A 6.5 km diameter crater at 29.674 N, 130.799 E, in the volcanic plains to the northwest of Elysium Mons has been identified as a possible source for the nakhlite meteorites, a family of similar basaltic Martian meteorites with cosmogenic ages of about 10.7 Ma, suggesting ejection from Mars by a single impact event. The dates of the igneous rocks of the nakhlites range from 1416 ± 7 Ma to 1322 ± 10 Ma. These dates plus the crater dimensions suggest a growth rate of the source volcano during that interval of 0.4-0.7 m per Ma, far slower than would be expected for a terrestrial volcano. This implies that Martian volcanism had slowed greatly by that point in history.