Egyptian Dakhleh Glass

New page: March 19, 2012

(Sorry everyone. This page had a cool background wallpaper, but it was causing problems for some viewers---)

Find a map of Egypt and put a pin right in the center. You'll find yourself way out in the Western Desert (part of the Libyan Desert) about 400 kilometers west of Luxor and the Valley of the Kings in one of the most remote human settlements in Egypt. Dakhleh Oasis occupies the basin of an ancient lake, the site of human habitation going back some 200,000 years or more.

In 1987, University of Toronto anthropologist Maxine Kleindienst reported the discovery of peculiar lumps of vesiculated glass in the lake sediments. Subsequent investigations have shown this material to be meteorite-related impact glass, possibly the result of a monster aerial burst, something like Tunguska, but much more intense (The Tunguska event did not vitrify the underlying ground surface at all). Dakhleh glass is highly similar to Argentine Escoria (see our Escoria page). Approximate lat-long coordinates for the known distribution of Dakhleh glass are 25°26" N to 25°32 N and 29° 03"E to 29° 22" E.

The airburst suggestion arises from the distribution of the glass, scattered over an area of about 400 square kilometers (too extensive for typical cratering events), and the absence of any recognized impact crater. The best radiometric date for the event is 145,000 years +/- 19,000. Evidence of human habitation is found in layers stratigraphically above and below the glass-bearing strata, showing that humans were on hand to see and experience this event (certainly not a good thing for anyone that was too close!).

Dakhleh glass is quite variable. Smaller pieces tend to be highly vesiculated while bigger lumps can be mostly crystalline and dense. The glass is chemically distinctive, being unusually rich in calcium and aluminum (up to 25% and 18 wt% respectively). This composition is consistent with derivation from calcarious and clay-rich lake sediment target material.

It contains small enclaves of very high silica glass (lechatelierite) which forms at temperatures greater than 1700 degrees C. Interestingly, about one third of the pieces show imprints of plant matter on their basal surface (for example, see the bottom view of the 61.1 gram specimen below), showing that the original blobs of bubbly glass were still of sufficiently low viscosity to flow over the plants they landed on. There is also sometimes seen a flow-stretching to the vesicles and a tendency for them to be present in greater abundance near the upper surface of a given specimen, again indicating fluid behavior that allowed the bubbles to stretch and rise.

The material resembles coal clinkers with smooth ropy surfaces and a highly vesiculated interior. (The presence of lechatelierite distinguishes it from some sort of ancient clinker). The greenish-yellow tint seen in many of the pictures is the result of a surface film. The interior color is brownish gray. Rare specimens show spherical beads up to 5 mm in diameter (see the top view of the 150.9 gram specimen below). Prismatic cavities appear to be spots where lake-bottom mud-chips have weathered out (remnants are locally present). Many of the vesicles are packed with rounded quartz grains which are not primary features, but introduced. Some vesicles are lined with thin crusts of crystalline calcite or films of chalcedony, both also introduced. I have made no effort to clean these specimens. They are as received from my supplier.

I have seen this material offered for sale only by only one supplier. I was able to buy a small assortment, carefully cherry-picked from the available inventory to capture the best features. Many of the specimens offered below show basal plant imprints. Where sufficient detail is preserved, the plants appear to be marsh reeds.

Recent investigations of Trinitite glasses from the initial atom bomb test in New Mexico suggest that the glass there did not form by in situ fusion of the crater wall, but instead rained down as vitrified blobs of target material that was initially drawn up into the mushroom cloud (Eby et al, 2010). The Dakhleh glass and Argentine escorias are remarkably similar in morphology to Trinitite, and indeed, the basal plant imprints directly imply that the glass rained down from above. One is led to picture an immense mushroom-cloud aerial burst that literally vacuumed material from the ground beneath, melted it in the heart of the turbulent fireball, and rained it back to earth.

Be sure to visit our Trinitite and Argentine Escoria pages for comparison.


References

Eby, N., Hermes, R., Charnley, N. and Smoliga, J. A., 2010, Trinitite-the atomic rock. Geology Today, v. 26: pp. 180-185.

Osinski, G.R., Haldemann, A.F.C., Schwarcz, H.P., Smith, J.R., Kleindienst, M.R., Kieniewicz, J., and Churcher, C.S., 2007, Impact Glass at the Dakhleh Oasis, Egypt: Evidence for a Cratering Event or Large Aerial Burst?, Lunar & Planetary Sci., v. 38.

Schultz, P.H., Zarate, M.A., Hames, W., Bunch, T., and Koeberl, C., 2004: Late Cenezoic Impact Record in the Argentine Pampas Sediments. Abs.: 67th Annual Meteoritical Society Meeting (2004).

Available Specimens

Click on the thumbnail for a larger image. Close that window to return here.

