The formations at the Apa High include metamorphosed limestone of Vendian Age and granites, metasediments, mafic gneisses and granitoid-pegmatititic intrusvies of Late Proterozoic age.[1] The Apa high is often considered the southernmost outcrop of the Central Brazilian Shield (also called Guaporé Shield) which is sometimes considered to form one sole shield (or at least craton) with the Guyana Shield called the Amazonian Shield.