Research ArticleARCHAEOLOGY

Pre-Clovis occupation 14,550 years ago at the Page-Ladson site, Florida, and the peopling of the Americas

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Science Advances  13 May 2016:
Vol. 2, no. 5, e1600375
DOI: 10.1126/sciadv.1600375
  • Fig. 1 Page-Ladson site map.

    (A) Location of Page-Ladson in northwestern Florida. (B) Map of the Page-Ladson underwater excavations, showing the entire sinkhole and previous excavation areas, as well as excavation areas and sediment cores reported in this paper. Core 4A is marked with a blue star. Other cores are marked with blue circles. Previous excavations are marked with yellow. Our excavations are marked with red. Contours are in meters below datum. (C) Detailed map displaying the location of bones (gray), drawn to scale, and artifacts (black) recovered from geological Units 3a to 3c and 4a to 4b.

  • Fig. 2 Stratigraphy of excavation units at the Page-Ladson site displaying pre-Clovis artifacts and radiocarbon ages.

    (A) Artifact 12209-a. (B) Artifact 12209-b. (C) Artifact 12242-1. (D) Artifact 12068-2. (E) Artifact 12068-1. (F) Artifact 12080-1. (A) to (E) are flakes; (D) shows evidence of use. (F) is a biface. (G) 2014 wall profiles showing stratigraphy, locations of artifact finds, and location of radiocarbon samples. (H) 2013 wall profiles showing stratigraphy, locations of artifact finds, and location of radiocarbon samples. For (G) and (H), white dots represent locations and ages of radiocarbon samples collected from profiles. Purple dots and text represent radiocarbon ages collected from within units, plotted with correct elevation, and northing or easting. Red triangles show locations of artifacts collected from within units, plotted with correct elevation, and northing or easting. Open red circle shows approximate location of artifacts found in the screen. Trees in the profile are represented by dark brown. Note that although the biface appears as if it were found in the middle of a tree, the tree only occurs in the south wall profile and does not extend into the excavation unit where the biface was found.

  • Fig. 3 Core 4A from Page-Ladson.

    From left to right: Uncalibrated radiocarbon ages and locations; depths below datum; images of core 4A to scale; stratum designations as discussed in text; Bayesian age model of radiocarbon ages from OxCal version 4.2.4 (3032); Sporormiella influx curve calculated from Sporormiella concentrations, age model, and sedimentation rates (Supplementary Materials); and archaeological components discovered at the Page-Ladson site plotted by geological association. Younger Dryas stadial (~12,850 to 11,700 cal yr B.P.) is indicated using the age model to determine boundaries.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/2/5/e1600375/DC1

    fig. S1. Overview of the Page-Ladson site.

    fig. S2. Location of underwater excavations and recovered sediment cores at the Page-Ladson site.

    fig. S3. Digital elevation model (DEM) map of the Page-Ladson site derived from satellite (LiDAR) imagery displaying boundaries of terrestrial testing, specific locations of diagnostic lithic artifacts, and densities of ceramic and lithic materials recovered from terrestrial testing.

    fig. S4. Generalized schematic of excavation methodology, facing south (downstream).

    fig. S5. Biface in situ.

    fig. S6. Biface close up, showing biface on digesta.

    fig. S7. Micromorphology sample locations, facing south (downstream).

    fig. S8. DEM of the Page-Ladson area derived from bare earth LiDAR imagery.

    fig. S9. Generalized cross section of preserved sediments on the western portion of the Page-Ladson site, facing south.

    fig. S10. Close-up composite of core 4A displaying unit designations as described below.

    fig. S11. Bayesian age model for core PLAD-AUC14-4A.

    fig. S12. Bayesian age model for excavation unit 50N/23E.

    fig. S13. Summary of magnetic susceptibility and gamma density for PLAD-AUC14 cores.

    fig. S14. Example hysteresis loops from PLAD-AUC14-4A.

    fig. S15. Composition of titanomagnetite from hysteresis parameters for samples from 3A and 4A.

    fig. S16. Day plot of hysteresis and backfield parameters for samples from 3A and 4A.

