Sorry, but it can't be erosion because the sedimentary layers are IN THE MIDDLE of the rock layers.
You've misunderstood the explanation, but let me start by clarifying that the sedimentary layers *are* the rock layers. For example, look at this photograph of the sedimentary layers of the grand canyon:
Each of the horizontal layers are sedimentary layers, and they are rock. Sediments once deposited can become deeply buried, and the resulting great pressure and accompanying heat turn them into rock.
The material that forms the sedimentary layers comes from erosion of areas at higher elevations. The eroded material is carried to lower elevations by wind and by streams and rivers. In general, upland regions are areas of net erosion, while low lying areas as well as seas and lakes and so forth are areas of net deposition of the sediments eroded from upland areas.
And that's why no scientists believe that a worldwide tsunami or a giant ice melt could be responsible for the world's sedimentary layers. Such singular events could not explain the many, many different sedimentary layers, each reflecting a different environment as well as different flora and fauna, and also dating progressively younger radiometrically the higher the layer in the geologic column.
Iceage, to whom you didn't reply, was kind enough to provide more complete information about the definition of sediment:
quote: sedÂ·iÂ·ment (sÄ•d'É™-mÉ™nt) pronunciation n. 1. Material that settles to the bottom of a liquid; 2. Solid fragments of inorganic or organic material that come from the weathering of rock and are carried and deposited by wind, water, or ice.
Obviously you would have found both these definitions in the Oxford English Dictionary, and it is the second definition that you want when discussing geology.
Thus, no scientists believe that the planet's sediments came from a worldwide tsunami or a giant ice melt, because such possibilities are not consistent with the evidence.
You don't really want to combine those definitions. The first definition, "Material that settles to the bottom of a liquid," is what gathers at the bottom of your glass of fresh squeezed orange juice.
The second definition, "Solid fragments of inorganic or organic material that come from the weathering of rock and are carried and deposited by wind, water, or ice," is the one from geology and is the one you want to use in this discussion.
The sediment that settled to the bottom of water was thus carried to rocks by water or wind.
Yes, absolutely correct. Scientists believe that sedimentary layers in the past formed the same way they do today. The products of erosion in upland regions are carried to lowland regions, and to ponds, lakes and seas, by wind, rain, streams and rivers. Sedimentary layers can accumulate to great depths, such as happens at the mouths of mighty rivers like the Mississippi, where the sediment depth is several miles.
The differences in sedimentary layers are due to differences in the products of erosion. For example, if a mountain range consisting largely of granite were located near a shallow sea, then the sediments that collect in the shallow sea would include eroded granite. On the other hand, if the region were largely desert, then the nearby sea would receive primarily sandy sediments. Because regions change over time, the type of sediments that are deposited also change over time, and that's why sedimentary rock appears in layers of different appearance, oftentimes strikingly so.
This is what scientists actually believe about the formation of sedimentary deposits. They do not believe they were formed by a worldwide tsunami or a giant ice melt. Keep in mind that such events would be hugely catastrophic, and while scientists understand that catastrophes do contribute to world geology, the evidence of the sedimentary layers indicates that in most cases they were deposited gradually over long periods of time, in pretty much the same way as we see happening today.
So it takes MUCH EFFORT to deny a global flood...
Scientists don't so much deny a global flood as formulate theories around existing evidence. The evidence of the geological layers, fossils, magnetic reversals, sea floor striping and radiometric dating all pretty much rules out the possibility of a global flood as responsible for world geology.
For those attempting to follow along, Repzion is responding to Message 46 from Anglagard.
With potentially 52 different (though flood-related) topics to discuss, I don't see how this thread could avoid becoming a mess, plus it's already 2/3 of the way to the 300 message limit. It might be a good idea to focus on just one or a very few topics. I vote for angular unconformities.
You disagree? So you're saying that the fact that 70% of the earth's surface is covered by water is evidence that the remaining 30% was also covered by water at one time? Why? Is there something about 70% in particular? If water only covered 60% of the earth, would that be sufficient evidence of flooding of the remaining portion? Of is the threshold some other number, maybe 50% or 40%? Or is it the mere presence of any amount of the earth's surface covered by water that provides sufficient evidence of flooding of the rest of it?
One wonders what it must be like inside that head of yours.
I think what you're trying to say is that for all we know, the current state of the world is not the normal state and that we could be in the middle of a world wide flood right now. I'm not going to address this argument because in the context of this discussion "world wide flood" means the entire world covered by water at the same time. The opening post states, "There is plenty of evidence that the flood happened just like the Bible says." That's pretty clear.