Amoco well
Outboard reef trend on distally steepened ramp. 

Two major types of reefs may occur both in an outboard an inboard position during latest Kimmeridgian and earliest Tithonian, resp.
Vanderbeck is an outboard reef, Reef is coral dominated at base but  rich in siliceous sponges and microbial crust at top.

Data refer to cement-rich coral-sponge-microbial boundstones and skeletal pack-/grainstones.
Best reservoir quality in shoal grainstone with reefal debris.

Ideal sequence in area
Top
marine shlae
marl
shallow lagoon
debris flow
coral-calcareous sponge microbiolite reef
reefal debris
debris fan
shallow outer ramp
sponge-thrombolite reef
upper deep marine ramp
coral-calcareous algal reef with washover fan
lagoon.

