Geology: A Science Where Theories Undergo Subduction

In plate tectonics, continental plates get subducted and melt under pressure. That’s like what happens to geological theories.

Read enough geology papers, and you will find old theories constantly being replaced. Classic examples include plate tectonics becoming the new normal after Wegener’s theory had been viciously attacked, and megaflood theory for the Channeled Scablands becoming the new normal after J Harlen Bretz had endured decades of ridicule. Here are some new examples of assumptions gone awry.

Dry Glaciers?

In Science Daily, we hear that “Glaciers in Mongolia’s Gobi Desert actually shrank during the last ice age.” One would think glaciers grew during an ice age. Geologists assumed they did in Mongolia, but new research suggests that the high deserts of Gobi actually remained dry. They mistakenly applied conditions in the Western hemisphere to those in the far East.

On some of the Gobi mountain ranges included in the study, glaciers started growing thousands of years after the last ice age ended. In contrast, in slightly wetter parts of Mongolia the largest glaciers did date from the ice age but reached their maximum lengths tens of thousands of years earlier in the glacial period rather than at its culmination, around 20,000 years ago, when glaciers around most of the planet peaked.

The findings reveal that cold alone is not sufficient to form glaciers. “The simple story says that during the last ice age, temperatures were colder and ice sheets expanded around the planet,” this article begins. Actually, what is needed is abundant precipitation, which requires warmer oceans. A doctoral student from the University of Washington has determined that glaciers “actually shrank as cold, dry conditions of the ice age became more intense. Then they grew when the warming climate of the Holocene brought more moist air, feeding the glaciers with more snow.” The moraines that were long thought to represent ice age remnants turned out to be too young by his calculations.

Boulder Transport

One would think scientists could find it easy to calculate how much energy is required to move a boulder of a given mass. Accordingly, geologists assumed that only major tsunamis would have the energy needed to move large boulders found on top of some Irish coastlines. Phys.org reports now about “Extraordinary boulder transport by storm waves,” showing they were wrong. Nothing like some eyewitness observations to falsify a theory:

It’s not just tsunamis that can change the landscape: storms shifted giant boulders four times the size of a house on the coast of Ireland in the winter of 2013-14, leading researchers to rethink the maximum energy storm waves can have—and the damage they can do….

It was previously assumed that only tsunamis could move boulders of the size seen displaced in Ireland, but the new paper provides direct evidence that storm waves can do this kind of work.

“Previously assumed” – by whom, you may ask? We need to change the verb from passive to active to reveal the Tontology: assumed by geologists, of course.

Extinct Lakes

Ancient shorelines can be seen on the mountains surrounding Death Valley. Photo by David Coppedge.

Throughout the western US, there are ancient shorelines of extinct Pleistocene lakes, Death Valley being a classic example, and Great Salt Lake representing a small remnant of ancient Lake Bonneville. The lead author of a new study asks, “Why are there lake systems under both colder and warmer climates, but not today?” Good question. Is it global warming? Astrobiology Magazine puzzles over the question. Simplistic ideas would say that lakes grow during cold, wet periods and shrink during dry periods. Some of them, however thrived in past warming periods. The paradigm “wet gets wetter, dry gets drier” doesn’t fit the evidence.

The new models have to explain the presence of large inland lakes during opposite conditions. Why did large inland lakes grow during warm periods? The authors appeal to “El Niño-like” conditions during the mid-Pliocene. The question then becomes, why aren’t we seeing large lakes like those in modern “El Niño-like” periods? A more pertinent question for us might be, ‘How do geologists know what will happen during the global warming predicted for the future?’ After all, those ancient lakes “led many scientists to view the Pliocene as a potential analogue for future climate change,” but the new study apparently “goes against projections of future warming.”

Misunderstood Stromatolites

The rounded lumps called stromatolites are up for another case of theory subduction. Living examples in the shallows of Shark’s Bay, Australia, have long provided a model for how fossil stromatolites must have formed. That model held up other theories built on top of it. New Scientist now reports on the discovery of living stromatolites forming in deep water. Colin Barras headlines the finding, “Deep sea discovery suggests world’s oldest fossils misunderstood.”

We might need to rethink what we know about the oldest fossils ever found. [Note: Look up Tontology.]

Some of the best evidence for early life is provided by structures called stromatolites. Many geologists assume these stromatolites were made by microbes living in shallow, sun-drenched water. This means that life, if it emerged on the deep seafloor as some scientists believe, spread to shallow regions rapidly.

A new discovery questions that conclusion. It is a stromatolite that formed recently in the deep, dark water at the bottom of the Arabian Sea.

Geological theories resemble their subject matter. Sometimes they are shaken by earthquakes, tsunamis, or changes of climate. Some undergo subduction and melt under heat and pressure.

Some of the new findings fit a Biblical flood model comfortably. Flood geologists know the power of moving water, and point to huge boulders in some sedimentary deposits (e.g., the Tapeats sandstone in Grand Canyon) as evidence that high-energy water transport was required, not calm, placid deposition. The stromatolite finding shows that these formations can form more rapidly than expected, not requiring millions of years. The inland lakes speak to remnants of a global flood gradually disappearing by evaporation or by dam breach events. In the uniformitarian scenario, it becomes difficult to explain why there were so many in the past under different climates, but not now. Finally, the post-Flood world accounts for a single ice age because the breakup of the fountains of the great deep would have increased precipitation tremendously by warming the oceans.

We all have the same observations, but in the historical sciences, for singular events, one can only present causes sufficient to explain the observations. When modern analogues do appear (such as the boulder transport that was witnessed), paradigms can fall.