Placer deposit

{
  "id": "MLC-T-ENV-021102",
  "term": "Placer deposit",
  "field": "Environment",
  "term_source": "Placer Deposit",
  "definition": "1. Mineral deposits consisting of dense, resistant and often economically valuable minerals which have been weathered from terrigeneous rocks, transported to the sea and concentrated in marine sediments by wave or current action.\n\n2. A sedimentary deposit of unconsolidated material (usually gravel in river beds or sand dunes) containing high concentrations of a valuable mineral or native metal, usually segregated because of its greater density.\n\n3. Mineral deposit that has achieved its present distribution through the prior action of moving water or wind. Placers are usually in poorly consolidated materials and are the sources of much, but not all, tin, titanium, rare earths, diamonds, and zirconium, and some gold.",
  "subject": "Natural environments",
  "references": [
    "NOAA Coastal Services Center Glossary of Coastal Terminology",
    "EPA Abandoned Mite Site Characterization and Cleanup Handbook; Appendix A: Acronym List and Glossary of Mining Terms at http://www.epa.gov/superfund/policy/remedy/pdfs/appendix.pdf",
    "Abandoned Mine Lands (AML) Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/placer-deposit/"
}