Publication Date:
2019-07-13
Description:
Laser (Ar-39)-(Ar-40) studies of clasts and groundmass in breccia 73255 are presented. They show a variety of ages indicating that some materials lost argon from sites that outgas at low temperature, while other materials have retained argon generated before the breccia-forming event. The estimate for the time of the breccia-forming event from thermal release studies is compared to the upper limit of the event from the laser studies; this work also shows that ages in excess of 4.0 G.y. determined on rocks containing devitrified maskelynite clasts probably have no chronological significance.
Keywords:
LUNAR AND PLANETARY EXPLORATION
Type:
Lunar and Planetary Science Conference; Mar 19, 1979 - Mar 23, 1979; Houston, TX
Format:
text