Mine: Baldur

Location
Found at -8.5 Latitude, -19.3 Longitude. Easily noticeable by the big trees in front of it.

As of patch 0.1.131, all party members enter at the same time. If you are in a party and one party member declines to enter or is offline while still in your party, you will not be able to enter.

Accessing the mine is not possible until you complete the Mission: Find Osiris 1 base, also known as Mark Watney Base.

Dungeon
The mine starts in an open area with a computer desk adjacent to a power switch. Activate this switch and some lights will turn on, once you've activated the power you should go down the stairs, which you'll find near the power switch. At the end of these stairs you'll find an entrance and another power switch to your left; activate the power switch and go deeper into the mine, once you've reached the bottom of the stairs you'll notice a tunnel to your right; before you enter that tunnel look to your left. There should be a cave entrance; enter the cave and you'll find a dead scientist, this is the commander of Osiris 1; Interact with him. After interacting with the scientist go back to the tunnel and walk through it. At the end of this tunnel, you'll find a Dome Kit.

Resources

 * Carbon
 * Iron
 * Lead
 * Aluminum
 * Copper
 * Lithium

Loot
You should be able to find a Dome Kit at the end.