Geological strata: they’re everywhere
Evidence for the global flood
Sedimentologist Guy Berthault was one of a team who made an important discovery regarding how the world’s sedimentary layers were deposited.1 These geological strata are clearly-defined beds of sedimentary rock that often have the appearance of bands or stripes of alternating or repeating layers. Most people have noticed them in cliffs, where they are often seen in side view. Grand Canyon comes to mind, where bold horizontal layering in the sides of the canyon is a major visual feature.
Geologists once thought that all such layers formed upwards. This conventional view of layer formation was one of the three principles of stratigraphy identified by creationist geological pioneer Nicolaus Steno (1638–1686).2 However, today the typical way this is explained is that sand, silt, and clay settled to the bottom of a placid lake or sea, and accumulated over eons of time. Eventually, a significant layer of sediment formed, which slowly hardened into rock. Then, a new layer of sediment started to deposit on top of the first, and so on.
The extent and form of layers
Seen nearly everywhere, on all the continents, sedimentary rock strata cover some 75% of the earth’s land surface. Strata are often horizontal but can also be tilted. The tilting may be due to tectonic movement or to the angle of original deposition, as strata can deposit at gradients exceeding 30o. Some strata have been deformed into curves due to subsequent tectonic movement while the sediments were still soft.3 Sedimentary layers come in many different thicknesses and types, from enormous formations hundreds of metres deep, down to tiny laminae less than 1 mm thick.
These layered rock formations continue under the ground, right under our feet. Individual layers frequently continue, unbroken, over huge areas of the continents. Another way to visualize them is as vast ‘blankets’ of rock, on top of each other in series.4 Some of these layers or blankets are flat, and others are heavily ‘rumpled’. Clean, knife-edge contact surfaces between layers are common.
Layers covering large areas of continents are extremely difficult or impossible to explain using standard uniformitarian explanations of sediment deposition, as we don’t see depositional layers of such vast geographical extent and magnitude forming today. So how did all this incredible layering come about?
Sideways formation, in fast currents
Sedimentologist Guy Berthault’s flume experiments demonstrated that layered sediments deposit rapidly in the manner of a horizontally advancing deposition in the direction of current flow. This is known as progradation. Sideways deposition of strata was first proposed by German geologist Johannes Walther (1860–1937). In the context of a global Flood, strata will form in wide currents of sediment-laden water when a ‘basin’ or lowered area is created. Enormous quantities of loose sediment particles are carried along by the water currents and fall down the advancing ‘face’, or front, of the layer of sediment. This is how the layer grows horizontally. Depositing sideways, the layers are laid down like a layer of cream or icing spread sideways on a cake. The illustration in figure 1 demonstrates how the process works.5
On a smaller scale, turbidity currents form layers by the same principle and these have been observed in modern times. An earthquake causes an undersea avalanche of sediment to suddenly flow down the edge of the continental shelf. This mass flow deep under the water forms many sedimentary layers over a wide area extremely rapidly.6 However, secularist geologists hesitate to equate these turbidite strata with the world’s truly large-scale layering, and instead talk of environmental change over eons. Secularists tend to believe, for instance, that an extensive desert environment could experience climate change and eventually become covered over with sediments deposited by a completely different and wetter environment. This is more the upwards belief of layer formation, rather than the horizontal one.
Sequence of deposition
In the year-long global Flood, the world’s deepest and largest sedimentary formations were deposited in just a few months, at mind-boggling speed. Indeed, Berthault’s experiments demonstrate that three layers can form together at the same time. As the layers form, further back (‘upstream’ of the current) another three can simultaneously begin to form horizontally on top of them. Still further back, another three layers can form simultaneously on top of those. Underwater, the growing formation of layers would look something like an extremely wide set of stairs of gentle gradient, advancing in the direction of the current.
The process can repeat until a great depth of sedimentary layers is built up. One likely cause of deposition is a gradual subsidence in areas of the earth’s crust due to tectonic movement. The advancing ‘fronts’ of these layers of sediment may have been hundreds of kilometres across.7 The prestigious journal Nature reported similar experiments by others a decade after Berthault’s first experiments.8,9
Sedimentary grains are naturally sorted by the flowing action of water transport. Fine particles accumulate with fine, and coarse with coarse. See figure 2.
