The GeoChristian

The Earth. Christianity. They go together.

Book review — The Grand Canyon: Monument to an Ancient Earth

GrandCanyonMonumenttoanAncientEarthThe Grand Canyon: Monument to an Ancient Earth (2016), edited and written by a number of highly-qualified, predominately Christian authors, is a devastating critique of the geological arguments of young-Earth creationism (YEC). The subtitle of this new book asks the question, “Can Noah’s Flood Explain the Grand Canyon?” which is an appropriate question, being that YECs often showcase the Grand Canyon as a place that defies standard, old-Earth geological explanations and can only be explained by a global catastrophic flood event. The authors present an overwhelming case that neither the rock units exposed in the canyon nor the carving of the canyon itself are in any way related to Noah’s flood.

YEC geological arguments for a 6000-year old Earth and the formation of most of Earth’s geological record by a global flood have already been thoroughly examined and rejected by Christian geologists and many others (I recommend The Bible, Rocks and Time by Young and Stearley), but this new book is unique and fills an important niche. I highly recommend this book for several reasons:

  • This book is authoritative – written by experts in the topics at hand and in the geology and paleontology of the Grand Canyon.
  • This book is well written and skillfully edited. Each of the twenty chapters clearly explains the topic (such as the formation of sedimentary rocks, folding and faulting of rocks, and fossils) and how these features may be used to interpret the origin and history of a given rock layer. The Grand Canyon: Monument to an Ancient Earth was written by eleven talented authors, and the editors have weaved their chapters together seamlessly.
  • This book is written at an appropriate level for a general, scientifically-interested audience, taking complex geological ideas and explaining them in a way most readers will understand, without any compromise in accuracy.
  • This book is fair to our YEC brothers and sisters in Christ. I have been reading YEC materials for close to four decades, and am familiar enough with YEC arguments to be able to say with confidence that the YEC side has been explained accurately.
  • This book is a work of art, with wonderful pictures and graphics and a professional layout. It will look good on any coffee table.
  • This book is affordable: only $21.05 on Amazon. That means you will have no problem buying copies for your church library, pastor, and youth workers.
  • This book is God-honoring, proclaiming the marvelous works of our wonderful Creator.

The name of the book is a play on the 1995 YEC book Grand Canyon: Monument to Catastrophe, written by Steven Austin of the Institute for Creation Research.

Summary of the book: What YECs get wrong about the Grand Canyon

The Grand Canyon: Monument to an Ancient Earth is fairly comprehensive, covering all of the key concepts involved in the interpretation of the geologic history of the Grand Canyon. Rather than giving a chapter-by-chapter summary of the book, I’ll focus on some items where YECs get it all wrong:

  • YECs get the Bible wrong. In Chapter 2 (What is Flood Geology?), the authors briefly outline instances where YECs wrongfully apply an overly-literalistic reading to the Old Testament rather than reading the text in a natural way. One example of this is taking the universal language (“all the world”) of the account of Noah’s flood to mean literally the entire globe (something ancient Hebrews may not have comprehended) when almost all other instances of universal language in the Old Testament (e.g. all nations coming to buy grain from Joseph in Genesis 41) are not to be taken literally.
  • YECs get rapid deposition wrong. YECs will claim that modern coral reefs, some of which are thousands of feet thick, could have formed since the flood through normal coral growth, which can occur at several inches per year. But they leave out the fact that while narrow extensions of corals can grow rapidly, entire reef surfaces grow upwards at substantially slower rates.
  • YECs get sedimentary structures wrong. Sedimentary structures include things like ripple marks, mud cracks, raindrop impressions, and cross bedding. These features are abundant in sedimentary rocks, and are very useful for determining the environment in which the rocks formed. Mud cracks form when clay-rich sediments are exposed to the atmosphere and dry out. Mud cracks are very abundant in some rock layers, and extremely difficult to fit into the flood geology model.
  • YECs get unconformities wrong. Unconformities are breaks in the sequence of rocks, such as the one billion year gap between the Precambrian crystalline basement rocks and the Cambrian Tapeats Sandstone. YECs describe these unconformities as if there was no evidence of weathering and erosion at the gap, while in reality the evidence for erosion at the unconformities is sometimes rather blatant, such as in the case of the channels filled in by the Temple Butte and Surprise Canyon Formations. The Surprise Canyon Formation fills what appear to be stream channels that cut up to 400 feet into the underlying Redwall Limestone.
  • YECs get radiometric dating wrong. If decay rates were much faster during Noah’s flood than they are at present, enough heat would have been released to vaporize Earth’s oceans, which clearly didn’t happen. YEC attempts to discredit radiometric dating of Grand Canyon rocks are flawed.
  • YECs get rock deformation wrong. YECs insist that the rock layers of the Grand Canyon were soft when the canyon was carved, and point to tight folding of certain layers as evidence. Upon close examination by geologists, however, these folded layers show an abundance of fractures that are consistent with folding of solid rocks and inconsistent with folding of soft sediments. Soft-sediment deformation is well-understood by modern geologists, and there is no evidence for large-scale soft-sediment deformation in the Grand Canyon.
  • YECs get erosion wrong. In the Grand Canyon, sandstone layers form cliffs, and shale layers form slopes. Have you ever tried to build a sand castle with water-saturated sand? It doesn’t work, as the sand flows as a liquefied mass. But YECs want you to believe that recently-deposited (and therefore water-saturated) sand layers would have formed cliffs when eroded. If the sediment layers in the Grand Canyon were soft when eroded, the most resistant layers would be clay (which forms shale). Differential erosion of layers in the Grand Canyon is the opposite of what it should be if YEC flood geology were correct.
  • YECs get fossils wrong. The order of fossils in the Grand Canyon is impossible to explain by YEC flood geology. Any explanation for the fossil record must explain the preservation of intact communities of organisms, not just individual fossil organisms. The absence of whole groups of fossils in Grand Canyon sediments (mammals, birds, dinosaurs, flowering plants) is impossible to explain by YEC flood geology.
  • YECs get pollen wrong. If YEC were true, there should be pollen from flowering plants in the rocks of the Grand Canyon. There isn’t any.
  • YECs get trace fossils wrong. Examples of trace fossils include footprints and burrows. Terrestrial footprints of organisms such as amphibians, spiders, and scorpions are virtually impossible to explain in the YEC flood geology scenario, but they are abundant in the Coconino Sandstone.
  • YECs get the carving of the Grand Canyon wrong. The YEC breached dam hypothesis doesn’t provide nearly enough water to do the work. Other examples of catastrophic canyon-carving (Channeled Scablands, Mt. St. Helens) produced features that are quite different from what is found at the Grand Canyon.

