Non-sedimentary Structures in the Drift


The unconsolidated sands and gravels of the drift with patterns of cross stratification can be explained as a product of a disintegration process. There are several non-sedimentary features associated with these sandy layers. Examples are the presence of lenses and balls of coarse material in fine sands, or lenses and balls of fine sand in coarse gravel layers. These are unlikely to have been produced in sedimentary environments, particularly when the sand balls have a distinct composition, or concentric structure, which points to concretionary processes. The drift also contains disintegrated boulders that could not have been transported to their positions, concretions, vertical pillars that may become eroded into hoodoos at the surface, and dikes.

Structures such the sand dike shown below are evidence against a sedimentary interpretation of the patterns of cross strata. This structure is called a "clastic dike" but that terminology implies an interpretation that the writer rejects. "Clastic" suggests that the material has been transported and deposited in streams. The so-called clastic dikes are usually attributed to injection of sand into a fissure from either above or below. That seems unlikely here, because of the unconsolidated nature of both the sand matrix and the dike contents. The sedimentary interpretation of patterns of cross stratification of the coarse material in the dike, usually attributed to deposition in fast currents, is the real root of the problem.

Dike of coarse sand and gravel in fine sand
The photo at left shows details of part of a clastic dike containing coarse sand with horizontal cross strata and pebbles. The dike is on the left, and the matrix of fine cross stratified sand on the right. All the sand in the photo is unconsolidated. Along the dike walls there are thin films of clay or silt sized material. The total width of the dike was about 0.5 m. The dike was observed in a gravel pit near Campbellville Ontario, about 2 km east of the Guelph line - Highway 401 intersection.

Problems with the conventional interpretation:

Explanation as a non-sedimentary structure

The formation of vertical dikes containing stratified sand and gravel is a serious problem for conventional geology but they are easily explained by the writer's in situ disintegration interpretation. In the former environment of rapid removal of overburden by fast currents, the sediments were compacted and rock was lithified. At the surface the rock was disintegrated and converted to sand and gravel, with the patterns of cross stratification evident in sandy layers. This pattern records the progress of the front of alteration as it penetrated the rock. In the case of the dike illustrated above this process disintegrated the rock between two adjacent joints, forming the coarse stratified sand and gravel between the joints. Subsequently the surrounding rock was also disintegrated.

See Also:

Clastic Dike in a Kame-Esker Complex
Bedrock Rafts and Megablocks in the Drift

References

Peterson, G.L. 1968. Flow structures in sandstone dikes. Sedimentary Geology 2(3):177-190

Spencer, P.K., and Jaffee, M.A., 2002. Pre-Late Wisconsinan Glacial Outburst Floods in Southeastern Washington-The Indirect Record. Washington Geology, vol. 30, no. 1/2, July 2002
http://www.dnr.wa.gov/geology/pdf/1news02.pdf
Figure 5 in the above paper shows a compound clastic dike in the Touchet Beds. (See p. 10)

Cox, D.E. 1978. (Discussion) Re: Roth:  Clastic Dikes (ORIGINS 4:53-55)
http://www.grisda.org/origins/05006.htm#Roth

Roth, A.A. 1992. Clastic dikes in the Kodachrome Basin. Origins 19(1):44-48.
http://www.grisda.org/origins/19044.htm

A rebuttal of the above paper is presented in:
Morton, G.R., 2002. Why Clastic Dykes Don't Indicate a Global Flood
http://home.entouch.net/dmd/clasdyke.htm

Copyright © 2006 by Douglas E. Cox
The Creation Concept | Controversy About the Glacial Theory