Berthault analyzed layered rocks by separating the constituent sand and silt particles from the cement, and ran the particles through the flume. The same layer thicknesses re-formed, which suggests that a similar process produced the original rock layers several at a time, not one layer at a time. Further, the layer thicknesses depended only on particle sizes, not flow rate. This would account for very even layers over large areas,10 whereas one layer depositing on top of a surface would not stay even for long.
The Tonto Group, part of the Grand Canyon strata, is an example of three layers extending over a large area that formed together during the global Flood. A layer of sand at the bottom, a clay mud layer in the middle, and a lime mud layer on top were deposited sideways and at the same time, early in the Flood. These later hardened into rock to become the Tapeats Sandstone, Bright Angel Shale and Muav Limestone strata.11 Further series of layers then deposited in water currents over the top of these sediments, in the same rapid and sideways manner, to form the entire Grand Canyon sequence of strata. The canyon itself was then eroded as the Floodwaters later poured off the continent.
Berthault also discovered that geological layering can rapidly develop after, not during, deposition of the sediments, due to desiccation (drying out) creating bedding plane separations in the sediments, as the entire formation gradually hardened into rock. Desiccation occurred after the Flood waters had drained away and the land began to dry out.
Strata point to the Flood
Berthault summed up his laboratory findings by stating:
“The true mechanism of sedimentation revealed by our flume experiment refutes, inter alia, the foundations of the geological column, and therefore, challenges the geological time-scale.”12
His observable, repeatable results strongly confirm that the global Flood was a real event in history, and that the earth is far younger than uniformitarian geologists say it is.
Such a Flood, caused by tectonic break-up of the crust, produced high energy water currents, massive erosion, and enormous quantities of loose sediment. Carbonate and other rock-forming minerals were dissolved in the floodwaters, and likely also welled up from beneath the crust, in the waters of the fountains of the great deep.13
Layers of sediment and dissolved minerals flowed into newly-forming sedimentary basins, forming the new continental land mass. Much of today’s topography was carved out by the retreating waters as the continents rose from the water. Fast hardening into rock was possible because the Flood thoroughly mixed cementing agents with the sediments. Such widespread geological strata are compelling evidence for the biblical Flood.
References and notes
- Julien, P.Y., Lan, Y., and Berthault, G., Experiments on stratification of heterogeneous sand mixtures, J. Creation 8(1):37–50, 1994; creation.com/sandstrat. Return to text.
- Walker, T., Geological pioneer Nicolaus Steno was a biblical creationist, J. Creation 22(1):93–98, 2008; creation.com/steno. Return to text.
- Geologists call this folding. See Allen, D., Warped earth, Creation 25(1):40–43, 2002; creation.com/warped-earth. Return to text.
- Walker, T., Sedimentary blankets, Creation 32(4):50–51, 2010; creation.com/blankets. Return to text.
- This is best seen in Guy Berthault’s video Experiments in Stratification, which at the time of writing was viewable on Youtube. See also the video Drama in the Rocks. Return to text.
- For discussion of other types of rapid, mass-flow multiple simultaneous sedimentary layer formation, similar to turbidite deposits, see Oard, M.J., Internal oceanic waves and sedimentation, J. Creation 27(1):16–18, 2013; creation.com/waves-and-sedimentation. Return to text.
- Reed, J.K. and Oard, M.J., Three early arguments for deep time—part 3: the ‘geognostic pile’, J. Creation 26(2):100–109, 2012; creation.com/geognostic-pile. Return to text.
- Makse, H.A. et al., Spontaneous stratification in granular mixtures, Nature 386(6623):379–382, 1997. Return to text.
- See also Snelling, A., Nature finally catches up, J. Creation 11(2):125–126, 1997; creation.com/sednature. Return to text.
- For example, Batten, D., Sandy stripes: Do many layers mean many years? Creation 19(1):39–40, 1996; creation.com/sandy. Return to text.
- Austin, S.A., Grand Canyon: monument to catastrophe, Institute for Creation Research, pp. 57–82, 1994. See also Berthault, G., Genesis and historical geology: a personal perspective, J. Creation 12(2):213–217, 1998; creation.com/flume-experiments. Return to text.
- Berthault, G., Sedimentation experiments: is extrapolation appropriate? A reply, J. Creation 11(1):65–70, 1997; creation.com/sedimentation-extrapolation. Return to text.
- Extensive limestone layering seems to point to this. Fossil marine animals in these layers were suddenly caught up in what appears to have been a watery carbonate ‘sludge’. The existence of carbonate pipes—possible conduits from carbonate deposits deep in the earth—seems to provide further evidence of this. Return to text.