Young-earth "proof" #22: The largest stalactites and flowstones could have formed in about 4400 years.
22. Since when is the age of the earth related to the age of a stalactite? If, in fact, a fat stalactite can form in 4400 years, so what? However, it does seems a bit suspicious that the minimum age given by Dr. Hovind is exactly that allotted to the postflood period. Such a figure begs investigation, but let’s take first things first.
Did you ever wonder how a cave, like Carlsbad Caverns, formed? It wasn’t dissolved out by rushing flood waters, being that calcium carbonate (the substance of limestone) is less soluble in water than granite! (Loftin, 1988, p.22). How many gorgeous caves have you seen carved out of granite? Nor was it carved out of soft sediment. The whole thing would have caved in like a cold soufflé long before the job was finished. Nor was it eroded out by rapid, underground rivers and streams. Vadose caves are formed in that manner, but their shape is very unlike the phreatic (solution) caves such as Carlsbad Caverns and Mammoth Cave. Diagrams of phreatic caves often resemble city maps with lots of streets intersecting at right angles. Hamilton Cave, in West Virginia, is an excellent example. You don’t get that kind of pattern with river or stream erosion. "Streams often flow through caves and contribute very slightly to the process, but this is almost always a later, secondary development." (Loftin, 1988, p.22).
Carlsbad Caverns was eaten out, cubic inch by cubic inch, by carbonic acid which turned the calcium carbonate to calcium bicarbonate. (The Caverns are unusual in that sulfuric acid has also played an important role.) Calcium bicarbonate dissolves easily in water and is carried away. Carbonic acid is a weak acid produced when carbon dioxide combines with water. Almost all the carbon dioxide involved in this cave-making process comes from "…the activity of plants and animals in the soil rather than from the air (Moore and Nicholas, 1964, p.7)." (Loftin, 1988, p.22). The atmospheric concentration is way too low to be of much use. It is the metabolism of plants and soil organisms which build up the carbon dioxide concentration to a point where it can do some good.
As rainwater percolates through the soil it combines with the carbon dioxide to form the weak, carbonic acid which becomes part of the general flow of water through the limestone. Cracks deep within the limestone are widened over the ages, and underwater caverns are eventually formed. Most of the etching action apparently goes on just below the water level, thus the tendency for phreatic caves to have distinct levels.
Before any stalactites, stalagmites, or flowstones can form, the water must be drained out of that portion of the cave. In allowing 4400 years for the largest stalactites and flowstones, Dr. Hovind has neglected to allot any time at all to the cave-making process! In his scenario the oldest stalactites start forming right after Noah’s flood drains away. Sorry, but I don’t buy the implied claim that Carlsbad Caverns was deposited by that flood! I know that Noah’s flood can perform miracles in the hands of scientific creationists, but I absolutely draw the line there! The cave-making process requires a whole lot more time than the stalactite-making process.
The [stalactites, stalagmites, and flowstones] are formed when calcium carbonate in solution in the water is deposited out, but this process is not one of simple evaporation. The air in most caves, even in the most arid regions, is highly moist; therefore, when water soaking down from above reaches the air of the open cave, it does not lose water to the air and leave minerals behind. This is clearly shown by the composition of the deposits, which consists of almost pure calcium carbonate. When the slightly acid water with its dissolved minerals meets the moist air of the cave, a minute amount of the carbon dioxide leaves the water and goes into the air. This process is almost exactly the reverse of the major process of cave formation, for, when carbon dioxide goes into the air, the solution becomes supersaturated and a small amount of calcium carbonate is precipitated out (Moore and Nicholas, 1964).
Needless to say, this is not the kind of operation you can turn up the spigot on. A rapid flow of water would simply carry the minerals with it, not to mention diluting the carbonic acid which is produced in limited quantities. We’re dealing with a drip-by-drip scenario.
Creationists sometimes point to some very rapid accumulations which superficially resemble the calcium carbonate formations in caves.
For example, on the mortared brickwork of old forts and places of that sort, formations which look to the naked eye like stalactites and stalagmites sometimes form in less than one hundred years. However, those formations are composed of gypsum, which is a salt of calcium sulfate. Unlike calcium carbonate, gypsum is moderately soluble in water, which means that transport and recrystallization can take place much more rapidly (White, 1976, p.304). There is a whole class of cave deposits called evaporite minerals which consist of those minerals which dissolve readily in water. As might be expected, these formations are ephemeral when compared to the carbonates which form all the really large and impressive cave formations. The chemistry of all this is not particularly complex and is very well understood.
Here’s some more information. This point is particularly important since creationists love to point out such examples.
Many people have found that stalactites forming on concrete or mortar outdoors may grow several centimeters each year. Stalactite growth in these environments, however, bears little relation to that in caves, because it does not proceed by the same chemical reaction. Although cement and mortar are made from limestone, the same rock in which the caves form, the carbon dioxide has been driven off by heating. When water is added to these materials, one product is calcium hydroxide, which is about 100 times as soluble in water as calcite is. A calcium hydroxide solution absorbs carbon dioxide rapidly from the atmosphere to reconstitute calcium carbonate, and produce stalactites. This is why stalactites formed by solution from cement and mortar grow much faster than those in caves. To illustrate, in 1925, a concrete bridge was constructed inside Postojna Cave, Yugoslavia, and adjacent to it an artificial tunnel was opened. By 1956, tubular stalactites 45 centimeters long were growing from the bridge, while stalactites of the same age in the tunnel were less than 1 centimeter long.
