Physics

Geology

Soil water

Organic chemistry

Seawater

Drainage basin

Oceanography

Soil production function

Geochemistry

Paleontology

Soil science

Geography

Pedogenesis

Nuclear physics

Chemistry

Earth science

Continental margin

Silicate

TRACER

Cartography

Tectonics

Weathering

Proceedings of the National Academy of Sciences

Significance The potassium stable isotope system is a powerful new geochemical tool for understanding continental weathering linked to Earth’s climate. Potassium isotopes fractionate strongly during silicate weathering, and δ 41 K values in riverine dissolved loads correlate with the silicate weathering intensity of drainage basins. We provide an estimate of the δ 41 K value for the global riverine input into the oceans and demonstrate the sensitivity of δ 41 K in seawater to the continental silicate weathering process.

K isotopes as a tracer for continental weathering and geological K cycling