Tuesday, May 3, 2011
Written by Stuart E. Nevins
THE SUBJECT of the age of the earth and the age of the world ocean is a matter of extreme importance. If there is evidence for an old ocean, then this could be used to support the evolutionist's supposition that life arose from primitive, inorganic marine chemicals more than a billion years ago. If, how ever, the world ocean can be shown to be a relatively youthful feature, then the evolutionist would seem to lose his case by default.
Two basic models for the world ocean can be imagined. According to evolutionary- uniformitarian geologists, the earth is approximately 4.5 billion years old. The world ocean is supposed to have formed by outgassing of water by volcanic processes early in the earth's history. By no later than one billion years ago, in the popular scheme, the ocean reached its present size and chemical condition, and primitive one-celled life forms had already evolved by chance processes from lifeless chemicals.
For a period of at least one billion years the ocean has remained at roughly constant salinity while the single-celled creatures evolved into mollusks, fish, reptiles, mammals, and, finally, man. During this vast period of time the continents have been eroding more or less continuously, with debris being steadily deposited as sediments on the ocean floor.
An alternate to the evolutionist's view of the ocean is the creationist's view. According to the creationist, the ocean formed very recently—perhaps only 10,000 years ago. The earth in its original condition was covered with water (Gen. 1:2), but later God formed the ocean basins by gathering the waters together, allowing the dry land to appear (Gen. 1:9). The ocean again covered the earth during the universal Flood in the days of Noah, and returned to the present basins following the Flood.
The purpose of this paper is to examine erosion and sedimentation rates to see which has the better model for the world ocean.
The floor of the ocean is blanketed by a layer of poorly consolidated material called sediment. Small rock particles and precipitated chemicals derived from the continents, especially by streams, form the bulk of this sediment. Chemically precipitated calcareous ooze is the most common deep-ocean sediment, while continent-derived sand and mud is most common in the shallower ocean and nearer to shore.
Deep-sea drilling and seismic surveys have provided much information about the thickness of sediments in the ocean. These data were quite surprising to early oceanographers who, assuming a great age for the ocean, expected a great thickness of sediment. The average thickness of deep-ocean sediments is less than 0.40 miles (2,100 feet). Greater thicknesses of sediments are encountered on the continental shelves and slopes. The best world average sediment thickness over the entire ocean (shallow and deep) would be about 0.56 miles or 2,950 feet. 1 This estimate is generous and would be accepted as approximately correct by most evolutionary uniformitarian geologists.
We can now calculate the volume of ocean sediments simply by multiplying the average thickness (0.56 miles) by the area of the world ocean (139.4 mil lion square miles).2 The calculation shows that 78 million cubic miles of sediment are present on the ocean floor.
Next, we can estimate the mass of ocean sediments by multiplying the volume of sediments (78 million cubic miles) by the average sediment density (10.7 billion tons/cubic mile or 2.30 grams/cubic centimeter).3 It will be dis covered that the mass of ocean sediments is about 830 million billion tons.
The present topographic continents above sea level have a volume of about 30.4 million cubic miles and a mass of about 383 million billion tons. If the present continents were eroded to sea level, about 383 million billion tons of sediment would be deposited on the ocean floor. This mass is a little less than half the mass of sediment present in today's ocean. Stated another way, it would take the erosion of only twice our present continental mass to produce today's mass of ocean sediments!
