Garnet crystals helped reconstruct history of tectonic plate movement - New issue of Science News "Reverse" In a study published October 1, 2026, in Nature Geosciences, scientists examined an ecologite from Suki Tov Island in eastern Papua New Guinea. Garnet crystals preserve microscopic inclusions of minerals formed at various stages of immersion. Particularly important was coesite, a type of silicon dioxide that is stable only at very high pressures. Its presence shows that the rock sank deeper than about 90 kilometers. But different regions of a single garnet crystal told an even more complex story. At depths of about 45 kilometers, the rock was unexpectedly hot: the estimated temperature gradient was about 470 degrees per gigaPascal. The regime then changed abruptly, and further subsidence occurred under much colder conditions typical of a mature subduction zone. The new work is important for reconstructing the history of Earth's tectonics. Based on the temperature of metamorphic rocks, scientists try to determine when modern plate tectonics appeared on the planet. If the maximum stress does not always reflect the entire path of the rock, some previous estimates of ancient subsidence zones may need to be revised. Read the transcript of the program on the Echo website. Listen to the program live on the Echo app or on YouTube.

Garnet crystals helped reconstruct history of tectonic plate movement - New issue of Science News "Reverse" In a study published October 1, 2026, in Nature Geosciences, scientists examined an ecologite from Suki Tov Island in eastern Papua New Guinea. Garnet crystals preserve microscopic inclusions of minerals formed at various stages of immersion. Particularly important was coesite, a type of silicon dioxide that is stable only at very high pressures. Its presence shows that the rock sank deeper than about 90 kilometers. But different regions of a single garnet crystal told an even more complex story. At depths of about 45 kilometers, the rock was unexpectedly hot: the estimated temperature gradient was about 470 degrees per gigaPascal. The regime then changed abruptly, and further subsidence occurred under much colder conditions typical of a mature subduction zone. The new work is important for reconstructing the history of Earth's tectonics. Based on the temperature of metamorphic rocks, scientists try to determine when modern plate tectonics appeared on the planet. If the maximum stress does not always reflect the entire path of the rock, some previous estimates of ancient subsidence zones may need to be revised. Read the transcript of the program on the Echo website. Listen to the program live on the Echo app or on YouTube.