Potential Evidence for The Great Oxidation Event

What’s the connection between fool’s gold and the bottom of the sea? University of Alberta’s Kurt Konhauser and colleagues have found a dramatic increase in chromium concentrations above the Archaean-Paleoproterozoic boundary. They attribute this increase to a chain of geochemical and biological events ultimately requiring aerobic bacteria to have evolved 2.48 to 2.32 billion years ago, 100 million years earlier than previously thought.1

Chromium does not easily dissolve, and the investigators say a very low pH was required to leach chromium from land. They assume all chromium found in oceanic sediments came from terrestrial run-off.2 The only mechanism by which the early earth could achieve a sufficiently acidic environment to dissolve chromium, they say, depends on the oxidation of iron pyrite by aerobic chemolithoautotrophic bacteria.

Konhauser explains, “The jump in chromium levels was triggered by the oxidation of the mineral pyrite (fool's gold) on land.”

Konhauser explains, “The jump in chromium levels was triggered by the oxidation of the mineral pyrite (fool's gold) on land. Aerobic bacteria broke down the pyrite, which released acid that dissolved rocks and soils into a cocktail of metals, including chromium. The minerals were then carried to the oceans by the run-off of rain water. Our examination of the ancient seabed data shows the chromium levels increased significantly 2.48 billion years ago. This gives us a new date for the Great Oxidation Event, the time when the atmosphere first had oxygen.”3

The mineral-eating bacteria require oxygen to live. Therefore, the investigators are certain that primitive oxygen-producing cyanobacteria had already evolved and filled the earth with oxygen by the time the high-chromium layers were deposited.

Co-investigator Mark Barley explains, “We live in a unique environment and Earth is the only planet we know that has an oxygen-rich atmosphere . . . vital for complex life. But the Earth's early atmosphere was oxygen-poor in the Archaean prior to the Great Oxidation Event, which happened between 2.5 and 2.3 billion years ago, so it's vital that we understand how oxygen rose. . . . We think we've resolved a major debate about when the bacteria that produced oxygen existed and how long it took for oxygen levels to rise enough to support growth of life.”

Barley further explains that there is no undisputed microfossil evidence of cyanobacteria in rock before the 2.3–2.5 billion year mark. However, he’s certain they must have evolved by 2.7 billion years ago to produce the oxygen required by the pyrite-eating bacteria.

The investigators see this method as a circuitous way to track the early “rise of atmospheric oxygen.”4 They write, “The evolution and activity of microbes is intimately linked with the redox evolution of the Earth’s surface, but as demonstrated here, sometimes in unexpected ways.”5

Writing that when Paleoproterozoic layers were deposited, “Cr was solubilized at a scale unrivalled in history,”6 the investigators are noting some sort of dramatic change happened at that time. There are many assumptions underlying their interpretation of the data. They accept the extreme age of these deep rock layers derived from radiometric dating based on unverifiable assumptions.7

They also assume the early earth was anoxic because biochemical building blocks of life could not form while exposed to oxygen. (See “The First Atmosphere—Geological Evidences and Their Implications” for information about this anoxic notion.) Yet in order for life to then evolve, they must assume that photosynthetic bacteria (cyanobacteria) evolved and produced an oxygen supply to support life.

In addition to making these untestable assumptions, the investigators ignore some data.

In addition to making these untestable assumptions, the investigators ignore some data. They discount data from rocks near Greenland wherein high chromium content was found in the deeper rock layers dated at 3.7–3.8 billion years. They assume there was contamination by detritus from the land because they cannot imagine how oxygen-producing bacteria could have evolved so very early, so close to the time evolutionists postulate asteroids bombarded the earth and boiled away whatever oxygen might have been around. They also ignore data in which high chromium concentrations are found in deep layers (2.7–2.8 billion years) near undersea volcanic chains, assuming volcanic activity supplied the chromium. They ignore whatever data violates their presuppositions about the timing of events on the early earth.

The Archaean rock layers are believed by many creationist geologists to have been formed early in the Creation week and the Paleoproterozoic about mid-week. Though we cannot be dogmatic about the exact correlation of these layers with the days of Creation week, the absence of fossils in them (other than microfossils in the Paleoproterozoic layers) is consistent with pre-Flood deposition. Explaining a change in mineral composition of succeeding layers does not require evolution of an oxygen-producing life form to supply an oxygen-requiring mineral-crunching life-form that digests enough rock to wash chromium into the sea.

When we consider the dynamic changes taking place as God created the earth and its atmosphere during the first two days of Creation week and dry land (and plants) on the third, a redistribution of the minerals and chemicals within these materials makes sense. Within the biblical creation framework, a “jump in chromium levels” in a particular layer would merely be a consequence of this redistribution. Volcanic material and detritus, for instance, such as that the investigators thought invalidated some of their samples, could have supplied the chromium in the layers they focused on. The Archaean-Paleoproterozoic layers are not a timeline of events occurring billions of years ago, but rather a snapshot of events occurring primarily during Creation Week about 6,000 years ago.

Furthermore, the Bible tells us that God created the early earth as a paradise for the life forms He put on it, especially Adam and Eve. The Great Oxidation Event was not a gradual filling of an otherwise poisonous atmosphere with oxygen by cyanobacteria, but rather the rapid production of an atmosphere able to sustain life in response to God’s words, “Let there be . . . .” Read more about the biblical interpretation of the rock layers, both those laid down in Creation Week and later during the Flood, in Dr. Andrew Snelling’s book Earth’s Catastrophic Past.