12:00 PM - 12:15 PM
[PPS07-05] A new method to constrain the termination ages of lunar tectonic structures
Keywords:Moon, Tectonics, Formation Age
In this study, we developed a new technique, which was named “one-dimensional crater chronology”, to constrain the termination ages of tectonic structures quantitatively. The craters superposed on a thrust indicate that they were formed after the thrust activities ceased. Therefore, the linear number densities of the superposed craters indicate the elapsed time after the thrust activities ceased. We simulated lunar surface to derive the crater size frequency distributions of craters on linear fault traces and to derive the linear number densities of craters as a function of time. The one-dimensional crater chronology requires the linear number density of superposed craters to estimate the termination age.
We applied the newly developed technique to a mare ridge in the northwestern Imbrium region. The termination age of the formation was estimated as young as ~0.2 Ga. This young ridge formation is inconsistent with the conventional hypothesis. The global cooling of the Moon or the cooling of the PKT region are possible origins.