  224.3 gms

 (click on this for view of bottom surface)
(#Dakh_2243) $250 A monster! About 6 X 3 X 1.5 inches. Nice full-thickness specimen with preserved surface and cellular plant imprints on the base. A museum piece.
  150.9 gms 

(click on this for view of bottom surface)
(#Dakh_1509) $200 The best of only two examples with spheroids. There is a little finger-sized reed imprint on the base.
  61.1 gms

 (click on this for view of bottom surface)
 (#Dakh_0611) $150 SOLDBe sure and check out the bottom surface image. This one has exceptionally clear reed imprints. A full-thickness specimen.
49.6 gms

(click on this for view of bottom surface)
(#Dakh_0496) $50 SoldExtremely vesiculated piece. Possibly two fused blobs. No clear external surfaces or plant imprints.
39.2 gms

(click on this for view of bottom surface)
(#Dakh_0392) $100 Sold Full thickness piece with good skin preservation, excellent plant impressions and a rounded nose connecting the upper and lower surfaces---the rim of an individual blob. On the image at left, it is the right edge that rolls over continuous with the base. Quite a significant example of the key character of Dakhleh.
39.0 gms

(click on this for view of bottom surface)
(#Dakh_0390) $65 No clear surface skin, but quite a nice 3-d plant mold on the base.
29.2 gms

(click on this for view of bottom surface)
(#Dakh_0292) $75 Our best example of ropy-skinned surface. No clear plant impressions on base.
24.4 gms

(click on this for view of bottom surface)
(#Dakh_0244) $35 This one seems to show a smaller ~1 inch blob (on upper left in surface image) fused onto a bigger underlying mass which has a probable (but somewhat uncertain) reed impression on the lower surface.
24.3 gms

(click on this for view of bottom surface)
(#Dakh_0243) $25 A heavier, denser piece. Highly vesiculated. No clear external skin surfaces.
23.6 gms

(click on this for view of bottom surface)
(#Dakh_0236) $50 SOLD This one preserves a patch of what may be baked or indurated sediments with 2 to 4 mm spheroidal beads (at lower right in image). One of only two examples found with such beads. Good top skin, but no clear plant imprints.
23.5 gms

(click on this for view of bottom surface)
(#Dakh_0235) $30 Very reminiscent of Trinitite or Escoria. Some good surface skin. No plant imprints.
21.0 gms

(click on this for view of bottom surface)
(#Dakh_0210) $35 Sold A good full-thickness piece with a lot of character. Has a great 2 cm diameter plant imprint.
19.4 gms

(click on this for view of bottom surface)
(#Dakh_0194) $20 SOLD Highly vesiculated. No clear primary surfaces.
18.3 gms

(click on this for view of bottom surface)
(#Dakh_0183) $25.SOLD Patch of original ropy surface preserved; possibly small plant imprint
17.2 gms

(click on this for view of bottom surface)
(#Dakh_0172) $25 Good full thickness piece with nice top skin; no obvious plant impressions.
16.8 gms

(click on this for view of bottom surface)
(#Dakh_0168) $25 Multiple plant imprints on lower surface, but no obvious top skin
16.7 gms

(click on this for view of bottom surface)
(#Dakh_0167) $50 SoldVery unusual piece, quite possibly a spindle bomb. Essentially complete individual. Very reminiscent of some Ries-Nordlinger flaedle specimens.
15.9 gms

(click on this for view of bottom surface)
(#Dakh_0159) $25Sold Essentially complete individual "blob" with an adhering sediment clast. Vegetal fragments visible in the sediment with magnification.
13.8gms

(click on this for view of bottom surface)
(#Dakh_0138) $15 Preserved patch of ropy surface skin; no plant impressions evident.
12.7 gms

(click on this for view of bottom surface)
(#Dakh_0127) $15SoldVesicular with minor patches of original exterior. No plants.
12.3 gms

(click on this for view of bottom surface)
(#Dakh_0123) $25SOLD Good full thickness blob-edge fragment with nice upper skin and a good plant imprint on the base.
10.9 gms

(click on this for view of bottom surface)
(#Dakh_0109a) $15 SoldVery irregular cinder-like individual, possibly quite complete, with adhering sediment patch. No obvious plant material.
10.9 gms

(click on this for view of bottom surface)
(#Dakh_0109b) $15 SOLDHighly vesiculated with patches of preserved outer skin. No obvious plant imprints.
10.1 gms

(click on this for view of bottom surface)
(#Dakh_0101a) $15SOLD Highly vesiculated piece with some very subtle plant imprints on base.
10.1 gms

(click on this for view of bottom surface)
(#Dakh_0101b) Full-thickness blob-edge fragment with nice ropy upper surface skin. No obvious plant imprints.
8.5 gms

(click on this for view of bottom surface)
(#Dakh_0085) $15Sold Excellently featured top skin with very thin-walled vesiculated interior. No obvious plants.
7.7 gms

(click on this for view of bottom surface)
(#Dakh_0077) $15 Great blob-edge fragment with nice external skin preservation and a possible crude reed mold on the base.
7.3 gms

(click on this for view of bottom surface)
(#Dakh_0073) $15Sold Small full-thickness piece with a clear plant impression on the base.
6.1 gms

(click on this for view of bottom surface)
(#Dakh_0061) $8 SOLD Mostly vesiculated fragment.
1.2 gms

(click on this for view of bottom surface)
(#Dakh_0012) $5 Just a tiny knob, but about 70% original intact skin.

If you entered through the front page, simply close this window to return there. If you came in through a back door, click on the following link to go to the front page: www.TektiteSource.com

To ask questions or place an order, email us at: nlehrman@nvbell.net We accept payment via Paypal.