Diamond data testifies to tectonic history—or does it?
Radiometric dating data on diamond impurities have been analyzed to shed light on the tectonic history which shaped the earth’s crust. The analysis of over 4,000 diamond inclusions, data collected over the past 25 years, is being interpreted to pinpoint the time when plate tectonics started.
Diamond formation requires certain conditions of temperature and pressure. The largest diamonds are formed below cratons (the stable ancient cores of the continents) in the upper mantle or in the cratons themselves at a depth of “more than 125 miles (200 km) where pressures are sufficiently high, but temperatures sufficiently low.” The diamond-hosting kimberlite and lamproite magmas must then be rapidly extruded to the surface in the pipe-like structures found in diamond mines.
Because diamonds are so hard, they protect any impurities they contain from contamination. Diamond inclusions are therefore considered by many geologists to be “unaltered, ancient minerals that can tell the story of Earth’s distant past.” That past includes the breakup of the earth’s crust that gave rise to the continents we see today.
“The Wilson cycle is responsible for the growth of the Earth’s continental crust, and the continental structures we see today.”
“The Wilson cycle is responsible for the growth of the Earth’s continental crust, the continental structures we see today, the opening and closing of ocean basins through time, mountain building, and the distribution of ores and other materials in the crust. But when it all began has remained elusive until now,” explains Carnegie Institute’s Steven Shirey.
“We used the impurities, or inclusions, contained in diamonds, because they are perfect time capsules from great depth beneath the continents. They provide age and chemical information for a span of more than 3.5 billion years that includes the evolution of the atmosphere, the growth of the continental crust, and the beginning of plate tectonics.”
Examining radiometric data for two kinds of inclusions, peridotites and eclogites, the researchers found “that before 3.2 billion years ago, only diamonds with peridotitic compositions formed—whereas subsequent to 3 billion years ago, eclogitic diamonds dominated.”
Peridotite minerals are typically found in basalt lavas and therefore are associated with magma that has cooled. Eclogite, on the other hand, is a metamorphic rock formed when cooled and crystallized basalt magma is subsequently plunged back down into the mantle. The researchers therefore concluded that the younger eclogite marks the time of “the initial subduction of one tectonic plate under the deep mantle keel of another as continents began to collide on a scale similar to that of the supercontinent cycle today.” They therefore mark 3 billion years ago as the beginning of plate tectonics.
Regular readers of this column know we want them to review the unprovable assumptions on which the radiometric dating methods are based. But with diamonds in view, the testimony of radiometric inconsistencies and the problems with uniformitarian assumptions comes into sharp focus.
First of all, geologists who accept radiometric dating methods assert that diamonds formed 1 to 3.5 billion years ago. Carbon-14, because of its half-life, should not be detectable after 95,000 years at most. Yet carbon-14 is routinely detected in diamonds, yielding conventional ages of 55,000–60,000 years (uncorrected for assumptions about past radiocarbon production rates) and just 5,000 years when corrected. So how can three-billion-year-old inclusions be encased in diamonds which must have formed within the past 5,000 years? At least one of those dates must be wrong.
Furthermore, geologists agree that the volcanic rocks containing diamonds must have made a rapid ascent through the hot mantle to preserve the diamonds. A slow ascent, such as would occur during billions of years of uniformitarian geology, would cause the diamonds to deteriorate into graphite. Catastrophic geologic change was required to transport the diamonds formed in the heart of the earth safely to the diamond mines where we find them.
Now when in history do we find catastrophic geologic change? How about at the time of the global Flood? The Bible tells us that “the fountains of the great deep were broken up
” (Genesis 7:11) as the Flood began. These catastrophic upheavals would have provided a way to bring diamond-containing material up rapidly from the depths of the earth.
The Flood geology model also explains the current research finding that some diamond inclusions are the type found in recrystallized magma, whereas others are the type of mineral produced when subduction of tectonic plates plunges crust back down into the earth’s hot mantle. If the plate tectonics which break and move the earth’s crust began their violent history at the time of the global Flood, then the diamonds containing peridotite probably formed before that time, whereas the diamonds containing eclogite likely formed after subduction began. Thus, within the Flood geology model, the two different times of diamond formation make sense. And the Flood geology model further explains from the Bible why the tectonic action started in the first place.
Remember, if you see a news story that might merit some attention, let us know about it! (Note: if the story originates from the Associated Press, FOX News, MSNBC, the New York Times, or another major national media outlet, we will most likely have already heard about it.) And thanks to all of our readers who have submitted great news tips to us. If you didn’t catch all the latest News to Know, why not take a look to see what you’ve missed?
(Please note that links will take you directly to the source. Answers in Genesis is not responsible for content on the websites to which we refer. For more information, please see our Privacy Policy.)
Answers in Genesis is an apologetics ministry, dedicated to helping Christians defend their faith and proclaim the good news of Jesus Christ.