{ "$comment": [ "Central awareness of the datasets these viewers draw, and of the decisions taken", "between a published source and the thing on screen.", "", "WHY THIS EXISTS. Two viewers in this family independently built a file called", "glaciations.json from the same underlying compilation, with different schemas, and", "neither knew about the other. Nothing was wrong with either -- but a third viewer", "would have built a third, and by then 'what does this family say about glaciation'", "would have had no answer. This file is that answer.", "", "WHAT IT IS NOT. It is not a canon. These pages are built on the position that several", "defensible reconstructions exist and a reader should be able to move between them;", "the same applies to every other dataset. So where genuine alternatives exist they are", "all listed, none is marked correct, and a viewer is expected to offer the choice", "rather than quietly pick one. Inconsistency between viewers is acceptable. Undeclared", "inconsistency is not.", "", "THE PART THAT MATTERS MOST is `derivation_choices`. A source publishes something; a", "viewer draws something; between the two sit decisions -- a smoothing window, a gap", "bridge, a latitude band, a time step. Those are invisible in the rendered page and", "invisible in the data file, and they are exactly what these viewers exist to surface.", "Anything in `derivation_choices` is OURS, not the source's, and should be marked that", "way wherever it reaches a UI.", "", "RELATIONSHIPS between entries under one concept:", " variant - competing estimates of the SAME quantity over the SAME range. A knob.", " component - different quantities, or the same one over a DIFFERENT range, composed", " into one display. Not a choice: a join, whose seams must be declared.", " reduction - the same data processed into a different shape, with the processing", " parameters recorded in derivation_choices.", "", "`covers_ma` is [oldest, youngest]. Outside it the answer is NO DATA, which is not the", "same as zero and must never be drawn as though it were." ], "schema_version": 1, "concepts": { "glacial_extent": { "quantity": "angular distance from the pole reached by ice, degrees", "note": "The margin latitude is 90 minus this.", "entries": [ { "id": "macdonald2019", "relationship": "component", "covers_ma": [525.0, 0.0], "source": "Macdonald, F.A., Swanson-Hysell, N.L., Park, Y., Lisiecki, L. & Jagoutz, O. (2019), Science 364, 181-184", "provenance": [ "TropicalSutures (GeodeViewers) reads it from the authors' own code_output/ice_LIP_suture_lengths.csv", "lips reads it from Ice_Extent.csv in Park et al. (2020)'s repository, their digitisation of the same figure" ], "verified": "The two paths were compared at all 105 overlapping ages and agree exactly. They are not variants; they are the same numbers by two routes.", "derivation_choices": {}, "used_by": ["TropicalSutures", "lips"], "files": ["https://github.com/siwill22/GeodeViewers/blob/main/TropicalSutures/data/macdonald2019.json", "lips/data/ice_extent.csv"] }, { "id": "macdonald2019-intervals", "relationship": "reduction", "of": "macdonald2019", "covers_ma": [525.0, 0.0], "quantity": "contiguous glaciated intervals with a peak extent each", "source": "as macdonald2019, reduced to discrete intervals by this project", "derivation_choices": { "bridge_myr": { "value": 3, "what": "Gaps in the continuous record shorter than this are bridged, merging what would otherwise be two glaciations into one.", "whose": "ours", "effect": "Changes how many glaciations the record contains. Not a published parameter." } }, "used_by": ["lips"], "files": ["lips/data/glaciations.json"] } ] }, "cryogenian_glaciation": { "quantity": "dated glaciation intervals, each boundary a bracket between two dated horizons", "note": "A different quantity from glacial_extent, over a range that compilation does not reach. Composed with it, never substituted for it. THE SEAM: 579.88-525 Ma is covered by neither and is NO DATA.", "entries": [ { "id": "hoffman2017-pu2016", "relationship": "component", "covers_ma": [717.5, 579.88], "source": "Hoffman, P.F. et al. (2017), Science Advances 3(11), e1600983, Table 1; Gaskiers from Pu, J.P. et al. (2016), Geology 44(11), 955-958", "derivation_choices": {}, "used_by": ["TropicalSutures"], "files": ["https://github.com/siwill22/GeodeViewers/blob/main/TropicalSutures/data/glaciations.json"] } ], "known_alternatives": [ { "id": "rooney2015", "status": "not a variant -- do not build as one", "source": "Rooney, A.D., Strauss, J.V., Brandon, A.D. & Macdonald, F.A. (2015), Geology 43, 459-462", "why": "It reads as a rival chronology (Sturtian 717-660 Ma, Marinoan termination 635 Ma) but it is not one: Hoffman et al. (2017) Table 1 cites Rooney's individual Re-Os dates among its own constraints -- 662.4 +/- 3.9 Ma for Laurentia, 659.0 +/- 4.5 for Tuva-Mongolia, >632.3 +/- 5.9 for