Bottoms up: developing a new bedrock surface for the Niagara Peninsula
Notice bibliographique
Résumé
The Niagara Peninsula three-dimensional (3-D) sediment mapping project was initiated in 2013 with the primary goal of constructing a model of regional-scale Quaternary deposits that form both regional and local aquifers and aquitards between Port Dover in the southwest, the Regional Municipality of Waterloo in the northwest and the Niagara River in the east. To date, the primary focus of the project has been on data acquisition. Five shallow, high-resolution seismic reflection lines, ranging from 4.5 to 21.5 km in length, were acquired by the Geological Survey of Canada's (GSC) Near Surface Geophysics Section to determine whether multiple thalwegs exist within the buried Erigan channel, to delineate the lateral extent and geometry of gravel beds observed during drilling and to provide insight into late-glacial moraine systems. Downhole geophysical logging was conducted in monitoring wells to investigate chemical and physical properties of the sediments, and to verify the conversion of seismic reflection time sections to depths.. A 6828 station ground gravity survey was conducted along selected roads and highways at a nominal spacing of 100 m. The calculated gravity residuals were used to identify buried-bedrock valleys and guide subsequent drilling. The survey was effective in identifying deeply incised valleys, such as St. Davids and the northern end of the Erigan, but less definitive where valleys broaden and the deep regional and shallow residual components of the gravity are not as easily separated. A total of 99 continuously cored boreholes with a combined length of 3192 m, 29 of which have been converted into monitoring wells, have been drilled for this project. The borehole data is augmented by 130 exposures, soil probe and hand-auger cores and extensive legacy datasets (water well records, oil and gas records, geotechnical records, published geological reports and archived field notes). A key first step in the 3-D modelling process is to generate a high-quality bedrock topographic surface that forms the foundation layer for the overlying sediment model. The surface is interpolated using Datamine Studio software after manually digitizing 3-D points identifying the top of rock onto the new and legacy borehole traces. Additional points were digitized adjacent to, or below, the borehole traces in order to refine the geometry of the surface and reduce potential effects of clustered data points. By modelling the gravity results using representative density values for the Quaternary and bedrock layers, and integrating with interpretations from seismic studies in the area, it is possible to further constrain the shape of the bedrock surface. The resulting surface shows southward-dipping bedrock separated by the prominent features of the Niagara and Onondaga escarpments. Deep and narrow re-entrant valleys bisect the resistant escarpments, becoming wider where they cross softer formations.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,002 | 0,001 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».