Age dating of basalt bank consoladating loans
The rock has a distinctively fragmental appearance, not an igneous texture, although in places in other pieces of 60025 a good igneous texture is seen easily.The rock has been affected by one or more impacts, but in spite of its fragmentation it is possible to extract a reliable age from it. In fact, geochronologists can determine the time when the metamorphism took place if the temperature was hot enough for long enough to reset chronometers.As this ocean of magma crystallized, plagioclase feldspar floated to the top, accumulating in large masses of a rock type called anorthosite (also abbreviated FAN, for ferroan anorthosite).
It's a good story that has provided a framework for understanding the formation of the lunar crust. If anorthosites make up the primary crust, they ought to be the oldest rocks on the Moon.
In fact, the work is based on Borg's perspective of spending 20 years trying to determine the solidification age of the Moon by dating lunar samples.
The upper 10–20 kilometers of the lunar highlands is a mixed-up pile of rocky rubble formed when the Moon was bombarded early in its history by countless planetesimals.
Reference: Knowing precisely when major rock types formed during construction of the lunar crust builds a quantitative framework for understanding the origin and geochemical evolution of the lunar highlands.
For example, a cherished idea in lunar science is that the Moon melted when it formed.