031020c

Microcoprolites made by callianassid shrimp, Parafavreina ziczac, Jurassic Smackover Formation, south Alabama, thin-section photomicrographs, some of which are stained with Alizarin red S, which stains calcite pink, but does not stain dolomite. Samples from between 2 and 3 miles below the surface

Pellet grainstone within thrombolite, well 2769, 12,306.3 feet, 2.5 mm wide

Pellet packstone, well 1571, 14,688 feet, 2.5 mm wide

 
Pellet packstone, well 10,255, 13,457 feet, 2.5 mm wide



Pellet in mixed particle grainstone, pellet containing burrow in lower right (circular area), well 5432, 12,935 feet, 1 mm wide

 
Intraclast containing pellet in partially dolomitized mixed particle grainstone, well 3988 14,432 feet, 1 mm wide.

 Pellets in partially dolomitized mixed particle grainstone, well 4557, 12,820.5 feet, 2.5 mm wide.

 Partially dolomitized pellet packstone in which some pellets are preferentially dolomitized, well 1903, 11,770.9 feet.2 .5 mm wide

Pelmoldic pellet packstone (pores filled with light blue to very dark blue epoxy), well 1878, 11,789 feet, 2.5 mm wide.

Pine Beach, Alabama, 2002

An unusual storm windrow mostly made out of favreinid fecal pellets. Only time I've ever seen this on the beach, though I have seen one in a rock core more than 100 million years old.*

The windrow was quite extensive. It consisted almost entirely of fecal pellets of callianassid burrowing shrimp. This green-gray blanket was deposited by Tropical Storm Isidore. How did the stormsort out just these soft & fragile cylindrical pellets?




*West Appleton oil field, Jurassic Smackover Formation, samples from a couple of miles underground.