I have only scratched the surface of the problems with YEC geology that are presented by the authors.

Endorsements

The Grand Canyon: Monument to an Ancient Earth has received endorsements from prominent geologists and theologians. Here are two endorsements from well-known, Bible-believing Evangelical scholars:

“Can Bible-believing Christians also believe that the earth is billions of years old and that the Grand Canyon could not have been formed by Noah’s Flood? Yes, insist the eleven authors of this fascinating book. On page after page, professional geologists explain that “flood geology” omits essential facts and fails to explain massive amounts of evidence in the Grand Canyon itself. This important book must be carefully considered by everyone involved in the debate about the age of the earth.” – Wayne Grudem, Phoenix Seminary

“The various authors of this book have done us all a tremendous service in their patient and clear exposition of geological thinking about the Grand Canyon (a magnificent place in its own right!). They are all clear that the “conflict” we’ve all heard about is not between “the Bible” and “Science,” but rather between interpretations of the Bible and the sciences. Those of us who study and respect the Bible will appreciated this calm laying out of the sciences, and of their discovery of the processes that appear to have been at work. These are God’s processes after all! I urge everyone to read this, believer or not—you will enjoy it.” – C. John (“Jack”) Collins, Professor of Old Testament, Covenant Theological Seminary.

One suggestion

An excellent book like The Grand Canyon: Monument to an Ancient Earth is unlikely to “convert” a die-hard YEC follower all by itself. I was once a YEC, and held on rather stubbornly to my YEC beliefs as a geology undergraduate student even as I increasingly saw scientific problems with YEC geology. It wasn’t until I was exposed to Biblical arguments for an old Earth (or better, arguments that a young Earth is not Biblically necessary) that I became open to an old Earth.

The Grand Canyon: Monument to an Ancient Earth does not contain an extensive Biblical argument for allowing an old Earth or for a local flood. I don’t criticize the editors of the book for their decision to focus mostly on geology rather than Biblical interpretation (my own textbook, Earth Science: God’s World, Our Home does not contain extensive Biblical arguments either; that wasn’t the purpose of the book).  My suggestion is that if one is giving The Grand Canyon: Monument to an Ancient Earth as a gift to a YEC or a young-Earth/old-Earth fence rider, that one also give them a book that presents a solid Biblical case. The three books I most often recommend are:

Anticipating the YEC response

So far, the YEC response to The Grand Canyon: Monument to an Ancient Earth has been a deafening silence. There have been no mentions of this book on the web sites of Answers in Genesis, the Institute for Creation Research, or Creation Ministries International. When I have mentioned the book on the Facebook pages of AiG and ICR, my comments have been quickly deleted (at least one other Christian geologist has made the same observation).

I anticipate that YECs will eventually write reviews of the book, but might put these reviews in the back corners of their web sites so as to give the book as little publicity as possible. YECs will say that the book is not based on the Bible (but of course, neither is YEC flood geology when you think about it), that the book was written by compromisers as evidenced by the inclusion of some non-Christian contributors (should we reject much of other sciences for the same reason?), and that there is always more than one way to interpret the facts (but not all interpretations have equal validity).

In the end, YECs will ignore this fantastic book and continue to present really bad science as Christian apologetics. The result will be a continued exodus of scientifically-minded youth from the church and the reinforcement of the wall YECs have put up that keeps scientists from considering Christianity as a viable alternative. People reject Christ because of bad YEC science every day, and this is a great tragedy.

But my hope and prayer is that The Grand Canyon: Monument to an Ancient Earth will have a tremendous impact on those who read it, and it sounds like sales are going well. I pray that God would use this book to build up the body of Christ, educate both young and old, and break down barriers to Christian faith.

Grace and Peace

 

July 3, 2016 Posted by | Age of the Earth, Apologetics, Christianity, Creation in the Bible, Creationism, Geology, Old-Earth creationism, Origins, Young-Earth creationism | | 4 Comments

Six bad arguments from Answers in Genesis (Part 6)

This is part six of a six-part series examining supposed evidences for a global flood that have recently appeared on the Answers in Genesis web site.
The people at AiG are my brothers and sisters in Christ, and I share their love for the Lord Jesus Christ, their respect for the Bible as the Word of God, and their desire to see people come to faith in Christ. However, I view their arguments for a young Earth and geological catastrophism as unnecessary Biblically, as poor apologetics, and as a serious obstacle to the evangelism of scientists.
Unfortunately, few people in our churches or Christian education system have the geological background to critically analyze these arguments. The result is that people read articles like these from AiG, find them to be rather impressive, and believe that these present sound arguments in defense of the Bible. The opposite, however, is true. A vast majority of Christian geologists find the arguments for a young Earth and the geologic work of the Flood to be untenable. It is my strong opinion that the young-Earth arguments of young-Earth creationist organizations like AiG have no place in our churches and Christian education system.
Part one examined the young-Earth creationist (YEC) argument that fossils at high elevations are proof of a global flood.
Part two examined the YEC argument that sedimentary rocks that contain dense accumulations of fossils can best be described by the action of Noah’s Flood.
Part three examined the YEC perception that transcontinental rock layers, such as the sandstone layer that is found at the base of the Paleozoic sediments throughout much of North America, can best be explained by Noah’s flood.
Part four looked at the YEC claim that long-distance transport of sand grains can only be explained by Noah’s flood.
Part five looked at unconformities and the boundaries between geological formations. The young-Earth crowd claims that there is no evidence for weathering and erosion between layers, which is simply not true.

