Global gold resources are highly concentrated. According to USGS 2024 data, over 90% of the world’s gold reserves are held by 18 countries, including Australia, Russia, and South Africa. By continent, Oceania holds the largest reserves at 13,100 tonnes (about 22.20% of the global total), followed by Europe (mostly Russia) with 18.81%, and Africa with 16.31%.
Based on occurrence and formation, gold deposits are broadly classified into lode gold (primary), placer gold (secondary), and nugget gold (native). Geogenetically, they include magmatic-hydrothermal, sedimentary (placer), metamorphic, volcanic, and seafloor hydrothermal vent types.
Lode gold deposits refer to gold hosted in primary bedrock, usually as invisible micro-fine particles (0.001–0.1 mm) within quartz veins or sulphide orebodies, requiring processing and smelting for extraction. They encompass a wide variety: conglomerate-hosted, greenstone-belt type, quartz-vein type, ductile-shear-zone type, Carlin type, porphyry type, epithermal, and volcanic-hosted deposits.
- Quartz-vein type: gold particles embedded within quartz veins.
- Porphyry type: associated with volcanic and intrusive rocks, gold enriched in fractures and pore spaces during magma cooling.
- Carlin type: a distinct micro-disseminated style, mainly found in Nevada (USA) and the Yunnan–Guizhou–Guangxi region of China.
Placer gold deposits are formed when primary gold ores weather and are transported by water, accumulating in riverbeds, paleochannels, or coastal sands as grains or flakes. They originate from mountain lode gold, freed from quartz veins by river erosion, and are a major component of gold resources.
Placers are divided by age into ancient (paleoplacer) and modern types. Ancient placers include Precambrian auriferous conglomerates or gold–uranium conglomerates, often large in scale and economically significant. Modern placers, formed since the Quaternary, include residual, deluvial, alluvial, lacustrine, and coastal varieties.
By-product gold deposits occur when gold is associated with pyrite and base-metal sulphides (Cu, Pb, Zn, Ni) through a complex magmatic-to-hydrothermal history. These deposits are processed primarily for non-ferrous metals, with gold recovered as a by-product—an important supplementary source of gold supply.
Global Gold Resource Distribution
Global gold resources are heavily concentrated. According to USGS 2024 data, more than 90% of reserves are held by 18 countries, led by Australia, Russia, and South Africa. By continent, Oceania ranks first with 13,100 tonnes (22.20% of global total), followed by Europe (mainly Russia) at 18.81%, and Africa at 16.31%.
Post time: Jul-06-2026
