'm new to Geologic, and I was wondering if last years Dynamic materials would be useful for Geo?

Re: Geologic Mapping C

Posted: November 4th, 2018, 8:27 am
by UTF-8 U+6211 U+662F
SciolyHarsh wrote:Hey guys, I'm new to Geologic, and I was wondering if last years Dynamic materials would be useful for Geo?
Yep, but geologic mapping also has a bunch of other stuff involving maps, strike, dip, etc.