In Shovel Knight what's special about the sparkling pits?
Solution 1:
You can buy a fishing rod in the first town; use it like any other item while facing a sparkling pit to enter a basic fishing minigame like the kind in Animal Crossing or what have you - use the item again when an exclamation mark appears above Shovel Knight's head to catch a fish.
These fish are either worth money, or will refill an empty ichor chalice.