the basal Sheepbed. Rooney is an INPUT to the entry above, not an alternative to it. Offering both as a knob would invent a disagreement that does not exist.", "a_real_variant_would_be": "A compilation drawing on a different body of geochronology, or one weighting the same constraints differently -- e.g. resolving the Sturtian termination toward Laurentia's 662.4 Ma rather than Hoffman's synthesised 659.3-658.5 Ma window. None is currently on disk." } ] }, "plate_reconstruction": { "quantity": "rotations, and the polygons they move", "note": "The clearest case of genuine variants in this family, and the one the other concepts should be modelled on: several defensible models, all offered, none marked correct.", "entries": [ { "id": "Merdith2021", "relationship": "variant", "covers_ma": [1000.0, 0.0], "source": "Merdith, A.S. et al. (2021), Earth-Science Reviews 214, 103477", "capabilities": ["topologies", "continent_polygons"], "derivation_choices": { "anchor_plate": { "value": 0, "whose": "source's convention", "effect": "Its 001-relative-to-000 sequence is identity, so 0 and 1 agree here." } }, "used_by": ["TropicalSutures", "zircons", "detrital-zircons", "lips", "plate-boundaries"] }, { "id": "TorsvikCocks2017", "relationship": "variant", "covers_ma": [540.0, 0.0], "source": "Torsvik, T.H. & Cocks, L.R.M. (2017), Earth History and Palaeogeography, Cambridge University Press", "rotation_file": "gprm's Torsvik_Cocks_HybridRotationFile.rot", "capabilities": ["continent_polygons"], "derivation_choices": { "anchor_plate": { "value": 1, "whose": "source's convention", "effect": "Plate 001 is the spin axis in this model; anchoring on 000 moves paleolatitude by up to ~9 degrees." } }, "used_by": ["TropicalSutures"] }, { "id": "TC2017_SHM2017_D2018", "relationship": "variant", "covers_ma": [540.0, 0.0], "source": "Torsvik & Cocks 2017 + Swanson-Hysell & Macdonald + Domeier (2018), as distributed in Macdonald et al.'s Arc_Continent_Analysis repository", "rotation_file": "TC2017_SHM2017_D2018.rot", "capabilities": ["continent_polygons"], "note": "The SAME NAMED MODEL as TorsvikCocks2017 from a different rotation file. At 445 Ma they place Laurentia 13 degrees apart in latitude, which roughly halves tropical suture length at the Hirnantian. Kept as separate entries deliberately: that disagreement is the point, not a defect to reconcile.", "derivation_choices": { "anchor_plate": { "value": 1, "whose": "source's convention", "effect": "as TorsvikCocks2017" } }, "used_by": ["TropicalSutures"] } ] }, "suture_compilation": { "quantity": "ophiolite-bearing suture geometry with magmatic, metamorphic and exhumation age intervals", "entries": [ { "id": "macdonald2019-sutures", "relationship": "component", "covers_ma": [1090.0, 0.0], "source": "Macdonald et al. (2019), Science 364, 181-184; Suture_Lines_M2021.geojson", "note": "115 sutures. Carries three plate-ID columns of its own -- PLATEID1 (Merdith2021), PLATEID_M (Matthews2016), PLATEID_CE (CEED). This project assigns no plate IDs.", "derivation_choices": { "activity_definition": { "value": "reader's choice of four", "whose": "source tabulates all four; the published curve used one", "effect": "Which age interval counts as 'active'." }, "latitude_band": { "value": "reader's choice of +/-10/15/20/40", "whose": "source's own output columns", "effect": "What counts as tropical." }, "band_edge": { "value": "hard or cosine taper", "whose": "hard is published; the taper is OURS", "effect": "Whether a suture crossing the edge counts fully or partly." }, "time_step_myr": { "value": 5, "whose": "ours", "effect": "Matches the source's own 5 Myr output rather than implying finer precision." } }, "used_by": ["TropicalSutures"], "files": ["https://github.com/siwill22/GeodeViewers/tree/main/TropicalSutures/data (per-model sutures.json)"] } ] }, "lip_compilation": { "quantity": "large igneous province extents and areas through time", "entries": [ { "id": "ernst-youbi2017-park2020", "relationship": "component", "source": "Ernst, R.E. & Youbi, N. (2017) present-day extents, edited by Park et al. (2020), AGU Geophysical Monograph 255, doi:10.1002/9781119507444", "known_alternatives": [ { "id": "green2022", "status": "wanted, not built", "source": "Green et al. (2022), PNAS, doi:10.1073/pnas.2120441119" } ], "used_by": ["lips"], "files": ["lips/data/lips_earthbyte.json", "lips/data/lip_flux.json"] } ] }, "continental_arc_length": { "quantity": "continental arc length through time, km", "entries": [ { "id": "cao2017", "relationship": "component", "covers_ma": [410.0, 0.0], "source": "Cao, W., Zahirovic, S., Flament, N., Williams, S., Golonka, J. & Muller, R.D. (2017), Biogeosciences 14, 5425-5439", "note": "Shipped inside TropicalSutures/data/macdonald2019.json (GeodeViewers) as the continental_arc_Cao2017 column, verbatim. Binned at 10 Myr by the source.", "used_by": ["TropicalSutures"] } ] } } }