SIGNIFICANCE OF THE GREAT THICKNESSES OF
SEDIMENTARY ROCKS IN THE APPALACHIAN
REGION1 AND OTHER AREAS
One important feature of the Appalachian Region of North America which we should consider here is that of the actual amount and number of limestone deposits which are found alternating with strata of quartz sandstones, siltstones, and shales. (We will here use the term "limestone" in the broad sense which includes dolostone.) These thicknesses and the enormous number of alternations of sediment type are practically ignored by the recent-creationist writers. When these characteristics arerecognized by them, they are regarded as having little significance with regard to time because the writers do not understand sediment types or rock formation processes.
1. Quantities of Lithified Sediments
A partial idea of the thicknesses of lithified sediments in the Appalachians can be obtained by examining Fig. 2, but only the most major changes from limestone to other types of rock strata can be shown in a small diagram of this type. When we examine isopach* (thickness) maps and measured sections2 of the various types of rock strata in eastern and central West Virginia, western Maryland, west-central Pennsylvania, and the western part of Virginia (the areas represented by Fig. 2), we find the following approximate thicknesses of limestone, beginning at the top of the Precambrian and proceeding upward:
The rates of deposition of sediments of the types found in the above-mentioned 20,000 to 35,000 ft of strata in the Appalachians vary greatly. Careful studies have shown carbonate deposition in a semitropical, shelf environment to be sometimes as high as 30 cm (about 1 foot) per 1,000 years (Goodell and Garman, 1969, pp. 527-528). Coral reef deposition has been found to range up to 8 meters per 1,000 years on the fastest growing parts of tropical reefs. Non-carbonate deposition on continental shelves usually averages 15 to 40 cm per 1,000 years, though it was greater during parts of glacial periods in the past (Gross, 1982, p. 105). All of the rates just given are for environments where deposition is rapid. The rates for both carbonate and non-carbonate deposition are muchslower on the deep ocean floors, but not many of the sedimentary strata of the Appalachians were deposited in a deep-sea environment. Most of the shale and mudstone strata were deposited in fairly deep waters in inland seas, and their rate of deposition was probably no more rapid than the slower rates we have cited for continental shelves.
Even when a body of water is tranquil, at least many hours are required for the settling out of a single clay particle to become part of a shale or mudstone deposit. Even if the suspended clay particles have undergone flocculation (clumping), the water has to be essentially tranquil as the small clumps of flocculated clay are not nearly so dense as grains of sand. We have referred to these alternating sandstone and shale series as a reminder that the conditions for their deposition over this and other broad areas could not have existed in a one-year flood of the sort visualized by Morris and Whitcomb (see Morris, 1974, pp. 117-118). One year just does not allow enough time for anything like the number of relatively quiet settling periods needed for the existing clay and mudstone layers.3 And we have to account also for the many thousands of feet of carbonate rocks and non-cyclic mudstones and sandstones which are present in the same local columns with the sandstone and shale series. Two well-known areas in the western half of the United States where many thousands of couplets of sandstone or siltstone with shale occur in vertical sequence over broad areal extents are in the Marathon region of western Texas (in Pennsylvanian strata) and in the Ouachita basin* of eastern Oklahoma (in Mississippian strata).
