Research ArticleENVIRONMENTAL SCIENCE

Miocene flooding events of western Amazonia

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Science Advances  03 May 2017:
Vol. 3, no. 5, e1601693
DOI: 10.1126/sciadv.1601693
  • Fig. 1 Core correlation and marine intervals in the Llanos and Amazonas/Solimões basins.

    (A) Location of seismic lines, wells, and outcrops used in this study in the Llanos Basin of Colombia and in the Amazonas/Solimões Basin near the Colombia-Brazil boundary. (B) Correlation of the stratigraphic units drilled in the Saltarin and 105-AM wells using age control established by palynology and sequence stratigraphy analysis. The depositional environment interpretation and the abundance of MPs identify the two intervals of marine incursions, the early Miocene incursion (EMI) and the middle Miocene incursion (MMI), in each well and indicate thicker deposition of marine deposits in the Llanos Basin. Biostratigraphic zones (T-) follow those in the study of Jaramillo et al. (56). MD, meters depth. (C) Macrofossils found in the Saltarin well: (1) tooth of a Carcharhiniformes shark (fig. S6) and (2) mantis shrimp (fig. S7). These fossils are further evidence of the marine incursion that covered the Llanos Basin. See the Supplementary Materials for a detailed description and identification of these fossils. Depositional environments were grouped into three broad categories: (i) Continental environment that represents accumulation in fluvial channels and adjacent floodplains by subaerial exposure; (ii) Marginal environment that represents accumulation on deltaic plains; low-energy wetlands with swamps, ponds, and channels; and shallow freshwater lacustrine systems; and (iii) Marine environment that represents shallow marine water. Notice that the Marine environment of 105-AM is shallower and less saline than the marine intervals in Saltarin.

  • Fig. 2 Paleogeographic reconstruction of the two marine incursions in the study.

    (A to I) The reconstruction is based on the stratigraphic correlation shown in Fig. 1 and on the stratigraphic analysis of nine wells in the Llanos Basin and one well and nine outcrops in the Amazonas/Solimões Basin (see the Supplementary Materials for descriptions of sections and a movie based on the construction of 30 paleogeographic maps). Marine ingressions occurred earlier in the Llanos Basin than in the Solimões Basin. The two basins were separated during the late Miocene (G, H, and I) by the uplift of the Vaupés Arch. Notice that marine intervals are shallower and less saline toward the 105-AM region.

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/3/5/e1601693/DC1

    section S1. General information

    section S2. Sedimentology and sequence stratigraphy analyses

    section S3. Marine intervals

    section S4. Basin-wide correlations

    section S5. Chronology of cores

    section S6. Sites from the literature used in this study

    section S7. Other published sites beyond the boundaries of this study

    fig. S1. Map of northwestern South America showing the sedimentary basins discussed in the text and the structural features that divide them.

    fig. S2. Location of the nine wells in the Llanos Basin, two wells in the Amazonas/Solimões Basin, and 13 seismic lines used for this study (geographic coordinates in tables S5 and S6).

    fig. S3. Sedimentological and sequence stratigraphic interpretation of the Saltarin well (see details of interpretation in table S7).

    fig. S4. Graphic correlation of Saltarin versus 105-AM using geological time as scale in both axes, rather than stratigraphic thickness.

    fig. S5. Photomicrographs of selected dinoflagellate cysts and acritarchs.

    fig. S6. Carcharhiniformes gen. et sp. indet. tooth from the core Saltarin, Carbonera C2 Formation, early Miocene, 630.08 m, specimen MUN STRI-40967.

    fig. S7. Dactyl of raptorial appendage (second thoracopod) of a fossil mantis shrimp from the Carbonera Formation, early Miocene, Colombia, MUN STRI-40281.

    fig. S8. Sedimentological and sequence stratigraphic interpretation of the 105-AM well (see details of interpretation in table S8).

    fig. S9. Stratigraphic correlation of the two major marine incursions (EMI and MMI) from the Saltarin well to the northernmost expression of the Vaupés Arch in the subsurface (well I).

    fig. S10. Stratigraphic correlation of the two major marine incursions (EMI and MMI) along the northern Amazonas/Solimões Basin.

    fig. S11. Graphic correlation between the standard composite section of Jaramillo et al. (56) and core Saltarin.

    fig. S12. Graphic correlation between the standard composite section of Jaramillo et al. (56) and core 105-AM.

    fig. S13. Seismic profiles in the Llanos Basin (see location in fig. S2; interpretation only at one extreme of the line) illustrate the seismic facies of the two marine incursions (EMI and MMI).

    fig. S14. Interpreted 2D seismic profiles showing the contrasting difference of seismic facies between undifferentiated Cenozoic and Cretaceous units in the Amazonas/Solimões Basin (see fig. S2 for the location of seismic lines).

    fig. S15. Graphic correlation between the cores Saltarin and 105-AM.

    fig. S16. Carbon isotope data (δ13C) versus stratigraphic position in core Saltarin on the left panel.

    fig. S17. Carbon isotope data (δ13C) versus stratigraphic position in core 105-AM.

    fig. S18. Photographs of shells from core 105-AM.

    fig. S19. Molluscan biostratigraphy of core 105-AM.

    table S1. Palynomorph counts for samples analyzed in core Saltarin.

    table S2. Palynomorph counts for samples analyzed in core 105-AM.

    table S3. Summary of palynological count data.

    table S4. BIT index for Saltarin samples.

    table S5. Geographic coordinates and information of outcrops and wells (coordinate system WGS 1984) used in this study.

