Deposition of object in a river

[Flex86]

Hello!
I am researching a scenario for 'real world' application, as follows:
A riverbed is flowing over an exposure of sedimentary rock from the Cretaceous period, which contains numerous fossilized items, and I need to project/estimate the most likely location for deposition of these fossils as the flow unearths each.
Lets say that each object is in the shape of an equilateral triangle, each side measuring 3 inches, and that they each weigh 4 ounces. The river flows at a normal average speed of 1.5 miles/hour. Further, one is considering only one single section of river, consisting of an upstream, straight-line flow into an S-curve, or 'meander,' and at the end of the S-curve the river resumes a straight-line flow. Obviously, each concave bank has the greater radius, and each convex bank has the smaller radius.
A storm initiates an increased, turbulent flow in the river, as in a flash-flood, which 'picks up' several of these triangular fossils, and begins to carry each downriver towards our S-curve. Lets say that the new flow rate is 3 times the norm, or 4.5 miles/hour.
Since this is all theoretical, imagine that the storm dissipates and the water flow ceases, immediately.
All the fossilized, triangular objects that were being transported are now in their most-likely depositional location, i.e., the flow and all the associated forces has carried them where they would be most apt to settle, and the continuing flow of the river is no longer a part of the scenario.
Looking only at the S-curve, where should the majority of these items be found?
Or, put in my real world terms, at what point in the S-curve should one dig to find the largest number of fossils: lower part of the first concave bank, furtherest edge of the first convex bank, area between the two curves of the "S", lower part of the second concave or concave bank, straight area of the river after the S-curver, etc, etc?

Thanks to all the math and science whizzes for your help!
If you will include your calculations and/or theories, it would be great!

[deleted-71896]

This sounds like a lot of fun and I'm very tempted to run through all the calculations (having to hold myself back even as I type this). However, I think that would defeat the purpose of your research project and this forum.

I think it would be more appropriate if I (or another expert) went over your calculations and checked for correctness in the mechanics, logic, arguments, assumptions (checked for validity), potentially overly idealized conditions (again checked for validity), etc.

Have fun!

[deleted-71588]

Rivers are constantly changing. The materials being eroded and deposited are not of uniform density or size and the flow rates are not uniform. This makes modeling a river system a challenging exercise because of the large number of variables and possibilities. This in turn makes for a good scientific area of investigation because you aren't likely going to be able to predict the actual results.

[Flex86]

Rivers are constantly changing. The materials being eroded and deposited are not of uniform density or size and the flow rates are not uniform. This makes modeling a river system a challenging exercise because of the large number of variables and possibilities. This in turn makes for a good scientific area of investigation because you aren't likely going to be able to predict the actual results.

Thus the manner in which I posited the question, and outlined the scenario...