Carbon polymorphs in Frontier Mountain ureilitic meteorites: A correlation with increasing the degree of shock?

Open questions on carbonaceous matter in meteorites

“…Initially developed for chondritic parent bodies 62 , graphite geothermometry has then been applied also to graphite in ureilites 63 . Following the first application on the famous Almahata Sitta ureilite originating from the 2008 TC3 asteroid, the first asteroid that has been completely observed from its identification in space to its impact in Sudan 64 , this method has been applied to different ureilites yielding temperatures between 1180 and 1398 °C 65 – 69 . These temperatures fall into the catalytic diamond synthesis field, as can be seen in the carbon phase diagram 70 , suggesting that with the help of Fe-bearing phases, which are widely available as they always accompany carbon-bearing aggregates in ureilites, this could be the temperature reached during the impact event which destroyed the UPB and formed ureilitic diamond directly from graphite.…”