14321 (240) Clast-rich, Crystalline-matrix Breccia
We would like to thank the following for the use of this sample:
14321 is a clastic rock with a variety of lithic and microbreccia clasts. It contains 30% clasts. Because of its large size it has been affectionatly been called "Big Bertha". The matrix of this sample is crystalline, moderately coherent and the result of sintering in hot ejecta blanket without digestion of clasts. Other authors attribute the recrystallisation of the matrix as due to “shock sintering”. The majority of the non-breccia clasts are aluminous basalts. Some are referred to as olivine vitrophyre. Only a small number of possibly-pristine plutonic rock fragments have been found and none of these are norite or ferroan anorthosite.
14321 weighed 8898 grams before analysis. The breccia matrix has not been well dated although 3.93 and 4.06 billion year ages are reported (Ar/Ar). Individual basalt clasts range from 3.84-3.94 billion years old.
Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/
Ma = Millions of years ago
Rock forming mineral:
- metallic iron