Beachrock marine cements

Figure 6.6. Photomicrographs of common marine cements. A) Whalebone Bay, Bermuda, 3m water depth. B) Beachrock from the Bahamas. C) Subaerial Holocene from the Bahamas. (Photomicrographs courtesy of R. Perkins.)...

Hanor J.S. (1978) Precipitation of beachrock cements Mixing of marine and meteoric waters vs. CO2 degassing. J. Sediment. Petrol. 48,489-501. 

Meyers J.H. (1987) Marine vadose beachrock cementation by cryptocrystalline magnesian calcite—Maui, Hawaii. J. Sediment. Petrol. 57,558-570. 

Figure 11.7 Scanning electron microscopy images of marine beachrock and meteoric cayrock cements. (A) Blades of high-magnesium calcite on constituent particles in beachrock. Northeast Sapodilla Cay, southern Belize Barrier Reef. (B) Dissolution cavity is lined with blockyand bladed low-magnesium calcite in cayrock. Cay Bokel, Turneffe Islands, Belize. (C) Low-magnesium calcite needle fibre (whisker) cement in cayrock. Harry Jones Point, Turneffe Islands, Belize.

El-Sayed, M.K. (1988) Beachrock cementation in Alexandria, Egypt. Marine Geology 80, 29-35. 

Holail, H. Rashed, M. (1992) Stable isotopic composition of carbonate-cemented recent beachrock along the Mediterranean and the Red Sea coasts of Egypt. Marine Geology 106, 141-148. 

Alexandersson, E.T. (1972) Mediterranean beachrock cementation marine precipitation of Mg-calcite. In The Mediterranean Sea a Natural Sedimentation Laboratory (Ed. Stanley, D.J.), pp. 203-223. Dowden, Hutchinson Ross, Stroudsburg, PA. 

My own experience in Joulter s Cay, Bahamas, reflects the rapidity of marine carbonate cementation in a beachrock setting (Friedman, 1998). Over a period of 10 yr, together with students and professional geologists I visited Joulter s Cay once a year. A year after one of our visits we found a sardine can from a previous visit. The cementation of the particles (ooids) was surprising. A bivalve shell had become cemented to ooids which had lithified on the underside of the can. 382 g of ooids and skeletal material had filled the can and lithified therein or had become cemented to the outside of the can (Friedman, 1998). This process is remarkable for 1 year s residence and contrasts with textbook statements that time is needed—cementation probably requires substantial amounts of time (Tucker and Wright, 1990, p. 325). 

Friedman G. M., Sanders J. E. and Allen R. C. (1971) Marine Uthification mechanism yields rock resembling beachrock, 50 53. In Carbonate Cements (ed. O. P. Bricker). John Hopkins University Press, 376 p, Baltimme, MD. 

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