SATELITE IMAGE REVEALS THE FULL GEOLOGICAL EXTENT OF GIZA'S CAVE UNDERWORLD.
More incredible is the fact that the shadow line on the TerraSAR-X radar satellite image seems to connect with another wider shadow line that starts at a position corresponding to a gully in the plateau's northern cliff, just west of the Tomb of the Birds, and curves towards the Second Pyramid, where it is finally lost from sight on the north side of the monument's square base. Once again, there are no visible features on the corresponding Google satellite map to explain this anomaly (actually, a second, more fainter, shadow line is also seen on the radar satellite image. It commences in the proximity of the caves explored so far and curves towards the Second Pyramid, where it is lost, finally, as it approaches the west side of the pyramid).
would be great to consider that this curving shadow anomaly, traced from the area
of the caves reached by ourselves to the proximity of the Second Pyramid, shows
the course of the caves. This is indeed possible, although the operators of the
TerraSAR-X satellite have been unable to comment on the anomaly, saying only that
to date they have a relatively limited understanding of just how far their radar
technology is able to record sub-surface or subterranean features.
it possible that the bird cult once associated with this site honoured Hermes,
the Graeco-Egyptian form of the Egyptian god Thoth, the keeper of ancient records
and guardian of the ancient wisdom? If correct then future excavations inside
the tomb and caves might well reveal that the bird mummies purportedly left here
as ritual offerings (and found by Vyse and Perring in 1837) contained the remains
of ibises, a bird sacred to Thoth-Hermes. If the birds found here were not ibises,
but raptors, such as hawks and falcons, then the cult here was probably that of
Sokar, the guardian of the Duat of Memphis, or Rostau, the ancient name for Giza.
Either solution will go some way to prove that the Tomb of the Birds was seen
as an entrance into a cave underworld.
Trismegistus holding the Emerald Tablet.
Limestone, like that present in the Giza bedrock, is dissolved over time by the CO2 content of rainwater taking the path of least resistance through natural faults in the rock.
Where this occurs above the local water table, the resulting caves are v-shaped in profile, being caused as the water erodes away the rock, as opposed to dissolving it. This type of cave is described by geologists as vadose.
Where water flowing through faulting actually passes beneath the water line of the local water table, it moves more slowly and actually dissolves (as opposed to eroding) the rock, enlarging the cracks and fissures in the process. The resulting cave passages are circular in profile, and tube shaped in appearance. This type of cave is described as phreatic.
Where the two types of cave - phreatic (circular) and vadose (v-shape) are found together, one on top of the other, creating a key-hole shaped profile, it means both types of cave creation were involved. Initially, the rainwater has passed through the fissures beneath the water table, carving circular caves. Then afterwards, when the water table lowers, if the water continues to flow through the caves, it carves a v-shaped trough at the base of the circular profile, producing a perfect key-hole shaped profile, which is what we see in the picture.
Since this is seen in the caves at Giza, it implies that at first the rainwater must have flowed beneath the level of the water table, but then at some point this water table lowered, creating the profile we see today. Thus parts of the Giza caves are both phreatic and vadose in nature.
The fact that the cave walls are often smooth, particularly in the deeper areas, is further confirmation of their creation by rain water, for as one correspondent on the subject of cave formation at Giza has noted:
"The smooth black layers [seen in the photos] are magnetite [Iron(II,III) oxide (Fe3O4) or ferrous ferric oxide], note that Magnetite forms readily when iron oxidizes underwater. This fact plus the smoothness of the layers confirms that these passages were originally flooded, i.e. phreatic in their formation."
"To summarise the plateau was at one time fully saturated, either under water or continuously subjected to torrential rains. This water flowed through natural fault lines creating phreatic passages and caves. As the rainfall eased the water table fell and passages became vadose in shape.
"This fall in the water table was slow enough to allow magnetite to form in the lower passages.
"Roughly parallel events can be seen in the Cheddar cave systems although more intense as there was also ice melt as well as rainfall."
This same correspondent, well versed in the subject of cave formation, goes on to suggest that we look for "swallets" and "resurgencies", holes through which the rainwater originally found entrance into the faulting to create the caves in the first place. These, he thinks, will most probably be inactive now, the entrances hidden by sand. Swallets, he says, are found mostly on hills, while resergencies are located generally at the base of hills.
The most obvious swallet, as a point of entry for the rainwater that created the caves at Giza, must have occupied a position now taken by the entrance to the Tomb of the Birds, which is located close to the highest point on the plateau. It is likely that at some point in dynastic times the crack or fissure leading into the caves, was expanded to create the rectilinear structures seen today inside the tomb. In doing so, the ancient Egyptians created an access point into the cave system, which was afterwards, perhaps, sealed off using stone and mortar.
In a personal email to me, Dr Hawass alluded to the tomb NC2 as being of Old Kingdom construction. If this is correct, and counters his earlier assertions that the tomb is of Late Dynastic origin, then it means that the caves were certainly accessible during the Pyramid age. Yet if the Tomb of the Birds began as a swallet, then it suggests that the caves might have been accessible long before this time.
One of the most obvious resurgencies found in association with the Giza cave complex is a spring in the southwest corner of the plateau. Located today in the local cemetery beneath the gaze of Gebel Gibli, the southern mount, it is said by the inhabitants of the nearby village of Nazlet el-Samman, to be an entrance into an underground tunnel system. We have even spoken to a local person who has actually been down the well and seen horizontal shafts at its base heading away towards the east and west.
Without knowing of the existence of this well, known as Bir el-Samman, my geological correspondent wrote: "At Giza if there is an active spring or springs at the foot of the plateau there must be a source of water in the lower cave passages, either seepage or an actual trickle along the cave floor.
"To verify a connection one normally adds fluorescent dye to the water, a harmless and highly visible dye, then looks to see if this appears in the spring water."
All this throws new light on the formation of the Giza caves, which seem unquestionably to be natural in origin, yet utilised by man once exposed. As to their age, this is difficult: they could have formed any time between the beginning of the Middle Palaeolithic era and the end of the Late Palaeolithic age, thus between 250,000 years ago and 12,000 years ago.
Dolphin, Lambert T., A. H. Moussa et al, Applications of Modern Sensing Techniques to Egyptology, SRI Institute, Menlo Park, CA, September 1977.
go out to Ian for his help in attempting to determine the forces behind the creation
of the Giza caves; Robin Rix for putting us in contact; also for Larry Hunter,
Nigel Skinner Simpson and Rodney Hale for their help in putting this piece together.
a comprehensive introduction to Andrew Collins's
buy BENEATH THE PYRAMIDS, Andrew's new book on the quest to find Giza's cave underworld,
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