Alaska, the largest state in the United States, is situated in the northwesternmost part of North America. When you look at a world map, Alaska is prominently positioned to the west of Canada, and below the Arctic Ocean, separated from the contiguous United States by Canada. For anyone wanting to delve deeper than just geographical location, the geological map of Alaska offers a wealth of information, revealing the intricateEarth science of this vast and fascinating state.
Understanding Alaska’s geological composition is crucial for numerous scientific disciplines and practical applications. The comprehensive geological map of Alaska is not just a static image; it’s a culmination of over a century of geological investigation and almost two decades of dedicated compilation work. This detailed map, available in both digital and simplified print versions, represents the collective effort of numerous geologists piecing together the complex geological puzzle of Alaska.
The genesis of this map dates back to September 1996, initiating with 1:250,000-scale data to create a regional map of central Alaska. The process was iterative, involving continuous refinement and correlation of individual geologic units. This ongoing effort resulted in a series of regional geological map compilations, progressively building towards the comprehensive statewide map. As more geological data became available, previous interpretations were revisited and updated, ensuring the map’s accuracy and relevance.
Compiling this map was a formidable task, primarily because the source maps originated from different generations of geologists, each employing varying methodologies and conceptual frameworks. Some older maps predate the understanding of plate tectonics and accreted terranes, while newer maps sometimes prioritized terrane analysis over traditional stratigraphic nomenclature. To reconcile these diverse approaches, the mapmakers adopted a traditional stratigraphic approach, emphasizing the age and lithology of map units, deliberately avoiding the often-debated and inconsistently applied terrane terminology.
This decision to prioritize a traditional approach is evident in the map’s focus on the age and lithological characteristics of geological units, rather than solely on fault-bounded rock packages. The team diligently worked to resolve conflicting interpretations and data from regional and individual source maps. While striving to preserve original geological information and incorporate new data, they exercised caution against over-interpreting the available data. Despite their efforts, some mapping discrepancies and stylistic differences remained unresolved, leading to “quadrangle boundary faults” in certain areas, highlighting areas for future research and fieldwork.
What sets this Alaska geological compilation apart is its integration with a rich database of spatial and attribute information. Every line and polygon within the spatial files is linked to its original source, with comprehensive references in related tables. Furthermore, the map includes attributes detailing typical lithology, geological setting, and age range for each map unit. Tables of radiometric ages are also incorporated, enriching the map’s data-driven utility. This map serves as an invaluable resource for researchers, policymakers, and anyone interested in the geology of Alaska, providing a detailed and authoritative view of the state’s subsurface.