Flood evidence number six” from Answers in Genesis is called “Rock Layers Folded, Not Fractured.”

This final article in Andrew Snelling’s six-part series on geology and the flood begins with another incredible mis-statement:

“How could a series of sedimentary layers fold without fracturing? The only way is for all the sedimentary layers to be laid down in rapid succession and then be folded while still soft and pliable.”

Basic diagram showing folded sedimentary rocks draped over a basement fault.

Fig. 1 — Basic diagram showing folded sedimentary rocks draped over a basement fault. The sediments were deposited as horizontal layers, and then folded as faulting occurred in the underlying crystalline rocks.

Snelling, who has a PhD in geology and is the director of the research department at Answers in Genesis, seeks to demonstrate that the entire sedimentary rock record in the Grand Canyon was unlithified (i.e. soft) when later folding and faulting occurred. If so, according to Snelling, these rocks could not have been deposited over a period of hundreds of millions of years, and must have been deposited during Noah’s flood.

Snelling describes folding of rocks associated with the East Kaibab monocline, a structure in the Grand Canyon (Fig. 1). The Tapeats Sandstone, for example, has locally experienced intense folding where it has been deformed by faulting in the underlying Precambrian basement rocks. The Tapeats Sandstone is at the base of the Paleozoic rocks of the Grand Canyon; the overlying rocks have been deformed as well.

Snelling simplifies the situation by saying that there are only two options (a common young-Earth creationist tactic):

  1. If the rocks were solidified, then they would deform in a brittle fashion, characterized by faulting or shattering (Fig. 2).
  2. If the rocks were soft, then they would deform in a ductile (or plastic) fashion, characterized by folding.
Snelling has a similar diagram in his article with the caption, "When solid, hard rock is bent (or folded) it invariably fractures and breaks because it is brittle. Rock will bend only if it is still soft and pliable, like modeling clay. If clay is allowed to dry out, it is no longer pliable but hard and brittle, so any attempt to bend it will cause it to break and shatter."

Fig. 2 — Snelling has a similar diagram in his article with the caption, “When solid, hard rock is bent (or folded) it invariably fractures and breaks because it is brittle. Rock will bend only if it is still soft and pliable, like modeling clay. If clay is allowed to dry out, it is no longer pliable but hard and brittle, so any attempt to bend it will cause it to break and shatter.”

Both of these statements are overgeneralizations to the point of being deceptive when used to make the young-Earth case.

The entire column of Paleozoic rocks at the locations described by Snelling is deformed by folding, so he concludes that the entire sequence of rocks must have been soft when deformed.

ANALYSIS

Snelling’s argument fails for several reasons.

1. First, Snelling has oversimplified the processes of rock deformation by stating that it is either ductile deformation of soft rocks, or plastic deformation of soft rocks. It is one thing to simplify a scientific concept for the sake of writing for a general audience, but Snelling has completely mislead his readers on this one.

Snelling states that only soft sediments are capable of ductile deformation; that soft sediments will deform like clay, while solid rocks are brittle and only capable of fracture. In reality, most solid rocks are capable of either brittle or ductile deformation, depending on the conditions. Factors that determine which will happen include the type of rock, the amount and type of stress applied to the rock; lithostatic pressure (due to the weight of overlying rocks), temperature, strain rate (fast or slow deformation), type of cement holding the grains together, and fluid pressure.

At low temperatures and pressures, such as those encountered at Earth’s surface, almost all rocks deform in a brittle manner. If one applies sufficient stress to these rocks, they will break. As one goes deeper in the Earth’s crust, temperature and pressure increases, and rocks are more likely to behave in ductile rather than a brittle fashion.  Some rock types can deform by folding at depths of less than one kilometer if stress is applied slowly. With increasing depth and temperature, more rock types can deform by folding rather than faulting.

The Tapeats Sandstone is presently buried beneath up to two kilometers of sediment, and was likely buried more deeply than this at the time of deformation.

2. A second problem for Snelling’s argument is that there are a variety of mechanisms by which a solid rock can bend rather than break. Think of a layer of sandstone, such as the Tapeats Sandstone at the base of the Grand Canyon Paleozoic sedimentary pile. A layer such as this can be folded without significant fracturing by several means:

  1. Intergranular movement — individual sand grains slide past each other
  2. Intragranular deformation — internal distortions within individual grains, often at the atomic level
  3. Recrystallization — atoms are rearranged at the atomic level, often in the presence of fluids.

Snelling completely ignores these, even though any of them could have been in operation at the time of deformation.

3. A third—and very serious—problem for Snelling’s argument is the nature of soft-sediment deformation. He tries to show that intense folding in the Tapeats Sandstone is the result of soft-sediment deformation. But if the Tapeats and overlying formations had been soft at the time of deformation, soft-sediment deformation and slumping would have occurred on a much larger scale than what is seen at this location in the Grand Canyon.

