placer mining
Definition
Noun: - The process of extracting valuable minerals from a placer deposit: This involves separating dense, valuable particles (like gold, diamonds, or tin) from sand or gravel using water. The methods typically include washing, panning, sluicing, or dredging loose sediments, often from riverbeds or beaches.
Usage
- General Context: Describes a specific, often small-scale, mining technique.
- Placer mining was responsible for several gold rushes in the 19th century.
- The environmental impact of placer mining on river systems can be significant.
Advanced Usage
- Contrast with other mining: Often contrasted with "lode mining" or "hard rock mining," which involves extracting minerals from solid rock.
- While lode mining requires tunneling into mountains, placer mining recovers minerals already eroded from their original source.
Variants and Related Words
- Placer (n): A deposit of sand or gravel containing valuable minerals that have been eroded from their original source.
- The prospector discovered a rich placer in the creek bed.
- Placer miner (n): A person who engages in placer mining.
Synonyms
- Alluvial mining: A very close synonym, specifically referring to mining sediments deposited by water.
- Surface mining: A broader category that includes placer mining.
Related Phrases
- Pan for gold: A specific, manual placer mining technique.
- Many tourists try to pan for gold in the old river.
- Sluice box: A channel used in placer mining to separate gold from gravel using flowing water.
Noun
-
mining valuable minerals from a placer by washing or dredging