Since we are describing orderly sequences of strata in the Appalachian Region it is necessary here to mention the bold claim which Morris has made, saying that the stratigraphic system and formations of the Appalachian Region have no orderly arrangement are only a disorganized "jumble of rock." In the book What is Creation Science?(Morris and Parker, 1982, pp. 198-200) he devotes a few paragraphs to this claim, taking as his authority an article which appeared in a 1979 issue of Science News. It is obvious, from his description of the article, and from the part of it that he quoted, that its author was not at all denying the existence of the orderly formations and systems here in the Central Appalachians. The author was referring to certain partsof the sedimentary cover in the Appalachians which were subjected to extreme lateral pressure during one or more of the orogenles,* and as a result were folded and crumpled. For example, in the Valley and Ridge Province, well drillers encounter multiple thicknesses of the same set of formations where they were folded. But these are no mysteryand are not difficult to identify. In fact, these folds and short overthrusts have been identified and mapped very carefully from seismic surveys4 and earlier drilling records, so that modern drillers usually know ahead of time which of the sedimentary formations they will encounter and which ones may be found a second or third time because of folding or faulting as they proceed down through the rock system. Then there are large areas of non-folded stratigraphic sequences of the Appalachian Plateau Province which have been mapped for the use of drillers and other interested persons. These maps (and also drilling logs*) are available from the West Virginia Geological and Economic Survey, and from the Pennsylvania Topographic and Geologic Survey.
Dr. Morris' idea of the Appalachian strata being a disorganized jumble stems from his lack of knowledge of it. He took the popular-level language of the Science Newsarticle to mean that all or nearly all of the Appalachian Region is unintelligible and mixed up. Such an idea can be nothing but absurd to the many petroleum geologists who work daily with the orderly geologic formations of West Virginia, Pennsylvania, and western New York. If Morris had checked with one of them before writing he could have avoided introducing another erroneous and confusing idea into the book.
Even if he had read the short article, "The 'Eastern Overthrust Belt': An Explanation of Oil and Gas Activities in Central and Eastern Pennsylvania," by J. A. Harper and C. D. Laughrey, in the October 1982 issue of Pennsylvania Geology,Morris could have understood that the horizontal thrusting which is evident on the east side of the Appalachians is not something that turned the whole area into a confused chaos. But he made the mistake of focusing on some of the more drastically affected parts—such as those of the mountains in the Southern Appalachians—and concluded that this is typical of the entire area. He was apparently entirely ignorant of the many thousands of square miles of the Appalachians which contain the orderly preservation of all of the rock strata systems from the Cambrian up through the Pennsylvanian.5 And east of the most intensely folded province (the Valley and Ridge) there are hundreds of linear miles of easily identifiable, continuous sequences of ancient, shallow-water, shelf carbonate sediments, preserved as they were formed and deposited. Some good references on these are: Spelman (1966, pp. 1-11, 54-76), Reinhardt (1974), Reinhardt and Hardie (1976, pp. 15-25, 42-49), Laporte (1975), Markello, et al. (1979), Pfeil and Read (1980), Read (1980), Kendall and Schlager (1981, pp. 196-205, and Table II-E), Ruppel and Walker (1984).
We will now come back to the great thicknesses of limestone in the Appalachians which we listed at the beginning of this chapter. These and other broad and thick sequences of limestone strata in different parts of the world are of great significance because of the fact that the limestone layers nearly always contain special features which give us some idea of the length of time required for their formation, as in the case of the Redwall Limestone of the Grand Canyon described in chapter one.
3. Unsupportable Hypotheses of Limestone Deposition
Some creationist authors, not being familiar with the special features of limestones, have supposed that most of the limestone deposits of the earth could have been formed rapidly by chemical precipitation* from seawater during the Flood. This assumption ignores the fact that very major deposits of the earth's limestone are composed almost entirely of biogenic materials. It also fails to realize that the waters of the ocean—no matter how supersaturated with CaCO3—could not have precipitated the vast quantity of limestone formations of the earth in the short time provided by "Flood geology." Consider the fact that there are large areas in the U. S. and other parts of the world where the thickness of limestone deposit is as great as the depth which the water itselflikely was over any part of the continents during the Flood! The problem of the inadequacy of precipitation is further compounded by the fact that the Flood is alleged to have been a convulsive event, with turbulent waters dominating it and not leaving the necessary periods of time for the settling out of precipitated minerals in quiet waters. If one counters this by responding that there was a long period of tranquil waters at the endof the Flood, this does not help either because there are often whole formations of sandstones, conglomerates, siltstones,* and shales intercalated* between the limestone formations—or overlying them—even in a single local stratigraphic column. In fact, the thickest limestone deposits of the Appalachians are usually in the lower parts of the column, sometimes covered by several miles of non-carbonates (Fig. 2).
