Late cenozonic geology of the southern Rocky Mountain trench, British Columbia
Bibliographic record
Abstract
Geologic studies which have provided information on the late Cenozoic history of the southern Rocky Mountain Trench, British Columbia include: (1) the St. Eugene Formation and the origin of the southern Rocky Mountain Trench, (2) the stratigraphy and correlation of Quaternary sediments, (3) the patterns of glacier flow and the origin of late Wisconsinan till, and (4) the sedimentology and paleohydrology of late Wisconsinan outwash. (1) The Tertiary history of the southern Rocky Mountain Trench is inferred from a study of the distribution, stratigraphy, fabric, lithologic composition, structure, and palynology of the Miocene St. Eugene Formation. This unit consists of flood-plain and fan facies and represents the uppermost Tertiary sediments filling block-faulted basins in the Trench. Sediment deposition was probably contemporaneous with faulting, but at least 600 m of displacement along the east side of the Trench postdates deposition of the St. Eugene Formation. The Miocene southern Rocky Mountain Trench was similar in morphology and position to the present Trench, but the Miocene climate was more temperate than the present climate of the area. Palynological results indicate that during the Miocene southeastern British Columbia had abundant summer precipitation and mild, moist winters. (2) Exposed Pleistocene sediments correlate with deposits of the Pinedale Glaciation and the preceding interglaciation. Deposits of three stades and two interstades of the Pinedale Glaciation are recognized. During the earlier interstade the floor of the Trench in southeastern British Columbia was deglaciated, whereas during the later interstade residual ice apparently remained locally along the center of the Trench-CS) Pinedale glacier-flow patterns and till genesis in the southern Rocky Mountain Trench were determined through a study of glacial landforms, till fabric, and till composition. A review of the ways in which directed till fabrics originate indicates that till associated with drumlins accumulated by lodgement of particles due to subglacial pressure melting. Landforms and till fabrics document one major shift in the pattern of glacier flow near the end of glaciation. In mountainous areas till composition is less sensitive as an indicator of such shifts than till fabric. Till composition instead reflects the dominant pattern of ice flow during glaciation. Till constituents decrease with distance from their bedrock sources because of progressive deposition, dilution through sediment mixing, and breakage and abrasion during transport. Other factors which may affect the distribution and relative abundance of constituents in Trench tills include reworking at the ice-sediment interface and transport of constituents englacially and subglacially by meltwater. (4) Late Wisconsinan channeled outwash is coarse, poorly sorted, shows large-scale cross-bedding, and was deposited in channel-bar complexes of high-energy rivers. Peak discharges calculated from channel morphometry and maximum particle size are larger than maximum discharges attributable to uninterrupted summer runoff. Many channels transmitted valleys. An empirical relationship between total volume discharged during documented jbkulhlaups and corresponding maximum instantaneous discharges is applied to one Pleistocene glacier-dammed lake in the study area to show that discharges equal to or larger than those calculated from channel morphometry were attained during jokulhlaups. Some applications of these geologic studies include the prediction of flood magnitudes from self-dumping glacier-dammed lakes, the determination of the source of ore clasts or minerals in till, and a preliminary assessment of the groundwater resources of the southern Rocky Mountain Trench.
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 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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.005 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.002 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
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.
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".