Firmground Zoophycos in the Lower Cretaceous Viking Formation, Alberta: A Distal Expression of the Glossifungites Ichnofacies
Bibliographic record
Abstract
Other| October 01, 2000 Firmground Zoophycos in the Lower Cretaceous Viking Formation, Alberta: A Distal Expression of the Glossifungites Ichnofacies JAMES A. MACEACHERN; JAMES A. MACEACHERN 1Earth Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada Search for other works by this author on: GSW Google Scholar JAMES A. BURTON JAMES A. BURTON 2Imperial Oil Resources, Calgary, Alberta T2P 3M9, Canada Search for other works by this author on: GSW Google Scholar PALAIOS (2000) 15 (5): 387–398. https://doi.org/10.1669/0883-1351(2000)015<0387:FZITLC>2.0.CO;2 Article history accepted: 26 Jun 2000 first online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation JAMES A. MACEACHERN, JAMES A. BURTON; Firmground Zoophycos in the Lower Cretaceous Viking Formation, Alberta: A Distal Expression of the Glossifungites Ichnofacies. PALAIOS 2000;; 15 (5): 387–398. doi: https://doi.org/10.1669/0883-1351(2000)015<0387:FZITLC>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyPALAIOS Search Advanced Search Abstract The substrate-controlled Glossifungites ichnofacies is a firmground suite of trace fossils that commonly demarcates erosional discontinuities in sedimentary successions. The Glossifungites ichnofacies typically is characterized by biogenic structures that are vertical to subvertical, sharp-walled, unlined and commonly passively infilled. The structures hitherto have been restricted to permanent or semi-permanent domiciles, and predominantly to vertical to subvertical burrows of suspension-feeding organisms.Several cores of the late Albian (Lower Cretaceous) Viking Formation from the Hamilton Lake Field of Alberta, Canada contain an atypical Glossifungites ichnofacies dominated by the foraging, probing and deposit-feeding/dwelling structures of firmground Thalassinoides, Rhizocorallium, and Zoophycos. The Thalassinoides are passively infilled with coarse grains of sand and chert granules. Rhizocorallium displays active stages of infill, although the final, horizontal U-shaped tube is passively filled. The Zoophycos, however, demonstrates active infill manifest by chert granules and coarse sand distributed in the spreite, and this is a departure from the normal expression of the Glossifungites ichnofacies.The firmground structures subtend from the regional stratigraphic discontinuity BD4, excavated into black, silt- and sand-poor offshore and shelf mudstones. BD4 is interpreted to reflect a transgressively modified sequence boundary. Most Zoophycos, Thalassinoides, and Rhizocorallium penetrate no deeper than 3–4 cm below the discontinuity into the underlying mudstones. Where BD4 overlies a sandier substrate, firmground Zoophycos are not present within the suite.The facies directly overlying BD4 consist of fining-upward, pebble-, granule-, and very coarse-grained sand-bearing, thoroughly burrowed muddy sandstones to sandy mudstones, typically 5–25 cm thick. This basal transgressive lag contains Teichichnus, Planolites, Palaeophycus, Diplocraterion, Chondrites and rare Helminthopsis, and is the source of the coarse-grained material incorporated into the fill of the firmground ichnogenera. The granule-bearing sandy mudstones overlying the transgressive lag contain abundant Teichichnus, Planolites, Helminthopsis, Anconichnus, Chondrites, and Terebellina, and reflect rapid deepening to proximal offshore conditions. Progressive deepening is recorded in the accumulation of distal offshore and shelf mudstones of the late Albian Westgate Formation.Although excavation of BD4 occurred above fairweather wave base, its colonization occurred under much lower energy conditions. Within distal softground settings, ichnogenera capable of deeply penetrating muddy substrates are largely restricted to Zoophycos, Thalassinoides, Rhizocorallium, and Chondrites. These ichnogenera constitute forms capable of being excavated, albeit shallowly, within a firm substrate. This is a low energy, distal expression of the Glossifungites ichnofacies. You do not currently have access to this article.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot 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.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.006 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".