Correlation of Triassic strata across the Rio Grande rift, north-central New Mexico

Abstract

Middle Triassic strata of the Moenkopi Formation and Upper Triassic strata of the Chinle Group are correlated from the Colorado Plateau eastward across the northern Rio Grande rift to the southern High Plains of eastern New Mexico. This correlation demonstrates the continuity of Middle and Late Triassic deposition across northern New Mexico and significant (tens of meters of) stratigraphic relief on the Tr-1, Tr-3, and J-2 unconformities. Relatively little regional stratigraphic relief on the Tr-4 unconformity is consistent with previous interpretations that suggest that it is an intrabasinal unconformity that represents a relatively brief temporal hiatus in deposition.