China’s rare earth dominance runs deeper than expected, geological study finds

China's Bayan Obo mine, already the world's largest rare earth deposit with 100 million tonnes in reserves, may be far bigger than previously thought. New geological research reveals the deposit formed across two volcanic stages — 1.32 billion and 430 million years ago — pushing vast mineral reserves deep underground. Shallow zones alone hold an estimated 333 million metric tons, but extracting deeper reserves remains costly and technically challenging.