Gold Distribution in Oceans and Soil

Short Answer:

It's reasonable to assume that over millions of years, a large portion of the gold that fell into the oceans ultimately ended up on or beneath the seafloor (rather than staying suspended in the water column). However, the exact distribution in seabed sediments varies, and significant hydrothermal and geological processes play a role-not just passive "sinking." As for comparing ocean-water gold concentrations to average near-surface soil, the commonly cited average crustal abundance of gold is around 1-4 parts per billion (ppb), which is higher than 1 gram per 100 million tonnes would suggest. So if you're positing only 1 gram per 100 million tonnes in soil, that's a far lower concentration than mainstream geological estimates.

Expanded Explanation

1. Gold in Seawater vs. Seafloor Sediments

• Ocean Water: Gold does exist in trace amounts-some studies estimate concentrations on the order of parts per trillion (ppt) to parts per billion (ppb), depending on location. Because gold is chemically inert in saltwater, it can remain dissolved (often as chloride complexes) or in microscopic particulate form for a very long time.
• Seafloor Sediments: Over geologic timescales, much of that tiny fraction in the water column can get deposited into marine sediments. Ocean currents, hydrothermal vents, and biological processes redistribute gold. It's not just a matter of "gold is heavy and sinks," but eventually, a lot of it accumulates in or under the seabed.

2. Why a Huge Share Could Be Under Water

Over 70% of Earth's surface is covered by oceans. Meteorite impacts that brought gold to Earth were effectively random, so a significant portion undoubtedly landed in regions now submerged. Some estimates suggest there could be multiple times more gold beneath the seafloor than in all known terrestrial deposits. However, whether it's four times as much-or significantly more or less-remains an open question due to the vastness of ocean basins and limited direct sampling.

3. Comparing to Soil Concentrations

• Typical Crustal Abundance: Many geologists cite an average gold concentration of 1-4 ppb (parts per billion) in the Earth's crust, or roughly 0.001-0.004 grams of gold per tonne of rock/soil.
• "1 Gram per 100 Million Tonnes": This ratio effectively equates to 0.01 parts per trillion (ppt), much lower than the generally accepted 1-4 ppb in crustal materials.
• Discrepancy: Sampling methods, localized geology, and weathering or leaching processes can skew near-surface readings, but standard geochemical data suggests the Earth's crust has a higher baseline than "1 g per 100 million tonnes."

4. Final Thoughts

Large portions of meteorite-derived gold likely impacted areas now covered by water, eventually finding its way into or under the seabed. While gold truly is widespread (though in tiny concentrations), comparing oceanic concentrations to soil must be done carefully. Mainstream geological estimates generally place the average crustal abundance in the 1-4 ppb range, which is still quite low-but notably higher than the ultra-trace levels implied by 1 gram per 100 million tonnes.