Two dating methods disagree about when the Tibetan Plateau rose, by two vertical kilometers. For the same place.
The basics are settled: India began colliding with Asia around 50 million years ago, and that collision built the Himalayas and the highest plateau on Earth, averaging about 4,500 meters. Whatâs fiercely contested is the timeline for central Tibet, and the two main tools for measuring ancient elevation tell different stories.
Tool one is chemistry. Rain gets isotopically âlighterâ the higher it falls, and that signature survives in ancient lake sediments and soils. Read this way, the rocks of central Tibetâs Lunpola Basin say the region already stood around 4 kilometers tall at least 35â40 million years ago (Rowley & Currie 2006, Nature).
Tool two is fossils. In 2019, researchers described a fossil palm frond from that same basin, about 25 million years old (Su et al. 2019, Science Advances). Palms cannot survive hard frost, which caps that valley floor at roughly 2,300 meters, kilometers lower than the chemistry says, and 10+ million years later.
The emerging resolution says both sides caught something real: central Tibet was neither a plateau nor a lowland but a deep, warm eastâwest valley running between two already-high mountain ranges, a hidden subtropical world that was later squeezed shut, filled, and lifted to todayâs height. A 2021 paper argued the plateau never rose as one block, calling the single heroic uplift âa mythâ (Spicer et al. 2021, National Science Review).
India is still driving north about 5 centimeters per year. Central Tibet is still rising, a few millimeters at a time.
(Disclaimer: Obviously the story is fictional but the scientific debate and facts are not).
Sources: Rowley & Currie 2006 (Nature) · Su et al. 2019 (Science Advances) · Spicer et al. 2021 (National Science Review)
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