Dutch Gap Canal (Cretaceous of the United States)

Where: Virginia (37.4° N, 77.4° W: paleocoordinates 31.5° N, 30.4° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Patuxent Formation (Potomac Group), Early/Lower Cretaceous (145.0 - 100.5 Ma)

• Brenner's pollen Zone I

Environment/lithology: fluvial-deltaic; unlithified sandstone and unlithified claystone

• "The sediments are interpreted as having been deposited in fluvial and deltaic environments possibly with some tidal influence (Glaser 1969, Upchurch and Doyle 1981)." (Pedersen et al. 1993)
• "The sequence at Dutch Gap consists mainly of crossbedded light sands with darker layers of laminated clays and silt and some gravel beds." (Pedersen et al. 1993)

Size classes: macrofossils, mesofossils, microfossils

Reposited in the FMNH

Collection methods: bulk, chemical, peel or thin section, sieve,

• "Fossils were extracted from the sediments by sieving in water. After sieving the plant material was rinsed in HF, HCl, and water and air dried... Material for ultrastructural and anatomical studies was dehydrated in an ethanol-propylene oxide series, embedded in Epon and sectioned on an LKB Ultratome III ultramicrotome with a glass knife (sections 3 micrometers thick) or diamond knife (sections about 600 angstroms thick)." (Pedersen et al. 1993)

Primary reference: K. R. Pedersen, E. M. Friis, and P. R. Crane. 1993. Pollen organs and seeds with Decussosporites Brenner from Lower Cretaceous Potomac Group sediments of eastern USA. Grana 32:273-289 [H. Sims/J. Cassara/J. Cassara]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 36515: authorized by Hallie Sims, entered by Jason Cassara on 01.02.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Brenneria potomacensis
with in situ Decussosporites microreticulatus pollen
Cycadeoideopsida
 Bennettitales -
Zamites (Dioonites) buchianus
bennettitalean leaves
Pinopsida
 Pinales - Podocarpaceae
Podozamites sp. Braun 1843
 Pinales - Cheirolepidiaceae
"Corollina (Classopollis) sp." = Classopollis, Pseudofrenelopsis parceramosa
"Corollina (Classopollis) sp." = Classopollis Pflug 1953
cheirolepidiaceous pollen...typically constitutes more than 20% of the palynoflora
Pseudofrenelopsis parceramosa Watson
cheirolepidiaceous conifer
 Pinales - Taxodiaceae
Taxodiaceae indet. Saporta 1865
 Gymnospermophyta -
Exesipollenites sp. Balme 1957
a possible conifer or bennettitalean grain of uncertain affinity...comprising more than 15% of the palynoflora