Found a strange formation

[desert-rat]

this formation sticks up for the desert floor and is about as big as an average house. It has been over with a fine tooth comb. This rock looks like a telephone pole after the woodpeckers got done with it from all the people that have pecked at it. Has anyone seen this before? What caused it to form?

 

[Clay Diggins]

Those are concretions. The main body is composed of an ancient mud lake bottom and the crystal cavities are usually Calcite with a rind of Aragonite and/or Siderite. All those minerals are carbonate based.

The theory is that when the lake bed dried out there were pockets formed in the clay that were filled with mineral rich fluids over time. Being a dry lake bed the most common soluble mineral was usually some form of Carbonate. In the case of Calcite that is Calcium Carbonate, Aragonite also a form of Calcium Carbonate and Siderite is Iron Carbonate. The mineral fluid pockets led to lining the cavity with crystals of the Carbonates and later with heat and pressure formed a rock with hollow crystal vugs.

Heavy Pans