LAUSR

We thank Joel Sarout for his perspective reading of our paper (Sarout 2016). First, we want to state explicitly that the physical constraints on c13 are not theoretical constraints; they are heuristic constraints based on observation of laboratory static measurement and physical intuition concerning the explanation of the behavior of a certain amount of hydrocarbon source rocks, to the author’s knowledge. As the title suggests, they only applied to hydrocarbon source rocks whose elastic properties can be described by transverse isotropy. This point is also emphasized in the discussion part of our paper.