Dr. William Goodman, Mr. David Gnage, Mr. Peter Smith, Ms. Crystal Hocking Town of LeRoy Ms. Lynne Belluscio
Well-known, wild-brining operations at Onondaga initiated the salt industry in New York State in 1789. Lesser-known, nineteenth-century, wild-brining sites (i.e., Montezuma, Galen, and LeRoy) extended across the evaporite-bearing, Silurian Salina Group subcrop belt in glaciated western New York State. Brine from the LeRoy wells was found in direct contact with halite beds; at other wild-brining sites, brine was drawn from glacial sediments and/or red shale of the Salina Group.
Salt exploration at LeRoy began in 1878. The first well hit sour gas and artesian salt water. After a period of corporate intrigue and failed starts, the LeRoy Salt Company formed and began production in 1884, relying on brine drawn from two wells. The company’s wellfield expanded over time to include at least 11 wells. Although ownership of the operation changed over time, salt production at LeRoy persisted until 1928.
Historical records for the LeRoy Salt Company wells confirm the salt-contact source for the brine. Wild-brining sites at Onondaga, Montezuma, Galen, and LeRoy indicate that the regional, salt- contact, brine aquifer extends across the northern rim of the Appalachian Basin for at least 150 kilometers (km).
The geochemistry of saline waters at LeRoy is stratified. Formation waters containing problematic magnesium chloride (MgCl2) are present in the Bertie Group that overlies the Salina Group and were cased off in the brine wells. The water in contact with halite beds was relatively pure (> 96%) sodium chloride brine with less than 0.05% MgCl2. Geochemical stratification of saline water types suggests that vertical, cross-formation water flow may not be the principal recharge mechanism for the brine aquifer. Instead, formation-parallel, early Tertiary preglacial or Pleistocene subglacial water injection into the scarp slope of the basin margin is proposed as the recharge mechanism. Bedding planes and fractures in the bedrock scarp slope that faced advancing glaciers were likely opened by high subglacial fluid pressures. A down-dip wetting front in otherwise dry, evaporitic strata likely migrated southward as the glacial advance continued. In this manner, groundwater was emplaced within the evaporitic stratigraphic sequence to a 5-km distance south of the subcrop belt near LeRoy. During and after glacial retreat, bedding planes and fractures at the subcrop belt that had served as recharge conduits reversed behavior to discharge conduits. The term “pocket aquifer” is proposed for this hypothesized glacial aquifer for which there is no down- dip discharge zone. Brine springs still dot the Salina Group subcrop belt and suggest that postglacial depressurization of the glacial “pocket aquifer” continues.
|Create Date||July 6, 2018|