The final drill results from the surface diamond drilling programme designed to test strike and depth extensions of the mineralisation away from the old historic mine intersected all four metals, with mineralisation defined over 250m and open to the north and the south.
Investors liked the news, with the company's shares up 5.31% Wednesday to 6.84p (US8.85c).
The intersections included 15.63% zinc and lead combined and 90.68g/t silver over 4.1m in one hole; and 15.57% Zn and Pb combined, 1.9% copper and 51.50 g/t Ag over 2m from 150-152m and 9.14% Zn and Pb combined with 92.89g/t Ag over 4.5m from 105-109.5m in another.
A third hole had a copper rich intersection, with 5m grading 4.7% Zn and Pb combined, 1.12% Cu and 29.3g/t Ag from 119.5-124.5m, including 3.5m grading 6.29% Zn and Pb combined, 1.59% Cu and 39.93g/t Ag from 121-124.5m.
Erris said new zinc soil anomalies had defined "parallel trends for further targeting with potential to expand the target zone".
The results built on previous intersections that had confirmed the mineralisation from the old mine continued south of the current workings and opened up new targets in the shale horizons at depth not previously considered prospective.
COO Aiden Lavelle said the recent holes had extended the strike of mineralisation under investigation and some very high-grade intersections of zinc, lead, silver and copper had been discovered.
"The additional surface drill holes have further improved our understanding of the controls on mineralisation and expanded the project potential with good continuity of mineralisation demonstrated south of the old Abbeytown mine," he said.
Going forward, Lavelle said Erris was planning to test the gap between the underground mine and the recent surface drilling using focused drilling from two underground drill pads to give maximum information on continuity and grade.