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Re: Geologic Mapping C
Posted: March 17th, 2015, 2:31 pm
by Dhruvster
boomvroomshroom wrote:Quick question: what's the most complicated problem you've ever seen, ever? Mine was actually at a regionals, where we had to calculate original apparent dip with like three faults in the way. State and Nats didn't even come close XD
Mine was the crazy problem at state (I think?) last year where they had you calculate the plunge and trend of the intersection of 3 planes. It was insane, and only us and one other team got it. Like without looking at all the stereo-net tutorials we would've had no idea where to start.
Re: Geologic Mapping C
Posted: March 24th, 2015, 5:37 am
by danielleandrebekah
Re: Geologic Mapping C
Posted: March 25th, 2015, 9:20 pm
by elephantower
That doesn't sound good...read the wiki and the links under it, then try some practice tests.
Re: Geologic Mapping C
Posted: April 1st, 2015, 9:47 am
by hipparcos
Um... yeah, here's a link to an explanation of geologic maps:
http://geomaps.wr.usgs.gov/parks/gmap/index.html#what.
I came across this problem: A conglomerate is oriented 050°,65° and has an apparent width of 500 m, measured in a horizontal North-South roadcut. a) What is the true thickness of the conglomerate? b) What is the vertical thickness of the conglomerate? The given answers were (a) ~ 340 m and (b) ~ 800 m.
What's with the terminology for orientation of roadcuts? I'm not sure if the apparent width is measured from north to south or from east to west. Assuming the former, this is what I did:
horizontal distance: 500 sin 50 = 383 m.
true thickness: 383 sin 65 = 347 m.
vertical thickness: 383 tan 65 = 821 m.
I guess that seems okay; could you guys check my work?
Re: Geologic Mapping C
Posted: April 6th, 2015, 12:41 pm
by furypanda1
hipparcos wrote:
Um... yeah, here's a link to an explanation of geologic maps:
http://geomaps.wr.usgs.gov/parks/gmap/index.html#what.
I came across this problem: A conglomerate is oriented 050°,65° and has an apparent width of 500 m, measured in a horizontal North-South roadcut. a) What is the true thickness of the conglomerate? b) What is the vertical thickness of the conglomerate? The given answers were (a) ~ 340 m and (b) ~ 800 m.
What's with the terminology for orientation of roadcuts? I'm not sure if the apparent width is measured from north to south or from east to west. Assuming the former, this is what I did:
horizontal distance: 500 sin 50 = 383 m.
true thickness: 383 sin 65 = 347 m.
vertical thickness: 383 tan 65 = 821 m.
I guess that seems okay; could you guys check my work?
Assuming that the slope is 0, then I agree with your answers. For the bed thickness and vertical thickness problems, what formulas are you using for a sloped surface? My partner and I came up with our own. We wanted to see what others are using.
Re: Geologic Mapping C
Posted: April 13th, 2015, 12:19 pm
by InfiniCuber
Can someone explain to me or lead me somewhere where I can learn more about the different kinds of faults (apart from usual strike-slip and dip-slip faults) such as ring faults or lystric faults?
Re: Geologic Mapping C
Posted: April 16th, 2015, 5:36 pm
by boomvroomshroom
InfiniCuber wrote:Can someone explain to me or lead me somewhere where I can learn more about the different kinds of faults (apart from usual strike-slip and dip-slip faults) such as ring faults or lystric faults?
O_o never even heard of those
*frantic googling commences*
Re: Geologic Mapping C
Posted: April 17th, 2015, 6:06 am
by InfiniCuber
boomvroomshroom wrote:InfiniCuber wrote:Can someone explain to me or lead me somewhere where I can learn more about the different kinds of faults (apart from usual strike-slip and dip-slip faults) such as ring faults or lystric faults?
O_o never even heard of those
*frantic googling commences*
XD alrighty then! I will follow suit lol
Re: Geologic Mapping C
Posted: April 19th, 2015, 6:53 am
by afrocdm
Hey everyone! So I was going through one of the practice tests and I came across a few problems that I wasn't sure how to solve:
1. A sandstone bed strikes 067° and dips 21° SE. In the bedding plane, it is observed that there are slickensides pitching at 58 degrees east. What is the trend and plunge of the slickensides? (Give trend as an azimuth. No Cardinal Direction needed for plunge)
2.In between Bald Eagle Mountain and Mt. Nittany in State College, PA, the Evil Rabbit Field Geology Team measures a shale at two different points, giving two apparent dips (plunge, trend). 35°, S20W, and 25°, S50E. What is the Strike and True Dip of the shale, given the two apparent dips measured? (Give your Strike as an Azimuth. Give True Dip as a degree with Dip Direction)
3. An anthracite coal seam is oriented with attitude 050°, 65° and has an apparent width of 500m, measured in a horizontal North-South roadcut. The vertical thickness of the seam is 800m. What is the True Thickness of the anthracite coal seam?
I just need a step-by-step on how to do these. I was trying to find some equations to solve these, but I kept finding some college-level stuff. Please help!!!
Thanks!
Re: Geologic Mapping C
Posted: May 21st, 2015, 6:24 am
by InfiniCuber
So what did you all think about the Nationals Geo Mapping test?
