Question from a YEC: What explains sedimentary rock other than a worldwide flood?

I was asked this recently and couldn’t remember the response of mainstream geology. He said that the sedimentary layers could only result from a catastrophic event because the layers are in the same sequence around the world.

He is trusted by his pastor to teach about science and the Bible. He will be teaching at a local apologetics ministry soon.

What should I say about the rock and the flood, as well as his desire to teach the young?

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First problem is how did a chaotic flood distribute sediment world wide and manage to get it in the same order everywhere?

Second problem is where did the sediment come from? The two main types are eroded rock or marine animals. You could assume the violent flood might scour the earth’s surface generating the massive quantities needed, but then when did the marine animals live and deposit their remains? This has to take place in 1 year remember.

Another problem that recently came to me is assuming the violent flood swept the land surface clean in generating the sediment needed, after the flood waters receded when did the soil on the surface form? Soil is a rather complex combination of mineral and organic matter with a health dose of biological life, think worms, nematodes, bacteria, and fungi. So where did the dirt come from for Noah to plant his vineyard?


Most interesting topic. You echo my question: where did the sediments come from? The sedimentary layers are on average 1 mile thick on the continents. If the sediments were deposited slowly over time where did the sediments for each additional layer come from? Ocean? Land? Space? If they came form land, is it possible to get the layers we have by eroding the surface and laying the material back down again. Seems like a cycle that would not generate the depth of sedimentary layers that we have. Looking forward to the explanation.

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Every notice that some mountains are eroded (rounded and lower) and others are not (taller and not rounded). As mountains erode the material is transported down hill by water and gets deposited. Obviously that takes very long periods of time.


There’s a cape here that I occasionally hike to right down at the beach level. It has a number of layers, primarily volcanic ones. But there are sedimentary layers between the volcanic ones, meaning that there were sediments deposited on top of the lower lava flows.
But the thing to note about those lava flows is that every one of them except for the very lowest visible one flowed across dry land, something that can be concluded from how the lava cooled, which can be determined from the shapes of rock within the flows. So if the sediments came from the Flood, there’s a problem since things happened in this order: the bottom-most lava flowed beneath wet sediments and lifted them, so there’s sediments on top of that lava layer; the next lava flowed onto dry land, then got covered by soil followed by more lava; then sediments accumulated on top of that lava; then there was lava that flowed on dry ground again. That would require the land rising, then sinking, then rising, then sinking, all the way to the top of the cape where there is soil but no sediment deposits.
The problem is that when land sinks or rises there is stress put on the layers, even more so when rising and sinking is repeated, and there is no evidence of any such stress. Worse for ‘flood geology’, the deposits making up this cape show that there was dry land where soil accumulated before another lava flow occurred and then the land sank again. This sequence is impossible for a single event, especially a single flood event, for two primary reasons: along a coastline, it takes years for new soil layers to build up because ocean winds blow loose material away; and during a single flood event with torrential downpours of rain no soil would be able to accumulate.

That’s just one geologic formation that is completely contrary to a single catastrophic event.

Further, he’s wrong about “the same sequence”: there are layers found in some places but not others, and enough variety in the layering that the deposits couldn’t come from the same event. The “same sequence” idea comes from over-simplified illustrations for middle-school kids, and any university-level geology student will know that ultimately such illustrations are not correct.


Superb point! All soil life would have died from the sea salt alone.


Where did you get that number? Average total accumulation of sediments (and other loose material) above bedrock is on the order of fifty meters.

Rivers eroding their channels, primarily; glaciers grinding away mountains; wind erosion to a much lesser extent; plus volcanic sources (ash, lava).

BTW, glaciers are evidence against a global flood – all the carving of rock due to glacial ice slowly flowing over rock could not have happened in a single event or in under ten thousand years.


Google is your friend: Average depth of sedimentary layers.

Great question. I like GBob’s (Glenn Morton, who worked for oil fields) discussion of how sediment can’t fit in to a rapid deposition, like the Flood:
Genesis is history and can’t be forced to fit with evolutionary theory - Faith & Science Conversation - The BioLogos Forum



Can those means generate the vast amount of sediments that we see? I’m not sure that the current paradigm can provide the explanation.

Ah – I was thinking actual sediments, not sedimentary rock.

