Varves: Layered Sediments as
Evidence for an Old Earth
A varve is a pair of thin layers of sediment. Typically, one band of the varve is light and composed of sand, pollen, and spores, while the second layer is dark and composed of very fine clay particles.
Varves are formed by seasonal variations in sedimentary deposition. The lighter band is laid down during the summer when a greater flow of water in nearby rivers and streams brings coarse, sandy material into the lake. The larger particles settle rather quickly, but the winds that constantly agitate the surface of the lake keep the fine clay in suspension. In winter, when the lake freezes over, the effect of the winds is not felt, and the clay particles slowly settle to the bottom. When the lake thaws, the cycle begins anew. Each varve, therefore, typically represents one year. One can determine the age of a varve formation by counting the number of couplets, just as one can determine the age of a tree by counting its rings.
Varve deposits display great age. The Salido, Castile, and Bell Canyon formations of west Texas contain 260,000 couplets. Hence, this formation is most naturally considered to be 260,000 years old. Core samples have also revealed that these varves have uniform thickness over many square miles.
Young Earth Creationists, of course, reject such an old age for this formation. They attribute its origin to Noah's Flood, which lasted about one year. To lay down 260,000 varves in one year, however, requires that about 720 couplets be laid down each day, or about one pair every two minutes - an implausible scenario given the evenness, extent, and alternating composition of the layers.
Young Earth Creationists are even more hard-pressed to explain the origin of the Green River Shales. These varves span parts of Colorado, Utah, and Wyoming, and cover 40,000 square miles with about 7.5 million paper-thin couplets. This formation is 2500 feet thick, and it lies upon another 25,000 feet of sedimentary rocks. Flood geologists attribute the entire 27,500 foot configuration to the work of Noah's Flood. This means that about 75 feet of sediments were deposited every day. For the shales, 75 feet amount to 225,000 couplets. This corresponds to 2.5 couplets formed each second, for one year, with the correct light-dark alternation of the bands, over an area of 40,000 square miles - an unbelievable feat.
Further difficulties with explaining all this sediment as laid down by the Flood arise from fossilized evidence of birds, such as nesting sites, egg shells, coprolites (fossilized feces), and foot prints - all in a layer just below the shales. These remains match present-day flamingo nesting sites in East Africa, so it is reasonable to attribute the fossilized sites to flamingos that lived by the lake in which the Green River Shales formed. It is hard, however, to see how flamingos could hatch their eggs, raise families, digest the food from which the coprolites were formed, and take walks with 75 feet of sediment piling on them every day!
Young Earth Creationists point out that fossilized fish that span hundreds of couplets are found in the shales. They argue that dead fish could not have lasted hundreds of years without disintegrating; hence, the varves do not indicate seasonal depositions. Chemical analysis of these sediments, however, reveals that the water of the lake in which the varves formed was very alkaline. The dead fish, in effect, were pickled; they would not decompose and would have lasted for such duration as it took to cover them with sediments.
In light of the positive evidence for the great age of these varves, combined with totally unacceptable explanations for their formation by Noah's Flood, it is clear that they are much older than the 10-20,000 years claimed by Young Earth Creationists as the age of the earth.
Dr. Perry G. Phillips
Materials for this tract were developed from:
Hayward, Alan. 1985. Creation and Evolution: the Facts and the Fallacies. Triangle Books, London. pp. 87, 88.
Judson, Sheldon; Marvin E. Kauffman ; and L. Don Leet. 1987. Physical Geology. 7th ed. Prentice- Hall. Englewood Cliffs, N.J. p. 310.
Morton, Glenn R. 1987. ``Geologic Challenges to a Young Earth,'' in Proceedings of the First International Conference on Creation. Ed. Robert E. Walsh, Christopher L. Brooks, and Richard S. Crowell. Creation Science Fellowship. Pittsburgh. Vol. II, pp. 137-146.