More than 150 attended the meeting at the Presbyterian Church in Cromwell, which was organised by anti-mine campaigners.
Meeting facilitator Mark Sinclair said Santana Minerals had "completely failed" to inform the community about its mine proposal, which Santana hopes to undertake using the fast-track legislation.
"They have had posters in a few locations and shared presentations with a few groups, but have not shared with the community.
"We are asking for details beyond the bold claims made."
Community group Sustainable Tarras had forwarded 55 questions to Santana asking for details of its proposal for open-cast and underground mines, but had not received answers.
The questions included asking whether Santana would comply with best practice international mining codes, not just New Zealand regulations.
Mr Sinclair said two community members reported being told by Santana chief executive Damian Spring the mine would look like "a chip in your windscreen from the road".
However, the reality would be a large blot on the landscape with four open-cast mines, the largest about 1km long and wide, a processing plant and a large tailings dam, speakers claimed.
Speakers, including a vineyard owner, and experts in botany and ecology, expressed concerns about loss of biodiversity in a conservation area and damage to the local economy.
Botanist and landscape ecologist Dr Geoff Rogers stressed open-cast mining would "destroy entire residual ecosystems".
Central Otago Environmental Society secretary Matthew Sole said the number of people attending the meeting demonstrated a desire to engage and find out more.
He had been "very disappointed" at the level of information provision by Santana.
"They promised to be open and share and instead are closing down."
Sustainable Tarras co-founder Marilyn Duxson expressed her concerns about the negative impact a large mine would have on the vineyard economy.
Mr Spring was in the crowd and was observed shaking his head.
When asked by the Otago Daily Times about the failure to answer Sustainable Tarras’ questions, he said information would be in the fast-track application and Santana had "done what we can" in terms of community engagement.
