Fig 1.
Serra do Ererê Hill as seen from the Amazon River in mid Spring.
To ancient navigators on the Lower Amazon River, this hill would be a place to replenish silicified sandstone lithic tools. Photo taken by Chris Davis on May 2, 2011.
Fig 2.
Two-piece large curved rock with central rectangular hole.
Discovered separate from each other in level 7, the left piece is well-polished on the dorsal side, including its part of the hole. The top edge of the left piece is also sharp, suggesting functional reuse after breakage.
Fig 3.
Painel do Pilão Painted Outcrop with its rock art surface in the center-to-left foreground, and a rocky perch at a distance in the top right background of the photo.
The sun intersects this "window" in the early afternoon, about two weeks before and after the winter solstice.
Fig 4.
Painel do Pilão Shelter Floor approximately 1.6 x 1.8 meter area excavated by Davis in May 2011.
The left (northeast) wall forms the base of a platform stage from which one can view the rock art. This wall was made straight and flat throughout the depth of the excavation unit, leaving evidence of wall flakes and large boulders in only the lowest stratigraphic levels. The right side wall and overhanging rocks show the unmodified, angular smooth surface of the natural rock.
Fig 5.
This wall forms the base of the platform from which one can observe the rock paintings above (Fig 3). The slanted grooves gouged into the middle lower portion of the wall were buried to a depth of 70 cm from the original surface (the top of excavation level 6). The photo was taken by Davis in May 2011.
Fig 6.
Painted Circular Boulder excavated from level 7 at Painel do Pilão.
The photo, taken by Davis (May 2011), is enhanced by correlation D-stretch-lab to make the red and yellow half circles and red smears more discernible. These red and yellow colors are not part of the natural rock, but instead were added to the surface before the rock was buried. Red and yellow pigment are the two colors used in the rock art panels above the rock shelter where this was excavated.
Fig 7.
Platform Wall Profile showing the wall gouges as well as projections of the excavation levels, the radiocarbon ages of charcoal from their stratigraphic locations, and art-associated artifacts.
The size and irregularity of boulders in the lower stratigraphic levels belies the depositional sequence of features. However, the resting base of the three artifacts (red ochre manuport, painted boulder, and the oldest fragment of the two-piece polished bore-hole fragments) lie underneath all the relevant charcoal dates.
Table 1.
Radiocarbon Dates of Excavated Gymnosperm Wood from Painel do Pilão.
Fig 8.
The grid contains 49 visible contiguous boxes in columns of 5, 6, and 7 rows. An additional fish-net lattice grid continues on the right-hand side. The true color photo shows that the painting is in mostly red ink, although D-stretch image enhancement reveals that yellow pigment traces over red lines, especially in the four columns seen to the left-hand side. The yellow paint, has faded significantly. D-stretch also enhances faded X-shaped tally marks in some of the central columns that currently appear as vertical lines. This suggests that the current image was retouched sometime in antiquity, perhaps to preserve or restore the original grid image. There is no indication that the grid overlays an entirely different image.
Fig 9.
Sky Orientation of Painel do Pilão showing the cardinal directions of the largest grid image, matrix of lollipop shapes, and the beginning image at the far western edge of the outcrop.
Also depicted is the sun capture window, which was laser measured from the viewing platform at a distance of 45 meters. It visibly "captures" the sun ~18–20 days before and after the winter solstice if an observer stands on the (12-meter long) platform at least 9 meters away from, while facing, the grid image.
Fig 10.
“Lollipop” Images to the left of the grid image face 66° azimuth.
Sixty six degrees is the furthest north that the sun rises on the eastern horizon, which, by definition, occurs on the day of the June 21st (northern/summer) solstice.
Fig 11.
Six long vertical lines were drawn at the far left edge of the southeastern wall, beyond vision from the stage and at difficult accessibility.
These lines face ~114°, which is the position that the sun rises on the day of the southern (winter) solstice. Presently, trees and vegetative overgrowth block view of the horizon.
Fig 12.
Delineating a solar year through rock art at Painel do Pilão as seen relatively from a bird's eye perspective looking down.
Not drawn to scale, the grey rectangle represents the cardinal orientation and position of the excavation and the hypothesized sky-themed rock art and tallies The yellow lines represent the path of the sun on the days of the winter and summer solstice, and the equinoxes.
Fig 13.
Red shelter circle above the excavation unit, but underneath the painted outcrop.
The circle faces 270° but the shelter prevents view of the western sky. However, beneath the red circle is a crevice that allows view of the eastern sky. The red circle marks a spot where the sun would shine through the crevice directly beneath the circle on the day of the equinox.