An Inland Salt Anomaly
The Janghangsaneseupji Saline Wetland presents a geological puzzle: a salt marsh ecosystem existing without a connection to the modern sea. Its salinity originates from ancient seawater trapped within layers of sediment. This phenomenon occurs in depressions where saline groundwater seeps to the surface. Over long periods, evaporation concentrates the salts in the soil and water, since local evaporation rates exceed the input from rainfall and runoff. The water source is entirely non-tidal, distinguishing it from typical coastal salt marshes.
The geological history of the Buan region, part of the Jeonbuk West Coast National Geopark, provides the context for this formation. The area has a complex series of rocks, with foundations of Precambrian metamorphic rock, intrusions of Jurassic-era granite, and extensive layers of volcanic and sedimentary rock from the Cretaceous period (145 to 66 million years ago). During periods of geologic activity and changing sea levels, pockets of marine water and salt-rich sediments became isolated inland. This trapped brine, percolating through the ground, now emerges at the surface, creating the saline conditions that define the wetland. The soil salinity can exceed 18 parts per thousand, creating a chemical environment hostile to typical freshwater plants.