Hi @JandJ, if you are chasing further detail then Guyana Gold have some good technical reports available on their website that are worth a read. Whilst their 3.3 million Oz Aurora Gold Mine lies in the adjacent Cuyuni belt, it still provides a good analogue for what Alicanto are chasing both at Ianna and Arakaka. North-East to North-West trending structures formed during the Trans-Amazonian Orogeny appear to be the key link. The following provides a decent overview taken from technical reports from both companies:
Regional Geology
The Guiana Shield (Shield) is the northern Amazon Craton, which was part of the West African Craton until the Atlantic Ocean opened about 115 Ma ago. The Amazon Craton was divided into provinces based on age determinations, structural trends, proportion of lithologies and geophysical trends. The Proterozoic greenstone areas of Guiana are in the Pastora-Amapa Province (2.2 Ga to 1.95 Ga} and consists of metavolcanic and metasedimentary rocks. Tropical weathering has transformed the upper 100 m of the Shield into a saprolite, highly variable in thickness but which can be mined at a relatively low cost.
Local Geology
The Barama, Cuyuni and Mazaruni are the greenstone belts in Guyana. The Aurora Prospect is in the Cuyuni belt, which consists of, basalts, overlain by andesite-rhyolites, overlain by shales and graywackes. Ultramafic and carbonate rocks occur locally. Most rocks were deformed by the Trans-Amazonian Orogeny (2.0 Ga). Brittle faults trending north-northwest or north-northeast were intruded by mafic dikes and north- northeast faults displaced mineralized zones.
Project Geology
The Ianna Gold Project covers greenstone belts and intra belt granitoids of the Barama- Mazaruni supergroup of the Paleo-Proterozoic Guiana Shield. The oldest rocks within the concession are interpreted to be tholeitic to calc-alkaline basalts, andesites and volcaniclastic sediments. Predominately mafic, volcano-sedimentary and conglomerate packages dominate the younger parts of the local stratigraphy. Numerous phases of plutonic activity have intruded the earlier sequences ranging from gabbroic to granitic in composition. Known mineralisation is structurally controlled and widely associated with arsenopyrite, pyrhotite, iron carbonate, sericite, pyrite and locally albitic alteration. Both the volcano-sedimentary packages and the intrusive rocks host mineralisation in the project area. Exploration is targeting orogenic and intrusion related gold mineralizing systems.
