Page 134 - Carbonate Facies in Geologic History

General Summary of Later Devonian Facies 121

Shelf or platforms of open circulation
3D. Normal marine lime wackestone-packstone. Often brown to cream color in Alberta.
Varied fauna dominated by crinoids, brachiopods (excluding rhynchonellids), and with
scattered rugose corals and bryozoans. Homogenized by burrowing, many lithoclasts,
bioclastic debris rather macerated. Lecompte's "quiescent zone". SMF-9. Jenik and
Lerbekmo 1968, Plate 2, Fig.l.
4D. Globular stromatoporoid-bearing shelf wackestone-packstone in biostromal layers. A
few corals and red algae are included. Matrix contains organisms typical of normal
marine limestone. The Cairn Formation of the Canadian Rockies is typical. They may
have formed just below wave base in very shallow shelf water. Special variety related to
SMF-9. Fischbuch 1968, Plates 12, 13 (Plate XVII).

Gentle slopes on banks
5D. Coral beds. Large heads of dendroid and fasciculate Rugosa such as Disphyllum and
massive forms such as Phillipsastraea, dendroid stromatoporoids like Stachyoides. Ma-
trix is bioclastic wackestone; particles have no micritized rinds. Relatively low on slope
in an argillaceous environment. Lecompte's "below turbulence zone". Termed coral
baffiestone by Embry and Klovan (1971) who give examples from the Arctic. Water
depth estimated as 20-30 m.
6D. Tabular stromatoporoids (25-50%) with much Stachyoides (dendroid stromatopo-
roids), sorted packstone-wackestone texture. Also includes angular nonsorted bioclasts
without micritized rinds. Biota is normal marine and varied, with brachiopods and
crinoids. Midslope "pure" limestone facies, nonargillaceous environment-associated
with coral beds in some examples, Lecompte's subturbulent zone. Termed coral-tabu-
lar stromatoporoid "bindstone" by Embry and Klovan (1971). Depth estimate from
10-20 m. Fischbuch, 1968, Plates 16, 17 (Plate XVIII).
7D. Stachyoides thickets. Boundstone with many irregular dendroid forms and some tabu-
lar stromatoporoids. Brachiopods, crinoids, and red algae. Some grainstone-packstone
down middle of slope. Fischbuch, 1968, p.19.

Bank margin facies
8D. Massive-irregular stromatoporoids. Middle of marginal slope with grainstone-pack-
stone matrix; much Stachyoides, red algae and normal marine bioclasts with micritized
rims. Fairly agitated water. Lecompte's "Zone of Turbulence," probable water depth of
few meters (Plate XVII).
9D. Massive-irregular stromatoporoid with wackestone interstitial matrix. Grades bank-
ward to backreef facies. Top of marginal slope. No normal marine bioclasts, more
spherical stromatoporoids. Includes much Stachyoides. Embry and Klovan's depth
estimate is from 10 m to sea level. Jenik and Lerbekmo, 1968, Plate 6, Figs. 1,2.
1OD. Bioclastic calcarenite, wackestone-packstone, not much stromatoporoid. Normal ma-
rine fauna, locally with onkoids; alternating with stromatoporoid beds all along slope
and front of bank; includes also Amphipora, a backreef organism which is probably
allochthonous in the marginal environment. SMF-9. Fischbuch 1968, Plate 10; Jenik
and Lerbekmo, 1968, Plate 4, Fig. 5.
Bank interior facies
11 D. Biostromes of Amphipora, a tiny spaghetti-like stromatoporoid in a pellet mudstone-
wackestone matrix. Some pellet calcarenite packstone. Microfauna of radiosphaerid
ca1cispheres and the foraminifera Parathurammina. Special biostrome with a variety of
SMF-6. Fischbuch, 1968, Plate 6, Fig. 1 (Plate XIX).
12D. Pellet calcarenite with ca1cispheres and foraminifera and no Amphipora. SMF-18.
Fischbuch, 1968, Plate 4, Fig. 2, Plate 9 (Plate XIX).
13D. Laminites offenestral algal mats. Some Amphipora. SMF-19. Fischbuch, 1968, Plate 5,
Fig.l.