Definition: A pinyon juniper woodland is a conifer woodland which has a tree community primarily composed of trees of the subsection Cembroides of the genus Pinus and the genus Juniperus.
Definition: A group of hydrous aluminium phyllosilicate (phyllosilicates being a subgroup of silicate minerals) minerals (see clay minerals), that are typically less than 2micrometres in diameter. Clay consists of a variety of phyllosilicate minerals rich in silicon and aluminium oxides and hydroxides which include variable amounts of structural water.
