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Rapid Lithification of Sedimentary Rock
Figure 2. Finely laminated sedimentary layers from the Green River Formation, Wyoming. The U.S. penny is for scale (1.9 cm diameter). The dark oblongshaped objects between the laminations are fish coprolites (feces). As many as ten laminations per mm can occur in these rocks. Photo by John Whitmore.
Long periods of time are not required to harden rock. Sedimentary rock generally consists of sediment (mud, sand, or gravel) that has been turned into rock. Sedimentary rocks include sandstones, shales, and limestones. Sedimentary rock is usually formed under water and is easy to recognize because of its many layers. A familiar example would be the layered rocks of the Grand Canyon (figure 1).
Layers in sedimentary rocks can be seen at small scales too, like the finely laminated beds from the Green River Formation in Wyoming (figure 2). When sediment turns into rock, or becomes hard, we say the sediment has become lithified. Lithification occurs during sediment compaction (which drives out water) and cementation, or gluing together of the sedimentary grains. The process of lithification is not time dependent, but rather dependent upon whether the rock becomes compacted or not and whether a source of cement is present (usually a mineral like quartz or calcite). If these conditions are met, sediment can be turned rapidly into rock.
Figure 3. Remains of a clock encased in sedimentary rock. It was found on a beach along the coast of Washington state by Dolores Testerman.
Many examples of rock forming rapidly have been reported in the creationist literature: a clock (figure 3),1 a sparkplug,2 and keys3 have all been found in cemented sedimentary rock. Also a hat4 and a bag of flour5 have been found petrified. Examples of bolts, anchors, and bricks found in beach rock have also been reported.6 All of these examples show that sediment and other materials can be hardened within a relatively short time span. In many of these examples, rock probably formed as microbes (microscopic bacteria and other small organisms) precipitated calcite cement, which in turn bound sediments together and/or filled pore spaces. Examples of rapid lithification of this type include limestones that have been cemented together on the ocean floor.7
Rapid Formation of Thin, Delicate Rock Layers
Thin, delicate rock layers don’t necessarily represent quiet, docile sedimentary processes; thin layers of rock can be formed catastrophically. On May 18, 1980, Mount St. Helens violently erupted. It was one of the most well-studied and scientifically documented volcanic eruptions in earth history, both by conventional scientists8 and creationists.9
Figure 4. Finely laminated beds produced during a violent pyroclastic flow from Mount St. Helens on June 12, 1980. Photo by Steve Austin, copyright 1989, Institute for Creation Research; used by permission.
The volcano remained geologically active during the months and years following the 1980 eruption. Fresh lava is still oozing out of the volcano today. During the violent eruptions of the volcano, pyroclastic material (hot volcanic ash and rock) was thrown from the volcano with hurricane force velocity. One of the most fascinating discoveries following the eruption was that some of these pyroclastic deposits, those that contained fine volcanic ash particles, were thinly laminated.10 When geologists see thin layers like this (figure 4), they usually assume that slow, delicate processes formed the layers (like mud settling to a lake bottom). However, in this case, the layers were formed during a catastrophic volcanic eruption.
Figure 5. A well-preserved fish (Knightia) from the Green River Formation, Wyoming. In order for fish to be preserved like this, before major decay ensues, the fish must be buried within days of death. Scale in cm. Photo by John Whitmore.
Figure 6. A fish (Diplomystus) that decayed for several days before burial, Green River Formation, Wyoming. Note the sloughed scales. Burial a few days after death, by a thin layer of calcite mud, arrested the decay and prevented the fish from complete destruction. Scale in cm. Photo by John Whitmore.
Other types of thin, delicate rock layers can also form quickly too. Fossil fish are very abundant in the thin, laminated mudstones of the Green River Formation of Wyoming (figure 2). After death, fish rot very quickly. Scales and flesh can slough off within a matter of days, and fish can completely disappear within a week or two.11 In order for the Green River fish to be preserved as well as they are, it would have been necessary for a thin layer of calcite mud to cover the fish immediately after death (figure 5).
These thin layers of mud are what make up the thin, laminated layers of the Green River Formation. If a fish is not covered immediately, but several days after its death, scales will slough off and scatter around the fish carcass (figure 6). Because many of the layers in the Green River Formation contain well-preserved fish, we can conclude that many of layers were formed within a day or two. A study of fish coprolites (feces) also concluded that the thin layers must have formed quickly.12 The Green River Formation was probably made in a post-Flood lake setting where sediments were accumulating rapidly.13 These few examples of thin layers being made quickly does not mean that all thinly laminated rock layers have formed quickly; it shows that some thinly laminated layers can form quickly.
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