The Gothic Dome: Kilometer-scale Miocene Exhumation in Colorado’s Elk and West Elk Mountains
Bibliographic record
Abstract
The Colorado Rockies were initially raised during the Laramide Orogeny ca. 70-45 Ma. But consensus exists that the range experienced a second, post-Laramide episode of surface uplift; the timing and cause of that post-Laramide surface uplift event remains enigmatic. Low-temperature thermochronologic studies conducted by us and others using apatite (U-Th)/He (AHe), apatite fission track (AFT), and zircon (U-Th)/He (ZHe) techniques reveal that a dome of kilometer-scale exhumation occurred in Colorado’s Elk and West Elk mountains between ca. 18-6 Ma. We call this feature the “Gothic Dome” because it is centered on Gothic Mountain, near the town of Crested Butte. We suggest the ~100-km-diameter Gothic Dome likely experienced Miocene surface uplift, which triggered the dome-shaped exhumation pattern documented by the low-temperature thermochronometry. The exhumation magnitude exceeds 4 km in the center of the dome (as revealed by a 16 Ma ZHe date on an Oligocene pluton) and diminishes toward its perimeter. This diminution of exhumation magnitude toward the perimeter is revealed by progressively older AHe, AFT, and ZHe dates in all directions away from Gothic Mountain. AHe dates for samples that lie outside the perimeter are Laramide-age or older, further documenting the dome-shaped nature of this Miocene exhumation event and illustrating the low magnitude of Miocene to recent exhumation outside the dome’s perimeter. Outcrops of ca. 11 Ma basalt surround the Gothic Dome to the north, west, and south, requiring that Miocene exhumation outside the dome’s perimeter was minimal. A suite of alkaline, low-volume, felsic plutons and ultramafic lamprophyres intruded the Gothic Dome between ca. 18-12 Ma. This alkalic magmatism began either immediately prior to or contemporaneous with the onset of Gothic Dome exhumation, hinting that the same root cause might be responsible for both. Workers elsewhere, including Tibet, the Altiplano, and California’s Sierra Nevada mountains, have attributed small-volume alkalic magmatism, surface uplift, and exhumation to the activity of lithospheric drips. We offer that Miocene activity of such a drip beneath Colorado’s Elk and West Elk mountains is an appealing mechanism to explain the near simultaneity of those same phenomena here.
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 | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| 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".