A correlation chart of the Mesozoic rocks of Utah has been prepared by a special committee of the Intermountain Association of Petroleum Geologists. For the purposes of illustrating the stratigraphic divisions and correlations of the Mesozoic, the state has been divided into twenty different physiographic and stratigraphic provinces each represented by a column in the chart. The work represents a summary of approximately one hundred published papers as well as considerable unpublished material particularly on subsurface correlations.

The lower boundary of the Mesozoic in much of central and western Utah is marked by an erosional unconformity or disconformity accompanied by a change in sedimentation from marine carbonates of the Permian to Triassic redbeds. Over much of eastern and southeastern Utah the boundary falls within a redbed sequence with few fossils so that a satisfactory division is difficult to make. The Triassic-Jurassic boundary is drawn at the top of the Wingate sandstone (formerly considered to be questionably Jurassic) in accordance with recent paleontologic evidence gathered by the United States Geological Survey. The Jurassic-Cretaceous boundary is drawn at the base of the Cedar Mountain, Burro Canyon, and Kelvin formations in Utah. No consistent criteria can be laid down for separation of the Me ozoic and Cenozoic in Utah. This boundary has been located by various workers on the basis of one or more of the following criteria: (1) change from marine Cretaceous to continental Tertiary, (2) orogenic activity, or (3) biologic (floral or faunal) changes.

The paper includes a bibliography and several index maps which supplement the chart.