Keywords: earth’s magnetic field, paleomagnetic field directions, basalt lava flows, Steens Mountain, Oregon, rapid geomagnetic polarity reversals, geodynamo, young-earth freely decaying electric currents model, Sulmona Basin, Italy, calcareous muds, tephra layers, post-Flood Ice Age, Ar-Ar dating, sanidine, accelerated radioactive decay.
Back in 1985 Coe, Prévot, and their scientific colleagues reported in three papers the evidence they had found of extremely rapid polarity changes of the earth’s magnetic field recorded in basalt lava flows at Steens Mountain in southern Oregon.1,2,3 These scientists carefully documented that Steens Mountain provided an excellent record of a geomagnetic reversal, because the volcano had spewed out 56 separate lava flows during that episode, so that each rock layer provided a time-lapse snapshot of the reversal.
Their studies resulted in a benchmark directional record with 49 distinguishable paleomagnetic field directions from two well-exposed rock sequence sections more than a mile apart. Within this detailed record were three gaps of approximately 90° between one directional group and the next. These gaps were thought possibly to represent interludes in volcanic activity, but the absence of evidence of any hiatus between successive flows either side of the gaps suggested instead that the geomagnetic field may have changed very rapidly at these times.
These tantalizing results spurred detailed sampling from bottom to top of flows that straddled these directional gaps. Results for the samples from the flow straddling the first directional gap were intriguing.4 They discovered that toward the top of that flow the basalt had recorded a different paleomagnetic orientation than the basalt lower down in the same flow (see Figure 1). Coe and Prévot interpreted this to mean that the geomagnetic field had shifted by about 3° per day during the few days it took this basalt lava flow to cool. Such a rate of change is about 500 times faster than that seen in direct measurements of the field today.
Continuing their painstaking work, a follow-on study reported results of detailed sampling of the basalt flows which straddle the second of the three gaps in the record of changes in the direction of the geomagnetic field.5 They reported that their results indicated the rate at which the orientation of the ancient geomagnetic field had rotated could have reached an astounding 6° per day over an eight-day period during cooling of one of these basalt flows.6 Furthermore, they argued that these field changes recorded in these basalt lava flows at Steens Mountain did reflect genuine changes in the earth’s main magnetic field.
Reactions to these claims of evidence for extraordinarily rapid changes in the geomagnetic field direction were swift and vocal, because such evidence was an affront to the uniformitarian mindset regarding their slow-and-gradual view of the earth’s geologic history. “Principle of Least Astonishment’” was the title of an opinion piece in the journal Nature, in which geophysicist Ronald Merrill of the University of Washington (Seattle) tried to grapple (unsuccessfully) with this newly published evidence confirming that extraordinarily rapid reversals of the earth’s magnetic field have indeed occurred.7 He wrote on the origin and history of the field:
“ . . . most geomagnetists dismissed the claim by applying the principle of least astonishment—it was easier to believe that these lava flows did not accurately record the changes in the earth’s magnetic field than to believe that there was something fundamentally wrong with the conventional wisdom of the day . . . .”
Indeed, these findings at Steens Mountain veer far from the standard college geology textbook image of how the earth is supposed to work. Said Roberts of the University of California, Los Angeles: “To a theoretician like myself, these results are almost inconceivable.”8 Yet earth scientists by their own admissions lack a firm understanding of the earth’s magnetic field. According to the current theory in uniformitarian thinking, slowly swirling currents of molten iron within the earth’s outer core create a dynamo that powers the magnetic field. It is believed that once every few thousand years the field flips orientation, swapping the north pole for the south pole. These magnetic reversals, as they are called, supposedly take about 10,000 years from start to finish, because it would take that long for the geodynamo to crank down so as to switch direction before cranking up again to generate the field again, but with the reversed polarity.
Most geophysicists questioned the original finding. “I can’t really understand the mechanism,” said Hoffman of California Polytechnic State University.9 In the face of this conundrum, some geophysicists tried (unsuccessfully) to explain the rapid field changes in terms of something else other than fluid movements in the outer core itself. Critics have pointed out that the magnetization recorded in the basalt lava flows might not be primary, because it is not uncommon to find basalt lava flows that have been remagnetized long after they cooled, for example, due to chemical alteration. Thus they claimed that the “alleged” rapid geomagnetic field changes in reality reflect imperfections in the paleomagnetic recording process, resulting in an “artefact” according to Bloxham of Harvard University.
