Related Experiment Video
Updated: Jul 12, 2026

Separation of Uranium and Thorium for 230Th-U Dating of Submarine Hydrothermal Sulfides
Published on: May 20, 2019
Himalayan tectonics, weathering processes, and the strontium isotope record in marine limestones
Abstract:
The time evolution of the isotopic composition of seawater strontium (the ratio of strontium-87 to strontium-86) over the last 500 million years has the form of an asymmetric trough. The values are highest in the Cambrian and Recent (0.7091) and lowest in the Jurassic (0.7067). Superimposed on this trend are a number of smaller oscillations. Consideration of the geochemical cycle of strontium and the dynamics of weathering shows that only Himalayan-style continental collisions can influence the isotope ratio on the scale observed. The contemporary Himalayan orogeny is by far the largest since the late Precambrian Pan-African event that produced the high in the Cambrian.
Related Concept Videos
Global Climate Change
The Fossil Record
Diversity of Protists III
Radioactive Decay and Radiometric Dating
Skeleton and Calcium Homeostasis
The Sulfur Cycle

