Hydrothermal Vents and Mineral Emission

White and Black Smokers

• White smokers have lower temperatures (30–350°C) and emit lighter-colored minerals primarily calcium, barium, and silicon.
• Black smokers have higher temperatures (up to 400°C) and emit darker mineral particles, mainly iron and sulfur.
• Both are mineral-laden water plumes emitted from hydrothermal vents.
• Location: Oceanic ridges and volcanic areas (e.g., hotspots). Average depth ~2,000m.
• Extremophiles (bacteria, tube worms, clams) inhabit these environments.

Hydrothermal Fluids

• Water (H₂O) and carbon dioxide (CO₂) are common volatiles.
• Considered fluids at modest temperatures and pressures due to their ability to dissolve and transport materials. The critical point occurs when the volume change from gas to liquid becomes zero, and they're no longer different phases.
• Other volatiles: Hydrogen sulfide, methane, nitrogen.

Gold, Silver, and Copper Alloys

• This ternary system forms a continuous solid solution (gold readily mixes with silver and copper indefinitely).
• Atomic structure: Face-centered cubic (FCC) lattice.
• Bonding: Metallic bonding.
• Properties: High conductivity, malleability.
• Specific gravity: Gold > Silver > Copper.
• Color change with composition: Gold (yellow) > Silver (white) > Copper (red). Greater ratios of gold give yellow, greater ratios of copper give red, greater ratios of silver give whitish colors.

Cinnabar and Gold Extraction

• Cinnabar (HgS): Mercury sulfide used in gold extraction by amalgamation.
• Process: Heating cinnabar to release mercury, which then combines with gold (amalgamation).
• Environmental Concerns: Mercury pollution and toxicity.

Quartz Veins and Ore Deposits

• Quartz veins often host gold and other ore minerals.
• Formation occurs through hydrothermal processes associated with large igneous systems.

Gossan and Ore Bodies

• Gossan: Oxidized weathered zone of ore bodies, indicates sulfide ores beneath.
• Minerals by Zone:
  • Gossan: Iron oxides
  • Leached zone: Clays, oxides, carbonates
  • Enriched zone: Copper, silver, gold
  • Primary ore: Sulfide minerals

Realgar

• Realgar (As₂S₂): Bright red arsenic sulfide mineral.
• Nickname "Powder of the Mine" for its powdery form and use in early mining.

Resource Curse

• Countries with abundant resources often face economic and political challenges due to dependence.

Acid Mine Drainage

• Acid mine drainage forms when exposed sulfide minerals react with water to form sulfuric acid, contaminating waterways and harming ecosystems.

Environmental Effects of Mining

• Environmental effects include deforestation, habitat loss, water contamination, air pollution, and soil erosion.

Deepest Gold Mine

• Located in South Africa, approximately 4 km deep.
• New drilling target: 4.5 km.
• Discovery: Early 20th century
• Temperature: Up to 60°C (from Earth's core heat)
• Main danger aside from blasting: Rock bursts due to pressure.
• Gold origin: Ancient placer deposits (conglomerate rocks).
• Age of gold: Very old.
• Extraction: Crushing, grinding, cyanidation.
• Blasting safety: Keep mouths open during blasts to prevent eardrum damage from pressure changes.

Explore the fascinating world of hydrothermal vents with this quiz. Learn about the differences between white and black smokers, the unique extremophiles they host, and the role of hydrothermal fluids. Test your knowledge on the mineral-laden plumes found in these extreme environments.