Florida spring

St Marks Sulfur Spring 1

A small sulfur-rich vent located on the west bank of the river, a short distance downstream of the major river rise. The spring issues through a crack or fissure in the limestone bottom, and is identified by a visible surface boil, a strong sulfur odor, and white sulfur‐bacterial mats coating submerged vegetation and adjacent banks. The pool is modest in size—approximately 12 ft (~3.7 m) across—and encircled by aquatic vegetation (hydrilla and elodea) and cypress/tupelo floodplain forest.