By the way, geologic opinion holds that the Carlsbad Caverns began to be etched out 60 million years ago. The present chambers were excavated from 1 to 8 million years ago, depending on their depth. As for stalactites, the Bulletin of the National Speleological Society (37: p.21, 1975) gave their observed growth rates as ranging from 0.1 to 10 centimeters per thousand years. An exceptional spurt of growth might exceed the higher rate for short periods of time, but it could no more be maintained than a winning streak at the Las Vegas poker tables. Moore and Sullivan (1978, p.47) give an upper average rate of "only a little more" than 0.1 mm/year [10 centimeters or 2.5 inches per thousand years]. Stalagmites grow at a similar rate. Areas with a lot of overgrowth and tropical temperatures would have the higher rates. Thus, a 60foot giant, as might be found in Carlsbad Caverns, would have a minimum estimated age of about 180,000 years.
Fornaca and Rinaldi (1968) used the Th-230/Th-232 ratio method to date an old stalagmite, probably in Europe, and got an age of 180,000 years for its formation. That stalagmite had stopped growing 90,000 years ago, as indicated by the radiometric dating method, so its true age is 270,000 years. A flowstone in the famous Romanelli cave of Apulia was dated at 40,000 years. Thus, an extrapolation of the observed rates of stalactite formation and the radiometric dating method (using thorium) put us in the same ball park for large cave formations. Dr. Hovind’s figure of 4400 years for the oldest stalactites is much too modest!
As it turns out, a careful study of the ratios of Oxygen-18 and Oxygen-16 allows us to estimate the temperature at the time a particular layer was added to a stalactite or stalagmite. Studies of this type have built up an interesting picture:
As we go to press, research is very active in this field. In the latest results, speleothems indicate that the average surface temperature in midlatitude cave regions reached a peak 3 degrees C above the present about 8000 years ago, that it was as much as 10 degrees C colder than at present from 15,000 to 80,000 years ago, warmer than now from 80,000 to 120,000 years ago, colder from 120,000 to 170,000 years ago, warmer from 170,000 to 200,000 years ago, and colder for an undetermined period before that.
What we have here is a remarkable record of the last three advances of the present Ice Age! The warm period of 80,000-120,000 years is centered on the Last Interglacial (Ipswichian) interlude; the warm period of 170,000-200,000 years ago takes in the Penultimate Interglaciation (Hoxnian) interlude. The cold period of 15,000-80,000 years starts near the known beginning of the last ice advance, which corresponds to our Main Wisconsinan glaciation. Is that just a coincidence? This data is also beautifully reflected in the study of foraminifera in deepsea cores (Strahler, 1987, p.252). Another coincidence?
Dr. Hovind claims that there was only one glacial episode which began after the earth had a collision with an icepacked comet. Overlooking the numerous impossibilities involved in that scenario, we might ask if there is any real evidence for more than one glacial advance. The answer is a resounding "Yes!"
But as the study of the glacial deposits was carried westward into Illinois, Wisconsin, and Iowa, two distinct sheets of drift were found at many places to be separated by old soil, beds of peat, or layers of till that had been leached and decayed (Fig. 18-10). Here the uppermost drift, like that in New England, appeared fresh, but the buried drift sheet showed the effect of chemical decay and was obviously much the older. Moreover, in places, the soil and peat, or gravels, between two such sheets of till included fossil wood, leaves, or bones, recording the existence of animals and plants of temperate climate. Thus it came to be realized, about 1870, that a continental ice sheet had developed more than once, and that warm interglacial ages had intervened.
In time it was found that there were several major advances of the present Ice Age, and that major fluctuations within these advances had occurred. The following table lists the approximate times of the glaciations in North America during the last two million years. These periods match a study of oceanwater temperatures interpreted from data of foraminifera in deepsea cores (Strahler, 1987, p.252).
(Based on D. B. Ericson and G. Wollin, 1968, Science, vol.162, p.233)
|0 – 15,000
|15,000 – 80,000
|Main Wisconsinan glaciation
|80,000 – 120,000
|120,000 – 170,000
|170,000 – 200,000
|200,000 – 250,000
|250,000 – 270,000
|270,000 – 320,000
|320,000 – 360,000
|360,000 – 540,000
|540,000 – 850,000
|850,000 – 880,000
|880,000 – 900,000
|900,000 – 1,390,000
|1,390,000 – 1,450,000
|1,450,000 – 1,500,000
|1,500,000 – 1,530,000
|1,530,000 – 1,580,000
|1,580,000 – 1,630,00
|1,630,000 – 1,670,000
|1,670,000 – 1,715,000
|1,715,000 – 2,000,000
As you can see, various evidences for an old Earth tie together. From a study of oxygen isotopes in stalactites we got the last few periods of glacial advance. Studies of the foraminifera of deepsea cores support the findings gleaned from stalactites. The study of foraminifera also supply information to flesh out the periods of the last three major glacial episodes. That there is more than one major glacial episode is, in turn, supported by the remains of temperate forests and animal fossils found between some of the sheets of drift, the bottom sheet showing a sharp increase in age as indicated by chemical weathering and other observations.
We can forget about Dr. Hovind’s snowball theory of the Ice Age. It can’t begin to account for real life data.