Maximum age of the basal Cretaceous Chinkeh Formation sandstones, Maxhamish Lake area, Liard Basin, British Columbia
Bibliographic record
Abstract
Research Article| September 01, 2016 Maximum age of the basal Cretaceous Chinkeh Formation sandstones, Maxhamish Lake area, Liard Basin, British Columbia M. McMechan; M. McMechan Geological Survey of Canada, 3303 33rd St. NW, Calgary AB T2L 2A7 Search for other works by this author on: GSW Google Scholar W. Matthews; W. Matthews Centre for Pure and Applied Tectonics and Thermochronology, Department of Geosciences, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4 Search for other works by this author on: GSW Google Scholar F. Ferri; F. Ferri Petroleum Geoscience Section, Tenure and Geoscience Branch, Ministry of Natural Gas Development Victoria, BC V9A 5N7 Search for other works by this author on: GSW Google Scholar B. Guest B. Guest Centre for Pure and Applied Tectonics and Thermochronology, Department of Geosciences, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4 Search for other works by this author on: GSW Google Scholar Author and Article Information M. McMechan Geological Survey of Canada, 3303 33rd St. NW, Calgary AB T2L 2A7 W. Matthews Centre for Pure and Applied Tectonics and Thermochronology, Department of Geosciences, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4 F. Ferri Petroleum Geoscience Section, Tenure and Geoscience Branch, Ministry of Natural Gas Development Victoria, BC V9A 5N7 B. Guest Centre for Pure and Applied Tectonics and Thermochronology, Department of Geosciences, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4 Publisher: Canadian Society of Petroleum Geologists Received: 11 Jan 2016 Accepted: 06 Apr 2016 First Online: 13 Jul 2017 Online Issn: 2368-0261 Print Issn: 0007-4802 © the Society of Canadian Petroleum Geologists Bulletin of Canadian Petroleum Geology (2016) 64 (3): 467–476. https://doi.org/10.2113/gscpgbull.64.3.467 Article history Received: 11 Jan 2016 Accepted: 06 Apr 2016 First Online: 13 Jul 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation M. McMechan, W. Matthews, F. Ferri, B. Guest; Maximum age of the basal Cretaceous Chinkeh Formation sandstones, Maxhamish Lake area, Liard Basin, British Columbia. Bulletin of Canadian Petroleum Geology 2016;; 64 (3): 467–476. doi: https://doi.org/10.2113/gscpgbull.64.3.467 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of Canadian Petroleum Geology Search Advanced Search Abstract Sandstone, shale and conglomerate of the Chinkeh Formation represent shoreface and channelized environments forming the base of the Cretaceous section in Liard Basin of northeast British Columbia, southeast Yukon and southwest Northwest Territories. Biostratigraphic constraints on the formation indicated a Hauterivian to Early Albian age. New U-Pb detrital zircon ages obtained from a subsurface core in the Maxhamish Lake area indicate a maximum depositional age of 112.6 ± 2.0 Ma and an Early Albian to latest Aptian age. Grain roundness and the diversity of zircon crystal morphologies suggest that most of the Cretaceous-aged zircons were derived from plutonic sources. Intrusions of the Anvil Suite, located approximately 550 km westnorthwest of the Maxhamish Lake area in the mid-Cretaceous, form the likely source. Erosion of the few kilometres of sediment originally overlying the intrusions would take at least a million years and plutonic zircon would not enter the sediment supply until then. Because of this delay in plutonic zircon availability, the new detrital zircon results suggest that the Chinkeh Formation in the Maxhamish Lake area is more likely Early Albian than latest Aptian in age, and support the Early Albian age assigned on the basis of foraminifera. Detrital zircon geochronology has proven to be a very useful tool in differentiating the Chinkeh Formation from similar Triassic strata. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.005 | 0.009 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.016 | 0.003 |
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".