Most of the historic placer gold recovered from the Indian River has been from the modern river gravel; however, a significant amount of placer gold has been mined from older deposits, including low-level, intermediate-level and high-level gravel terraces.
Significant placer gold reserves exist in Indian River drainage in various forms. Prospective targets include 1) modern (Holocene) alluvial channels, alluvial fans and tributary gulches; 2) modern (Holocene) low-level buried and/or abandoned alluvial terraces; 3) early to late Pleistocene intermediate-level buried abandoned terraces and alluvial fans; 4) early Pleistocene (pre-Reid) glaciofluvial gravel sequences; 5) Pliocene high-level alluvial terraces (White Channel gravel); and 6) technogenic (tailings) deposits.
Fine-grained placer gold existing in size ranges not recovered efficiently by conventional sluicing operations has been found in alluvial and glaciofluvial gravel and tailings deposits. These deposits may represent an important resource and any future mining operations must address the metallurgical implications to maximize recovery.