When layers of solid rock deform, they maintain their integrity as distinct layers. For example, whether folded or faulted, the Redwall Limestone of the Grand Canyon retains its identity as a distinct layer, without mixing with other rock units. Soft sediments, on the other hand, can respond to stress in a number of ways. In addition to folding, a results of deformation of soft sediments includes different types of soft sediment deformation and differential loading structures, such as intense localized folding, diapirs, sand pillows, and clastic dikes (Fig. 3). These structures are formed because of the inherent instability of a stack of unconsolidated sediments of varying densities and water contents.

Fig. 3A — Clastic dike — the layer going from upper left down to lower right has been intruded along a fracture, cross-cutting the original bedding. This happened while the sediments were still soft.

Fig.3B –Soft sediment deformation — the upper and lower sediments are undeformed, while the middle layers are intensely folded. These are glacial lake sediments (varves), and the deformation may have been caused by the movement of glacial ice above the sediments.

Fig. 3C — Load casts — sediment with greater density sags down into soft sediments below

Figures 3A 3B 3C Credit: Dr. Steven Dutch, used by permission.

 

Soft sediment deformation structures are common within individual layers of the geologic column, having been formed when these layers were unlithified. For the young-Earth creationists to make their case, however, they need to be able to demonstrate that soft sediment deformation is present in the geologic record on a massive, inter-formational scale. It would not be enough to point out isolated instances of soft-sediment deformation within layers.

Fig. 5 -- x

Fig. 4 — Folding of soft sediments would cause considerable slumping.

4. Related to the problem of soft-sediment deformation is the problem with slumping. If this stack of sediments—a few thousand meters thick—were faulted as in Figure 1, one would expect the upper layers to slide downhill under the influence of gravity (Figure 4). As a rule, this sort of thing is not observed in the geological record, and where it is (e.g. Heart Mountain, Wyoming) it clearly occurred in the solid state.

CONCLUSION

It is common for young-Earth creationists to state that the geological record can be easily explained by Noah’s flood. They say that most sedimentary rocks are best explained by global, catastrophic processes, and that the fossils these rocks contain represent the organisms that died in the year-long deluge. The geological field evidence, on the other hand, really does not fit the flood catastrophism model.

It must be emphasized that the Bible does not say that the sedimentary rock record was formed by Noah’s flood. Unlike Snelling, most Christian geologists (along with their non-Christian colleagues) look at the rock record and agree that it was formed by slower processes operating over a long period of time. This is not something that geologists read into the rock record, but something they read from the rock record.

The young-Earth creationist approach is to try to make the Earth fit a very rigid understanding of Genesis. The result is often like trying to force a square peg into a round hole; it can only be done by distorting either the peg or the hole (or both). The end result is that neither young-Earth science nor young-Earth Bible interpretation is believable. A better approach is the “all truth is God’s truth” approach. I start with the assumption that both the Bible and what God tells us through science is true. It is not wise to make one fit the other in an unnatural way. Does this lead to tension? A little, but not as much as either the young-Earth creationists or the atheists/skeptics would have you believe. We do not fully understand either science or the opening chapters of Genesis. When we do (not in this life, I suspect) then the tension will be gone.

With love for the body of Christ, and for those who are hindered from seeing the glory of Christ by bad apologetics.

==============================================

P.S. I felt I worded this much more succinctly as a comment on another blog:

————————————–

I’ve read the AiG article, and it just doesn’t work.

The question is whether folds were formed when the rocks were solid or unconsolidated. Other Christian geologists I know have pointed out that Snelling uses selective evidence in his study, as other parts of the same layers show very clear signs of solid-state deformation.

The way to see how solid rocks can bend is to take rocks and put them in a press in an engineering laboratory and see how they behave under stress. That has been done many times, and indeed you can do all sorts of things to rocks by putting pressure on them. In Earth’s crust, this results in the folds and faults that make up much of the world’s major mountain belts. These rocks show many signs of solid-state deformation.

If one applies the same sorts of pressure to layers of unconsolidated sediments (sand, silt, clay, etc.) the results are very different. Instead of getting folded layers of rocks, one gets chaos, with blobs of material distorting and either sinking or rising, depending on density. This is called soft-sediment deformation, and is readily distinguishable in the field from solid-rock deformation.

What is observed on a massive scale in the Earth’s crust (with some exceptions) is deformation of solid rocks, not soft-sediment deformation. If the bulk of the sedimentary rocks were laid down by Noah’s flood (and the Bible does not say that they were) then soft-sediment deformation on a massive scale should be a dominant feature of the sedimentary rocks, and it isn’t.

The “all sediments must have been laid down rapidly and while being soft” argument is not consistent with laboratory and field studies, and should not be used as Christian apologetics.

With respect,
Kevin N (Christian geologist)

October 6, 2009 Posted by | Apologetics, Geology, Origins, Young-Earth creationism | , , | 12 Comments

Six bad arguments from Answers in Genesis (Part 5)

This is part five of a six-part series examining supposed evidences for a global flood that have recently appeared on the Answers in Genesis web site.
The people at AiG are my brothers and sisters in Christ, and I share their love for the Lord Jesus Christ, their respect for the Bible as the Word of God, and their desire to see people come to faith in Christ. However, I view their arguments for a young Earth and geological catastrophism as unnecessary Biblically, as poor apologetics, and as a serious obstacle to the evangelism of scientists.
Unfortunately, few people in our churches or Christian education system have the geological background to critically analyze these arguments. The result is that people read articles like these from AiG, find them to be rather impressive, and believe that these present sound arguments in defense of the Bible. The opposite, however, is true. A vast majority of Christian geologists find the arguments for a young Earth and the geologic work of the Flood to be untenable. It is my strong opinion that the young-Earth arguments of young-Earth creationist organizations like AiG have no place in our churches and Christian education system.
Part one examined the young-Earth creationist (YEC) argument that fossils at high elevations are proof of a global flood.
Part two examined the YEC argument that sedimentary rocks that contain dense accumulations of fossils can best be described by the action of Noah’s Flood.
Part three examined the YEC perception that transcontinental rock layers, such as the sandstone layer that is found at the base of the Paleozoic sediments throughout much of North America, can best be explained by Noah’s flood.
Part four looked at the YEC claim that long-distance transport of sand grains can only be explained by Noah’s flood.
Credit: USGS http://3dparks.wr.usgs.gov/coloradoplateau/grandcanyon_strat.htm

