Strange Calcium Carbonate Structures

[Smotzer]

So myself and a client were digging at our calcium carbonate spot that it is Spring Branch Texas with these being found in Glen Rose Formation (maybe upper im not sure). We are trying to loosen at least couple hundred (lbs or kg) chunk of calcium carbonate. These were found on the edge of the chunk and along side a a large piece of fossilized mollusk with a spiral shell (I will take a picture and upload it). I have pulled a couple hundred kg of calcium carbonate out from the spot but these were deeper down and did not look entirely geological in structure, they are extremely irregular and the crevasses in the calcium in some places go all the way through. Can anyone lend a light on how these ribs and banding formed, or what I am looking at, every other piece I have dug out have all been solid and these are completely set apart. Please let me know if anyone needs more information, or pictures!

 

 

 

 

[Smotzer]

Could this be layers of bacteria?? 

[Wrangellian]

Are there caves in that area? The first one in particular reminds me of the 'drapery' formations you sometimes see in caves. Evidently the voids were later lined with crystals.

[JohnJ]

10 hours ago, Wrangellian said:

Are there caves in that area? The first one in particular reminds me of the 'drapery' formations you sometimes see in caves. Evidently the voids were later lined with crystals.

 

There are caves and other smaller karstic features in the area.  I agree with Eric that this appears to be a speleotherm.

[Myrmica]

Or possibly deposits formed a spring; one at which calcium carbonate was being deposited?