    fig. S17. Magnetic susceptibility for PLAD-AUC14-4A showing high susceptibility in Units 4 and 6.

    fig. S18. Correlation of magnetic susceptibility with sea level in the Gulf of Mexico and globally averaged ice-volume equivalent sea level change.

    fig. S19. Diatom sample locations in PLAD-AUC14-4A.

    fig. S20. Diatom abundance in core PLAD-AUC14-4A.

    fig. S21. The locations of the block micromorphology samples within the 2013 south wall profile, the locations of the microstrata within the block samples, and representative photomicrographs of the microstrata.

    fig. S22. Left is slide 12257 in oblique incident light (OIL), 43 mm across.

    fig. S23. Left is slide 12255 in OIL, 43 mm across.

    fig. S24. From Unit 4b in PPL, the root residue in a channel (left, slide 12257) and the probable earthworm granule (right, slide 12254).

    fig. S25. Flakes recovered from lower strata at Page-Ladson.

    fig. S26. Biface (AM 12080-1) from Unit 3c.

    fig. S27. Photo of marks on Page-Ladson mastodon tusk (UF 150701) taken shortly after excavation, before formation of desiccation fractures of the cementum layer.

    fig. S28. Photo of marks on Page-Ladson mastodon tusk (UF 150701) taken after formation of desiccation fractures of the cementum layer.

    fig. S29. Comparison of early photos of marks taken before and after formation of a desiccation fracture (figs. S27 and S28).

    fig. S30. Underwater photo of Page-Ladson mastodon tusk in situ.

    fig. S31. Composite photomicrograph of new cast made from Webb’s patch mold (24).

    fig. S32. High-resolution photo (low-angle lighting from upper left) of a cast replicating part of the lateral flank of the dorsal half of the proximal tusk segment of UF 150701.

    fig. S33. Lateral aspect of polyurethane mold (and fiberglass mother mold) of the complete left alveolar cavity in the skull of the Hyde Park mastodon (33), rendered from a three-dimensional model.

    fig. S34. Location of Sporormiella samples collected from PLAD-AUC14-4A.

    fig. S35. Images of fossil Sporormiella from PLAD-AUC14-4A.

    fig. S36. Sporormiella influx by depth for core PLAD-AUC14-4A.

    fig. S37. Sporormiella influx by cal yr B.P. for core PLAD-AUC14-4A.

    table S1. Present (2015) unit designations related to nomenclature from Kendrick (13).

    table S2. Radiocarbon ages from core 4A.

    table S3. Radiocarbon ages from 2013 excavation units.

    table S4. Radiocarbon ages from 2014 excavation units.

    table S5. Radiocarbon ages from previous excavations (34) used to calculate Unit 5/6a boundary.

    table S6. Modeled ages of each stratum according to PLAD-AUC14-4A showing age spans of each stratum and sedimentation rate for each stratum.

    table S7. Magnetic measurements from cores 3A and 4A.

    table S8. Diatom percent relative abundance in sediments from the Page-Ladson Site, Florida.

    table S9. Micromorphology of Page-Ladson 2013 south profile, north 50.

    table S10. Artifacts recovered from lower strata at Page-Ladson.

    table S11. Macrofaunal remains recovered from Units 4b to 3a during 2012–2014 excavations.

    table S12. Sporormiella samples from the Page-Ladson site.

    References (33103)

  • Supplementary Materials

    This PDF file includes:

