Recognition VISU: Rock of creamy white, with abundant fossils of centimetric size, with some porosity, and very effervescent to be attacked with cold HCl.

MICROSCOPIC STUDY:
Major minerals: Calcite 
Accessory minerals: Opaque 
Texture: Several fossil fragments of centimetric size in a matrix of micritic calcite incipiently recrystallized.

Comments: carbonated sedimentary rock of marine origin, formed by a large amount of fossil organic remains in a micritic calcite matrix with incipient recrystallization.
The fossil organic fragments are composed of a microcrystalline calcite micritic type (grain size less than 5 microns) calcite matrix also largely micritic, observing where the calcite recrystallization reaches 0,0150 and 0,0625 sizes between mm.