My take on this is the greisen, which hosts the lithium mica, is...

My take on this is the greisen, which hosts the lithium mica, is sub-horizontal but the tin veins are sub-vertical. Historic operations targeted the tin veins. I’m guessing the ‘pinge’ is an area where these tin veins came close to surface and were either mined in the pit or there was a breakthrough from shallow underground workings.

Workings for lithium will be back filled to limit the likelihood of collapse. And I have no doubt operations on the Czech side will avoid populated areas as much as possible. I don’t know if this could or would be the case on the German side,