This article is from
Creation 43(1):36–39, January 2021

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Chalk challenges deep-time dogma

by Gavin Cox

The iconic White Cliffs of Dover of England’s south coast are one of the most recognizable landmarks of the British Isles. They are a spectacular sight when they gleam pristine white on a brilliant summer’s day.

Overlooking the English Channel, they stretch 16 km (10 miles) either side of the port city of Dover, reaching a maximum height of 110 m (360 ft). In France, across the Channel, there are corresponding white cliffs that guard the port city of Calais. The chalk that gives them their whiteness extends between them, under the English Channel. It goes even further, into the North Sea (where it averages over 1,000 m (½ mile) in thickness), and further inland across England and adjoining areas of Northern Ireland and northern Europe. Chalk beds also occur in Israel and in North America (Alabama, Mississippi, Tennessee, Nebraska, and Kansas).¹

What is chalk?

NancePomerene (public domain) Wikimedia Commons

Chalk is a soft, white rock, consisting of 98% calcium carbonate (CaCO₃), which comes from the ‘skeletal’ remains of single-celled algal marine plankton.

The predominant type in the Dover chalk is coccolithophores. These have an external mineral skeleton surrounding them called a coccosphere.

This consists of plates called coccoliths, made of calcite (calcium carbonate)—figure 1. These plates can be shed during life, but also remain after the plankton dies, forming sediment (calcareous ooze) on the ocean floor.

(Below the ‘calcite compensation depth’ of about 5 km (3 miles), individual coccoliths dissolve, so these do not form ooze.)

On today’s ocean floor, bacteria help turn such calcareous ooze into chalk by driving a chemical process that causes interlocking calcite crystals to form.

This process is further aided by the weight of the overlying sediment that squeezes out the water from between the particles.²

Chalk origins

Old-earth geologists say the chalk formed gradually over vast eons. This was supposedly in placid, shallow, warm oceans during the Cretaceous period (Latin creta = chalk).

They imagine the coccoliths settled slowly out of the water and deposited on the sea floor between 145–66 million years ago.

However, there is strong evidence within the chalk deposits consistent with their rapid formation and a biblically youthful age.

Chalk purity—hallmark of catastrophe

See reference 4 in main article

Although chalk may vary in consistency, it does not vary in purity. Thick, worldwide beds of 98% pure calcium carbonate testify that they could not have been deposited over millions of years—otherwise, the chalk would be contaminated with sediments from continental erosion.³

The Cretaceous and the biblical Flood

Secular geologists claim that their Cretaceous period ended with one of Earth’s mass extinction events. They also believe, strikingly, that at one time during this period most of the world was under water! Geological maps of Upper Cretaceous chalk demonstrate the supposed extent to which the oceans covered the continents. This is known as a ‘marine transgression’ (figure 2).⁴

Creationist geologists have connected this period to before the middle of Noah’s Flood about 4,500 years ago. In particular, around day 120, before the floodwaters peaked on day 150.⁵ Genesis 7:23 says God “blotted out every living thing that was on the face of the ground, man and animals and creeping things and birds of the heavens … Only Noah was left, and those who were with him in the ark.” The Flood—to which we will see the chalk testifies—really was a global-level extinction event.

Chalk data debunks deep-time dogma

Secular scientists have recently suggested that all the calcium carbonate for Dover’s white cliffs came from giant ‘blooms’ of coccolithophore algae.⁶ Such blooms form yearly in the Southern (Antarctic) Ocean in the ‘Great Calcite Belt’. This is an area of warmer water in which the algae grow explosively. The blooms cover a staggering 52 million km² (32 million sq. mi). They are even visible from space (figure 5, p. 39), because the sea appears brighter due to sunlight reflecting from the calcite plates.⁷ The mass blooming seems to be from large quantities of nitrate, iron and other nutrients upwelling to the surface as different water masses converge.

On the ocean bottom beneath this yearly algal bloom is a layer of calcite-rich sediment (calcareous ooze) around 500 m (1,600 ft) thick.⁸ Deposition rates for coccolithophore oozes are supposed to be very slow. In fact, lab observations have caused researchers to question how coccoliths could ever settle.⁹ The rates for ooze formation are typically given in figures of cm/1,000 years.

Long-agers have used this to maintain that chalk can only form very slowly, seemingly contradicting Genesis history.

Importantly, these figures are not from counting sinking coccoliths. They are based on radiometric dating from drill cores,¹⁰ so they completely depend upon assumptions about the unobserved past.

However, recent studies have shown how coccoliths reach the ocean bottom quickly. The section below explains four different mechanisms for this—even present-day rates are much faster than previously thought.

Long-agers claim that 500 metres of calcareous ooze on the Southern Ocean floor could not build up in only 4,500 years. However, this only requires an average deposition rate of about 11 cm/year (4 inches), a perfectly reasonable figure.

Noah’s Flood accounts for chalk!

However, the position of most chalk in the geological record indicates it is a Flood rock, formed as the floodwaters were rising towards their peak levels.¹¹ To explain the huge quantities of chalk laid down over this much shorter period requires far more catastrophic processes.

(After Hüneke H. and Mulder)⁹ from page 222.

Psalm 104:6–8 states:

“ … the waters stood above the mountains. At your rebuke they fled … . The mountains rose, the valleys sank down to the place that you appointed for them.”

Clearly the Flood was a tectonic event, catastrophically moving the earth’s crust and radically altering its horizontal and vertical topography. This provides the perfect conditions for the formation of chalk. Fast-moving warm water, with vast quantities of suspended biological material, would have triggered an explosive worldwide growth of algal blooms.

All mechanisms for rapid coccolith sinking (see below) would have been amplified to a huge extent during the Flood. Because the availability of algal food was greatly increased, grazing plankton would massively proliferate. And they would excrete their coccoliths in the form of fast-sinking fecal pellets (figure 3). Genesis 8:3 describes how, after the Flood’s first 150 days, the waters receded off the land continually for more than 7 months. This, and the wind God sent (Genesis 8:1) would have greatly enhanced water velocities both at the ocean surface and at depth. This, in turn, would cause the small particles to clump together (flocculate), and direct ocean currents downward. This would cause the coccolith matter to settle catastrophically, likely in days.

Flood currents would have swept this calcareous material into deeper areas on the ocean floor, which geologists call ‘basins’. In some places like the North Sea and northwest Europe, the chalk has accumulated to a thickness of 1,000 m (3,000 ft) or more.

Summary

The inadequate processes available to secular long-age philosophy are swept aside when we factor the biblical Flood into our thinking. Many characteristics of chalk, such as its consistent purity, are a puzzle to explain from a long-age perspective. However, chalk formation is not a challenge to the biblical timescale. Modern insights into how coccoliths settle and become chalk show that it is more than reasonable to have chalk form in a short time.

Therefore, millions of years are not needed. Once again, real geology is consistent with Noah’s Flood.

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