However, Coe and Prévot (with Camps) tackled such criticisms head-on in their reports, making a convincing case against the “magnetic artefact” argument. The two lava flows they had studied have quite different magnetic properties and yet show similar signals, making it harder to blame some glitch in the recording of the paleo-geomagnetic field in these basalts. Hoffman agreed: “We haven’t found anything really questionable about the rock magnetics.” Similarly, they convincingly countered other hypotheses, such as that the changes in the magnetization reflected changes in the external geomagnetic field associated with, for example, a magnetic storm.
Bloxham acknowledged that he and his fellow geophysicists had a hard time explaining away the findings. “People are taking them seriously,” he said. Indeed, Merrill agreed:
“They are some of the best experimentalists in the world. They’ve made it much more difficult to be a skeptic.
In short, if Coe et al. are correct, then the consequences could be much more profound than they say. All this leaves us with a dilemma: we would like to apply the principle of least astonishment, but to which data and interpretations? Some scientists will accept the view as given by the authors [Coe et al.]. Others, I suspect, will choose to believe the rock record is still inaccurate . . . .”
However, Merrill and all his uniformitarian colleagues failed to consider his own stated alternative—that there is “something fundamentally wrong with the conventional wisdom of the day” on the origin and history of the earth’s magnetic field. Why do they fail to consider that alternative? Because they would have to abandon their dynamo theory and its millions of years timescale!
Enter a Young-Earth Explanation
Even before Coe, Prévot, and their colleagues announced their discoveries, a viable alternative model for both the origin of the geomagnetic field and the rapid field polarity reversals that fits all the data had been proposed and published. Back as early as 1973 young-earth creationist Thomas Barnes had proposed a model for the generation of the earth’s magnetic field by freely-decaying electric currents in the earth’s core.10 Subsequently, Russ Humphreys built on that model,11 and then used it to explain the paleomagnetic evidence recorded in the basalt lava flows in the sea floor of geomagnetic field polarity reversals having happened rapidly during the Flood and its aftermath (see Figure 2).12
Humphreys was able to demonstrate that during the upheaval of the Flood the flow of the molten iron in convection cells in the outer core carrying the freely-decaying electric currents meant that the resultant geomagnetic field generated would have rapidly changed direction and reversed its polarity because of that fluid movement.13 On the sea floor at the earth’s surface new basalt lava flows were erupting rapidly due to the rifting apart of the old pre-Flood ocean floor and mantle plumes in mantle convection cells rising as a result of the catastrophic plate tectonics during the Flood.14 Each new basalt lava flow recorded the polarity direction of the geomagnetic field at the time it cooled. So due to the geomagnetic field reversing rapidly, and the basalt lava flows being erupted rapidly, the result was that these geomagnetic field polarity reversals were recorded in these sea floor basalts, both laterally and vertically. This paleomagnetic “striping” within the sea floor basalts was one of the key pieces of evidence that convinced geologists that the sea floor plates had spread, pushing the continental plates with them, albeit at a drift pace within their uniformitarian paradigm.
However, Humphreys was able to demonstrate that because the paleomagnetic recordings of the polarity reversals were often in patches within the basalt sea floor and even within individual basalt flows, the reversals having occurred rapidly within days was a better explanation. The catastrophic plate tectonics model for the geology of the Flood thus provided a better context to explain the geomagnetic field polarity reversals. Thus Humphreys had even predicted that evidence of rapid reversals would be found before Coe, Prévot and their colleagues announced their discoveries, which of course then provided confirmation of both the Humphreys geomagnetic field model and the catastrophic plate tectonics model of the Flood.
How much more data then did Coe, Prévot and their colleagues need to generate before the geophysical community was prepared to abandon its failed geodynamo theory? More work continued at Steens Mountain, with other investigators finding additional evidence to support the original findings that the earth magnetic field had reversed its polarity rapidly in the past within days to a week or two.15 Coe also had other investigators work with him at other nearby sites to correlate the sequence of basalt flows and paleomagnetic findings at those sites with the sequence of lava flows that outcrop on Steens Mountain with their reported paleomagnetic record.16 They thus claimed in their 2011 paper to have provided “the most detailed account of a magnetic field reversal yet observed in volcanic rocks (with) forty-five new distinguishable transitional (T) directions together with 30 earlier ones reveal(ing) a much more complex and detailed record…”. They also stated that the additional data “confirms most parts of the earlier record but also reveals a more complex reversal history.”
