38. The Bayesian network of claim 37 where the coupling between the root nodes and the leaf nodes to enable the Bayesian network to predict sand-grain composition and texture comprises: the root nodes being coupled to the leaf nodes in causal relationships that honor observations of natural systems.
38. The Bayesian network of claim 37 where the coupling between the root nodes and the leaf nodes to enable the Bayesian network to predict sand-grain composition and texture comprises: the root nodes being coupled to the leaf nodes in causal relationships that honor observations of natural systems. 43. The Bayesian network of claim 38 where the one or more leaf nodes comprises: a probability table for each leaf node; each probability table having a respective one or more predefined states; and each predefined state having associated with it a probability that the leaf node is in that state.