Stromatolites of the Morrison Formation (Upper Jurassic), Union County, New Mexico--A preliminary report
— Kenneth R. Neuhauser, S. G. Lucas, J. Stephen de Albuquerque, Robert J. Louden, Steven N. Hayden, Kennety K. Kietzke, Wayne Oakes, and David Des Marais

Stromatolitic bioherms are present in lacustrine facies of the medial portion of the Morrison Formation at two localities in the Dry Cimarron Valley, Union County, New Mexico. The stromatolite-bearing lacustrine facies of the Morrison probably represents an extensive, closed lake basin that covered much of the southern High Plains during part of the Late Jurassic. The Morrison stromatolites are similar to Rivularia bioherms, and display laterally-linked, undulatory to pseudocolumnar laminations. Carbon- and oxygen-isotope measurements indicate multiple episodes of carbonate deposition. The isotope data also indicate the stromatolitic carbonate was deposited in a lake fed by continental rainfall.