    • fig. S1. Overview of the Page-Ladson site.
    • fig. S2. Location of underwater excavations and recovered sediment cores at the Page-Ladson site.
    • fig. S3. Digital elevation model (DEM) map of the Page-Ladson site derived from satellite (LiDAR) imagery displaying boundaries of terrestrial testing, specific locations of diagnostic lithic artifacts, and densities of ceramic and lithic materials recovered from terrestrial testing.
    • fig. S4. Generalized schematic of excavation methodology, facing south (downstream).
    • fig. S5. Biface in situ.
    • fig. S6. Biface close up, showing biface on digesta.
    • fig. S7. Micromorphology sample locations, facing south (downstream).
    • fig. S8. DEM of the Page-Ladson area derived from bare earth LiDAR imagery.
    • fig. S9. Generalized cross section of preserved sediments on the western portion of the Page-Ladson site, facing south.
    • fig. S10. Close-up composite of core 4A displaying unit designations as described below.
    • fig. S11. Bayesian age model for core PLAD-AUC14-4A.
    • fig. S12. Bayesian age model for excavation unit 50N/23E.
    • fig. S13. Summary of magnetic susceptibility and gamma density for PLAD-AUC14 cores.
    • fig. S14. Example hysteresis loops from PLAD-AUC14-4A.
    • fig. S15. Composition of titanomagnetite from hysteresis parameters for samples from 3A and 4A.
    • fig. S16. Day plot of hysteresis and backfield parameters for samples from 3A and 4A.
    • fig. S17. Magnetic susceptibility for PLAD-AUC14-4A showing high susceptibility in Units 4 and 6.
    • fig. S18. Correlation of magnetic susceptibility with sea level in the Gulf of Mexico and globally averaged ice-volume equivalent sea level change.
    • fig. S19. Diatom sample locations in PLAD-AUC14-4A.
    • fig. S20. Diatom abundance in core PLAD-AUC14-4A.
    • fig. S21. The locations of the block micromorphology samples within the 2013 south wall profile, the locations of the microstrata within the block samples, and representative photomicrographs of the microstrata.
    • fig. S22. Slide 12257 in oblique incident light (OIL) (left), 43 mm across.
    • fig. S23. Slide 12255 in OIL (left), 43 mm across.
    • fig. S24. From Unit 4b in PPL, the root residue in a channel (left, slide 12257) and the probable earthworm granule (right, slide 12254).
    • fig. S25. Flakes recovered from lower strata at Page-Ladson.
    • fig. S26. Biface (AM 12080-1) from Unit 3c.
    • fig. S27. Photo of marks on Page-Ladson mastodon tusk (UF 150701) taken shortly after excavation, before formation of desiccation fractures of the cementum layer.
    • fig. S28. Photo of marks on Page-Ladson mastodon tusk (UF 150701) taken after formation of desiccation fractures of the cementum layer.
    • fig. S29. Comparison of early photos of marks taken before and after formation of a desiccation fracture (figs. S27 and S28).
    • fig. S30. Underwater photo of Page-Ladson mastodon tusk in situ.
    • fig. S31. Composite photomicrograph of new cast made from Webb's patch mold (24).
    • fig. S32. High-resolution photo (low-angle lighting from upper left) of a cast replicating part of the lateral flank of the dorsal half of the proximal tusk segment of UF 150701.
    • fig. S33. Lateral aspect of polyurethane mold (and fiberglass mother mold) of the complete left alveolar cavity in the skull of the Hyde Park mastodon (33), rendered from a three-dimensional model.
    • fig. S34. Location of Sporormiella samples collected from PLAD-AUC14-4A.
    • fig. S35. Images of fossil Sporormiella from PLAD-AUC14-4A.
    • fig. S36. Sporormiella influx by depth for core PLAD-AUC14-4A.
    • fig. S37. Sporormiella influx by cal yr B.P. for core PLAD-AUC14-4A.
    • table S1. Present (2015) unit designations related to nomenclature from Kendrick (13).
    • table S2. Radiocarbon ages from core 4A.
    • table S3. Radiocarbon ages from 2013 excavation units.
    • table S4. Radiocarbon ages from 2014 excavation units
    • table S5. Radiocarbon ages from previous excavations (34) used to calculate Unit 5/6a boundary.
    • table S6. Modeled ages of each stratum according to PLAD-AUC14-4A showing age spans of each stratum and sedimentation rate for each stratum.
    • table S7. Magnetic measurements from cores 3A and 4A.
    • table S8. Diatom percent relative abundance in sediments from the Page-Ladson Site, Florida.
    • table S9. Micromorphology of Page-Ladson 2013 south profile, north 50.
    • table S10. Artifacts recovered from lower strata at Page-Ladson.
    • table S11. Macrofaunal remains recovered from Units 4b to 3a during 2012?2014 excavations.
    • table S12. Sporormiella samples from the Page-Ladson site.
    • References (33–103)

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