Oxroad Bay Exposure D, Horizon 9 (Carboniferous of the United Kingdom)

Where: Scotland, United Kingdom (56.0° N, 3.0° W: paleocoordinates 10.3° S, 1.7° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Sunnyside/Rhodes Limestone Member (Garlton Hills Volcanics Formation), Tournaisian (358.9 - 346.7 Ma)

• Occurs at the center of the most disrupted strata. Occupies a mini-graben bounded by two parallel SW-NE oriented faults. Sediments produce a pseudochannel. Grading is common.

•Scottish Midland Valley

• bed-level stratigraphic resolution

Environment/lithology: lacustrine - large; graded, bioturbated, pyritic, gray siltstone and graded sandstone

• A valuable analogue for these deposits is provided by the thicker, more extensive, and better-know Burdiehouse Limestone Fm...which were deposited in an extensive but shallow meromictic lake (Lake Cadell)...(Loftus 1985; Loftus & Greensmith 1988)
• Horizons vary greatly in degree of texture (siltstones to coarse lapilli tuffs) and degree of induration. In general the coarser and/or more calcareous horizons are more strongly indurated. Grading is common in coarser sections.Grading is common and most evident in the coarser horizons. Upward-fining horizons outnumber upward coarsening horizons, and flame structures occur at the top the coarse lapilli tuff of horizon 2.25. Two horizons near the base of the sequence (1.5 and 1.9) contain abundant in situ pteridosperm roots and can therefore be confidently described as paleosols. Two thick siltstone horizions...contain nodular calcareous concretions. The lower siltstone is a slightly darker grey and richer in pyrite than the upper...

Size classes: macrofossils, mesofossils, microfossils

Preservation: adpression, permineralized, charcoalification

Collection methods: quarrying, surface (in situ), mechanical, peel or thin section,

• 28 blocks collected from section 2.12, 11 blocks collected from section 1.17.

Primary reference: R. M. Bateman and G. W. Rothwell. 1990. A reappraisal of the Dinantian floras at Oxroad Bay, East Lothian, Scotland. 1. Floristics and the development of whole-plant concepts. Transactions of the Royal Society of Edinburgh 81:127-159 [H. Sims/J. Allen/H. Sims]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 36236: authorized by Hallie Sims, entered by Jason Cassara on 19.01.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Specimens collected from two sections within horizon (see comments field).
Oxroadia gracilis
section 2.12: axes, rootlets, strobili, megaspores; section 1.17: axes, leaves, rootlets, megaspores
Amyelon spp.
section 2.12
cf. Sphaerostoma sp.
section 2.12: questionable occurrence
cf. Melissiotheca sp.
section 2.12
 Calamopityales - Calamopityaceae
Eosperma oxroadense
section 2.12: questionable occurrence