Stratigraphy of Grand Canyon National Park showing the position of the Tapeats Sandstone and Redwall Limestone.Credit: USGS http://3dparks.wr.usgs.gov/coloradoplateau/grandcanyon_strat.htm

Flood evidence number five” from Answers in Genesis is called “No Slow and Gradual Erosion.” Young Earth geologist Dr. Andrew Snelling begins this article with a major overstatement:

“Today we see the effects of weathering and erosion all around us. But where is the evidence of millions of years between rock layers? There is none.”

To say that there is no evidence for extensive weathering and erosion in the geologic column is simply not true.

The geologic record is comprised not only of rocks formed by deposition of sediments, but also by the gaps between these rock layers which represent times of non-deposition or erosion. In order to make his case that there is no evidence for long periods of weathering and erosion in the geologic record, Snelling looks at four examples of contacts between formations in the Grand Canyon, while ignoring perhaps the greatest example of weathering in the canyon’s sedimentary rock layers. In each of these cases, the standard geological interpretation is that there was a period of time—in some cases over 100 million years—between the deposition of these formations. Snelling attempts to show that deposition of these units occurred during Noah’s flood, with only minimal time gaps between the formations.

Snelling uses the following examples:

1. The contact between the Cambrian Tapeats Sandstone and the underlying Precambrian rocks.

The Precambrian rocks at the base of the Grand Canyon include layered sedimentary rocks (see picture below) as well as metamorphic rocks. These were eroded to a flat surface before the Tapeats Sandstone was deposited (the Tapeats was discussed back in part 3 of this series).

Tapeats Sandstone (horizontal layer at top) overlaying Precambrian sedimentary rocks, which have been tilted and then eroded to a flat surface. Credit: Doug Dolde, public domain, http://en.wikipedia.org/wiki/File:Deep_Canyon.jpg

Tapeats Sandstone (horizontal layer at top) overlaying Precambrian sedimentary rocks, which have been tilted and then eroded to a flat surface. Credit: Doug Dolde, public domain, http://en.wikipedia.org/wiki/File:Deep_Canyon.jpg

According to Snelling, there is no evidence for weathering (e.g. soil formation) on the Precambrian surface.

Response:

  • It may be true that no paleosols (ancient soil layers) have been found beneath the Tapeats in the Grand Canyon, but certainly the deposition, lithification (process of turning sediment into stone), and tilting of the Precambrian sedimentary rocks and their subsequent beveling off took some time and involved erosional processes. Some young-Earth creationists would claim that these Precambrian rocks are pre-Flood deposits, but it should be noted that they contain some fossils, such as stromatolites and even possible jellyfish.
  • If the Flood had eroded the Precambrian (pre-Flood rocks in the young-Earth scenario), we should expect to see a very uneven surface. The basement rocks (Vishnu Schist and associated granitic rocks) would be very resistant to erosion and should have formed topographic highs. The Precambrian sedimentary rocks would have had varying levels of resistance to erosion, and should have formed a series of ridges and valleys, with the more-resistant layers forming the ridges. It is difficult to visualize a global flood creating a flat surface like what is observed.
Snell5-GU1

Precambrian rocks beneath the Tapeats Sandstone are eroded to a level surface.

If the Precambrian surface had been eroded by the Flood, one would expect more-resistant rocks to form topographic highs.

If the Precambrian surface had been eroded by the Flood, one would expect more-resistant rocks to form topographic highs.

  • There is a modern analog for a flat surface on Precambrian rocks. The Canadian Shield is a vast region covering much of eastern Canada as well as portions of northern Minnesota and Wisconsin. It is composed of hard metamorphic and igneous rocks, which once formed the roots of mountain ranges. The Canadian Shield illustrates that erosional processes can reduce even the most resistant rocks to a level surface. (The Canadian shield is not perfectly flat, of course, though relief in most of the region is low. It was likely considerably more planar before being scraped by glaciers repeatedly during the Pleistocene Ice Ages.)
ddddd

Canadian Shield (reddish area covering most of eastern Canada). Credit: The North America Tapestry of Time and Terrain, http://pubs.usgs.gov/imap/i2781/

  • There may not be paleosols (soil horizons) developed on the Precambrian rocks in the Grand Canyon, but they are present elsewhere, such as the contact between Precambrian basement rocks and the Cambrian Lamotte Formation in Missouri.

2. The contact between the Mississippian Redwall Limestone and the underlying Devonian Temple Butte Formation and Cambrian Muav Limestone.

Snelling correctly observes that the top of the Muav contains what appear to be erosional channels, some of which are filled with the material that makes up the Temple Butte Formation. However, Snelling dismisses these as evidence for stream erosion, preferring to interpret these channels as having been caused by the Flood.

Snelling goes further to claim that the Redwall and Muav show signs of interbedding. The contacts between some rock units are distinct. For example, higher in the geologic column, there is a distinct point where the Hermit Shale ends and the Coconino Sandstone begins (see #4 below). There is no mixing of any sort between the two.

