Re: Most difficult geology concept?
- From: "George" <george@xxxxxxxxxxxxxxxxxxxxx>
- Date: Tue, 20 Sep 2005 07:45:23 GMT
"Jo Schaper" <joschapern4ospam@xxxxxxxxxxxxxxxxx> wrote in message
news:11ivbb81ora2re4@xxxxxxxxxxxxxxxxxxxxx
> George wrote:
>> "Jo Schaper" <joschapern4ospam@xxxxxxxxxxxxxxxxx> wrote in message
>> news:11iv1udpaupvl9e@xxxxxxxxxxxxxxxxxxxxx
>>
>>>What was/is the most difficult geological concept you wrestled with in
>>>school? What I mean is: the one hardest to wrap your brain around and
>>>have it make sense.
>>>
>>>My most difficult one was the law of superposition.
>>>While it should be self evident that the oldest rock is on the bottom,
>>>(unless they've been jumbled, of course) this was counter-intuitive to
>>>me because in my region (due to regional tilt and initial draping) the
>>>oldest rocks are also the highest in elevation. and as one goes down in
>>>elevation, traveling laterally, you also go into younger and younger
>>>rocks. The rocks are not folded or jumbled, just tilted.
>>>
>>>Next?
>>>
>>
>>
>> Which, of course, is why determining the upright orientation of beds is
>> critical, as well as taking accurate strikes and dips. There are some
>> regional folds in your area, aren't there, Jo?
>
> Not really. there are some faults,lineaments, horsts, grabens, things
> like that. There are slumps associated with paleokarst sinks. There are
> some very localized and gentle anticlines, and some marble cake strata
> tens of feet across along faults. However the only real fold I've ever
> seen here in 35 years is in the Osceola-Weaubleau structure, and that is
> only tens of feet across, in a quarry and associated with a paleo-impact
> site.
>
> If you mean big regional folds like in the Appalachians, no never seen
> anything even close to that. Those exist in the Ouachita Mountains at Hot
> Springs, Ar., but not the Missouri Ozarks. Where I grew up the top of the
> elevation was in the Kimmswick (Ordovician) at 960 ft. Going down over a
> 20 mile straight shot to 432 ft at the Arch, you go up in the column to
> the St. Louis. Starting at the Precambrian knobs in the St. Francois at
> 1700 ft, and taking a cross-section down to the Mississippi, you can
> travel in a straight line, cross only slightly dipping beds, and be down
> (up?) to the St. Gen at about 350 feet at the Mississippi.
>
> Now I realize of course that if you drill down in one place, the beds are
> in the correct sequence (except for the missing ones). But most roadcut
> geos don't have a drill rig at their disposal. I know there is a basin in
> northwest Missouri, and parts of Missouri nick the Illinois Basin, but
> generally Ozark geology is convex, with the St. Francois Mts. being the
> marshmallow beneath lots of layers of sedimentary tablecloth.
>
>
>
>> Like some arches, and such? Its been a while since I've looked at a
>> Missouri Geological map. I know about the Ozarks and the St. Francis
>> Mountains, of course. As I recall, everything dips away from the St.
>> Francis Mts. Am I correct?
>>
>
> Hydro was only difficult because in the course I took, you were supposed
> to be able to look at the formulae, and equations, and derive the actual
> landforms and behavior from them. It was basically a math class. One of
> the problems too is that if one is very familiar with the craziness which
> is karst hydro, non-karst hydro, while much simpler, does seem based on
> entirely different premises (slow groundwater transport, no conduits,
> alluivium/sand/gravel, not rock). Once I determined that everything I
> knew from observation about karst hydro was the inverse of the right
> answer, I did ok, though I never much understood how one is supposed to
> derive reality and be able to visualize structure from equations, not
> vice versa.
I can appreciate that. Karst is oftentimes conduit flow, diffuse flow, or
a mix of the two, but rarely difuse flow alone. So in many instances,
darcy's law doesn't apply. Many geologists in Kentucky have fought the
State Underground Storage Tank Branch tooth and nail on their rules
regarding groundwater monitoring in karst terrain. Basically, even after
numerous studies over a period of decades that demonstrate conclusively
that you cannot monitor groundwater contamination in a karst setting with a
typical defuse flow regimen of 2 downgradient wells and one upgradient
wells, they've been adament on continuing the insanity. The stupidity just
boggles the mind. They have in the last few years begun to recognize the
error of their ways, although trying to get them to approve a dye trace
study conducted by consultants anywhere in the state is like pulling teeth
without novacaine. Apparently, unless their hand is forced by the Feds,
they don't want to know if residual contamination has moved offsite into
Jack Sprats pond or water well. I had two clients die of massive tumours
related to years of drinking groundwater laced with benzene. The state
knew about one of them and dragged their feet for years before they did
anything. There were other wells in that area as well that they weren't
even bothering to monitor until I got the enforcement branch to shove a bug
up their arses. My other client's wife died after drinking
benezene-contaminated well water for nearly seven years. When I first
tested it, the concentration was 10 mg/L Benzene. That's about 10,000
times the drinking water standard. I got them set up with a temporary
water supply, and then the state tried to sweep the issue under the rug. I
helped them get a good lawyer, and the state finally moved on it.
.
- References:
- Most difficult geology concept?
- From: Jo Schaper
- Re: Most difficult geology concept?
- From: George
- Re: Most difficult geology concept?
- From: Jo Schaper
- Most difficult geology concept?
- Prev by Date: Re: Mars Exploration Rover Update - September 19, 2005
- Next by Date: Re: crossposting warning
- Previous by thread: Re: Most difficult geology concept?
- Next by thread: Re: Most difficult geology concept?
- Index(es):
Relevant Pages
|