Careful study of modern rivers on a world-wide scale shows that vast quantities of rock are being transported to the ocean. Suspended sediment, small rock particles that are carried along by river turbulence, makes up the bulk of sediment added to the ocean. The best estimate from river data suggests that 20.2 billion tons of suspended sediment enter the ocean each year.4
Rivers also carry dissolved chemical substances into the ocean. The chemicals, mostly bicarbonate, silica, and salts, add about 4.6 billion tons of sediment to the ocean each year.5
Glaciers at higher latitudes are presently breaking apart and adding icebergs to the ocean. When the ice melts, the entrapped sediments are deposited on the sea floor. Ice appears to be delivering about 2.2 billion tons of sediment to the ocean each year.6
Although little is known about the migration of fluids at great depths in the earth, water is presently being added to the oceans through the sea floor from the continents and from springs and volcanoes on the sea floor. This water also contains dissolved chemicals. A conservative estimate suggests that 0.47 billion tons of sediment are added to the ocean each year by ground waters. 7
The seashore is constantly being worn by waves that deliver sediment to the sea. A good estimate suggests that marine erosion adds 0.28 billion tons of sediment annually. 8
Wind-blown dust, especially from desert areas, and dust from volcanoes finds its way to the sea. About 0.06 billion tons goes into the ocean each year. 9
Evaporation and wind remove a small amount of salts from the ocean and deposit these on the land. The amount of sediment removed in this salt spray process as aerosols is estimated at 0.29 billion tons each year. 10
Now that we have examined the processes that deliver and remove sediment from the ocean, we are ready to calculate the total amount of sediment going into the world ocean each year. The previous erosion estimates, added together, give a total sediment input to the ocean of 27.5 billion tons every year. This is an enormous quantity of sediment! Most evolutionary uniformitarian geologists would admit that this total is approximately correct.
For the sake of illustration, imagine that all of this yearly sediment was loaded into railroad freight cars, each having a capacity of 11 tons. We would need 2.5 billion train cars! This train would extend to the moon and back 34 times! If this train were traveling past you at 60 miles per hour, it would take 32 years to pass. The sediment total shows that 80 train cars of sediment per second are being added to the ocean!
How long would it take to deliver the present continents to the ocean if the present rate of erosion continued? There is about 30.4 million cubic miles of continental crust above sea level, with a mass of 383 million billion tons. To calculate the amount of time required to deliver the present continents to the ocean we need only divide the mass of continents above sea level by the annual rate of erosion. The calculation would be:
383 million billion tons = 14 million years
27.5 billion tons per year
The continents are being denuded at a rate that could level them in a mere 14 million years! Yet, evolutionary uniformitarian geologists feel certain that the continents have existed for at least 1 billion years. During this supposed interval of time the present continents could have been eroded more than 70 times! Yet—miracle of miracles—the continents are still here and do not appear to have been eroded even one time!
Even though the continents could be eroded and transported to the ocean in just 14 million years, assume that some mysterious uplifting process continues to raise the continents as they are eroding. How much sediment would form at present rates of erosion in one billion years? The answer is found by multiplying the annual rate of addition of sediments to the ocean (27.5 billion tons per year) by the alleged evolutionary age of the ocean (1 billion years). During 1 billion years 27.5 billion billion tons of sediment would be produced. This is enough to cover the entire ocean floor with 97,500 feet (18.5 miles) of sediment! In order to produce this colossal quantity of sediment an incredible layer of rock 200,000 feet (38 miles) thick would have to be eroded off the continents. Thus, if we assume the present rate of erosion and exposed continental volumes to have existed over the evolutionist's supposed 1-billion year history of the world ocean, we would expect a staggering layer of sediment almost 100,000 feet thick to cover the sea floor today! Since such a monumental layer does not exist, it seems that evolutionists have grossly overestimated the age of the world ocean.
Another question is in order. How long would it take to deposit the present thickness of sediments on the ocean floor, assuming constant rate of erosion? To obtain the answer we must divide the mass of sediment in the ocean by the yearly rate of sediment input. The calculation is:
830 million billion tons = 30 million years
27.5 billion tons per year
In only 30 million years, assuming constant rate of erosion, all the ocean sediments could have accumulated. This age does not square with the more-than-1- billion-year age assumed by evolutionary uniformitarian geologists.
It is important to note that according to evolutionary-uniformitarian geologists the last 30 million years were the time of considerable continental denudation. The greatly accelerated erosion rates of the late Cenozoic were climaxed by the ice age, "a time when the weather went wild." 11 Modern river flood plains show evidence that vast quantities of water once passed into the ocean, exceeding modern river discharges. Scientists who have been working in deep-sea drilling of sediments were recently surprised at how far back the evidences of glaciation and more humid climate go into the sedimentary record. Therefore, the assumption of constant rate of sedimentation is not valid but requires greatly increased erosion rates in the past. This increased rate of sediment input to the ocean might decrease the apparent age of ocean sediments calculated above by a factor of ten to a hundred, making it even harder to reconcile with the evolutionary model.