Snell5-AB

Not all contacts between formations are this sharp; some are considerably more transitional. Interbedding is a type of transition where there are alternating beds of the upper and lower formations, so rather than going directly from formation A to formation B, the transition might go A-B-A-B-A-B.

Snell5-ABABAB

The two preceeding diagrams represent what one might see in an individual outcrop. Over greater distances—tens or even hundreds of kilometers—the situation might look more like this:

Snell5-ABinterbedding

This could represent a migrating shoreline as the sediments pile up, with unit A being deposited further to the right at some times, and further to the left at others. An important part of this concept is that A and B are being deposited at the same time, one closer to the shoreline, and one further out.

If the Muav and Redwall were truly interbedded, it would be a major challenge to accepted interpretations. The Muav is Cambrian, and the Redwall is Mississippian, so there should be over 100 million years of non-deposition or erosion represented by the boundary between the two. If they are interbedded, this would imply that they were being deposited at the same time.

Response:

  • The channels beneath the Redwall appear to be real stream channels, though as far as I know this cannot be conclusively demonstrated at this time.
  • The Temple Butte Limestone fills these channels. Paleontological evidence suggests that this is a freshwater limestone. How did this happen during a global salt-water flood?
  • A diagram of the supposed interbedding is shown here (figure 3). The blotchy nature of the contact between what the authors call the Muav and what they call  the Redwall looks like a secondary, post-depositional feature (diagenetic) rather than a primary, depositional feature. This could have been formed by groundwater at any time after the deposition of the Redwall Limestone. If this were true interbedding, it certainly would have been puzzled over by many a geologist hiking along the very popular North Kaibab Trail in the Grand Canyon.

3. The contact between the Permian Hermit Shale and the underlying Pennsylvanian Esplanade Sandstone.

Snelling claims that interbedding of the Hermit and Esplanade proves that there was not millions of years between their deposition.

Response:

  • This may be a case where interbedding is legitimate; they could represent adjoining sedimentary environments, at least for a time.  There is not a huge time gap between the two formations.
  • The erosional relief on top of the Esplanade is up to 16 m (60 ft), which appears to be the result of stream erosion. (USGS Geologic Investigations Series I–2688). Snelling doesn’t mention this.
  • Paleontological and petrologic (rock) evidence indicates that both of these units were formed in swampy environments, not in a global flood.

4. The contact between the Coconino Sandstone and the underlying Hermit Shale, both of Permian age.

In the previous two examples, Snelling says the boundaries between formations appeared to be too diffuse to represent vast gaps in geologic history. The Coconino-Hermit boundary, on the other hand, appears to Snelling to be too sharp.

Response:

  • The Coconino is a wind-deposited sandstone, with terrestrial arthropod and reptile tracks, as well as animal burrows. What were paleo-lizards doing running around on the sand in the middle of the flood? By itself, this ought to rule out a flood explanation for the Coconino.
  • In an increasingly arid environment, it should not be surprising that there is little in the way of stream channel erosion or soil development beneath the Coconino.

Snelling completely ignores two compelling pieces of evidence for long periods of weathering and erosion in geologic history:

1. Paleosols — I have briefly referred to paleosols (ancient soils) already. The formation of a soil on top of bare rock or sediment takes a combination of physical weathering, chemical weathering, biological processes, and time, and is a process that normally takes thousands of years. If paleosols exist within the geologic record, they are strong evidence that there were long periods of time when rocks or sediments were exposed on the surface to the atmosphere.

My graduate research was in the Palouse Loess of Eastern Washington, which contains multiple, stacked paleosols. Each of these paleosols contains soil horizons identical in character to modern soil profiles in the area, complete with root casts and animal burrows. Each paleosol would have taken several hundred or even thousands of years of surface stability to form, only to be buried by an influx of wind-blown silt, setting the stage for the next time of soil formation. The Palouse Loess is a Quaternary formation, and young-Earth creationists would say that this was formed after the Flood.

I did a quick search in the Geological Society of America Bulletin, and came up with the following articles describing paleosols in Paleozoic and Mesozoic rocks:

This is from just one journal; there are undoubtedly thousands of documented paleosols in the geologic record. A majority of the articles I found were about Cenozoic paleosols, but I ignored these for brevity and also because many young-Earth creationists describe Cenozoic rocks as being post-Flood (a position which has just about as many problems as the rest of young-Earth creationism).

2. Paleokarst — Karst topography is formed by the dissolution of carbonate rocks, such as limestone. Features of karst topography include caves, sinkholes, and disappearing streams.

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Extreme karst topography, Yangshuo China. Credit: Ericbolz, http://en.wikipedia.org/wiki/File:YangshuoFromTvTower.jpg

Karst topography is common in areas underlain by limestone, and one would expect that this would have been the case throughout geologic history. Snelling completely ignores the greatest evidence for weathering and erosion in the Grand Canyon, and this is the paleokarst (ancient karst) that exists in the Redwall Limestone. Snelling wrote about the bottom of the Redwall, but not its top! The Redwall appears to have all the features of karst topography, such as rubble (breccia) filling sinkholes, and a chaotic upper surface.

Karst topography on top of the Redwall implies that there was a considerable amount of time when the consolidated limestone—as opposed to fresh limey sediments—was exposed to the atmosphere, with freshwater circulating through the rocks. This could not have happened in the context of a global flood.

Additional problems for the flood-geology/young-Earth position:

Many of the features I have described are difficult to explain within the young-Earth model for Earth history. These include ancient soil layers, ancient karst systems, and the difficulty of producing the flat surface that underlies the Cambrian in the Grand Canyon.

Young-Earth creationists seem to acknowledge that the geologic record contains evidence of periods of non-deposition and erosion, as well as periods of deposition. The difference would be a matter of time scales. Geologists are willing to talk about periods of millions of years, whereas young-Earth creationists have to squeeze these events into periods of hours or days.

