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Geologic Mapping C

Posted: August 4th, 2018, 11:46 pm
by Adi1008
Geologic Mapping C: Teams will demonstrate understanding in the construction and use of topographic maps, geologic maps, and cross sections, and their use in forming interpretations regarding subsurface structures and geohazard risks.

Geologic Mapping Wiki

Geologic Mapping Test Exchange 2018

Past Threads: 2012 (NY Trial), 2013 (NY Trial), 2014, 2015, 2016

Past Question Marathons: 2014, 2015, 2016

Re: Geologic Mapping C

Posted: September 17th, 2018, 2:49 pm
by ScottMaurer19
How complex of a geologic compass do people recommend? What type of equal area stereonet should we use?

Re: Geologic Mapping C

Posted: September 17th, 2018, 4:56 pm
by Unome
How complex of a geologic compass do people recommend? What type of equal area stereonet should we use?
Don't buy a geologic compass until before Nationals (for you, maybe State). The chances of it showing up at any tournament other than Nationals are very close to zero. Past Nationals questions involving the geologic compass only used it for a dip measurement, as far as I can remember.

I printed my stereonet off of the internet, although I was really bad at stereonets when I competed.

In case I've misinterpreted the second question (and for the benefit of others who may not know), the intended stereonet is the Lambert equal-area projection - for example, this stereonet.

Re: Geologic Mapping C

Posted: September 17th, 2018, 6:47 pm
by syo_astro
How complex of a geologic compass do people recommend? What type of equal area stereonet should we use?
Don't buy a geologic compass until before Nationals (for you, maybe State). The chances of it showing up at any tournament other than Nationals are very close to zero. Past Nationals questions involving the geologic compass only used it for a dip measurement, as far as I can remember.

I printed my stereonet off of the internet, although I was really bad at stereonets when I competed.

In case I've misinterpreted the second question (and for the benefit of others who may not know), the intended stereonet is the Lambert equal-area projection - for example, this stereonet.
@Compass: Or try to contact a university? They might be far, but it can be an easier way to get a hold of one. They can also be incredibly expensive. You could also just use a regular basic compass (like http://www.libertymountain.com/SupplyIm ... 40x340.jpg), and try problems out with it as if it were the real deal (which should be fine if they just want you to measure strike and dip?).

Printing stereonets off the internet is fine! What Unome said is correct, but I'll add that it might help to have one that has the numbers, etc labeled (EX: http://www.yasareren.net/yasareren/ders ... reonet.jpg). Do search around, though.

Other things you'll need: See through paper (you can get tracing paper from art stores or online). Everyday paper is usually only semi see through or completely opaque. Whatever works, though, I've heard some use parchment paper (though, I liked the tracing paper when I did it...). You also want to get thumbtacks/pins with a flat bottom, like https://www.amazon.com/BAZIC-Brass-Thum ... B00KGDETJO but maybe could find a cheaper option.

Re: Geologic Mapping C

Posted: September 17th, 2018, 7:18 pm
by ScottMaurer19
How complex of a geologic compass do people recommend? What type of equal area stereonet should we use?
Don't buy a geologic compass until before Nationals (for you, maybe State). The chances of it showing up at any tournament other than Nationals are very close to zero. Past Nationals questions involving the geologic compass only used it for a dip measurement, as far as I can remember.

I printed my stereonet off of the internet, although I was really bad at stereonets when I competed.

In case I've misinterpreted the second question (and for the benefit of others who may not know), the intended stereonet is the Lambert equal-area projection - for example, this stereonet.
@Compass: Or try to contact a university? They might be far, but it can be an easier way to get a hold of one. They can also be incredibly expensive. You could also just use a regular basic compass (like http://www.libertymountain.com/SupplyIm ... 40x340.jpg), and try problems out with it as if it were the real deal (which should be fine if they just want you to measure strike and dip?).

Printing stereonets off the internet is fine! What Unome said is correct, but I'll add that it might help to have one that has the numbers, etc labeled (EX: http://www.yasareren.net/yasareren/ders ... reonet.jpg). Do search around, though.
I'm assuming for compasses they would use a basic one. I would hope they don't have problems that would require of the expensive ones as that would definitely give an unfair advantage to some teams.

Would it be helpful at all to print out the stereonet on clear plastic? I'm not exactly sure what we use it for yet as I haven't really looked at past tests or anything.

Re: Geologic Mapping C

Posted: September 17th, 2018, 7:24 pm
by syo_astro
I'm assuming for compasses they would use a basic one. I would hope they don't have problems that would require of the expensive ones as that would definitely give an unfair advantage to some teams.

Would it be helpful at all to print out the stereonet on clear plastic? I'm not exactly sure what we use it for yet as I haven't really looked at past tests or anything.
Yeahhh...when I competed we never even used compasses, and it doesn't sound like Unome did much either. But I recall it in the rules this year from skimming, right? It probably won't be a huge issue either way >.>.

It won't be helpful (to my knowledge) to print out the stereonet on anything special. Imo a lot of the tools necessary are mostly meant to be cheapish (though, I guess it stacks up b/c printing, thumbtacks, etc). To get an idea of what you'll be doing, you can check out a video like: https://www.youtube.com/watch?v=V5_3W-UrP8k (the videos used to suck when I did it in 2012...at least since 2014 I would hope they've improved >.>). There are various (hopefully now) better resources for actually understanding what a stereonet is / how to work with one, though.

Re: Geologic Mapping C

Posted: September 19th, 2018, 4:34 am
by pikachu4919
I'm assuming for compasses they would use a basic one. I would hope they don't have problems that would require of the expensive ones as that would definitely give an unfair advantage to some teams.

Would it be helpful at all to print out the stereonet on clear plastic? I'm not exactly sure what we use it for yet as I haven't really looked at past tests or anything.
Yeahhh...when I competed we never even used compasses, and it doesn't sound like Unome did much either. But I recall it in the rules this year from skimming, right? It probably won't be a huge issue either way >.>.

It won't be helpful (to my knowledge) to print out the stereonet on anything special. Imo a lot of the tools necessary are mostly meant to be cheapish (though, I guess it stacks up b/c printing, thumbtacks, etc). To get an idea of what you'll be doing, you can check out a video like: https://www.youtube.com/watch?v=V5_3W-UrP8k (the videos used to suck when I did it in 2012...at least since 2014 I would hope they've improved >.>). There are various (hopefully now) better resources for actually understanding what a stereonet is / how to work with one, though.
Yeah, I did this event the last time it was around (and hated it soooooo much!) but I remember back then the rules said "stereonet and tracing paper," so I guess that meant you could print the stereonet normally like how you would print anything else and then when you actually use it, you would put tracing paper on top of it to do all the drawing needed to solve the problem.

Re: Geologic Mapping C

Posted: September 28th, 2018, 7:54 pm
by freed2003
Can someone link me to a good resource on how to solve three-point problems?
Also i cant find how to solve numbers 1-6 on this test:
https://scioly.org/wiki/images/f/fa/Pen ... g_Test.pdf
this figure is linked here
https://scioly.org/wiki/images/c/c1/Pen ... IGURES.pdf

may someone please explain?

Re: Geologic Mapping C

Posted: October 18th, 2018, 3:44 pm
by OrigamiPlanet
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!

Re: Geologic Mapping C

Posted: October 18th, 2018, 4:15 pm
by UTF-8 U+6211 U+662F
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!
I don't really know much about them, but they're the shape of folds/faults/etc. underground.