Jimmy Higgins

Rounded aggregate, hmm...

I know when classifying soils, a good way to determine man made fill is to look for angular aggregate. We know that coarse grained soils laid down as sediment becomes rounded due to the flowing water's friction on the aggregate over time.

Here's the question. Can the flood have created the rounded aggregate. Heck where did the aggregate even come from?

Selsaral

I'm not sure I understand the question too well, and I am by no means an expert, but my initial guess is that 'a' flood could not round all the sediments significantly. You would need a lot of time and a lot of water to round grains. Well-sorted, well-rounded grains generally indicate they were moved a larger distance from the source than less-sorted, less-rounded grains. It can also indicate the manner of transport (i.e. high-energy versus low-energy). Floods can do a good job of moving sediment around however.

The source of sandstones is most commonly igneous rocks, such as mountains. (Shales are much like sandstones only they have a particularly small grain size, less than 1/16 mm I believe, and contain mostly clay minerals). Erosion and weathering can break down the exposed rocks into smaller pieces. The source for limestones are the CaCo3 shells of marine organisms.

Of course the process by which sedimentary rocks form takes a great deal of time. It's not like a flood deposits some material and next year you have some sandstones.

SULPHUR

The con glomerates are a common pre cambrian/cambrian rocks on the west of tasmania. The owen conglomerate is partly metamorphosed contain ing quartzite rounded pebbles in a fine matrix. The pebbles appear to be rounded by the action of running water

Jimmy Higgins

What I'm asking is can the flood round the aggregate? If not, then how did this rounded aggregate get into the system, mainly in the conglomerate sandstones, such as seen in Northeast Ohio and Pennsylvania. We just cored some beautiful conglomerate near Warren, OH. I've got to get a few pictures of it.

Selsaral

When you say 'the flood', I sorta thought you meant the biblical flood. If you mean 'can generic floods over geologic time scales round sediments', I would guess absolutely. Of course I am not so sure it's simply the fact of water running over the particles that rounds them, as it is the water pushing the particles along, and as they roughly bounce and flop along their edges get broken off, or other particles the water is pushing along slam into them as they pass over, knocking the edges off.

It sounds like the conglomerates both you and SULPHUR are talking about are similar. They were nice sandstones that were uplifted, eroded into chunks, and redeposited. As they were moved from their source to their final deposition, they were rounded, and then they were cemented into the conglomerate. Does that sound right? By all means post some pictures of the conglomerate you mentioned, sounds cool.

Baloo

/me puts on YEC thinking cap...


Okay, the thing about the Flood (as compared to any flood you might be familiar with) is that there was a lot of pressure. Now, if you have a beach ball, all deflated and crushed up (kind of shaped like the original rocks you're talking about), and then you bring just a little bit of air pressure into the mix, what happens? That's right: you get a perfectly round beach ball.

Now, I know exactly what you're going to say: it would take a LOT more pressure to do that to a rock than to a beach ball. But remember, the Flood did have a lot of pressure (not only was it more pressure, but water is more dense than air, so it was more powerful pressure still). It had enough pressure to easily "puff" all of the rocks into the exact circular shapes you see today.

These round rocks actually prove that the Flood did happen, and I will thus go and add one more item to my list of proofs agains athiestic evolution.

Arikay

The rocks werent Puffed I dont believe, they were smoothed. Pressure would do the opposite and crush the rocks. (well it probably wouldnt even do that, since the rocks would probably be strong enough to resist the pressure )

Yep, nothing like atheistic evolution to assume you dont know what your talking about. since evolution has no religion, nor is it religions.

Jimmy Higgins

There are a couple reasons I ask this.
I started a thread in Tweb which is getting no signal at all regarding varving. I've decided to take a, atleast to me, unique angle on the Green River Formation. I let the YEC's have their model of varve production, whatever that is. But what I don't give them is the assumption that the material existed to create the varves. If you've got clay and silt particles in the water, someone has got to ask the question, where in the heck did these particles come from?

I ask on the aggregate for the same reason. From the YEC model, there was no rain prior to the flood, therefore any sort of river flows would have been greatly insignificant. Also the weathering of rocks to produce the aggregate in the first place would be in great question. So I then looked at the flood creating the rounding. I don't know the answer to the question. Would a rock be more transported in the raging flood waters or could it be shaped as well?

roxrkool

Hmmm... haven't quite heard the puffed rock theory before. Definitely a new one.

As mentioned, rocks are rounded due to abrasion. The further rocks are transported, the rounder they get. Since it it much easier to transport rock by water, you will tend to the more rounded rocks associated with fluvial systems.

Rounded rock material is also associated with glacial systems, which have been known to transport sediment, rocks, and boulders great distances.

A flood will certainly aggressively abrade rocks, however, unless the flood last a good long time, that abrasion is relatively short-lived.

BTW, the YEC flood model has no rain? Where did the water come from? Is there a place where I can read about this model? Thanks.

Jimmy Higgins

There was no rain prior to the flood, not no rain during the flood. A "decent" flood site may be www.kjvbible.org