This map presents the field observations and initial geological interpretations for the Barnes Ice Cap northwest area (NTS 37-E west), Baffin Island, Nunavut. The regional bedrock geology depicted on CGM maps 402 to 406 comprises Archean tonalitic to monzogranitic gneiss that includes mafic to intermediate components, and relatively homogeneous monzogranite-granodiorite intrusions. The Archean Mary River Group forms discontinuous volcano-sedimentary belts, consisting of mafic volcanic rocks interlayered with siliciclastic strata, banded iron-formation, and felsic to intermediate and ultramafic volcanic units. The supracrustal rocks are intruded by monzogranite-granodiorite plutons. Pelitic to psammitic units, marble, and calc-silicate of the middle Paleoproterozoic Piling Group unconformably overlie the Archean units. Archean units are also unconformably overlain by Mesoproterozoic clastic and carbonate platform sequences of the Bylot Supergroup. These strata were deposited within a graben that forms part of the larger Borden Basin. Paleozoic (Cambrian to Ordovician) strata lie unconformably upon Archean and Paleoproterozoic felsic plutonic rocks in the western portion of northern Baffin Island.
Global demand for critical raw materials, including phosphorus (P) and rare earth elements (REEs), is on the rise. The south part of Norway, with a particular focus on the Southern Oslo Rift region, is a promising reservoir of Fe-Ti-P-REE resources associated with magmatic systems. Confronting challenges in mineral exploration within these systems, notably the absence of alteration haloes and distal footprints, we have explored alternative methodologies. In this study, we combine machine learning with geological expertise, aiming to identify prospective areas for critical metal prospecting. Our workflow involves processing over 400 rock samples to create training datasets for mineralization and non-mineralization, employing an intuitive sampling strategy to overcome an imbalanced sample ratio. Additionally, we convert airborne magnetic, radiometric, and topographic maps into machine learning-friendly features, with a keen focus on incorporating domain knowledge into these data preparations. Within a binary classification framework, we evaluate two commonly used classifiers: a random forest (RF) and support vector machine (SVM). Our analysis shows that the RF model outperforms the SVM model. The RF model generates a predictive map, identifying approximately 0.3% of the study area as promising for mineralization. These findings align with legacy data and field visits, supporting the map’s potential to guide future surveys.
The Central Mineral Belt (CMB) in Labrador, Canada, hosts multiple U (±base ± precious metal) showings, prospects and deposits in metamorphosed and variably hydrothermally altered Neoarchean to Mesoproterozoic, igneous and sedimentary rocks. Previous work has recognized U mineralization locally associated with Fe-Ca and alkali metasomatism typical of metasomatic iron oxide and alkali-calcic alteration systems (IOAA) that host iron oxide-copper-gold (IOCG) and affiliated critical metal deposits. However, the type, extent and temporal or genetic relationships between the diverse Fe, Ca and alkali metasomatism and the regionally distributed U mineralization remains poorly understood. Combined unsupervised machine-learning and classification of alteration from a large geochemical dataset distinguish the main alteration phases in the CMB, identify compositional changes related to U mineralization, and infer lithological/mineralogical information from samples with censored (i.e., missing), limited and/or inaccurate metadata. Weak to intense Na and Na + Ca-Fe (Mg) metasomatism in the southwest (Two-Time and Moran Lake areas) and eastern (Michelin area) portions of the CMB pre-dates U mineralization and Fe-oxide breccia development, similar to albitite-hosted U and IOCG deposits globally. Rare earth elements and spider diagrams highlight both preservation and disruption of normally immobile elements. Principal component and cluster analysis indicate significant variations in Fe-Mg ± Na contents in the rocks from combinations of Na, Ca, Fe, and Mg-rich alteration, while protolith REE signatures can be locally preserved even after pervasive albitization-hematization. Cluster analysis identifies mineralized felsic and mafic rocks in the Michelin deposit and Moran Lake area, facilitating inference of relevant lithological/mineralogical information from samples lacking or with limited meta-data. The methods outlined provide rapid and relatively inexpensive means to optimize identification of mineral systems within large geochemical datasets, verify drill core or field observations, highlight potentially overlooked alteration, and refine economic mineral potential assessments. Based on our results and previous work, we suggest the mineral potential of the southwestern and eastern CMB needs to be re-assessed with modern exploration models for IOAA ore systems and their iron oxide-poor variants.
This map presents the field observations and initial geological interpretations for the Nina Bang Lake area (NTS 37-F west and part of 37-C west), Baffin Island, Nunavut. The regional bedrock geology depicted on CGM maps 402 to 406 comprises Archean tonalitic to monzogranitic gneiss that includes mafic to intermediate components, and relatively homogeneous monzogranite-granodiorite intrusions. The Archean Mary River Group forms discontinuous volcano-sedimentary belts, consisting of mafic volcanic rocks interlayered with siliciclastic strata, banded iron-formation, and felsic to intermediate and ultramafic volcanic units. The supracrustal rocks are intruded by monzogranite-granodiorite plutons. Pelitic to psammitic units, marble, and calc-silicate of the middle Paleoproterozoic Piling Group unconformably overlie the Archean units. Archean units are also unconformably overlain by Mesoproterozoic clastic and carbonate platform sequences of the Bylot Supergroup. These strata were deposited within a graben that forms part of the larger Borden Basin. Paleozoic (Cambrian to Ordovician) strata lie unconformably upon Archean and Paleoproterozoic felsic plutonic rocks in the western portion of northern Baffin Island.
Foreword The Geo-mapping for Energy and Minerals (GEM) program is laying the foundation for sustainable economic development in the North. The Program provides modern public geoscience that will set the stage for long-term decision making related to investment in responsible resource development. Geoscience knowledge produced by GEM supports evidence-based exploration for new energy and mineral resources and enables northern communities to make informed decisions about their land, economy and society. Building upon the success of its first five-years, GEM has been renewed until 2020 to continue producing new, publically available, regional-scale geoscience knowledge in Canada's North. During the summer 2016, GEM program has successfully carried out 17 research activities that include geological, geochemical and geophysical surveying. These activities have been undertaken in collaboration with provincial and territorial governments, northerners and their institutions, academia and the private sector. GEM will continue to work with these key collaborators as the program advances.
