Re: Angles and Erosion Rates - For John Harshman


Seanpit wrote:
Richard Forrest wrote:
Seanpit wrote:
<snipped>

You're quite mistaken. Exposed layers that are tilted at a high angle
get eroded away, perpendicularly, at a much much higher rate than their
horizontal condition.
<snipped>

Well, apparently these bits of geology didn't know that.
http://ess.nrcan.gc.ca/esic/gallery/images/180345.jpg
Note the erosion surface along the top, which is quite independent of
the tilt of the strata forming it.

http://ponce.sdsu.edu/travelphotosi06ab.jpg
Note that the top of the cliff is flat, when the strata turn from
horizontal to vertical.

http://images.google.co.uk/imgres?imgurl=http://uregina.ca/~sauchyn/geog323/303.jpg&imgrefurl=http://uregina.ca/~sauchyn/geog323/image1.html&h=475&w=636&sz=57&tbnid=J8-254GFMwYgqM:&tbnh=100&tbnw=135&hl=en&start=11&prev=/images%3Fq%3Dfolded%2Bstrata%26svnum%3D10%26hl%3Den%26lr%3D%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official_s%26sa%3DG
Note that the erosion surface at the top of the cliff is not formed by
the angle of the strata.

http://images.google.co.uk/imgres?imgurl=http://academic.emporia.edu/aberjame/struc_geo/folds/fold12.jpg&imgrefurl=http://academic.emporia.edu/aberjame/struc_geo/folds/fold1.htm&h=328&w=515&sz=41&tbnid=6E8BhjzrinxcXM:&tbnh=81&tbnw=128&hl=en&start=48&prev=/images%3Fq%3Dfolded%2Bstrata%26start%3D40%26svnum%3D10%26hl%3Den%26lr%3D%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official_s%26sa%3DN
How has the angle of the strata affected the rate of erosion here?

http://images.google.co.uk/imgres?imgurl=http://academic.emporia.edu/aberjame/struc_geo/folds/fold12.jpg&imgrefurl=http://academic.emporia.edu/aberjame/struc_geo/folds/fold1.htm&h=328&w=515&sz=41&tbnid=6E8BhjzrinxcXM:&tbnh=81&tbnw=128&hl=en&start=48&prev=/images%3Fq%3Dfolded%2Bstrata%26start%3D40%26svnum%3D10%26hl%3Den%26lr%3D%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official_s%26sa%3DN
Or here?

You are flatly wrong, Sean.

You are under a mistaken notion that just because some aspects of
tilted layers may get eroded away faster than others that this means
that the perpendicular rate of erosion must not have been increased in
those places that were more slowly eroded. This notion is what is
flatly wrong, Richard. The perpendicular rate of erosion of these
areas was also increased by tilting vs. their horizontal condition -
just not as much as other areas.

The notion that increasing the angle of a *** of sediment increases
its perpendicular rate of erosion at every point is a fact. This is
not just my notion. There simply is no argument here. Your notions to
the contrary are simply wrong.

RF

Sean Pitman
www.DetectingDesign.com


The images I have posted show I'm not.
You live in a fantasy world, Sean.

But if you want to carry on making yourself look utterly ridiculous
with your silly
assertions, feel free.
RD

.

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