Also known as Kukpowruk River/Cape Lisburne floras
Where: western North Slope County, Alaska (68.8° N, 163.2° W: paleocoordinates 78.8° N, 98.2° W)
• coordinate stated in text
• outcrop-level geographic resolution
When: Corwin Formation, Albian to Albian (113.0 - 93.9 Ma)
• middle Albian to Cenomanian
• group of beds-level stratigraphic resolution
Environment/lithology: wet floodplain; coal and carbonaceous shale
•fine-grained sandstones were exposed in large bluffs. Two prominent
•yellow/grey fine-grained sandstones occur near the top of the
•exposure. Podozamites was found in all lithologies but was sparse in
•fine sands where Ginkgo predominated. Ginkgo was rare in other
•lithologies. Pityophyllum ex gr. nordenskiodii and P. ex gr. staratschinii
•were most frequent in coaly units, whereas abundant large-leaved
•Podozamites commonly occurred as a monodominant taxon in
•bright yellow- or orange-weathering ironstone nodules in carbonaceous
•shales. Equisetites, Birisia alata, Podozamites and Ginkgo ex gr.
•adiantoides were found in the more sandy sediments. Coals up to
•1 m thick were sub-bituminous. Abundant compressed logs, up to
•0.5 m diameter, occur parallel to bedding through the section.
•However, some logs were almost circular indicating early mineralization.
•Calcite and iron minerals permeated all the wood, but the
•growth of calcite crystals enlarged the tracheids and destroyed
•the structure.
•Interpretation. This locality reveals the youngest rocks exposed along
•the river in the Coke Basin syncline. It represents heavily vegetated,
•predominantly interfluve and wooded floodplain environments, including mires subsequently inundated by near channel sediments.
•There appears to be a facies-related heterogeneity in species distribution
•with Pityophyllum producers dominating the stable mires,
•Podozamites producers in slightly more clastic-influenced swamps,
•and Ginkgo associated with the near-channel disturbed sites.
Size class: macrofossils
Collection methods: quarrying,
• Material stored at the Earth Sciences Department, The Open University, collection # 96 RAS.
Primary reference: R. A. Spicer and A. B. Herman. 2001. The Albian-Cenomanian flora of the Kukpowruk River, western North Slope, Alaska: stratigraphy, palaeofloristics, and plant communities. Cretaceous Research 22:1-40 [D. Royer/D. Royer/D. Royer]more details
Purpose of describing collection: general faunal/floral analysis
PaleoDB collection 33500: authorized by Dana Royer, entered by Dana Royer on 01.08.2003
Creative Commons license: CC BY (attribution)
Taxonomic list
unclassified | |
| |
Polypodiopsida | |
| |
Cladophlebis sp. Brongniart 1849 | |
Ginkgoopsida | |
Ginkgo ex gr. adiantoides Unger 1845 ginkgo found in more sandy sediments; dominates in fine sands, rare in other lithologies; does not co-occur with Podozamites
| |
Gnetopsida | |
"Pityophyllum ex gr. staratschinii" = Pityophyllum staratschini, "Pityophyllum ex gr. nordenskioldii" = Pityophyllum nordenskioeldi
"Pityophyllum ex gr. staratschinii" = Pityophyllum staratschini Nathorst 1899 most frequent in coaly units
"Pityophyllum ex gr. nordenskioldii" = Pityophyllum nordenskioeldi Heer 1899 most frequent in coaly units
| |
Podozamites spp. Braun 1843 podocarp found in all lithologies but sparse in fine sands where Ginkgo dominates; commonly occurred as a monodominant taxon in bright yellow- or orange-weathering ironstone nodules in carbonaceous shales
| |
Pinopsida | |
? Cephalotaxopsis sp. Fontaine 1889 yew |