When Morris (1974, p. 104) says that "Nothing less than massive precipitation from solution in chemical-rich waters ... seems adequate to account for [the great limestone deposits in the geologic column]" it is obvious he is unaware of: (a) the actual extent and nature of the limestone deposits of the earth; (b) the conditions necessary for extensive deposition by mineral precipitation; (c) the fact that known carbonate sediment production characteristics and rates on the Bahama banks and in several other parts of the earth areadequate to account for the earth's limestone deposits; and (d) the fact that biogenic components are dominant in most of the great number of limestone formations which have been studied. M. E. Tucker gives a helpful summary of the careful studies of these limestones, and of limestone formation processes, which have been made during the last three decades, saying:
Also, there is no possible way that the surging flood waters could transport the shell material inland without mixing it with terrigenous* materials on the way. And how would the flood waters bring in layers of pure clay, silt or sand a few minutes later, to deposit the shale, siltstone or sandstone layers over great areas of shell material? Non-carbonate layers of these types often appear within a limestone layer sequence, and sometimes regularly alternate with limestone layers in the local column.
We must face the facts of physical laws which control sediment suspension and transport, and realize that fine sediments cannot settle out of surging flood waters to form neat, smooth and uniform layers—also that seashells of all sizes do not float like masses of seaweed and then suddenly sink down in a uniform layer. To suppose that deposition of sediments occurred in a manner which violates the physical laws which God created certainly appears to dishonor God. And even if shell materials could have been transported inland in pure and more-or-less uniformly thick slurry* sheets 50 miles or so broad, think how many such sheets would be needed in order to make up a limestone formation even 200 feet thick in what are now the states of Illinois, Indiana, and Ohio! Isopach maps such as those in the Indiana Geological Survey bulletin, Cambrian and Ordovician Stratigraphy and Oil and Gas Possibilities in Indiana (Gutstadt, 1958), show that such a 200-foot formation would amount to only about 10% of the average total limestone thickness throughout Indiana. The average thicknesses of limestone for Illinois and Ohio are even slightly greater than for Indiana, and in large areas of the Appalachian Highland Region the thickness is 2 to 5 times as great (Cook and Bally, 1975, pp. 8, 14, 15, 26, 28-35). Thus no method is known to mankind by which even a minute fraction of the existing limestone strata could have been deposited by either precipitation or rapid transport of shell materials.
4. In SituGrowth Structures Ignored by Young-Earth Creationists
Another insuperable problem for any and all proposals of rapid formation of the limestone deposits which we have been discussing is the in situbiological growth structures which they contain. These include stromatolites* and algal mats* (both formed by marine algae which either collect or secrete calcium carbonate), small bioherms,* large organic banks, and coral-algal reefs. Obviously, any limestone formation which contains such structures could not have been formed by rapid precipitation or by transport of calcareous shell material from elsewhere during the Flood. All of these kinds of growth structures are found in Europe as well as North American, and have been carefully identified many times and in many places. The technical literature describing them is truly abundant. For example, in M. R. Walter's work on stromatolites (Walter, 1976), the bibliography contains 2,034 entries (with no repetitions) relating to stromatolites and carbonate algal mats. The bibliographies for ancient bioherms and reefs (including fossilized true-coral reefs) are at least as large; see Wilson (1975, pp. 96-280) for a summary treatment and references on ancient reefs and bioherms.
