http://www.psrd.hawaii.edu/June14/Mars-meteorite-ages.html

The Importance of WhenThe Importance of When

Two important age studies of Martian meteorites:

Clasts in Black Beauty impact melt breccia

Baddeleyites in shergottite NWA 5298

Evolved, alkalic clasts in Black Beauty sample NWA 7533 indicate an early age for crust formation on Mars. Ages of baddeleyite crystals in NWA 5298 indicate that shergottites are young.

Evolved, alkalic clasts in Black Beauty sample NWA 7533 indicate an early age for crust formation on Mars. Ages of baddeleyite crystals in NWA 5298 indicate that shergottites are young.

http://www.psrd.hawaii.edu/June14/Mars-meteorite-ages.html

Ancient Clasts in Black BeautyAncient Clasts in Black Beauty

http://www.psrd.hawaii.edu/June14/Mars-meteorite-ages.html

Shergottite Age ConundrumShergottite Age Conundrum

Pb isotopic data indicate old ages for Martian meteorites, including shergottites.

But internal isochrons suggest young ages for shergottites.

(From Borg et al., 2003, GCA, v. 67(18), p. 3519-3536.)

http://www.psrd.hawaii.edu/June14/Mars-meteorite-ages.html

Baddeleyite Data Suggest Shergottites Are YoungBaddeleyite Data Suggest Shergottites Are Young