Research ArticleGEOLOGY

Volcanic mercury and mutagenesis in land plants during the end-Triassic mass extinction

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Science Advances  23 Oct 2019:
Vol. 5, no. 10, eaaw4018
DOI: 10.1126/sciadv.aaw4018
  • Fig. 1 TJB timeline and correlation of the Stenlille-1 record with Kuhjoch, Austria, and New York Canyon, Nevada.

    (A) U/Pb ages for CAMP intrusives (white circles), CAMP basalts (brown circles), and ash beds from Nevada and Peru (yellow circles), and ammonoid events (1, 7, 8, 32, 34). Note that U/Pb ages 4, 7, 11, and 14 are all from the North Mountain Basalt. 1, Kakoulima intrusion (7); 2, Tarabuco sill (7); 3, Messejana dike (7); 4, North Mountain Basalt (8); 5, Amelal sill (8); 6, Amazonas sill (low Ti) (7); 7, North Mountain Basalt (7, 8); 8, Palisades sill (8), feeder of the Orange Mountain Basalt; 9, York Haven intrusive (8); 10, Rapidan intrusive (8); 11, North Mountain Basalt (7); 12, Fouta Djalon sill (7); 13, Hodh sill (7); 14, North Mountain Basalt (1, 2); 15, Amazonas sill (high Ti) (7); 16, Shelburne dike (7); 17, Rossville intrusive (8); 18, Preakness Basalt (8); 19, Foum Zguid (7); 20, Ash bed LM4-86, Peru (1, 2); 21, Ash bed LM4-90, Peru (1, 2); 22, Ash bed NYC-N10, Nevada (1); 23, Ash bed LM4-100/101, Peru (1, 2); 24, Amazonas Basin sill, Brazil (33); 25, Solimões Basin sill, Brazil (33). (B) Ammonite zones and extinction interval (32). (C to E) Bulk organic C-isotope (as ‰ of Vienna Pee Dee belemnite) (9, 32) and Hg/TOC (in ppb/%) records for (C) Stenlille-1, (D) Kuhjoch, Austria (17, 34), and (E) New York Canyon, Nevada (16). For an expanded version of this figure showing correlations of Hg/TOC-records and Hg -records of all studied localities, see fig. S2.

  • Fig. 2 Selected photos of LTT-spores teratology, arranged after teratology category defined in Table 1.

    In black frames: (A to F) representatives of normal spores. In white frames, mild teratology: (G and H) dwarfs, (I to K) unexpanded forms. In yellow frames, mild to moderate teratology: (L and M) uneven trilete mark, (N) uneven trilete mark and aberrant exine cracks, (O to Q) aberrant exine cracks or folds, (R to U) thickened labra or with growths, and (V) dwarf with thickened labra. In orange frames, moderate teratology: (W) quadrilete specimen, (X) monolete specimens with thickened labra, (Y and Z) mono- or multilete specimens, (AA) monolete specimen with deformed labra and possibly deformed outline, and (BB and CC) specimens with deformed outline. In light red frames, moderate to severe teratology: (DD) specimen with weakly deformed trilete mark and deformed outline, (EE) weakly deformed proximal area on a quadrilete specimen, (FF) weakly deformed proximal area with weakly discernable laesura and deformed outline, and (GG) conjoined twins. In dark red frames, severe teratology: (HH and II) severe proximal deformation. Scale bar, 20 μm. For sample number and England Finder coordinates, see table S1.

  • Fig. 3 Organic δ13C, total organic carbon, Hg loading and Hg/TOC, and total teratology for Stenlille-1 and Rødby-1.

    (A) Stenlille-1, and (B) Rødby-1. The LTT- and LCT-spore teratology is expressed as percentage of the total number of specimens counted within each genus per sample, as well as total severity of sample expressed as colors. Lithology and intervals used to subdivide the TJB succession mainly after reference (32). Stars denote approximate position of terrestrial coal/coaly beds in the Danish Basin (45). Number of stars indicates frequency of wildfires. Larger star size indicates higher estimated burning temperature (45). Red arrows on (A) mark levels where Hg and Hg/TOC decrease, while TOC levels remain high. Note that TOC values below the detection levels are marked with white squares and that no Hg/TOC values were calculated for these samples. VPDB, Vienna Pee Dee belemnite.

  • Fig. 4 TOC, Hg loading and Hg/TOC, and total teratology for Stenlille-4 and Norra Albert/Albert-1.

    (A) Stenlille-4 and (B) Norra Albert/Albert-1. The LTT- and LCT-spore teratology is expressed as percentage of the total number of specimens counted within each genus per sample, as well as total severity of sample expressed as colors. Lithology and intervals used to subdivide the TJB succession mainly after (36). Red arrows on (A) mark levels where Hg and Hg/TOC decrease, while TOC levels remain high. Note that TOC values below the detection levels are marked with white squares and that no Hg/TOC values were generated for these samples.

  • Fig. 5 Hg loading and Hg/TOC versus cumulative abundance and severity of LTT-spore teratology.

    (A) Stenlille-1, (B) Stenlille-4, and (C) Rødby-1. (A) to (J) Teratological severity categories; characteristics can be found in Table 1. Original plots for the cumulative abundance and severity can be found in fig. S2 to S4, and the data are listed in tables S2 to S4.

