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Problems

Problems of the Stenon’s stratigraphy

This model based upon a postulate, which takes into account only one particular case of sedimentation – the absence of current, implying succession of time on a global scale, according to the vertical sequence of strata is not in accordance with experimental and field investigations.

The first part of the definition of the principle of superposition is: At the time when one of the highest stratum formed, the stratum underneath it had already acquired a solid consistence. A stratum between 50 cm and 1 m is considered thick. Consequently, submarine drillings should encounter solid strata in the stratified oceanic sediments after a few meters.

The results of sea bottom drilling showed that the first semi-consolidated sediments appeared about 400-800 metres (in depth). The isolated instances of certain beds of chert (siliceous beds) have been found under 135 metres of sediment near the zones of the oceanic transform faults (Logvinenko, 1980). Stenon’s definition, therefore, relative to successive hardening, which extends greatly the total length of time of deposition, is not supported by the sedimentological observations mentioned above.

Animation 1 (no sound)

No sedimentary layer goes all around the Earth. Seismic readings and sub-marine coring demonstrate that the strata in ocean deposits are not always horizontal and the rate of sedimentation is not uniform on a global scale of the Earth’s oceans.

In the first part of the definition for the principle of continuity Stenon affirms that: Strata owe their existence to sediments in a fluid.

Stenon says nothing about the action of the fluid on sediments, so that the relative stratigraphic chronology resulting from his principles did not take it into account (the two later principles of paleontological identity and uniformitarianism changed nothing in this respect). Currents exist in present day oceans, which erode, transport, and deposit sediments, as shown by Straknov in 1957. Geologists have attributed the change in orientation of stratification and erosion surfaces in sedimentary rocks to marine transgressions and regressions. This is the object of study in sequence stratigraphy today. Diagrams in this latter discipline, however, give no indication of the current velocity of these transgressions and regressions, only variations in the level of the oceans. Detrital sedimentary rocks alone (resulting from mechanical desegregation) would have required a minimum current to transport the particles from where they were eroded to their sedimentation site.

Charles Lyell added a principle of uniformitarianism, giving as an example layers deposited in fresh water in Auvergne. Observing that the layers were less than 1 mm thick, he considered that each one was laid down annually. At this rate, the 230-m-thick deposit would have taken hundreds of thousands of years to form. In the next section I show that these layers, which are laminae, do not always corresponded to annual deposits and may be generated in a time interval much less that the modern geological time-scale indicates.