The Baita Plai mineralisation in geological terms is the most important manifestation of skarnhosted mineralisation in the Apuseni Mountains. The mineralisation hosts a large number of mineral species (about 90), some of which were described for the first time in the world (rezbanyite, szaibelyite or ascharite, and kotoite).

The main economic minerals, notably Cu, Pb, Zn, Au, Ag, Mo, Bi, W, and B, are concentrated in favourable sites due to the interaction of local faults (notably the Blidar contact) and a number of lesser fractures that have localised the mineralised veins, magmatic alteration, and favourable host rock lithologies (limestone and dolomites).

The orebody is hosted within Triassic limestones and dolomites, in faulted contact with underlying Permian shales across the Blidar fault. The skarn alteration is related to a granite intrusion which is interpreted to lie beneath the sediments as at yet an undetermined depth. Dykes of granitic, andesitic and lamprophyre origins cut the sediments at high angles but are reported to be pre-skarn. The host limestones and dolomites have undulating sub-horizontal dips, varying from 0-30 degrees.

A mineralogical study on metallurgical samples sent to Grinding Solutions (UK) was conducted during 2020 in which the main copper bearing minerals were identified as chalcopyrite, bornite and chalcocite, the main lead bearing mineral is galena and the main zinc bearing mineral is sphalerite. The dominan ........

Access to the underground workings is by means of vertical shaft number 1 (V1#) from surface to 13 level, corresponding to an elevation of 619m and 417m respectively. Men and material access to underground is provided via a short adit on 6 level elevation (576m) to V#1.

Further access into the mine is provided by sub-vertical shaft number 3 (SV3#) from the 13- level elevation to the deepest point in the mine on 18 level (elevation at 224.1m). A second sub-vertical shaft, sub-vertical shaft number 2 (SV2#) extends from 13 level to 15 level (elevation of 317.5m).

SV3# is the main transport route for men and material and the tramming of ore to surface. SV2# serves as a second escape way for men via travelling ways between 18 level and 15 level. In addition, SV#2 serves as the main return airway from 18 level through the mine to ventilation shaft at Baia Rosie.

The historical mining method has predominantly been overhand cut-and fill, with stopes being approximately 1.5 - 20m wide although stopes more than 40 meters wide have been observed on old plans. About 80% of the orebody is excavated as ore. Low grade areas are preferentially left as support pillars or, together with waste material, used as backfill in the stopes to fill the void and create working platforms for the drilling and blasting of the hanging wall.

Excavated ore is removed from the stopes using 1m3 pneumatic powered loaders and transported to the ore pass inside the sto ........

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