Unfortunately most creationist authors do not know that the lime-secreting organisms responsible for building the in situstromatoids,*6 algal mats, bioherms and reefs have been accurately identified in abundance and from many ancient limestone formations. Neither do they know that these growth structures really arefound in their natural growth positions, relatively undisturbed, in many places. Because of this lack of information these authors—including Morris and Nevins/Austin—usually dismiss the idea of such growth structures as imaginary. It is true that the identification of the algae which produced the ancient stromatolites and the fossilized algal mats was difficult at first, but with the advent of the scanning electron microscope and improved usage of standard electron microscopes it has become possible to see and identify the cells and filaments of the fossilized algae in the stromatoids (Walter, 1976, pp. 251-259; Flügel, 1977, pp. 57-60; Schopf, 1977). Furthermore, the process of formation of calcareous* algal structures of types very similar to these ancient ones, by present-day species of marine algae, has been observed in many places, such as the Bahamas, Bermuda, the Persian Gulf, the Red Sea, and the western coast of Australia (Friedman, et al., 1973; Ginsburg, 1975, pp. 198-232; Kendall, 1968; Walter, 1976, pp. 193-203).
Anyone who is interested in observing the in situgrowth structures of limestone formations can do so by visiting ancient limestone exposures which crop out in many places in the Valley and Ridge Province of the Appalachians, and in many ancient limestone exposures in Canada and in southern Europe. Another way to study them is to go to the state Geologic Survey offices and examine the well cores from deep wells which have penetrated the limestone formations. The personnel at such offices are usually very helpful to persons requesting the use of their resources. There is thus no reason to continue supposing that the great limestone formations could have been produced by a rapid deposition of carbonate materials by flood action.
5. Analogical Theory and Created Order
Sometimes it is said by young-earth creationists that the recognition of ancient environments, tidal flats, carbonate shelves,* algal growths, coral atolls, etc., which are buried in the sedimentary strata is a mere application of analogical theory. Such critics assert that we have no grounds for thinking that ancient life, growth, and sedimentation were similar to that which we observe today, and that the finding of modern analogs which appear to have a valid similarity to ancient structures or deposited layers is only worthless speculation. Such an accusation is improper and unreasonable. We, as rational beings recognizing God as an orderlyCreator, are notat liberty to assume that such specific structures in the ancient strata were built by processes which are inconsistent with the marine life and growth processes which exist today. Making such an assumption amounts to a denial of the orderliness of God and of his works. For example, some extremists refuse to recognize fossilized clam shells or sea urchin skeletons as the real remains of living organisms. We believe God's creation was and is consistent and rational. We know that ancient clam shells, with their scars from muscle attachment, and sea urchin skeletons, with their many mouth parts for food handling, are not of some origin different from the shells and urchin skeletons in today's oceans.
1The term "Region" is used of the entire Appalachian area. The Region is divided up into Provinces.
2A "measured section" is a sequence of formations or parts of formations, with their various types of rock layers which have been measured and recorded in detail, with the thickness of each type of rock given. Such section measurements are usually made at road cuts, river canyons, rock quarries, or mountainside cliffs.
3Dr. Alan Hayward, an old-earth creationist, has written an unusually vivid, yet essentially correct, portrayal of this problem:
The "Flood geologist" looking at the Haymond formation has a problem. How did the Flood bring in a thin layer of sand and deposit it over a large area, then bring in a thin layer of clay and all this to settle quietly—all in a matter of minutes? And then repeat the whole performance fifteen thousand times?
It seems rather obvious that there is only one way in which such a series of events could possibly occur. God would have had to direct and control the whole process miraculously to achieve this result. But what of our agreed rules, that God would not use his powers to produce an effect which would mislead scientists, and that the Flood operated by Whitcomb's "purely natural processes"? (Hayward, 1985, pp. 123-125).
5Concerning the absence of some formationsof these systems, see [GIVE LINK OR SECTION!!] pages 58-63 of this book.
6A "stromatoid" is an
many-layered unit of a stromatolite—a "stromatolite" being the rock
which contains stromatoids. Stromatoids are thus small mounds which are
built up as a result of the growth of marine algae in the same way that
thinner algal mats are formed. A stromatoid is therefore a rather
algal mat which has many algal-built laminations in its thickened,