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Creation 43(1):36–39, January 2021

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Chalk challenges deep-time dogma



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 Commonsfig-1-coccolithophore
Figure 1. Scanning electron microscopic image of the marine planktonic coccolithophore species Calcidiscus (or Cyclococcolithus) leptoporus. Seen here is the coccosphere ‘skeleton’ (c. 0.03 mm or 1/1000th inch in diameter) surrounding its single cell. This is made up of calcite plates called coccoliths.

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 articlefig-2-british-oceans-cretaceous-2
Figure 2. Extent of oceans secular geologists say covered Britain during the Cretaceous (after Matthews, 2013). Geological maps are ‘conservative’ in their presentation of the data, allowing that the remaining islands of land were also likely submerged at some stage.

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.fig-3-coccoliths-sink-2
Figure 3. Within fecal pellets, coccoliths sink dramatically faster, and reach the floor of even the deepest oceans.

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.

Fast coccolith deposition

Major present-day factors

  1. Zooplankton digesting coccolithophores

    Multicellular plankton species and jellyfish graze on the single-celled coccolithophore plankton, digesting them to produce coccolith-containing fecal pellets. These are large enough to quickly sink to the ocean floor by gravity (figure 3). This process can transport the coccoliths past the calcite compensation depth of 5 km. Sinking-rate estimates for individual coccoliths are ≤ 0.15 metres/day, but are 160 m/day in a fecal pellet—over 1,000 times faster!1

  2. Ekman spiral currents
    Wikipedia Commonsfig-4-ekman-spiral-effect-2
    Figure 4. Ekman spiral effect (1. Wind; 2. force from above; 3. Effective direction of ocean current; 4. Coriolis effect, caused by the earth’s rotation.)

    Sinking rates are further enhanced by increased water velocity driven by surface winds. It is now known that surface wind velocity can cause a structure known as an Ekman spiral consisting of sinking, spiralling currents (figure 4). This produces downward water velocities up to 1 m/s that have strong impacts on deep sea environments, to depths of thousands of metres.2

Factors operating especially during the biblical Flood

  1. Flocculation

    Chalk coccoliths have a fine covering of smectite, a type of clay mineral. Smectite is a hydrothermal product (from the action of hot water, generally in a volcanic setting), likely injected into the ocean by the fountains of the Great Deep (Genesis 7:11). Interestingly, smectite makes coccoliths settle out of suspension quickly.3 Industrial water treatment involves a process called flocculation, using clays (bentonite, containing primarily smectite). These cause contaminating particles (like lime) to instantly come out of suspension, clump together and sink.4,5 Flocculation would greatly enhance the settling of coccoliths during the Flood.

  2. Fast currents

    Uniformitarian geologists have long claimed that, like coccoliths, mud particles took a very long time to settle under tranquil conditions. During periods of turbulence, they would be kept in suspension. However, experiments in glass-sided flumes have shown these long-age ideas of mudstone formation to be false. At high water velocity very fine mud particles will flocculate and come out of suspension instantaneously to form laminated sediments.6 Sedimentologists have admitted that “mudstone science is poised for a paradigm shift” (a radical change in thinking).7 This effect of fast water movements is clearly relevant to the speed of coccolith sediment formation, too.

    Oceanographic study has demonstrated that ocean waves are not just restricted to the surface. They can also propagate underwater and down the slope of continental shelves to generate high-speed water currents.8 The Flood wind of Genesis 8:1 would also play a major role in increasing current velocities (see point 2 above).

References and notes

  1. Hüneke, ref. 9, main text, p. 222.
  2. Hüneke, ref. 9, main text, p. 153. The Ekman spiral contributes to the Ekman pump, or downwelling force, and to Ekman transport including Ekman suction.
  3. Matthews, ref. 8 main text, p. 36.
  4. Abdelaal, A.M., Using a natural coagulant for treating wastewater, Eighth International Water Technology Conference, IWTC8, Alexandria, Egypt, pp. 781–792, 2004.
  5. This video shows the process in real time: Wastewater Treatment using Bentonite Clay Flocculant; youtube.com/watch?v=L2UuG6WgOQw, 5 Feb 2013.
  6. Walker, T., Mud experiments overturn long-held geological beliefs, creation.com, 9 Jan 2008.
  7. Macquaker, J.H.S. and Bohacs, K.M., On the accumulation of mud, Science 318(5857):1734–1735, 2007, cited in Walker, ref. 6.
  8. Oard, M.J., Internal oceanic waves and sedimentation, J. Creation 27(1):16–18, 2013.


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.

Posted on homepage: 7 March 2022

References and notes

  1. Snelling, A.A., Can Flood geology explain thick chalk beds? J. Creation 8(1):11–15, 1994; chalk in Nebraska and Kansas is predominantly made up of foraminifera shells. Return to text.
  2. van der Molen, A.S., Sedimentary development, seismic stratigraphy and burial compaction of the Chalk Group in the Netherlands North Sea area, Utrecht University, Ultrecht, pp. 14–15, 2004. Return to text.
  3. Snelling, ref. 1, p. 4. Return to text.
  4. Matthews, J.D., Why was the UK once totally under water? J. Creation 27(1):107–113, 2013. Return to text.
  5. Most dinosaur tracks in the western US show that much sediment was overlaid, which was subsequently eroded during the Recessional Stage of the Flood. Return to text.
  6. American Geophysical Union press release, Giant algal bloom sheds light on formation of White Cliffs of Dover; news.agu.org, 15 Sep 2016. Return to text.
  7. Balch, W.M. et al., Factors regulating the Great Calcite Belt in the Southern Ocean and its biogeochemical significance, Global Biogeochem. Cycles, 30:1124–1144, 2016. Return to text.
  8. See ngdc.noaa.gov/mgg/sedthick/data/version3/fig_2_new_press.png. Return to text.
  9. Matthews, J.D., Chalk and ‘Upper Cretaceous’ Deposits are Part of the Noachian Flood, Answers Research Journal 2:29–51, 2009. Return to text.
  10. Hüneke H. and Mulder, T., Developments in Sedimentology 63, Elsevier, Oxford, 2011. Refers to oxygen-isotope and K/Ar dating methods on pp. 2 and 795. Return to text.
  11. See Tas Walker’s biblical geological modelReturn to text

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