The English word «keyhole» has given the reason to denote this type of symbols in the general file with letters SK and a green character made up by two circles.
The space image below shows two typical characters. The size of the large geoglyph is about 120x50 meters, and that of the small one is 20x25 m.
SK 731 and SK 732 Symbols
This image is good enough to characterize most of the classic SK symbols. In size it gives about the maximum and minimum value. In shape, they can be oval, elongated, close to a circle, have a different orientation of the corridor, but they are always a point in a circle with the corridor beginning from the point, and all of it encircled into an ellipse. There are about one and a half thousand such symbols.
The majority of SK geoglyphs are concentrated in the eastern part of the Tassili’n-Ajjer Plateau, in various places. These are mainly the “shores” of sandy rivers and the slopes of small hills.
The following images give some more classic examples.
SK 980 Symbol.
This geoglyph is precisely oriented along the East-West axis.
SK 2326 and SK 2327. Symbols.
SK 926, SK 927, SK 928. Symbols
SK 754. Symbol
SK 18451 Symbol
SK 18468 Symbol
SK 18481 Symbol
SK 18557 Symbol
SK 18434 – SK 18436 Symbols
SK 18472 – SK 18474 symbols
SK 2023 Symbol
SK 2650 и SK 2651 Symbols
There are several more photographs of geoglyphs of this type, made in the immediate vicinity of them. These objects are also laid out of stones, which were most likely collected in the vicinity.
Photo Michel Bec
Photo Faed CHADYROV
Photo Michel Bec
As you can see in the first photo, this geoglyph has another designated center. And this is not an isolated case. In addition to the center point, the SK symbols may contain one more or several points.
Sometimes there are combinations of SK symbols together with outlined circles. Such symbols are denoted by the letters SKR. Below some typical examples are given.
SKR 482 symbol
SKR 915 symbol
SKR 13 symbol
SK 14443 и SKR 14444 symbols
SKR 249 symbol
SKR 248 и SKR 249 symbols
SKR 2308 symbol
SK 499 symbol
There is another, slightly modified, subspecies of SK symbols. There are a few such geoglyphs found so far, about 2 dozen.
The point from which a narrow straight passage begins, for these symbols, starts from the edge of the oval and ends on the opposite side.
Such geoglyphs are designated by the letters SKM.
SKМ 194 symbol
SKМ 147 symbol
Symbols of this type are located quite compactly and are actually found in one place. They have different roundness and different directions, but towards the east.
There are only a few dozen such geoglyphs, but they are very unusual and, apparently, play a special role.
SKM 188 geoglyph.
In this case, the orientation of the symbol corresponds to a pentagram angle of 108 ° measured from the direction to the north.
SKM 18904 и SKM 18905 geoglyph.
Looking at these geoglyphs, we can say that the SK symbol gradually tends to turn into a symbol of another type, whose basis is made up of a point and two rays departing from it. These symbols begin to appear next to the SK symbols as you move south. We will consider them in the next section.
By clicking on the links you can see photos of some geoglyphs such as keyhole.