Crystal Geyser Quarry (UMNH VP Loc. 157) (Cretaceous to of the United States)

Also known as CGDQ, CGQ

Where: Grand County, Utah (38.9° N, 110.1° W)

• Paleocoordinates: 34.8° N, 44.4° W (Wright 2013)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Yellow Cat Member (Cedar Mountain Formation), Berriasian to Berriasian (145.0 - 132.9 Ma)

• base of member, fossils from basal units 1-3; date from sandy unit just above bonebed

•

•Joeckel et al. 2019: Of the 10 samples collected from the Yellow Cat Member for U–Pb zircon geochronology, nine are from mudstones and one is from a fine- to medium- grained sandstone at the base of the Yellow Cat Member (Table 1). Table 1 summarizes the Concordia ages, weighted mean ages and youngest single-grain ages from these samples. The youngest single-grain ages (Dickinson & Gehrels 2009) from all but one of the mudstones span a 206Pb/238U age range from 133.7 + 2.7 to 139.5 + 3.1 Ma (at 2σ uncertainty), within the Valanginian Stage of the Lower Creta- ceous. The remaining mudstone sample, which has a distinct sand component, and the sandstone sample from the base of the Yellow Cat Member have youngest single zircon grains with ages of 142.5 + 2.7 and 141.9 + 3.9 Ma that both fall into the preceding Berriasian Stage.

• group of beds-level stratigraphic resolution

Environment/lithology: spring; concretionary, pebbly, argillaceous, sandy mudstone and lenticular limestone

• "preserved in or near a spring"
• "The CGDQ consists of a basal, bone-bearing limestone; bone-bearing, sandy mudstone unit; interbedded sandy mudstone and limestone; and a silicified limestone caprock. The basal limestone layer has a maximum thickness of 12 cm and laterally pinches out to a pisolitic horizon. The overlying bone-bearing mudstone consists of smaller clay clasts, pisolites, isolated pebbles, carbonate nodules and concretions. The nodules and concretions increase toward the top of the bone-bearing mudstone. Bones are often encrusted with micrite calcite, and some concretions contain dinosaur bone or bone fragments."

Size class: macrofossils

• Falcarius utahensis most common taxon

Preservation: concretion

Collected by Utah Geol. Survey & UMNH in 2001-

Collection methods: quarrying, surface (float), surface (in situ), chemical, mechanical,

• Some chemical treatment for REE study of bones; bones prepared mechanically

Primary reference: J. I. Kirkland, L. Zanno, D. Deblieux, D. Smith, and S. D. Sampson. 2004. A new, basal-most therizinosauroid (Theropoda: Maniraptora) from Utah demonstrates a pan-Laurasian distribution for Early Cretaceous (Barremian) therizinosauroids. Journal of Vertebrate Paleontology 24(3, suppl.):78A [M. Carrano/M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 50052: authorized by Matthew Carrano, entered by Matthew Carrano on 05.05.2005

Creative Commons license: CC0 (CC0)

Taxonomic list

• Also present: polacanthine indet. fragments; theropod bone; turtle; croc teeth
Show authors, comments, and common names
Reptilia
 Crocodylia -
Crocodylia indet.1
Crocodylia indet.1 crocodilian
Teeth
 Theropoda -
Theropoda indet.1, Falcarius utahensis n. gen. n. sp.2
Theropoda indet.1 Marsh 1881 theropod
Falcarius utahensis n. gen. n. sp.2 Kirkland et al. 2005 coelurosaur
MNI, perhaps actually hundreds in total
 Ornithischia -
Ankylosauria indet.3
Ankylosauria indet.3 ankylosaur
scutes
 Ornithischia - Polacanthidae
Polacanthidae indet.1
Polacanthidae indet.1 Wieland 1911 ankylosaur
1Kirkland and Madsen 2007; 2Kirkland et al. 2005; 3Suarez et al. 2007