Late Wisconsinan Morphosedimentary Sequences of the Lower Coppermine River Valley, Nunavut and Northwest Territories
Bibliographic record
Abstract
A series of late Wisconsinan sedimentary sequences occupy parts of the Coppermine River valley, and are grouped into five morphosedimentary zones representing four environments at the time of last ice retreat: glacial, paraglacial, lacustrine and marine. The sequences commonly interfinger, and document episodic deposition in time-transgressive environments related to ice frontal positions. Glacial and paraglacial sediments are, in part, reworked in a glaciolacustrine environment extending from delta topsets of bouldery gravel to bottomset rhythmites of silt-clay. The glacial-lake rhythmites formed the matrix of a later sequence of debris-flow events, which emplaced a wedge of massive diamicton in the postglacial marine sediments. This sedimentary sequence, composed of a chaotic mass of heterogeneous material that is intimately mixed, and is accumulated in the form of a semi-fluid body in a marine environment, is possibly the best exposed Quaternary olistostrome. A general overview of the Quaternary history of the area east of Great Bear Lake and north of Point Lake shows: a) deglaciation proceeded by large-scale downwasting with no discernable readvance pulses, b) that the Coppermine River valley between Point Lake and Rocky Defile Rapids was ice-free by 10 250 14 C years BP, and, c) that earth-shaping processes were intensely active for a short period at the time of deglaciation; since then the landscape has been mostly quiescent. SOMMAIRE Des sequences sedimentaires de la fin du Wisconsinien qui occupent des sections de la vallee de la riviere Coppermine definissent cinq zones morphosedimentaires representant quatre environnements differents du retrait glaciaire, soit les milieux glaciaire, paraglaciaire, lacustre et marin. Ces sequences qui s’interdigitent souvent, documentent des episodes sedimentaires de milieux qui varient avec le temps et les changements de position du front glaciaire. Les sediments glaciaires et paraglaciaires sont en partie remanies dans des milieux glaciolacustres allant des lit topset deltaiques de gravier a blocs jusqu’a des rythmites de limon-argile. Les rythmites glacio-lacustres constituent la matrice d’une sequence subsequente de lave torrentielle, qui a depose un enorme prisme de diamictons dans les sediments marins postglaciaires. Cette sequence sedimentaire, composee d’une masse chaotique de materiaux heterogenes intimement melanges accumulee sous forme semi-fluide en milieu marin, est peut-etre le meilleur affleurement d’olistostrome quaternaire. Un coup d’œil sur l’histoire du Quaternaire de la region a l’est du Grand lac de l’Ours et au nord du lac Point, montre : a) que la deglaciation s’est deroulee par fonte du glacier sans reavancee discernable, b) que la vallee de la riviere Coppermine entre le lac Point et les rapides de Rocky Defile etait libre de glace vers 10 250 14 C BP, et c) que les mecanismes d’erosion ont ete intenses pendant une courte periode au moment de la deglaciation; depuis lors, le paysage est demeure relativement statique.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 teacher head, 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".