While the difficulties encountered with the evolutionary model are readily apparent, the creation model is consistent with the evidence. According to the creation model, the ocean reached its present condition only after the Noachian Flood. Some of the oldest ocean sediments appear to have been deposited rapidly from debris-laden water immediately after the Flood. These sedimentary layers do not require an associated long history of continental erosion.
The most recent ocean sediments appear to have been deposited in the centuries after the Flood when the climate was quite humid and when rates of erosion were significantly greater than at present. Most of the recent ocean sediments are probably not derived from erosion of continental granite, but from sedimentary rocks. Thus, the more re cent ocean sediments appear to be chiefly "recycled" and do not require a long history. It is eminently reasonable to believe in a young ocean with an age of 10,000 years or less.
The Evolutionist's Dilemma
If the world ocean is a billion years old, there should be an enormous quantity of ocean sediments. Yet, even the evolutionist is aware of the scarcity of sediments. What would be his rebuttal to the arguments presented so far?
In order to have an ocean more than a billion years old yet possessing a meager carpet of sediments, the evolutionist must have some process that constantly removes sediments from the sea floor. The first process that comes to mind is removing sediment by uplifting the sea floor and returning ocean sediments back to the continents. This may ac count for a little ocean sediment loss, but the total amount of sediments on the continents is about equal to the amount on the ocean floor. Adding all the sediments on the present continents to those in the modern ocean would still be far short of the anticipated 100,000 feet of ocean sediments that should exist if the ocean is a billion years old. This process does not solve the evolutionist's dilemma.
The second process is very ingenious. If the major quantity of sediment is not being removed from the ocean by uplifting, then the evolutionist must suppose some process that plunges deep ocean sediments into the depths of the earth! The favorite method is called "sea floor spreading," and suggests that the ocean floor is like a conveyor belt. Ocean crust is assumed to form continuously at the mid-ocean ridges, then it accumulates sediments as it slowly moves away from the ridge, and finally both crust and sediments are destroyed by remelting when dragged below ocean trenches. The best estimates by evolutionary-uniformitarian geologists suggest that about 2.75 billion tons of sediment per year12 are being destroyed by sea floor spreading. This rate is only one tenth of the modern rate of addition of sediments to the ocean. Stated another way, ocean sediments are forming today at a rate ten times faster than they are being destroyed by sea floor spreading! Thus, sea floor spreading is not able to destroy sediments fast enough.
After careful analysis of the erosion of continents and associated sedimentation in the world ocean, we must ask two urgent questions: Where is all the sediment if, as the evolutionist assumes, the ocean is more than 1 billion years old? Who has the better model for the ocean—the evolutionist or the creationist? We feel confident that the true answers concerning the origin of the ocean are presented in Scripture: "The sea is his, and he made it" (Ps. 95:5).
1 In my estimate of world average sediment thickness I have used the most recent data of M. Ewing, G. Carpenter, C. Windisch, and J. Ewing, "Sediment Distribution in the Oceans'. The Atlantic," Geological Society of America Bulletin, vol. 84, January, 1973, p. 83. Correction was made for Pacific Ocean sediments, which are not as thick on the average as Atlantic Ocean sediments.
2 John N. Holeman, "The Sediment Yield of Major Rivers of the World," Water Resources Research, vol. 4, August, 1968, p. 737.
3 The density of deep-sea sediments, according to several authorities, averages about 2.3 grams per cubic centimeter.
4 Robert M. Garrels and Fred T. Mackenzie, Evolution of Sedimentary Rocks (New York: W. W. Norton & Co., 1971), pp. 104-106.
5 Ibid., pp. 102, 103.
6 Ibid., p. 110.
7 Ibid., pp. 103, 104.
8 Ibid., pp. 110, 111.
9 Ibid., p. 111.
10 Ibid., p. 108.
11 See the excellent discussion of late Cenozoic erosion by R. W. Fairbridge, "Denudation," in The Encyclopedia of Geomorphology (New York: Reinhold Book Co., 1968), pp. 261-271.
12 Y. Li, "Geochemical Mass Balance Among Lithosphere, Hydrosphere, and Atmosphere," American Journal of Science, vol. 272, February, 1972, p. 133.