Beneath the vast waters of the World Ocean, researchers have charted a concealed natural laboratory, symbolically dubbed our planet’s “golden kitchen.” It is precisely here, in the convergence zones where oceanic tectonic plates subduct beneath one another, that unique volcanic island arcs materialize, characterized by an astonishingly high concentration of the precious metal. Specialists debated for many years regarding the rationale behind this peculiar phenomenon, striving to comprehend the true nature of such rich deposits. A research contingent, spearheaded by marine geologist Christian Timm from a German scientific facility, has managed to uncover fresh insights into these inquiries. The experts concluded that the pivotal element enriching the rocks with gold is a specific, multi-stage melting process occurring within the water-saturated mantle. Under these extreme conditions, the deep-seated rock functions as an intricate mechanism, repeatedly concentrating minute particles of the valuable substance. To substantiate their hypothesis, the scientists gathered 66 samples of volcanic glass from the seabed north of New Zealand. These singular natural glasses are formed when superheated lava rapidly cools in the frigid water, thereby preserving the magma’s initial chemical makeup untouched. Detailed scrutiny revealed that the gold content in these specimens several times surpasses figures found in typical magmas originating from mid-ocean ridges. “Upon analyzing these samples, we noted that the gold concentration within them was often multiplied several times over,” the head of the scientific team emphasized. Scientists have moved closer to reviving the extinct Tasmanian Tiger. It emerged that the mantle in these specific areas undergoes liquefaction at exceptionally high temperatures in the presence of water. Researchers initially posited that water originating from the subduction zone directly regulated the gold accumulation, but it turned out that its role is merely to facilitate the melting process itself. The principal driver is, in fact, the high degree and recurrence of material reprocessing. Gold within the mantle is usually bound within sulfide minerals; under intense melting, these minerals completely disintegrate, liberating their entire precious metal content into the molten magma. “Our findings indicate that gold enrichment is not the outcome of a solitary melt event, but rather a process comprising multiple phases,” the scientist added. This discovery offers a completely novel perspective on how gold-rich ore bodies form around island arcs. It serves to prove that chemical alterations deep within the mantle are just as crucial as processes occurring closer to the Earth’s surface. As Christian Timm summarized, the specialists managed to observe the very initial phase in the life cycle of this precious metal—the moment it begins its lengthy transit from the planet’s depths toward the vents of future volcanoes. This truly geological marvel originates long before the gold ever reaches the Earth’s surface.
Source: https://sciencexxi.com/morskie-geologi-nashli-nastoyaschuyu-zolotuyu-kuhnyu-zemli-gluboko-pod-okeanom/
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