Royal Creek Sec. 1, at 160-168 meters (525 - 550 feet) (Devonian of Canada)

Where: Yukon, Canada (64.8° N, 135.2° W: paleocoordinates 0.1° S, 41.7° W)

• coordinate stated in text

• local area-level geographic resolution

When: Monograptus yukonensis graptolite zone, Road River Formation, Pragian (410.8 - 407.6 Ma)

• Lenz (1977) tentatively assigns this part of the section to the Upper Lockhovian; however, he later (in Blodgett, Frýda & Lenz 2001) calls it Early Pragian. Brachiopod biozone: Davidsoniatrypa johnsoni; Conodont biozone: Spathognathodus sulcatus; Graptolite biozone: Monograptus yukonensis.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified carbonate and lithified shale

• During the Late Silurian and Early Devonian, the Royal Creek area lay at the margin of a deep-water embayment. The transition from shallow to deep water was relatively abrupt, with very thick shallow-water (including intertidal and shallow subtidal), sparsely fossiliferous carbonates accumulating on the large platform immediately to the east, southeast, and south of the study area, and deep-water, graptolite-rich shales and calcareous shales of the Road River Group accumulating in a northwest-facing trough that joined to the Blackstone River and Richardson troughs (Lenz, 1972 ; Norford, 1997 ). In the transitional zone, perhaps no more than one kilometer in width, brachiopods flourished, and trilobites, bryozoans, corals and gastropods were relatively common (Lenz, 1977a, 1977b, 1982 ). Sea-level fluctuations through this time period are evidenced in the area by tongues of the deeper water facies trangressing over the shallower-water carbonates, alternating with tongues of the latter facies prograding over deeper water facies. During times of shallow-water deposits prograding over deeper water facies, coupled with a relatively steep slope margin (still visible in a few localities), benthic organisms found themselves in a very unstable environment and, perhaps triggered by earth tremors, cascaded into deeper waters. As a result, the most richly fossiliferous carbonates are predominantly debris-flow deposits, in which shallower and deeper dwelling benthic faunas within any debris-flow bed are entirely intermixed. (From Blodgett, Frýda & Lenz 2001.)

Size class: macrofossils

Preservation: replaced with silica

Collection methods: bulk, chemical,

• Lenz (1977) gives this as 525-550' whereas Blodgett et al. (2001) give it as 160-168 meters.

Primary reference: A. C. Lenz. 1977. Upper Silurian and Lower Devonian brachiopods of Royal Creek, Yukon Canada. Part 1. Orthoida, Strophomenida, Pentamerida, Rhynchonellida. Palaeontographica Abteilung A 159(1-3):37-109 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 43668: authorized by Pete Wagner, entered by Pete Wagner on 21.08.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Collection 24933 (Lenz 1999) summarizes this and other Royal Creek Section 1 beds. Specimen counts for brachiopods sum brachial, pedicle and articulated specimens.
Strophomenata
 Strophomenida - Douvillinidae
Rhynchonellata
 Spiriferida - Ambocoeliidae
 Protorthida - Skenidiidae
 Rhynchonellida - Machaerariidae
 Rhynchonellida - Leiorhynchidae
Gastropoda
 Euomphalina - Tubinidae
Semitubina yukonensis1 Blodgett et al. 2001 snail