Metallogenesis and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera
Bibliographic record
Abstract
The Proterozoic and Phanerozoic metallogenic and tectonic evolution of the Russian Far East, Alaska, and the Canadian Cordillera is recorded in the cratons, craton margins, and orogenic collages of the Circum-North Pacific mountain belts that separate the North Pacific from the eastern North Asian and western North American Cratons. The collages consist of tectonostratigraphic terranes and contained metallogenic belts, which are composed of fragments of igneous arcs, accretionary-wedge and subduction-zone complexes, passive continental margins, and cratons. The terranes are overlapped by continental-margin-arc and sedimentary-basin assemblages and contained metallogenic belts. The metallogenic and geologic history of terranes, overlap assemblages, cratons, and craton margins has been complicated by postaccretion dismemberment and translation during strike-slip faulting that occurred subparallel to continental margins. Seven processes overlapping in time were responsible for most of metallogenic and geologic complexities of the region (1) In the Early and Middle Proterozoic, marine sedimentary basins developed on major cratons and were the loci for ironstone (Superior Fe) deposits and sediment-hosted Cu deposits that occur along both the North Asia Craton and North American Craton Margin. (2) In the Late Proterozoic, Late Devonian, and Early Carboniferous, major periods of rifting occurred along the ancestral margins of present-day Northeast Asia and northwestern North America. The rifting resulted in fragmentation of each continent, and formation of cratonal and passive continental-margin terranes that eventually migrated and accreted to other sites along the evolving margins of the original or adjacent continents. The rifting also resulted in formation of various massive-sulfide metallogenic belts. (3) From about the late Paleozoic through the mid-Cretaceous, a succession of island arcs and contained igneous-arc-related metallogenic belts and tectonically paired subduction zones formed near continental margins. (4) From about mainly the mid-Cretaceous through the present, a succession of continental-margin igneous arcs (some extending offshore into island arcs) and contained metallogenic belts, and tectonically paired subduction zones formed along the continental margins. (5) From about the Jurassic to the present, oblique convergence and rotations caused orogen-parallel sinistral, and then dextral displacements within the plate margins of the Northeast Asian and North American Cratons. The oblique convergences and rotations resulted in the fragmentation, displacement, and duplication of formerly more continuous arcs, subduction zones, passive continental margins, and contained metallogenic belts. These fragments were subsequently accreted along the margins of the expanding continental margins. (6) From the Early Jurassic through Tertiary, movement of the upper continental plates toward subduction zones resulted in strong plate coupling and accretion of the former island arcs, subduction zones, and contained metallogenic belts to continental margins. In this region, the multiple arc accretions were accompanied and followed by crustal thickening, anatexis, metamorphism, formation of collision-related metallogenic belts, and uplift; this resulted in the substantial growth of the North Asian and North American continents. (7) In the middle and late Cenozoic, oblique to orthogonal convergence of the Pacific Plate with present-day Alaska and Northeast Asia resulted in formation of the present ring of volcanoes and contained metallogenic belts around the Circum-North Pacific. Oblique convergence between the Pacific Plate and Alaska also resulted in major dextral-slip faulting in interior and southern Alaska and along the western part of the Aleutian- Wrangell arc. Associated with dextral-slip faulting was crustal extrusion of terranes from western Alaska into the Bering Sea.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.007 | 0.000 |
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 teacher head, 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".