What sort of erosion would occur in a global flood? The young-Earth literature implies that the flood began with an intense period of erosion, with forces powerful enough to pulverize granite. It seems that this continued in various places throughout the flood. Would we not expect, therefore, that a significant feature of the geologic record would be mega-scouring of soft sediments? Snelling refers to something called “sheet erosion” which conveniently doesn’t scour soft sediments. I don’t think he can have it both ways: sufficiently strong to shatter granite, but gentle enough to produce smooth surfaces on mud and sand.

There are numerous other indicators of a passage of time within the rock record. These include vertebrate (amphibian, reptile) nests, which imply a time when the land was sufficiently dry for a long enough time to allow mating, nest-building, and rearing of young (at least some dinosaurs cared for their young). This could not have happened in the middle of the Flood. Other shorter-term indicators of periods of non-deposition include worm burrows, raindrop impressions, and mudcracks, all of which are common.

Conclusion:

There is considerable evidence in the geologic record for long periods of slow, gradual weathering and erosion. Paleosols represent periods of stability, when sediments or rocks were exposed to the atmosphere for long periods of time. These ancient soils include features such as plant roots and animal burrows. The contacts between sedimentary formations represent periods of erosion or non-deposition, and often are somewhat irregular, being cut by stream channels. In other places, limestone formations show signs of having been exposed to freshwater groundwater circulation, resulting in paleokarst.

As with the other “flood evidences,” this one turns out to be completely inadequate as an explanation for how the Earth got to be the way it is. Because of this, Flood Evidence #5 ought not to be used in defense of the truthfulness of God’s holy word, the Bible.

Up next: Flood Evidence #6: Rock Layers Folded, Not Fractured.

With love for the body of Christ.

August 9, 2009 Posted by | Apologetics, Geology, Old-Earth creationism, Young-Earth creationism | , , | 14 Comments

Six bad arguments from Answers in Genesis (Part 3)

This is part three of a six-part series examining supposed evidences for a global flood that have recently appeared on the Answers in Genesis web site.
The people at AiG are my brothers and sisters in Christ, and I share their love for the Lord Jesus Christ, their respect for the Bible as the Word of God, and their desire to see people come to faith in Christ. However, I view their arguments for a young Earth and geological catastrophism as unnecessary Biblically, bad apologetics, and a serious obstacle to the evangelism of scientists.
Unfortunately, few people in our churches or Christian education system have the geological background to critically analyze these arguments. The result is that people read articles like these from AiG, find them to be rather impressive, and believe that these present sound arguments in defense of the Bible. The opposite, however, is true. A vast majority of Christian geologists find the arguments for a young-Earth and the geologic work of the Flood to be untenable. It is my strong opinion that the young-Earth arguments of organizations like AiG have no place in our churches and Christian education system.
Part one examined the young-Earth creationist (YEC) argument that fossils at high elevations are proof of a global flood.
Part two examined YEC argument that sedimentary rocks that contain dense accumulations of fossils can best be described by the action of Noah’s Flood.
Credit: USGS http://3dparks.wr.usgs.gov/coloradoplateau/grandcanyon_strat.htm

Stratigraphy of Grand Canyon National Park showing the position of the Tapeats Sandstone and Redwall Limestone.Credit: USGS http://3dparks.wr.usgs.gov/coloradoplateau/grandcanyon_strat.htm

Flood evidence number three” from Answers in Genesis is called “Transcontinental Rock Layers.” In this article, young-Earth creationist Andrew Snelling describes sedimentary rock layers that cover large areas of continents, and tries to show that the vast extent of these layers is evidence for a global flood.

His first example is the Tapeats Sandstone, which forms the base of the Paleozoic record in the Grand Canyon in Arizona. This formation is of Cambrian age, and sits unconformably above Precambrian sediments of the Grand Canyon Group. The main part of the Tapeats is composed of a very clean quartz sandstone. Almost all of the mineral grains in this sandstone are well-rounded quartz; there are very few grains with different composition, and there is very little clay in between the grains. This is typical of a well-worked sandy beach or eolian (wind-blown sand) environment.

Sandstones analogous to the Tapeats Sandstone form a continuous layer at the base of the Cambrian sediments in much of North America. In Montana this layer is known as the Flathead Sandstone, in Colorado it is the Sawatch Sandstone, in the Midwest it is the St. Simon Sandstone, and in New York it is the Potsdam Sandstone.

Snelling discusses the Tapeats Sandstone as follows:

The lowermost sedimentary layers in Grand Canyon are the Tapeats Sandstone, belonging to the Sauk Megasequence. It and its equivalents (those layers comprised of the same materials) cover much of the USA (Figure 3). We can hardly imagine what forces were necessary to deposit such a vast, continent- wide series of deposits. Yet at the base of this sequence are huge boulders (Figure 4) and sand beds deposited by storms (Figure 5). Both are evidence that massive forces deposited these sediment layers rapidly and violently right across the entire USA. Slow-and-gradual (present-day uniformitarian) processes cannot account for this evidence, but the global catastrophic Genesis Flood surely can.

Snelling actually understates the extent of these very similar basal Cambrian sandstones. Derek Ager, in his influential book The Nature of the Stratigraphical Record describes this as a feature of global, not just continental, proportions:

Even more remarkable than the basal Ordovician quartzite is the one that is found, almost all over the world, at the bottom of the Cambrian. […] Perhaps all that it is safe to say in this context is that very commonly around the world one finds an unfossiliferous quartzite conformably below fossiliferous Lower Cambrian and unconformably above a great variety of Precambrian rocks. This is true wherever one sees the base of the Cambrian in Britain, it is true in east Greenland, it is true in the Canadian Rockies and it is true in South Australia. In fact it is even more remarkable than this, in that it is not only the quartzite, but the whole deepening succession that tends to turn up almost everywhere; i.e. a basal conglomerate, followed by marine shales and thin limestones. In the northern Rockies one can even recognize at this level the “Pipe Rock’ of the Scottish Highlands–a bed full of borings known as Skolithos.

