isotope geochemistry

Eastward Growth of the Tibetan Plateau Linked to Cenozoic Orogenic Wedge Deformation and Fluctuating Melt Sources

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Digital elevation map of the southeastern Tibetan Plateau showing sample locations and major faults.

Scientists studied granitoids from the Kangding area in the southeastern Tibetan Plateau, using new elemental and isotopic data, including the first silicon isotope measurements for these rocks, to trace how the plateau’s crust grew eastward over the last 35 million years. The granites fall into two groups, and one of them shows a temporary shift … Read more…

PNAS: High 3He/4He in central Panama reveals a distal connection to the Galapagos plume

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Significance We report the discovery of anomalously high 3He/4He in “cold” geothermal fluids of central Panama, far from any active volcanoes. Combined with independent constraints from lava geochemistry, mantle source geochemical anomalies in Central America require a Galapagos plume contribution that is not derived from hotspot track recycling. Instead, these signals likely originate from large-scale … Read more…