However, it would seem that Coe has been under enormous pressure to somehow recant his previous findings with some new way to explain away the previous impeccable evidence he had championed. That this has been the case is evident from a paper he had published in 2014 in which he states it “is important to set the record straight”, citing “the Steens rapid-field-hypothesis . . . was misinterpreted by creationists in their attempts to reconcile the geological and biblical time scales (e.g. Humphreys, 1990).”17
In this 2014 paper, Coe used a new batch of samples from the basalt flow at Steens Mountain which straddled the first geomagnetic field directional gap and which in his 1989 paper he had announced their laboratory measurements had shown that within that single basalt lava flow the geomagnetic field had shifted by about 3° per day during the few days it took that basalt lava flow to cool. In processing these new samples in his laboratory, Coe abandoned using the step-heating technique which he had used previously to measure the paleomagnetism in the basalt lava low samples, instead using a relatively new technique which is not as well-known and as thoroughly tested. He also abandoned the alternating-field demagnetization procedure, which is not quite as reliable but still widely used.
The step-heating technique is very well-tested and has been relied on in paleomagnetic studies since the 1940s. In this technique a sample’s loss of magnetization is measured as it is heated up slowly through a series of small temperature steps. Instead, he used a relatively new technique in which the basalt samples were continuously and rapidly heated at 40 degrees Celsius (72 degrees Fahrenheit) per minute, measuring the demagnetization continuously. Coe also invented a new scenario called “thermal alteration”, in which the slow reheating of a basalt flow, as in the step-heating technique, supposedly altered its paleomagnetic record. However, this scenario is questionable, as heating basalt to temperatures below its Curie temperature of about 500°C, which is well below its melting point, should not affect the paleomagnetism it has recorded. Instead, this new rapid-heating technique is supposed to give less time for thermal alteration to occur.
Thus the results using this new rapid-heating technique, Coe and his new collaborators now claim in this 2014 paper, call into question the earlier results from his 1989 paper, which showed a steady change of the geomagnetic field direction, by about 60 degrees, for samples going deeper and deeper into the interior of this basalt lava flow which straddled the first geomagnetic field directional gap in the sequence of basalt lava flows at Steens Mountain. However, if the new technique is right, then it would call into question nearly 75 years’ worth of paleomagnetic conclusions in hundreds of other studies all based on the well-tested step-heating technique.
In the normal step-heating technique, the experimenter waits for several minutes at each temperature for the basalt sample to get demagnetized before further heating the sample up through the next temperature increment. This puts the experimental emphasis on the larger magnetic grains in the basalt sample (grains of the iron oxide mineral called magnetite) because they are slower to change their magnetization at high temperatures, and because they are unlikely to change their magnetization after the basalt lava cooled after it erupted and flowed. However, in the rapid continuous-heating technique the magnetite grains have only a few seconds to change their magnetization at each temperature. That tends to put the experimental emphasis on smaller magnetite grains that can change magnetization more easily. Therefore those smaller grains are more likely to have been re-magnetized by the recent thousands of years in which the earth’s magnetic field has had normal polarity after these basalt lava flows cooled.
Thus the old step-heating technique primarily tested the magnetization of the more robust, magnetically “stable” set of larger magnetite grains in the basalt, but this new continuous rapid-heating technique primarily tested the magnetically “unstable” smaller magnetite grains. The results produced by the old well-tested technique are thus not influenced much by the smaller, magnetically “unstable” grains, so that technique should be a much more reliable way of determining the earth’s past magnetic field while the basalt was cooling down below its Curie temperature, about 500°C. If secular paleomagnetic experts were not so eager to join Coe in discarding his earlier results from this basalt lava flow because of the time implications, then they would not be so eager to trust this new experimental technique. Yet Coe and his collaborators still admitted at the end of their 2014 paper that “the question (of) whether or not brief episodes of field change much faster than current secular variation have occurred is very much alive and debated.”
A New Independent Study
This “story” doesn’t end there. The results of a new independent study, in which different samples from a totally different geologic and geographic situation were used, have since been published.18 And what is especially helpful, this new study did not use basalt lava flows samples, so the possibility of thermal alteration of them is not an issue.
