I have long appreciated the work that Ken Wolgemuth and his colleagues at Solid Rock Lectures do in using their expertise in geology to help their fellow evangelical Christians (especially at seminaries) to be comfortable with modern science as it relates to the creation of the earth. These folks contributed much to The Grand Canyon, Monument to an Ancient Earth: Can Noah’s Flood Explain the Grand Canyon? , a lavishly illustrated book which shows how the geological features of the Grand Canyon are better explained by conventional geology than by the Flood geology of young earth creationism.
When I learned that Ken was going to present two talks at an apologetics conference last fall, I decided to register to be able to see his talks on-line, along with all the other presentations. It turns out that many of these presentations were interesting and valuable, so I have decided to write up a number of them in the form of blog posts. This was the 2020 annual National Conference on Christian Apologetics (NCCA), whose theme was “Hold Fast”.
I will typically cover more than one talk per post. (My style is to write fewer, longer posts, so they are often more like short journal articles, not the typical 3-minute-read found on many blogs). Today I will summarize Ken’s two talks.
The Abstract reads:
Christian homeschooling is dominated by curriculum from young-earth organizations that typically does not present the scientific understanding of the earth held by the vast majority of Christians who are scientists. As a Christian geologist, I will cover three dominant topics that all students should know about when headed for a university education.
(1) The processes of plate tectonics that move continents over geologic time scales, and how we know about the age of the earth.
(2) Radiocarbon dating as a wonderful tool to determine the age of bones, wood, and charcoal, with the inherent limits of ~40,000 years, that includes biblical archaeology.
(3) Ice cores reveal that God has gifted mankind with 10,000 years of stable climate for the flourishing of modern technological cultures.
The slides note that historically Christianity viewed science as a friend rather than an enemy in providing an improved understanding of God’s creation. For instance, the early astronomer Johannes Kepler (1571-1630) wrote, “The chief aim of all investigations of the external world should be to discover the rational order and harmony which has been imposed on it by God”, and “Science is the process of thinking God’s thoughts after Him.”
Observations regarding the motion of crustal plates help to bring home the vastness of geologic time. The image below shows, as yellow dots, the locations of thousands of significant earthquakes that were detected over a ten year period.
These earthquakes tend to fall along lines which demarcate the boundaries between the plates of the earth’s crust. From matching fossils and rock formations, it is clear that South America and Africa were once part of one giant continent which split apart. How long did it take for them to get to their present positions? With geopositioning measurements from satellites and radiometric dating of oceanic crustal rocks, we can determine that these two continents broke apart 140 million years ago and drifted far apart to where they are today.
Another example in the slides is the archipelago of the Hawaiian islands (all formed from volcanos) plus a long, long string of submerged remnants of volcanos (seamounts) that extend to the northwest and north. This image shows how all these volcanic islands and seamounts were formed, by the crustal plate sliding over one persistent hot spot in the mantle which has pushed lava up through a narrow plume for millions of years. As the plate keeps moving, the old volcanos go dormant and move off to the northwest and then start to erode from wave and water action. A new volcano is already forming underwater just to the south of the Big Island of Hawaii.
Radioactive dating was done on the rocks from these islands and seamounts, and shows a consistent pattern of increasing age for the seamounts further north/northwest, which formed earlier and have since moved away. With these dates and the distances between these features, we can calculate the velocities of the Pacific plate over the past 80 million years:
The estimated velocity of the most recent leg of motion from these results is about 3.2 inch (8.1 cm)/yr. From geo-positioning measurements from satellites, we can directly measure the current motion of this plate, and find that it is moving at about 3.1 inch/yr. This agreement (3.1 vs. 3.2 in/yr) between two completely different methods gives confidence in these results, which again point to the earth being many millions of years old.
With further illustration of plate tectonics, Ken showed slides illustrating how, as the plate of what is now India collided with Asia, limestone sediments which were originally deposited along the south shore of Asia, were folded and lifted up to become the Himalayan Mountains. This is consistent with millions of years of crustal movement, but not with a 6000 year old earth.
