Modifies a noun

• tube: Below, a short phreatic tube, with a gravel floor, leads to the terminal sump.

• rift: A steeply ascending phreatic rift was gained heading north east to reach a point some 45m above the start of the climb.

• passage: Heading along the rift a climb up over boulders, yields a small squeeze to the left into phreatic passage.

• maze: At the bottom of the traverse a phreatic maze leads back to the junction.

• tunnel: Back in the top of Maple Leaf Passage the way on is over a mud bank to a large section of fine phreatic tunnel.

• chamber: The right hand route immediately gains an awkward, tight climb into a phreatic chamber.

Preposition: in

• origin: Geomorphology The cave is basically phreatic in origin, with some vadose modification.