Al dating system

29 Feb

ost meteorite experts believe that CAIs and chondrules formed in the solar nebula by high temperature processes. These shock waves moved through the dusty cloud at supersonic speeds, produced frictional heating, and melted the dust particles.

These processes included condensation, evaporation, and, for all chondrules and many CAIs, subsequent melting during multiple brief heating episodes. According to the jet flow model developed by Frank Shu (University of California, Berkeley), chondrules and CAIs formed near the Sun (at ~0.04-0.08 AU) by sunlight and radiation associated with solar flares and were transported later to the asteroid belt region by a bipolar outflow [see articles Relicts from the Birth of the Solar System and The Oldest Metal in the Solar System for more information.] Ages (relative or absolute) of CAIs and chondrules can provide important constraints on their origin, but past calculations are either controversial or insufficiently precise.

Or lead might have migrated into the chondrule when the rock was heated in an asteroid.

hondritic meteorites (chondrites), the oldest rocks in our solar system, provide a significant record of the processes that transformed a disk of gas and dust into a collection of planets, moons, asteroids, and comets.

They are considered to be the building blocks of the inner planets, Mercury, Venus, Earth, and Mars.

We also report the On lead isotope plots, materials with the same age will fall along a single line.

The data for chondrules from Acfer 059 (solid line) and for CAIs from Efremovka (dashed lines) define precise lines and indicate ancient ages.