Where: Oman (25.4° N, 56.1° E: paleocoordinates 26.4° S, 140.0° E)
• coordinate stated in text
• outcrop-level geographic resolution
When: Lower Member (Rann Formation), Floian (477.7 - 470.0 Ma)
• Lower member goes from mid-Floian to basal Dapingian. Trilobite beds are from the lower part of the formation.
• member-level stratigraphic resolution
Environment/lithology: shoreface; lithified, green siltstone and lithified, bioturbated, quartzose, brown, white sandstone
• The sediments are shallow-marine and storm/wave-dominated, deposited in water depths of a few 10s of metres (Cruziana and Skolithos ichnofacies). The thinner bedded quartzitic sands and shell beds are typical storm tempestites.
• Green shales and interbedded brown-white quartzitic sandstones, fossiliferous shell beds, Cruziana spp. Several lithologies are present: green-grey listric shales, < 0.1–5 m thick brown-white quartzitic sandstones, and thin, orange-brown, partly decalcified shell beds (Figure 4). Sandstones increase in abundance towards the top of the interval (Figure 5). Many of the sandstone beds are sharp based with trace fossils, tool marks and small phosphatic pebbles. The sands are fine- to medium-grained with horizontal lamination, low-angle swaley cross-stratification and wave ripples. Thicker sandstone beds show occasional sets of trough cross-stratification. Shell concentrations occur as layers or lenses at the base, within or at the top of sandstone beds. Sometimes shells are packed convex-up and elongate shells are orientated. The trilobite material is meagre, consisting of external moulds of fragmentary material on the surface of sandstone blocks.
Size classes: macrofossils, mesofossils, microfossils
Preservation: cast, mold/impression
Reposited in the BMNH
Primary reference: R. A. Fortey, A. P. Heward, and C. G. Miller. 2011. Sedimentary facies and trilobite and conodont faunas of the Ordovician Rann Formation, Ras Al Khaimah, United Arab Emirates. GeoArabia 16(4):127-152 [P. Wagner/P. Wagner]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 192975: authorized by Pete Wagner, entered by Pete Wagner on 28.04.2018
Creative Commons license: CC BY (attribution)
Taxonomic list
Show authors, comments, and common names
| Trilobita |
| Asaphida - Taihungshaniidae |
|
| Phacopida - Calymenidae |
|