In this study, the researchers investigated the sediment layers that were deposited on the floor of what was once a small lake in the Apennines of Italy. This small lake existed during the Ice Age of the so-called Pleistocene, which within the biblical chronology we would all agree was post-Flood. The lake filled with layers of whitish, faintly laminated to massive calcareous muds, interspersed with numerous tephra (volcanic ash) layers resulting from nearby volcanic eruptions. Today what remains is a small sedimentary basin called the Sulmona Basin, and the continuous sequence of mud and tephra layers in three main unconformity-bounded alluvial-fluvial-lacustrine units are now well exposed in outcrop (see Figure 3).
In a previous paleomagnetic investigation this research team had drilled to a depth of 65 meters (213 feet) through the former lake’s strata sequence and had constrained the location of the so-called Matuyama-Brunhes geomagnetic polarity reversal to being within the oldest and lowermost unit. Within the recovered core they identified at least ten tephra layers that could be correlated by being continuously traced laterally to those recognized in the surrounding outcrops of the Sulmona sequence. So in this study they located the same stratigraphic interval cropping out about 500 meters (1640 feet) to the southeast of their previous drill-hole site and carefully sampled the correlated 3 meter (10 feet) section of interest with 46 contiguous hand samples each spanning 6–16 cm (15–41 inches) of stratigraphic thickness.
In the laboratory at least one sample per layer had its magnetic susceptibility and natural remnant magnetization (NRM) measured. For 36 samples, distributed throughout the section, they also carried out a stepwise thermal demagnetization, in 10–11 steps up to 450°C. They also did careful measurements of the variation of magnetic susceptibility in heating-cooling cycles in order to identify the Curie temperatures of the main magnetic minerals in the samples, and to check the possible occurrence of significant alteration during heating.
Pristine sanidine (K-feldspar) crystals were handpicked under a binocular microscope from the three tephra layers within and spanning the 3 meter (10 feet) stratigraphic section being investigated. A total of 124 crystals were submitted for argon-argon (Ar-Ar) dating at two laboratories. Both laboratories used the sanidine standard from the Alder Creek Rhyolite as the neutron fluence monitor. Rather than absolute ages, the reported ages were calculated relative to the age of the Alder Creek sanidine standard because the objective was to provide a determination of the time intervals spanning the stratigraphic section and the measured paleomagnetic properties of the samples within it.
This research team found that these Sulmona lake calcareous mud sediments in the 3 meter (10 feet) stratigraphic section they so carefully investigated are characterized by excellent paleomagnetic properties, which allowed the reconstruction of the Matuyama-Brunhes geomagnetic polarity transition in very fine detail. The strong correlation and consistency between the rock magnetic and paleomagnetic stratigraphic trends between this stratigraphic section and the original drill-hole core demonstrated the lateral continuity of the experimental results and the reliability of the paleomagnetic signal for their high-resolution geomagnetic reconstruction. They also found that their data were consistent with magnetite (Fe3O4) being the main carrier of the magnetic remanence and indicated that the concentration of magnetic minerals is generally uniform throughout the investigated sequence.
They found that the 180° polarity flip (reversal) associated with the Matuyama-Brunhes geomagnetic polarity transition occurred sharply in a 2 cm (0.8 inch) sub-layer cut from the same hand sample block between two adjoining levels, at 152 cm (59.8 inches) and 154 cm (60.6 inches) of stratigraphic depth respectively. And it was recorded consistently between seven independent sub-samples via both series of paleomagnetic measurements.
Next, the high precision Ar-Ar dates obtained on the three tephra layers spanning this stratigraphic interval in which this geomagnetic polarity reversal was recorded and preserved were used to provide tight chronological constraints on this Sulmona sequence of calcareous mud and tephra layers. Assuming the Ar-Ar ages are correct, they calculated an average sedimentation rate for the calcareous mud layers of about 21 cm (8.3 inches) per thousand years, or about 2 mm (0.08 inch) per year. Thus at that rate of deposition, this implies the 2 cm (0.8 inch) sub-layer that recorded the Matuyama-Brunhes geomagnetic polarity reversal accumulated in about 100 years, and therefore the geomagnetic field reversal transition occurred in less than 100 years, which is still extremely fast compared to the usually assumed transition times of hundreds of thousands of years to millions of years (see Figure 4).