    table S6. Geographic coordinates and information of 2D seismic lines (coordinate system WGS 1984) used in this study.

    table S7. Summary of lithological and palynological indicators for depositional environment interpretation of the Saltarin well.

    table S8. Summary of lithological and palynological indicators for the depositional environment interpretation of the 105-AM well.

    table S9. LOC data points for Saltarin versus composite, 105-AM versus composite, and 105-AM versus Saltarin.

    table S10. Age of individual samples derived from the graphic correlation analysis.

    table S11. Total carbon, total inorganic carbon, total organic carbon, total nitrogen, and carbon isotope data for all studied samples.

    table S12. Mollusks identified in core 105-AM.

    file S1. GPlates project.

    file S2. R code.

    file S3. Graphic correlation.

    file S4. Biostratigraphic and sequence stratigraphic events.

    file S5. Lithological description of the cores 105-AM and Saltarin.

    file S6. Excel tables.

    References (65134, 138185)

  • Supplementary Materials

    This PDF file includes:

    • section S1. General information
    • section S2. Sedimentology and sequence stratigraphy analyses
    • section S3. Marine intervals
    • section S4. Basin-wide correlations
    • section S5. Chronology of cores
    • section S6. Sites from the literature used in this study
    • section S7. Other published sites beyond the boundaries of this study
    • fig. S1. Map of northwestern South America showing the sedimentary basins discussed in the text and the structural features that divide them.
    • fig. S2. Location of the seismic lines and studied sites.
    • fig. S3. Sedimentological and sequence stratigraphic interpretation of the Saltarin well (see details of interpretation in table S7).
    • fig. S4. Graphic correlation of Saltarin versus 105-AM using geological time as scale in both axes, rather than stratigraphic thickness.
    • fig. S5. Photomicrographs of selected dinoflagellate cysts and acritarchs.
    • fig. S6. Carcharhiniformes gen. et sp. indet. tooth from the core Saltarin, Carbonera C2 Formation, early Miocene, 630.08 m, specimen MUN STRI-40967.
    • fig. S7. Dactyl of raptorial appendage (second thoracopod) of a fossil mantis shrimp from the Carbonera Formation, early Miocene, Colombia, MUN STRI-40281.
    • fig. S8. Sedimentological and sequence stratigraphic interpretation of the 105-AM well (see details of interpretation in table S8).
    • fig. S9. Stratigraphic correlation of the two major marine incursions (EMI and MMI) from the Saltarin well to the northernmost expression of the Vaupés Arch in the subsurface (well I).
    • fig. S10. Stratigraphic correlation of the two major marine incursions (EMI and MMI) along the northern Amazonas/Solimões Basin.
    • fig. S11. Graphic correlation between the standard composite section of Jaramillo et al. (56) and core Saltarin.
    • fig. S12. Graphic correlation between the standard composite section of Jaramillo et al. (56) and core 105-AM.
    • fig. S13. Seismic profiles in the Llanos Basin (see location in fig. S2; interpretation only at one extreme of the line) illustrate the seismic facies of the two marine incursions (EMI and MMI).
    • fig. S14. Interpreted 2D seismic profiles showing the contrasting difference of seismic facies between undifferentiated Cenozoic and Cretaceous units in the Amazonas/Solimões Basin (see fig. S2 for the location of seismic lines).
    • fig. S15. Graphic correlation between the cores Saltarin and 105-AM.
    • fig. S16. Carbon isotope data (δ13C) versus stratigraphic position in core Saltarin on the left panel.
    • fig. S17. Carbon isotope data (δ13C) versus stratigraphic position in core 105-AM.
    • fig. S18. Photographs of shells from core 105-AM.
    • fig. S19. Molluscan biostratigraphy of core 105-AM.
    • Legends for tables S1 to S12
    • file S1. GPlates project.
    • file S2. R code.
    • file S3. Graphic correlation.
    • file S4. Biostratigraphic and sequence stratigraphic events.
    • file S5. Lithological description of the cores 105-AM and Saltarin.
    • file S6. Excel tables.
    • References (65–134, 138–185)

    Download PDF

    Other Supplementary Material for this manuscript includes the following:

    • table S1 (Microsoft Excel format). Palynomorph counts for samples analyzed in core Saltarin.
    • table S2 (Microsoft Excel format). Palynomorph counts for samples analyzed in core 105-AM.
    • table S3 (Microsoft Excel format). Summary of palynological count data.
    • table S4 (Microsoft Excel format). BIT index for Saltarin samples.
    • table S5 (Microsoft Excel format). Geographic coordinates and information of outcrops and wells (coordinate system WGS 1984) used in this study.
    • table S6 (Microsoft Excel format). Geographic coordinates and information of 2D seismic lines (coordinate system WGS 1984) used in this study.
    • table S7 (Microsoft Excel format). Summary of lithological and palynological indicators for depositional environment interpretation of the Saltarin well.
    • table S8 (Microsoft Excel format). Summary of lithological and palynological indicators for the depositional environment interpretation of the 105-AM well.
    • table S9 (Microsoft Excel format). LOC data points for Saltarin versus composite, 105-AM versus composite, and 105-AM versus Saltarin.
    • table S10 (Microsoft Excel format). Age of individual samples derived from the graphic correlation analysis.
    • table S11 (Microsoft Excel format). Total carbon, total inorganic carbon, total organic carbon, total nitrogen, and carbon isotope data for all studied samples.
    • table S12 (Microsoft Excel format). Mollusks identified in core 105-AM.

    Download Tables S1 to S12

    Files in this Data Supplement:

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