Two things brought me to this idea:
1. The lakes are sometimes disturbing and there is a need to fill them...
2. Need for mining deeper (sometimes, when material goes out)
The machine to do the open cut needs lots of ressources; two kinds exists:
1. Open cut miner
2. Open cut deployer
The miner works exactly like the mining drill (maybe it shows where it digs/fills up currently), except it is much, much faster (maybe fills one belt completely?), covers a much bigger area (aka 15x15), needs only one piece of land as the base, he can't touch and needs lots of power.
As long as it is positioned on a mineable area, it tries to empty the field, like mines. In normal mode, it stops when all is mined.
Switching to mode 2 (autoswitched when placed on an empty area), it digs into the earth and finds by decreasing probability any supply (iron, coal, copper...) and by increasing probability dirt.
Dirt is ... just dirt. Can't be used nowhere but in lakes, to fill them up. Therefore you need the open cut deployer. Any item the deployer gets will be used to fill up lakes. (So you can get also rid of too many trees etc.)
When the miner reaches a limit of X items digged on a piece of land, a piece of lake will be created instead. The other way round is with the deployer: When deploying X number of items, a piece of lake will become land. In both situations, the miner/deployer jump to the next reachable field and continue work.
Optional: Both, miner and deployer have sitches, how deep/high they go. So that the digger/deployer doesn't change the landscape. So a digger has 3 modes: "mineable only", "dig ground", "dig ground to lake" - and the deployer has 2 modes: "fill lake", "fill lake to land"
I think it would be fun to handle the amount of material, that comes out. Perhaps, dirt cannot be destroyed, so the way to put all dirt into a chest and destroy the chest is "not so good".
