Hey thanks ya'll. The shell mound tops that are exposed are only about 2% of whats there under the mud.. The gooey stuff is about 2 inches to a foot thick depending. ( mud under water acts as a self-leveler, filling all the valleys and high spots) I probbed the area about 30 years ago and found how far out they ran. I even lost my boots in the process when I found a bigggggggg hole between shell piles and sank to my hips.
Every square foot is loaded with bone, pottery ,and the tiniest flint debitage you ever did see. The shell midden is resting on the Texas Grey Clay foundation. In some spots the shell is three feet deep below the mean water level, and I've found points and tools from the archaic forward here. This area is spread out pretty good with an average projection from the shoreline about 30 feet and it's about 400 feet long.
Here's some of the first points I found there years ago. Thanky Lone Star