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Record W2109354430

The Eocene flora of Svalbard and its climatic significance

2012· dissertation· en· W2109354430 on OpenAlexaboutno aff
Abigail Joy Clifton

Bibliographic record

VenueWhite Rose eTheses Online (University of Leeds, The University of Sheffield, University of York) · 2012
Typedissertation
Languageen
FieldEarth and Planetary Sciences
TopicGeological Studies and Exploration
Canadian institutionsnot available
Fundersnot available
KeywordsPodocarpusPodocarpaceaeEcologyAlderPaleogeneFagaceaeFloodplainDeciduousBotanyBiologyPaleontologyPollen
DOInot available

Abstract

fetched live from OpenAlex

Fossil plant remains are preserved within the deposits of the Eocene Aspelintoppen Formation on Svalbard. These sediments form the youngest continental deposits of early Paleogene age. The Aspelintoppen Formation sediments represent crevasse splay, backswamp and ephemeral lake deposits that represent a broad lowland floodplain that was subject to frequent flooding. The forests grew at a palaeolatitude of 75°N. New collections (1032 specimens) ofthe Aspelintoppen Formation flora are dominated by angiosperms including the Fagaceae? (Ushia olafsenii), Betulaceae (Corylites and Craspedodromophyllum), Hamamelidaceae (Platimelis pterospermoides), Platanaceae (Platimeliphyllum and Platanus), Ulmaceae (Ulmites ulmifolius), Trochodendraceae (Zizyphoides flabella), Cercidiphyllaceae (Trochodendroides), Juglandaceae (Juglans laurifolia) and Hippocastinaceae (Aesculus longipedunculus). In addition, conifer fossils include Metasequoia shoots and cones, as well as Thuja shoots. Fern fronds of Osmunda and Coniopteris are present, along with the horsetail Equisetum. The Aspelintoppen Formation vegetation grew locally on the floodplain with angiosperms dominating the riparian environment and a mixed angiosperm Metasequoia-dominated flora in the backswamp environment, with Equisetum and ferns occupying the margins of ephemeral lakes and post-disturbance environments. The Aspelintoppen Formation flora is similar in composition and ecology to other early Paleogene Arctic floras from the Canadian Arctic, Greenland, Alaska and north-east Russia, showing that Polar Broadleaved Deciduous Forests were a dominant part of the Arctic environment. Palaeoclimate estimates were derived from the 22 angiosperm morphotypes using both physiognomic and nearest living relative methods. CLAMP results are considered to be the most reliable and indicate that the Eocene climate of Svalbard was temperate with a mean annual temperature of 11.6°C, a warm month mean of 18.rC and a cold month mean of 4.5°C. Precipitation estimates indicate high levels of precipitation with growing season precipitation estimates from 320 to 1531mm, and a strong wet or dry seasonal signal with 356 to 656mm precipitation for the three wettest months and 112 to 247mm for the three driest months. These estimates support sedimentary evidence that Eocene Arctic environments were seasonally warm and wet.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.058
Threshold uncertainty score0.115

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0020.002
Science and technology studies0.0010.000
Scholarly communication0.0010.000
Open science0.0000.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0030.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.024
GPT teacher head0.191
Teacher spread0.167 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations2
Published2012
Admission routes1
Has abstractyes

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