However, this conclusion assumes the rate of radioactive decay of 40K, the basis of the Ar-Ar dating method, has remained constant in the past at the slow decay rate measured today. Yet there are several lines of good evidence that radioactive decay rates were accelerated during past catastrophic events, especially during the Flood year when geological processes were also operating at catastrophic rates.19 Then at the close of the Flood it is logical to envisage that the tempo of geological processes did not slow abruptly, but tapered off, and this is borne out by the abundant evidence of localized superstorms and catastrophic flooding resulting in localized sedimentary deposits in the decades before the post-Flood Ice Age gripped the planet.20 Thus it would be expected that deceleration of the radioactive decay rates also occurred during the same period and on into the post-Flood Ice Age, and the evidence of “inflated” radioactive ages for post-Flood rocks is consistent with that logical expectation.
Therefore, if accelerated radioactive decay was still decelerating, and the rates were still significantly faster than today’s measured slow rates, in the period after the Flood and continuing on into the post-Flood Ice Age, then the sediment deposition rate in the Sulmona Basin, Italy, as determined by the Ar-Ar dating of the interspersed tephra layers (albeit with 40K radioactive decay still more rapid than today’s measured slow rate), could easily have been more like 4 cm (1.6 inches) per year, a quite reasonable rate during the several centuries long, stormy Ice Age. That would reduce the geomagnetic field polarity transition time to just a few months. Such a rapid polarity reversal rate compares quite well with the evidence for fast reversals that were still occurring in the last stages of the Flood. It also supports the general picture we have of many fast reversals during the Flood itself. This all collapses the so-called paleomagnetic time scale down from millions of years to just months.
For many years studies of the paleomagnetism recorded in basalt lava flows on Steens Mountain in southern Oregon had provided impeccable evidence that reversals of the geomagnetic field polarity had in the past occurred extraordinarily rapidly, in a matter of only days to weeks. This has been a severe embarrassment to the conventional geoscience community because such a rapid rate for geomagnetic field polarity reversals is totally inconsistent with their preferred millions-of-years geodynamo model for the generation of the earth’s magnetic field. Their embarrassment was intensely heightened by young-earth creation scientists being able to use this evidence at Steens Mountain to support their young-earth freely-decaying electric currents model for the generation of the earth’s magnetic field and rapid polarity reversals during the Flood and its aftermath. This explains Coe’s recent efforts to use the results of a new untried rapid-heating technique to re-measure the paleomagnetism stored in those Steens Mountain basalt lava flows in order to “reinterpret” and overturn his earlier evidence of the extraordinarily rapid geomagnetic field polarity reversals. However, the original results using the long-established step-heating measurement technique are not so easily overturned and disregarded.
Instead, a totally independent study by a different research team in a different location and geologic setting has found unmistakably clear further evidence supporting past rapid polarity reversals of the earth’s magnetic field. In the muddy sediment layers of a former post-Flood Ice Age lake they have found the indisputable record that the so-called Matuyama-Brunhes geomagnetic polarity transition occurred rapidly. They used high precision Ar-Ar dating of sanidine crystals from volcanic ash (tephra) layers between the mud layers to constrain the timeframe of sedimentation and therefore the polarity reversal recorded in one thin mud layer to just 100 years or less. However, when the evidence for grossly accelerated radioactive decay rates during the Flood and their deceleration through the post-Flood Ice Age are factored into the Ar-Ar dating, the rates of both the sedimentation of the thin mud layer and the geomagnetic field polarity reversal recorded in it reduce to just a few months. This is thus consistent with the Steens Mountain evidence of extraordinarily rapid geomagnetic field polarity reversals, which are only consistent with the young-earth creationist model for the generation and rapid reversals of the earth’s magnetic field during the Flood and its aftermath.
The majority of geoscientists believe the earth is billions of years old, and so they have been striving for nearly a century to develop a successful “dynamo” model to explain how the earth’s magnetic field might maintain itself over that long time. After reviewing analytical theories, computer simulations, and laboratory experiments, young-earth creation scientist Humphreys has concluded that all those efforts have fallen short of proving the geomagnetic field could be maintained by a dynamo.21 In contrast with this apparent failure, Humphreys has demonstrated with the remarkable success how his creationist model for the origin and operation of the geomagnetic field explains the magnetic fields of other bodies in our solar system, especially for the planet Mercury, a model consistent with the young biblical age of the earth and the universe of only about 6,000 years.