The phosphate deposits on Nauru, western Pacific Ocean

Explained by biblical history

wikimedia.org nauru-satellite
Satellite image of Nauru, 2002. Length (NE–SW) about 6 km. Numerous phosphate mines are visible in the interior.

Today’s feedback is from G.S. from Australia who said:

I have just been challenged by an atheist/evolutionist who claims that the large phosphate deposits in places like Nauru could not have come about in thousands of years—but only in millions of years. Are you aware of any articles or information which might be relevant?

CMI geologist responded:

Dear G.S.,

When faced with such a question, I first check the creation databases. “Creation evolution literature database” is a good one, and may be found by Googling “celd database” However, I did not find anything about phosphate deposits there.

Next I search using Google, and in this case I found much about the deposits on Nauru using keywords “origin phosphate deposits nauru”, including a comprehensive book published by Cambridge University Press about phosphate deposits of the world.1

The Nauru phosphate deposit amounts to some 90 million tonnes consisting of two units draped over a thick carbonate deposit, the surface of which has been dolomitized (chemically altered by replacing calcium with magnesium) and eaten away forming an irregular surface called a karrenfeld.2 Figure 1 shows the irregular surface of the carbonate deposit, with abundant ‘pillars’ and grooves. Piper et al. report the pillars, or pinnacles, can be 3–5 metres high. In figure 1, the phosphate has been mined from above and between the pillars, leaving exposed the irregular surface of the carbonate deposit.3

Piper et al. discuss ideas about the origin of the phosphate deposit, reporting that early investigators said it was due to bird droppings. However, to be able to produce this much phosphate from bird droppings in the 4,500 years since the Flood seems unreasonable, which suggests there is likely another explanation.

Guilbert and Park in their book The Geology of Ore Deposits4 report that 76% of the world’s phosphates are regarded to have formed by chemical precipitation on the continental shelves. 23% of global phosphate deposits are derived from igneous rock sources, including carbonatite (a rock formed from molten carbonate).

FauzInfoVids nauru-phosphate-crop2
Figure 1. Irregular surface of the carbonate platform after the phosphate has been mined (ref. 3)

The remaining 1% is said to come from bird droppings, or guano. Phosphate from Nauru, which is one of the main components of the 1%, is attributed to this source. The idea is that bird droppings are rich in phosphates, which are inherited from coastal marine food sources.

That most phosphate deposits are derived from chemical precipitates and igneous sources suggests that much of the remaining 1% may have been wrongly attributed to bird droppings. It is more likely that these deposits on the Pacific Islands were formed in the same way as the other marine phosphate deposits.

The standard explanation for these is that the phosphate formed in a shallow marine environment as water circulation from deep to shallow caused the precipitation of calcium phosphate, forming thick deposits. The suggested mechanism is related to the different solubility of phosphate in water of different temperature.4 This model is based on uniformitarian thinking, which restricts its explanations to modern environments, and which does not recognize that Noah’s Flood occurred.

However, once we consider the effects of Flood we discover many more possibilities to explain the situation. The Flood would have greatly impacted oceanic conditions—temperatures, sea levels, water currents, chemical composition, etc. Towards the end of the Flood as the floodwaters receded from the continents, the movements of the crust and the high concentration of dissolved phosphates would provide conditions that would allow its precipitation. Water circulation and differential solubility likely would also have been significant. Late-Flood conditions would also explain the chemical alteration of the carbonate that produced the irregular karrenfeld surface.

At this time there is likely to have been acidic conditions that would have accelerated the formation of the karst topography by dissolving the bedrock. Acidic reactions may also have produced some hydrothermal alteration products and ore mineralisation, including the phosphate itself.5,6,7

So, although little that has been written about Nauru phosphate deposits from a creationist perspective, these brief investigations have led to some interesting conclusions. It has allowed us to understand how the phosphates can be explained from a biblical perspective, as well as suggesting avenues for further study.

If I were talking to your friend I would make points such as these:

The idea that such an enormous deposit was created by bird droppings stretches one’s credibility, even if we grant millions of years for the sake of argument. 99% of the world’s phosphate deposits are considered to have a non-bird origin. 23% are thought to have formed from a molten carbonate (carbonatite). 76% are regarded to have formed by precipitation as sediment on the continental shelves. That should raise suspicions that much of the remaining 1% on the islands of the world has been wrongly attributed to bird deposits. It is more likely that the deposits on the Pacific Islands were formed in a shallow marine environment in the same way as the other marine phosphate deposits. There may be some guano that has been deposited on top of the exposed phosphate rock on the islands in the time since the Flood, but this would be minor compared with the bulk of the deposit.

All the best,

Tas Walker
Geologist, writer, speaker

Published: 12 September 2015

References and notes

  1. Piper, D.Z., Loebner, B., and Aharon, P., Physical and chemical properties of the phosphate deposit on Nauru, western equatorial Pacific Ocean, pp. 177–194; in: Cook, P.J., and Shergold, J.H., (Eds), Phosphate Deposits of the World: Neogene to modern phosphorates, Cambridge University Press, 1990. Return to text.
  2. Piper et al., ref. 1, p. 176. Return to text.
  3. FauzInfoVids, Canary in a phosphate mine - Republic of Nauru, youtube.com, screen shot at 1:20, accessed 2 July 2015. Return to text.
  4. Guilbert, J.M, and Park, C.F. Jr., The Geology of Ore Deposits, W.H. Freeman and Company, pp. 715–720, New York, 1986. Return to text.
  5. Oard, M.J., Rapid cave formation by sulfuric acid dissolution, Journal of Creation (formerly TJ) 12(3):279–280, 1998; https://creation.com/rapid-cave-formation-by-sulfuric-acid-dissolution. Return to text.
  6. Silvestru, E., Bubbles of Surprise, Journal of Creation (formerly TJ) 15(2):89–93, 2001; https://creation.com/bubbles-of-surprise Return to text.
  7. Oard, M., The paradox of Pacific guyots and a possible solution for the thick 'reefal' limestone on Eniwetok Island, Journal of Creation (formerly TJ) 13(1):1–2, 2001; https://dl0.creation.com/articles/p102/c10256/j13_1_1-2.pdf Return to text.

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