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+--- Thread: Plastiglomerate: Far below the planet’s surface, humanity has left its imprint (/thread-7221.html)
Plastiglomerate: Far below the planet’s surface, humanity has left its imprint - C C - Jun 14, 2019
https://www.theatlantic.com/magazine/archive/2019/07/robert-macfarlane-underland/590632/
EXCERPT: On the shores of Kamilo Point, in Hawaii, geologists have identified a new kind of stone. A sediment of recent history, the agglutinated rock displays milky-blue flecks, iotas of dull green, and fibrous orange twists. It is known, because of its unique properties, as “plastiglomerate.” That the name grinds together two familiar-sounding words is a clue to the stone’s qualities as an amalgam. What we are talking about is a rock veined not with metal or quartz, but with plastic. Plastiglomerate forms where polymer flotsam (trash, washed up on the tide line in this instance) is subject to high heat and melts, wrapping together particulate such as shell grit or sand. It then solidifies as it cools. Or, if liquefied plastic drips into hairline fissures in basalt or other porous minerals, what is left behind—a rock crazed with ersatz colors—can also be deemed plastiglomerate. Campfires are one source of that high heat. Plastiglomerate may also emerge along the scorched trail of a wildfire, or it might be cauterized into the ground by lava. It almost certainly appears in places where people burn their rubbish. Call it the birthstone of the age of unintended consequences.
Novel metals and mineraloids are everywhere today, not made by nature but engineered in the course of human industry. [...] Plastiglomerate—neither natural nor fabricated, exactly—may represent the most direct conduit between our current consumer society and the far-flung future. This is how shopping enters the fossil record. Researchers say that in all probability, plastiglomerate will be deposited into top-level strata, plasticizing the landscape itself. But the churning of the planet’s mantle could carry plastiglomerate steadily down, over centuries or longer, to form a seam of crushed consumables underground—as lurid as opal and as imperishable as ore. In cementing together two different types of matter—synthetic plastic and geochemical rubble—plastiglomerate also offers an object lesson in the melding of different timescales.
[...] In Underland: A Deep Time Journey, the British writer Robert Macfarlane pursues the subsurface evidence of today’s major environmental changes, following what trickles down into the Earth and what migrates upward from beneath. This plunge beneath the planet’s topsoil into caves, catacombs, sinkholes, mines, meltwater moulins, and whirlpools opens new terrain to a naturalist whose adventures before now have soared skyward and reached outward. ... Macfarlane’s significant contribution to an emerging canon of popular ecological writing is to articulate how the ground beneath our feet is not an immutable foundation, indifferent to human dominion. Far from it. Whether through the gouging work of multinational corporations, or as an insidious consequence of pollution (and the two are connected), the reach of human activity now extends, more pervasively than ever, into the mineral plane. (MORE - details)