# Ancient rocks reveal when Earth's tectonic engine 'switched on' > HelixNews · Web page: https://helixnews.one/story/349184 · All pages for agents: https://helixnews.one/llms.txt 1 outlet covering · First listed: Phys.org, Nov 10, 2026, 6:10 PM · Read it: Scientists have identified a major turning point in Earth's geological history, when the processes shaping the planet's crust changed dramatically and began to resemble the plate tectonics we see today—about 2.5 billion years ago. ## Who's covering it In the order they published: - Nov 10, 2026, 6:10 PM: [Ancient rocks reveal when Earth's tectonic engine 'switched on']() — Phys.org (Science news) Scientists have identified a major turning point in Earth's geological history, when the processes shaping the planet's crust changed dramatically and began to resemble the plate tectonics we see today—about 2.5 billion years ago.