15. The method of claim 7 further comprising: establishing one or more intermediate nodes; and where coupling the root nodes to the leaf nodes to enable the Bayesian network to predict sand-grain composition and texture comprises: coupling at least some of the one or more root nodes to at least some of the one or more leaf nodes through the one or more intermediate nodes.
17. The method of claim 15 where coupling the root nodes to the leaf nodes to enable the Bayesian network to predict sand-grain composition and texture comprises: defining for each root node one or more outputs that connect to other nodes that the root node causes; defining for each intermediate node: one or more inputs that connect to the other nodes that cause the intermediate node; one or more outputs that connect to other nodes that the intermediate node causes; and defining for each leaf node one or more inputs that connect to other nodes that cause the leaf node.