Fig 1.
Rayon reef section, Valles-San Luis Potosi platform, northeastern Mexico.
(a) Rayon reef outcrop images, with the black clay layer that marks the K/Pg boundary. (b) Schematic section column, with descriptions of matrix, fossil assemblage, abundance and fossil images.
Fig 2.
Rayon K/Pg boundary section with the diagnostic impact indicators (see text).
(a) Lignite patches and carbonized vegetal matter fibers. Views of lignite and charred and semi-charred material. (b) Spherules, fragmented spherules, spherules with conchoid fractures, translucent spherules and spherule clusters, quartz, impact glasses, lignite, gypsum, metallic particles and nuggets in the black clay layer.
Fig 3.
Spherules on fossil shells, withspherule incrusted on coral, spherules incrusted on shells and spherules in crystals.
Fig 4.
Quartz crystals showing distinct planar deformation features (PDFs).
(a) Planar deformation features in impact glasses. (b) Views of planar deformation features, with different orientations (see text).
Fig 5.
(a) Metallic particles and particle agglomerates, views of different sizes and geometries. (b) Gypsum tabular, prismatic and fibrous crystals, with planar deformation features.
Fig 6.
Scanning electron images and elemental analysis of crystals, with enrichment of PGE.
(a) Crystal 3−1 with Pr, Nd and Os. (b) Crystal 3−2 with Nd and Os (c) Crystal JRTH IG 4P3 with Os and Ir.
Fig 7.
Scanning electron SEM analysis and elemental composition of impurities of pure iron and nickel.
Images of the metallic particles analyzed are shown, with the electron microscopy images and corresponding SEM graphs.
Fig 8.
(a) Scanning electron analysis and elemental composition on gypsum flakes, with elemental analyses of iron and nickel inclusions in gypsum. (b) Scanning electron image of broken zircon.
Fig 9.
Rayon reef K/Pg boundary section, with the black clay and the lower and upper sandstones.
(a) Rayon section with summary of characteristics of clay layer, lower and upper sandstone layers. (b) Close up view of clay layer. (c) Geochemical data for the clay layer and lower and upper sandstones.