re: Topography/Geology of Vidalia vs Natchez

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and the answer is the river.

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Yep, and dirt flying thru the air.

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I've heard it was the prevailing winds over a long period of time blowing dust/dirt in the atmosphere from the Great Plains in the west. As the dust crossed over the river, the moisture caused it to drop out on the east side creating the hills.

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one of the dumber things I've read online. reason is river cut a path with its eastern edge along a well established plateau. any area flat around the river is alluvial land, a delta that has been built. the reason the river's not farther east is the natural levee that exists as an elevated land mass. river keeps chewing it away, which is why the bluffs falling into the river.

the hills are not wind blown creations. That was a stupid phd dissertation from some kid at miss state back in the 1950s. long since disproved.

if loess is the case, you would have a sharp decline in elevation after the bluffs. but instead, elevation steadily climbs through mississippi. much older process, probably something to do with formation of appalachain mountains.

I don't think anyone is disputing that. It's just irrelevant to the question posed. The entire area was pretty much the same stuff. that stuff still exist west of the river as well.

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the predominant wind in that area is from the southeast.

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The predominant wind around there/here is pretty much due south, but I will concede that that it is SE more than West. What the predominant wind was during the ice age or whenever the frick those hills were made was I have no idea. And until you can lay out a better theory for the creation of said hills I am going to go with the general consensus.

too many holes in the theory about the bluffs being loess. biggest is the land behind the bluffs gradually elevates while there is no elevation at the edge of the bluffs. the real two forces: the river and the long ago creation of the appalachains.

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it's just a plain bad theory. you think just by chance the mississippi river runs directly smack dab in the middle of the supposed loess peak?

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So even accroding to that map, there are only 30 ft of loess.

The bluffs are much higher than that, so is it two tectonic plates meet at the river?


eta, house on Natches side is 250ft above sea level, LA side is only about 50ft. (according to google earth)

No I don't but the map doesn't illustrate how and across what time scales those features came to be, whether one before the other or concurrently... think of Grand Canyon but on a different scale.

The MS river is located along the MS embayment, which is basically a synclinal fold or passive continental margin that split the Ouachita from the Appalachian mountains. The location of Natchez along the river is a good example of what is essentially a fault zone that distinguishes significant the uplift to the east from the more gradual slope along the west. This is exactly why the river is where it is, because of the disparity in elevation on either side makes the fault/embayment the point of least resistance. I'd venture to guess the reason for less prominent loess deposits seen on the west is just because of the power of the river meandering and eroding and deposits along the lower elevation areas, as well as the many tributaries along the west side of the embayment copying those processes. Louisiana Fault Map

tl;dr I know. just my 2 cents of washed up geology. It's interesting to me. Maybe pectus will come back and shed some more accurate light on the issue

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the LA side was where the river path has been moving from, leaving natural flat lands comprised of sediment it has been further shifting towards MS and cutting into the hilly lands of course, this has all been slowed/killed by man made levees and control

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This is your answer. La side has black dirt, were the other side has red dirt. That and over the years, plate drift to the west pushed up the land on the east side of the river.