Actually a good question. I am not a geologist, but it appears there is no way a world wide flood could generate significant sediment. It takes decades of constant water flow to erode bedrock a significant amount. You only have to look at a rocky seashore to see that even after decades of heavy waves pounding 24 hours a day, it still looks much the same. If the historical account of the flood was reality, after forty days of rain, all would be covered, and in the deep areas, little erosion would take place as turbulence at depth is minimized. The rest of the year would be the gradual recession of water, which would also cause minimal erosion.
The only thing that explains the deep layers of sediment, is deep time. With deep time and seasonal variations, you also get freeze/thaw cycles which crack apart rocks and biologic activity with roots and lichens as well as leaching of minerals with time, none of which would happen in a year’s flood.
The other big issue with sedimentary rocks which has been touched on, is that there are many varied types of sediment layered, caused by changing climate, changing sea levels and uplifts and downward recessions, You have limestones from shallow seas, topped with sandstones from sand deposited close to shore from rivers, covered by silty shales deposited in deeper water as the fine silt settles out, and all variations as the sea level changed, in some areas with igneous rock from lava flows interspersed . In a global flood scenerio, you would see much less layering, and certainly not the variation typical of long term changes we find to be present. If anything, you would see a layer of coarse deposits, then sand, then a top layer of silt as the fine stuff settled near the end of the flood.
In short, the deep layers of sediment, and along with the processes required to produce those layers, is proof that there was no global flood 5000 years ago. And that does not even touch on the fossils contained within those layers.


In the ringwoodite thread I posted an overview of the Hydroplate theory, the perspective that I approach geological history from. You can read Dr Browns online book for full details.

According to the Hydroplate theory: the crust ruptured along the path of the oceanic ridges, 40,000+miles. Along that path the rupture eroded to a width of 1400 miles, providing the material for asteroids, comets, etc, as well as sediments to form the earth’s sedimentary layers. Water was escaping the subterranean water layer between the granite crust and the top of the mantle eroding both as it escaped and depositing sediments into the water on the surface to become the sedimentary rock.

The flood was essentially the displacement of water from below the crust to above the crust.

Theories have supporting evidence. I see none there, only rhetoric.

The old Age of Rocks blog had an article giving an answer to this question. In short, we can see sedimentary rock layers forming across continents today by standard geological processes on the continental shelves.

What qualifications does he have to teach about science in his church?

The important thing to stress to him is that he needs to be making sure that his facts are straight, and that what he is teaching is accurate. As a teacher in his church, he is in a position of trust, and teaching things that are factually inaccurate or untrue is a breach of that trust. This is important, because the number one stumbling block for young people when it comes to science and faith is learning that the things their pastors and church leaders had been teaching them about it were simply not true.

If he does not have any scientific qualifications (a university degree or equivalent work experience in a relevant field), he will be at a disadvantage here because he won’t have the skills or experience needed to fact-check what he is teaching. On the other hand, if he does have a university degree in science, teaching things that are inaccurate or false will be an even more serious matter, because while pastors with no scientific background can be excused on the grounds of ignorance if they teach scientific falsehood, he does not have the luxury of that excuse.


My recollection from a few years ago looking into it is that most YECs don’t even credit it any more.

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This is appropriate in any discussion about YECism:

    The Defeat of Flood Geology by Flood Geology


No such thing – even in geology physics has to be included, and that means math showing how the processes resulted in the world we live in. So-called hydroplate theory results in a vaporized planet.



While it is true that sedimentary rock layers correlate across continents, the problem with saying that they all happened in the same catastrophic event is that the rocks tell a different story. The rocks suggest that they were formed by a variety of processes including rivers, glaciers, wind, and through sediment and shells from micro-organisms accumulating on the seabed. These processes would all have taken thousands if not millions of years longer than the 40 days described in the Genesis flood story. Another problem is the fossil record. You find fossils in a more or less orderly sequence as predicted by evolution. For example, you never find dinosaurs and humans or trilobites and rabbits mixed together. If a global flood had deposited the fossiliferous layers, you would expect a more random assortment of fossil types. In short, the geologic layers don’t look like they were formed by a global flood and the only way to make it look so is to force-fit the data into a “global flood” model. As for what to say about his goal to teach, I would say that he needs to make sure his facts are straight and that he makes it clear that this is not the only way to look at how the Bible and geologic history fit together. It is only one among several views on the interpretation of Genesis. I don’t expect this to happen, but he should make it clear to his students that if they go to a university, learn about geology and find that he is wrong, then they are free to disagree with him without abandoning their faith since young earth creationism is just one view among several on the relationship between Biblical truth and science.


Another aspect of this is the fossil record. If a global flood occurred a few thousand years ago, we would expect to err either a chaotic fossil record that made nonsense such as humans with dinosaurs and so on. Or perhaps it would be really organized and deposit fossils by mass or size. But that’s not what we see.

We see different species in specific places at specific times. These records also showcases basal forms diverging over time. So we never see humans in the same strata as dinosaurs and we never see humans before the earliest primates we see certain species on the west coast and not the east coast and vice versa. No giant flood washing them 2,000 miles.

Then we can also look at chemical half lives as well.