North Cork – Fermoy Block
Situated in NE County Cork, the Fermoy block presents a dual exploration target: for Irish-type zinc-lead and Tullacondra-type copper-silver in Lower-Carboniferous carbonates. The licence block covers an area of approximately 483 km2 and is comprised of fourteen (14) prospecting licenses.
The area was primarily considered a copper target due to the similar geology and structure with the adjacent Tullacondra Cu-Ag deposit (3 Mt @ 0.7% Cu, 29 g/t Ag) whereas the potential for Irish-type zinc-lead mineralization was largely disregarded/ignored. To date only six (6) holes have been drilled on the block (Moore Park) to test the basal Waulsortian. Recent review of the drill logs and geochemical maps suggests that the block is more structurally complex than originally understood and that the geochemical anomalism has not fully tested.
Five prioritised targets were identified on the block based on review of historic geochemical sampling, structure, and stratigraphy:
- Moore Park: Shallow and Cobra soils returned maximum Zn values of 852 ppm and 570 ppm respectively. Drill testing of the basal Waulsortian contact revealed the structural complexity of the area but did not intersect significant mineralization.
- Careysville: Shallow and Cobra soils returned maximum Zn values of 300 an 1100 ppm Zn, respectively. Pilcon drilling confirmed the Zn anomalism and IP over the area revealed an E-W trending zone of weak chargeability while gravity surveys noted a coincident gravity high.
- Derryvillane: Veinlets hosting galena and sphalerite were noted within dolomitized mudbank micrites closed to the faulted basal contact. Shallow soils returned maximum values of 278 ppm Zn and 260 ppm Pb.
- Bettyville: Malachite-stained brecciated calcite veins containing chalcopyrite hosted in weathered limestones and traces of sphalerite noted on basal limestones. Copper in shallow and Cobra soils in excess of 119 and 190 ppm, respectively. A Zn value of 1645 was returned from samples overlying basal sub-Waulsortian. Dipole-dipole IP revealed a small chargeablity anomaly associated with geochemical anomalies.
- Mitchelstown: Zn and Pb anomalism occurs near the inlier margin with shallow soils samples returning maximum values of 270 ppm Zn and 229 ppm Pb.
Modern exploration effectively ceased on the MFM licences in 2002 and the area would benefit from data capture and assessment, a tectono-stratigraphic view, site visits, and exploration employing modern techniques.