(Ager, The Nature of the Stratigraphical Record, 2nd edition, p.11).

[a few explanations: 1. For our purposes here, quartzite is a very-well cemented or slightly metamorphosed sandstone. 2. Skolithos is a trace fossil interpreted as worm borings or tubes]

The standard geological explanation of these Cambrian sandstones is that they were deposited in a shallow marine to intertidal environment. The Skolithos worm borings are consistent with this explanation, as are the variety of sedimentary structures (e.g. cross bedding) that are found in these units.

The Madison Limestone at Gates of the Mountains, Montana. The Madison Limestone is equivalent to the Redwall Limestone of the Grand Canyon. Credit: Richard I. Gibsonhttp://en.wikipedia.org/wiki/File:Gatesofmts.jpg

Snelling also uses the Redwall Limestone of the Grand Canyon as a example of a sedimentary rock unit that covers a very large area:

Another layer in Grand Canyon is the Lower Carboniferous (Mississippian) Redwall Limestone. This belongs to the Kaskaskia Megasequence of North America. So the same limestones appear in many places across North America, as far as Tennessee and Pennsylvania. These limestones also appear in the exact same position in the strata sequences, and they have the exact same fossils and other features in them.

Unfortunately, these limestones have been given different names in other locations because the geologists saw only what they were working on locally and didn’t realize that other geologists were studying essentially the same limestone beds in other places. Even more remarkable, the same Carboniferous limestone beds also appear thousands of miles east in England, containing the same fossils and other features.

Again, Snelling is understating the extent of these Mississippian Limestones. Similar limestones can be found not only throughout the American and Canadian West, but up to Alaska, into the Midwest, and in continental Europe and the Himalayas (Ager, pp. 7-8).

Snelling’s conclusion is that the only way to explain extensive layers like these is by invoking Noah’s Flood. He states that these layers could have only been deposited rapidly in a very short time. But there are a number of problems with Snelling’s explanation of these sediments:

  1. Snelling, like other young-Earth creationists, uses the wide extent of these units as evidence for large-scale, or even global-scale processes. I think that the opposite may be true: that the scale of these units works against the catastrophist explanation. For example, the fact that much of the North American continent (as well as large portions of other continents) is covered by the Cambrian Tapeats Sandstone and its equivalents means that all of the other Flood sediments—let’s say the rest of the Paleozoic and Mesozoic—had to already be in suspension in the waters above the pure-sand Tapeats:
  2. FloodSequence

  3. While all of these sediments were in suspension, according to the AiG/Snelling model, there could have been no mixing of sediments of different ages. There was no mixing of Ordovician with Silurian, or Paleozoic with Mesozoic.
  4. Likewise, there could have been no mixing of sediments from different sedimentary environments. Reef sediments (complete with intact ecological zonation: fore reef, back reef, breaker zone, etc.) couldn’t have mixed with beach sediments, deep water sediments couldn’t have mixed with intertidal sediments, and marine sediments couldn’t have mixed with non-marine sediments.
  5. Additionally, there could never have been any kind of turbulence that would place rock units out of order. The sequence isn’t Cambrian-Ordovician-Silurian-Devonian in one place, and Cambrian-Devonian-Silurian-Ordovician in another place.
  6. The boulder and cobble-bearing layers (conglomerates) of the Tapeats and its equivalents tend to be near what seem to be islands that stuck up above the sea, and the size of the grains decreases with increasing distance from the source areas. The rock types of the grains matches that of the islands. These are, therefore, local features; not the result of a global flood. The conglomerate layers likely originated during storms. (Additionally, the conglomerate layers don’t always occur at the base of the Cambrian sandstones as Snelling states).
  7. Snelling really gives no evidence in his article that these various units were deposited rapidly over large areas. He gives a few examples of rapid deposition on a smaller scale, such as the preservation of supposed water-laid dunes in the Coconino Sandstone (which most geologists interpret as wind deposits, not water deposits), but provides no evidence that catastrophism is the dominant means of deposition of any of the rock units he describes. Local deposition may be catastrophic for a short period of time, as in storm conglomerates, but it is a wild extrapolation to say that the entire geologic column was deposited rapidly, and there is plenty of evidence that it wasn’t.

The standard geological explanation of the Cambrian sandstones is that the sand was first blown around on the barren continental surface. This lead to exceptional rounding of the grains, distinctive microscopic textures on the sand grains, and a winnowing of virtually all clay. Eventually the sand was blown into shallow seas that covered large portions of the continents. Here the sand was reworked by various currents, as indicated by ripple and dune features (sedimentary structures) preserved in the sandstone. Actual deposition did not occur over the entire continent at once, but shifted as sea levels rose throughout the time of deposition. This explanation works well, is consistent with a variety of field and experimental data, and doesn’t require that all post-Tapeats sediments already be in suspension while the Tapeats and its equivalents were being deposited.

Remember: the Bible doesn’t say that the sedimentary rock record was laid down by Noah’s Flood. Organizations like Answers in Genesis do a considerable amount of arm waving and wild extrapolation in order to make the rocks fit their model, but this is completely unnecessary.

Up next: Flood Evidence #4: Sand Transported Cross Country.

With love for the body of Christ.

May 19, 2009 Posted by | Age of the Earth, Apologetics, Creation in the Bible, Geology, Origins, Young-Earth creationism | , , , , | 8 Comments