How do I collect from an Anomaly tile?

Basically it just boosts the normal FIDS yield of the tile it's on - it's not actually a special resource like Glassteel or Emeralds that you have to build an extractor on - it's just a tile that gives more FIDS than normal.

So to extract it, just get a city/borough tile next to it, or on top of it. Reaching out with boroughs to access one of these tiles usually requires getting a bunch of population in your city, and thus a long amount of play time.

The notable thing with anomalies is:

• They tend to give a lot more FIDS than normal - sometimes an even spread of food/dust/industry, but other times just a ton of, say, food.
• They sometimes give 10, or even 20 approval in the specific city that is harvesting them - approval is rare and precious.
• There are special quest-events, buildings, and hero abilities that amplify them. Ardent Mage heroes can mine an extra ~9 or so science from them, and Roving Clans heroes can do the same with Dust. The Cryogenic Monitors can add +15 science (but just in one city). There's also a trait for custom factions - Landscapist that gives them a small amount of extra yields.