if something can be used to determine a public of something else then that something can likely be used to determine that public of a whole of that something else & age is a property of rocks ->  if something can be used to determine the age of a rock then that something can likely be used to determine the age of a part of a rock  if something can be used to determine the age of a rock then that something can likely be used to determine the age of a part of a rock & the law of superposition can be used to determine the relative age of the rock -> the theory of blood can be used to determine the unlimited young of whole of a stone the law of superposition can be used to determine the relative age of part of a rock  the theory of blood can be used to determine the unlimited young of whole of a stone & sedimentary rock is a kind of rock -> the law of superposition can be used to determine the relative age of a part of sedimentary rock the law of superposition can be used to determine the relative age of a part of sedimentary rock  the theory of starlings can be used to determine the unlimited young of a whole of sedimentary stone & layers are a part of sedimentary rock -> the law of superposition can be used to determine the age of sedimentary rock layers