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Record W4313322381 · doi:10.1130/2022.1220(19)

Neoproterozoic of Laurentia

2022· book-chapter· en· W4313322381 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

aboutThe title or abstract carries a Canadian signal from the geographic lexicon.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueGeological Society of America eBooks · 2022
Typebook-chapter
Languageen
FieldEarth and Planetary Sciences
TopicGeological and Geochemical Analysis
Canadian institutionsnot available
Fundersnot available
KeywordsLaurentiaRodiniaGeologyBalticaPaleontologySupercontinentLarge igneous provincePaleomagnetismRiftIgneous rockTerraneCratonTectonicsOrdovicianMagmatism

Abstract

fetched live from OpenAlex

ABSTRACT Neoproterozoic to Cambrian isolation of Laurentia during the breakup of Rodinia was associated with multiple large igneous provinces, protracted multiphase rifting, and variable subsidence histories along different margin segments. In this contribution, we develop a paleogeographic model for the Neoproterozoic tectonic evolution of Laurentia based on available stratigraphic, paleomagnetic, petrologic, geochronologic, and thermochronologic data. Early Tonian strata are confined to intracontinental basins in northern Laurentia. Breakup of Rodinia around Laurentia began in earnest with emplacement of the ca. 778 Ma Gunbarrel large igneous province, interpreted to have accompanied separation of the North China block along the Yukon promontory, and onset of localized, intracratonic extension southward along the western margin. Eruption of the ca. 760–740 Ma Mount Rogers volcanic complex along the Southern Appalachian segment of the eastern margin may record extension associated with separation of the Kalahari or South American terranes. At about the same time, the Australia-Mawson blocks began separating from the Sonoran segment of the southern margin and Mojave promontory. Emplacement of the ca. 720 Ma Franklin large igneous province along the northern margin was likely associated with separation of Siberia and was followed by widespread bimodal volcanism and extension along the western margin spanning ca. 720–670 Ma, leading to partial separation of continental fragments, possibly including Tasmania, Zealandia, and Tarim. Emplacement of the ca. 615 Ma Central Iapetus magmatic province along the eastern margin marked rifting that led to separation of Baltica and Amazonia, and partial separation of the Arequipa-Pampia-Antofalla fragments. During the late Ediacaran to Cambrian, the western, northern, eastern, and southern margins all experienced a second episode of local extension and mafic magmatism, including emplacement of the ca. 585 Ma Grenville dikes and ca. 540–532 Ma Wichita large igneous province, leading to final separation of continental fragments and Cambrian rift-drift transitions on each margin. Cryogenian rifting on the western and northern margins and segments of the eastern margin was contemporaneous with low-latitude glaciation. Sturtian and Marinoan glacial deposits and their distinctive ca. 660 Ma and 635 Ma cap carbonates provide important event horizons that are correlated around the western and northern margins. Evidence for Ediacaran glaciation is absent on Laurentia, with the exception of glacial deposits in Scotland, and putative glacial deposits in Virginia, which both formed on the poleward edge of Laurentia. Patterns of exhumation and deposition on the craton display spatial variability, likely controlled by the impingement of mantle plumes associated with mantle upwelling and extensional basin formation during the piecemeal breakup of Rodinia. Glaciation and eustasy were secondary drivers for the distribution of erosion and Neoproterozoic sedimentation on North America.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesInsufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Other design · Consensus signal: none
GenreCandidate signal: Other · Consensus signal: none
Teacher disagreement score0.885
Threshold uncertainty score0.999

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0000.000
Science and technology studies0.0000.001
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.1910.000

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.

Opus teacher head0.015
GPT teacher head0.184
Teacher spread0.169 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it