Geology and paleontology of the Upper Jurassic (Morrison Formation: Brush Basin Member) Peterson Quarry, central New Mexico
Andrew B. Heckert, Kate E. Zeigler, Spencer G. Lucas, Justin A. Spielmann, Patricia M. Hester, Ronald E. Peterson, Rodney E. Peterson, and N. V. D'Andrea


The Upper Jurassic Peterson quarry, located in Bernalillo County, central New Mexico, is New Mexico’s most extensive and productive Jurassic dinosaur locality. The quarry is developed in the upper part of the Brushy Basin Member of the Morrison Formation, approximately 26 m below its contact with the overlying Jackpile Member. Fossil bones occur low in a 1.1 m-thick sequence of well-indurated, trough-crossbedded, subarkosic sandstone. Preserved elements range from scattered bones to articulated assemblages of bones from a single individual, and the long bones are preferentially oriented along a generally east-west-trending axis. The occurrence of associated-to-articulated bones in a trough-crossbedded sandstone underlying a fl oodplain mudstone suggest deposition of the fossils in the mixed fi ll of an abandoned channel in a typical Brushy Basin Member fluvial system. Particularly important dinosaurs from the Peterson quarry include a large (1100 mm estimated femoral length) Saurophaganax-like allosaurid theropod and the anterior portion of a sauropod skull and lower jaws similar to Diplodocus. Camarasaurid teeth are also relatively common at the quarry and some can be assigned to Camarasaurus. Excavations at the quarry are an excellent example of partnerships between the Bureau of Land Management and a natural history museum. To date at least 6000 volunteer hours have been donated excavating the quarry, and volunteer preparation may double that total.


  1. Heckert, Andrew B.; Zeigler, Kate E.; Lucas, Spencer G.; Spielmann, Justin A.; Hester, Patricia M.; Peterson, Ronald E.; Peterson, Rodney E.; D'Andrea, N. V., 2003, Geology and paleontology of the Upper Jurassic (Morrison Formation: Brush Basin Member) Peterson Quarry, central New Mexico, in: Geology of the Zuni Plateau, Lucas, Spencer G.; Semken, Steven C.; Berglof, William R.; Ulmer-Scholle, Dana S., New Mexico Geological Society, Guidebook, 54th Field Conference, pp. 315-324.

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