  • Table 1 Teratology: Characterization, severity, and possible cause.

    TeratologyCharacteristicsSeverityPossible cause
    (A) Dwarfed
    forms
    Aberrant small
    size. Often
    dense exine.
    Immature.
    MinorPremature
    shedding.
    (B) Unexpanded
    forms
    Poorly inflated.
    Immature.
    MinorPremature
    shedding.
    (C) Uneven
    trilete rays
    Uneven length
    of trilete rays or
    deformed
    (sinuous) trilete
    rays.
    Minor to
    moderate
    One or more
    aborted spore
    in tetrad.
    (D) Aberrant
    folding
    Exine with
    transverse folds
    and/or cracks.
    Minor to
    moderate
    Mild genetic
    disturbance?
    (E) Labra
    thickened or
    with growths
    Aberrant wide
    labras or with
    growths
    (baculae,
    granae, and
    verrucae) on
    labra.
    Minor to
    moderate
    Mild genetic
    disturbance.
    (F) Mono- or
    multilete
    Aberrant mark
    with too few or
    too many rays.
    ModerateDisturbed
    meiosis
    resulting in
    either a
    tetragonal
    tetrad
    configuration,
    or more than 4
    spores, or due
    to fused twins.
    Unbalanced
    cytokinesis.
    (G) Deformed
    outline
    Indentations on
    spore margin,
    not caused by
    folding or
    preservation.
    ModerateProbably not
    only related to
    uneven spore
    development in
    a tetrad.
    Genetic
    disturbance
    affecting cell
    growth.
    Incomplete
    cytokinesis.
    (H) Minor
    proximal
    deformation
    Thickened and/
    or wrinkled
    proximal area
    with trilete
    mark partially
    discernable.
    Moderate to
    severe
    Genetic
    deformation
    affecting the
    proximal
    (germination)
    area.
    (I) Deformed or
    fused tetrads or
    dyads
    Not merely
    separate spores
    still in tetrad or
    dyad
    configuration.
    Moderate to
    severe
    May indicate
    genetic
    disturbance
    and
    unbalanced
    cytokinesis.
    (J) Major
    proximal
    deformation
    Thickened and
    wrinkled
    proximal area
    where the
    trilete mark is
    not discernable.
    SevereSevere genetic
    deformation of
    proximal
    (germination)
    area.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/5/10/eaaw4018/DC1

    Supplementary Text

    Fig. S1. Selected photographs of LTT-spores teratology, arranged after teratology categories defined in Table 1.

    Fig. S2. Expanded correlation from Fig. 1.

    Fig. S3. Plots showing the stratigraphic occurrence and abundance of each teratological form of LTT-spores.

    Fig. S4. Correlation between the localities studied herein.

    Fig. S5. Correlation of organic C-isotopes (4), charcoal data (56), PAH (52), and mercury data (17) from Astartekløft, Greenland.

    Table S1. Sample and slide numbers and England Finder coordinates for the LTT-spores illustrated in Fig. 2.

    Table S2. Stenlille-1: Counts of total and aberrant LTT-spores.

    Table S3. Stenlille-4: Counts of total and aberrant LTT-spores.

    Table S4. Rødby-1: Counts of total and aberrant LTT-spores.

    Table S5. Norra Albert/Albert-1: Counts of total and aberrant LTT-spores.

    Table S6. Stenlille-1: Counts of total and aberrant LCT-spores.

    Table S7. Stenlille-4: Counts of total and aberrant LCT-spores.

    Table S8. Rødby-1: Counts of total and aberrant LCT-spores.

    Table S9. Mercury and TOC values for the investigated localities.

    Table S10. Sample and slide numbers and England Finder coordinates for the LCT-spores illustrated in fig. S1.

    References (6176)

  • Supplementary Materials

    This PDF file includes:

    • Supplementary Text
    • Fig. S1. Selected photographs of LTT-spores teratology, arranged after teratology categories defined in Table 1.
    • Fig. S2. Expanded correlation from Fig. 1.
    • Fig. S3. Plots showing the stratigraphic occurrence and abundance of each teratological form of LTT-spores.
    • Fig. S4. Correlation between the localities studied herein.
    • Fig. S5. Correlation of organic C-isotopes (4), charcoal data (56), PAH (52), and mercury data (17) from Astartekløft, Greenland.
    • Table S1. Sample and slide numbers and England Finder coordinates for the LTT-spores illustrated in Fig. 2.
    • Table S2. Stenlille-1: Counts of total and aberrant LTT-spores.
    • Table S3. Stenlille-4: Counts of total and aberrant LTT-spores.
    • Table S4. Rødby-1: Counts of total and aberrant LTT-spores.
    • Table S5. Norra Albert/Albert-1: Counts of total and aberrant LTT-spores.
    • Table S6. Stenlille-1: Counts of total and aberrant LCT-spores.
    • Table S7. Stenlille-4: Counts of total and aberrant LCT-spores.
    • Table S8. Rødby-1: Counts of total and aberrant LCT-spores.
    • Table S9. Mercury and TOC values for the investigated localities.
    • Table S10. Sample and slide numbers and England Finder coordinates for the LCT-spores illustrated in fig. S1.
    • References (6176)

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