3-D mapping of Quaternary deposits in the southern part of Simcoe County
Notice bibliographique
Résumé
A 3-dimensional (3-D) Quaternary sediment mapping project in the southern part of Simcoe County is one of several investigations being undertaken as part of a broader groundwater geoscience initiative in the Greater Golden Horseshoe region. Outputs of the project are designed to provide the basic geologic foundation for groundwater studies in a part of the province that is expected to experience significant population growth over the next few decades. A basin analysis approach similar to that used by the GSC in the Oak Ridges Moraine to the south was undertaken in southern Simcoe County to construct the 3-D model. Following the capture and standardization of all available subsurface information (much of which was provided by the Conservation Authorities Moraine Coalition), a series of geophysical surveys (ground gravity, airborne TDEM, downhole logging and reflection seismic profiling) were undertaken to assist with the refinement of bedrock topography and the characterization of the geometry and contact relationships of overlying units. Continuous-coring of Quaternary sediments down to bedrock was undertaken at 25 sites, guided by the results of the geophysical surveys, to establish the regional Quaternary stratigraphic framework and support the subsequent modelling exercise. The southern part of Simcoe County overlies the Laurentian Valley, a broad, bedrock depression extending from Georgian Bay southward to Lake Ontario. The maximum depth to bedrock encountered in the OGS boreholes exceeded 175 m. Surficial sediment thickness increase to the south of the study area, over the Oak Ridges Moraine, and diminish to the west as one approaches the Niagara Escarpment. Much of the study area is characterized as a till-capped upland incised by a network of deep valleys that are partially infilled with postglacial sediments. Uplands consist of an upper, Late Wisconsin till (Newmarket Till) overlying a thick sequence of glaciolacustrine deposits correlative with the Thorncliffe Formation (Middle Wisconsin). An unconformity characterized by deep subaerial weathering and organic-bearing alluvial deposits at the base of the Thorncliffe Formation is AMS dated at 37.9 to >52.8 14C ka BP. The unconformity, which possibly spans Middle Wisconsin through to Sangamon time (based on fossil evidence) is developed on an older sequence of tills and stratified deposits overlying bedrock and presumed to be Illinoian in age. The valleys, which are in some cases incised completely through regional upland strata, have been previously interpreted to be tunnel channels. They are partially infilled with fine-textured glaciolacustrine deposits capping variable thicknesses of coarse glaciofluvial sand and gravel either resting on, or incised through, Newmarket Till. Streamlined till has been observed on the upland surfaces as well as on the flanks and bottoms of several valleys suggesting continued deposition by active ice following erosion of the valleys. Significant groundwater resources are restricted primarily to the highly permeable aquifers at the base of tunnel valleys. Thick, productive aquifers are rare within most of the uplands with the exception of the extreme northern part of the study area where the Thorncliffe Formation coarsens and sandy and gravelly facies are common. Waters from deeply buried aquifers often contain extremely high dissolved solids and some may contain methane limiting their use for municipal water supply.
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 | 0,002 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
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 ».