U–Pb geochronology in Liverpool Land and Canning Land, East Greenland — the complex record of a polyphase Caledonian orogenyThis article is one of a series of papers published in this Special Issue on the theme of<i>Geochronology</i>in honour of Tom Krogh.
Bibliographic record
Abstract
The Liverpool Land – Canning Land region in East Greenland is the central-most basement high in the northeast Atlantic Caledonides. It contains a variety of rocks derived from the whole section of the Caledonian crust, permitting correlations and comparisons of tectonomagmatic events at all crustal levels. Here, we present U–Pb thermal ionization mass spectrometry (TIMS) data combined with field studies suggesting that the region can be divided into distinct tectonostratigraphic domains: (1) The Southern Liverpool Land eclogite terrane with garnet-peridotite and eclogite lenses, the product of a polyorogenic history with a latest-Paleoproterozic and Mesoproterozoic origin, eclogitization at 398 Ma and migmatization at 387 Ma. (2) The migmatitic Mariager Fjord Dome in central Liverpool Land with gneisses that formed leucosome at 409 Ma. Both areas are separated by high-strain zones from (3) the overlying Hurry Inlet plutonic terrane, which consists of metasedimentary rocks first intruded by granodiorite to granite at ca. 440–430 Ma, and, after local deformation, by a major 426–424 Ma granitic to monzonitic suite. (4) Structurally higher, and probably above another high-strain zone, low-grade Neoproterozoic to Cambrian sediments are intruded, by syn-contractional 427 Ma leucogranite. All these units are unconformably overlain by Devonian and younger deposits. Collectively our data document a distinct variation in time for Caledonian magmatism and metamorphism in the various tectonostratigraphic domains, implying that the diverse terranes were juxtaposed after magmatism, and that the gneiss domes of Liverpool Land have a different origin than other nappes of the East Greenland Caledonides.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".