The influence of Trypanites in the diagenesis of Devonian stromatoporoids

Stromatoporoids from the Late Devonian (early Frasnian) Waterways Formation near Fort McMurray, Alberta, contain well preserved Trypanites Mägdefrau. The stromatoporoid heads are formed of an initial growth of Clathrocoilona inconstans Stearn that is encased by a second stage growth of Trupetostroma papulosum Stearn. These two stages were separated by a period of no growth and erosion. The first two generations of boring penetrated the skeleton of C. inconstans while the third generation borings penetrated both C. inconstans and T. papulosum. The borings in the stromatoporoids are filled with light colored micrite, dark colored micrite, skeletal fragments, dolomite, non-ferroan calcite, and ferroan calcite. Analysis of the borings, the growth stages of the stromatoporoids, the boring fill, and the orientation of the geopetal fabrics indicates that the stromatoporoids were subjected to repeated cycles of growth-boring-filling and eorientation. This complex interaction of biologic and physical reworking had a profound influence on the diagenetic transformation of the stromatoporoid heads. This example clearly illustrates the role that biogenic agents can play in the production of diagenetic fabrics of hard carbonate substrates.