He described briefly the basis of radioactive dating of rocks, and showed this chart to illustrate that there are a number of different ways for believers to interpret the Genesis creation narrative:
Ken touched briefly on evidence for evolution, although that was not his focus. He described carbon-14 dating of artifacts, and how this method can give results consistent with the Bible record. For instance, the tunnel dug in Jerusalem for water delivery in the time of Hezekiah has been found, and wood fragments there are dated to the time indicated by the biblical text. Hopefully this can make conservative Christians more comfortable with the findings of this technique, even though some carbon-14 results point to an age of the earth longer than 6000 years.
The last section described some results from examination of ice cores drilled down through the ice sheets in Greenland and Antarctica. The annual layers in Greenland ice cores show the earth to be at least a hundred thousand years old. Snowfall in Antarctica is very low, and ice cores show the earth to be hundreds of thousands years old. The picture below shows the temperature swings over the past 400,000 years as inferred from an Antarctic ice core.
In this time period, the earth has spent most of its time with a relative cool climate, with glaciers covering Canada and northern Europe. The interglacial periods (circled in red above), when temperatures climbed to around today’s values, were very brief. The temperature spiked, then went right back down again. The most recent warm spell, labelled “Today”, has lasted a relatively long time, about 12,000 years so far. This long period of fairly warm, stable climate has helped humans to develop the civilization we have.
Homeschooled students need to be exposed to these sorts of evidences for an old earth, so that they don’t get shaken when they go to university and are taught such things there. Ken offered that if someone, especially a home schooler, sends him an email (address given above), he will send them a set of key slides from this talk.
As noted above, Ken is a co-author of an authoritative book on the geology of the Grand Canyon and how evangelicals should regard it, The Grand Canyon, Monument to an Ancient Earth: Can Noah’s Flood Explain the Grand Canyon? . It specifically addresses the claims of the “Flood Geology” which underlies modern Young Earth creationism. This view proposes that the earth is only about 6000 years old, and that most rock layers, including those of the Grand Canyon, were laid down rapidly as part of Noah’s world-wide Flood, about 4500 years ago. YE creationists claim that the rock formations of the Grand Canyon support their point of view. Ken and his colleagues show in their book why that is not the case. In talk Ken steps through some aspects covered in this book.
One aspect of their book that I found very helpful was a middle section where they give a full tutorial on how sedimentary rocks form. That allows us to look at present-day formations, and “read” much of the history of how they must have formed. There are other educational chapters on radioactive dating of rocks, plate tectonics, fossils, and folding and fracturing of rocks:
The talk then addresses the claim of YE creationists that the layers of the Grand Canyon represent 4,000 feet of “layer cake” sediments, with no erosion or significant channels between the layers. Ken showed some clear examples where there is in fact erosion between some layers, where the surface had been exposed to the atmosphere for long periods of time before the next sedimentary layers were deposited. That is obviously inconsistent with the notion that all these layers were deposited within the space of one year.
Another claim of YE creationists is that a certain portion of the Tapeats Sandstone Formation (shown in lower left of the image above) was tightly folded but with no fracturing, indicating that formation was still soft at the time (as though it had been freshly deposited). Ken pointed out that in fact this folded portion is fractured, showing it was hard rock at the time, not a freshly deposited wet sand layer. (We have discussed this folded rock formation in more detail here).
Ken showed how the patterns of fossils in the Grand Canyon layers are consistent with modern geology, but not with expectations of Flood geology. If these layers were the result of one giant, earth-scouring Flood, we would expect to find land and marine animals largely jumbled together, and large marine reptiles like mosasaurs buried alongside large marine mammals (like whales, dolphins, and seals). But in fact terrestrial and marine fossil groups are largely separate, and there is a clear line of demarcation below which there are large marine reptiles but no marine mammals, while in the upper layers there are fossils of marine mammals but no large reptiles other than turtles.
The talk concludes by addressing how it impacts Christian young people to have misinformation given to them in the name of Christianity, and poses questions of how scientists who are Christians should treat the evidence. All in all, these two presentations do a good job presenting the geological evidence for the great antiquity of the earth, and of the importance of getting this right for Christian students.
(Side comment: See here for a long article on the geology of the Grand Canyon, addressing age-of-the earth issues).
Next post in series on 2020 NCCA apologetics conference: Richard Howe: How Do I Know That I Know?; Defining the Good [2020 NCCA Apologetics Confc, 2]