Placer mining

Placer mining (/ˈplæsər/)[1] is the mining of stream bed (alluvial) deposits for minerals.[2] This may be done by open-pit (also called open-cast mining) or by various surface excavating equipment or tunneling equipment.

Placer mining is frequently used for precious metal deposits (particularly gold) and gemstones, both of which are often found in alluvial deposits—deposits of sand and gravel in modern or ancient stream beds, or occasionally glacial deposits. The metal or gemstones, having been moved by stream flow from an original source such as a vein, are typically only a minuscule portion of the total deposit. Since gems and heavy metals like gold are considerably denser than sand, they tend to accumulate at the base of placer deposits.

Placer deposits can be as young as a few years old, such as the Canadian Queen Charlotte beach gold placer deposits, or billions of years old like the Elliot Lake uranium paleoplacer within the Huronian Supergroup in Canada.[3]

The containing material in an alluvial placer mine may be too loose to safely mine by tunnelling, though it is possible where the ground is permanently frozen. Where water under pressure is available, it may be used to mine, move, and separate the precious material from the deposit, a method known as hydraulic mining, hydraulic sluicing or hydraulicking.

Etymology
The word placer derives from the Spanish placer, meaning shoal or alluvial/sand deposit, from plassa (place) from Medieval Latin placea (place) the origin word for "place" and "plaza" in English.[4] The word in Spanish is thus derived from placea and refers directly to an alluvial or glacial deposit of sand or gravel.
...
https://en.wikipedia.org/wiki/Placer_mining


Позната су испиралишта злата на златоносним рекама: Пеку, Буковачкој реци, Лисичјем потоку, Комчи, Речици;У долини Млаве, у Новаковом потоку, откривена су стара окна и галерије. У Великом Бубњу и Јокином потоку откривени су пирити и златоносни кварц.
https://sr.wikipedia.org/wiki/Племенити_метали_у_Србији



　In June 2022, a symposium was held at the International University of Japan in Niigata Prefecture, where Sado Island is located, to publicize the cultural value of the gold mines. Sado Island, 40 km off the coast of the prefecture and covering 855 km2 in the Sea of Japan, has two types of gold deposits. ***The Nishimikawa area has a placer gold mine where sandy gold is found in the layers of sediment***. The Aikawa-Tsurushi area, on the other hand, has lode deposits where gold lies in the veins that penetrate through the rocks. The different characteristics of these gold mines led to different mining techniques. ***In Nishimikawa, miners used water flowing from artificial reservoirs to extract the placer gold***, while in Aikawa-Tsurushi, advanced techniques were developed for efficient mining, such as digging drainage or ventilation tunnels separately from the main tunnel.

https://www.japan.go.jp/kizuna/2022/06/sado_island_gold_mine...

placer gold mine = злато се добија испирањем наноса, не копањем рудних окана.

https://yandex.ru/search/?text="испиралишта"
https://yandex.ru/search/?text="испиралиште"