Many separate fragments of this previously rare carbonaceous chondrite group have been found on the 4,000 km² Dar al Gani plateau in the Libyan Sahara Desert. The individual mass that is numbered 749, comprising 2,100 fragments and weighing a total of 95 kg, represents the main impactor of this shower. Accordingly, it is located at the farthest end of the extensive strewnfield. The first mass that was classified, the 1,932 g DaG 005 fragment, became the namesake for the 60 likely paired finds. The weight and coordinates of each of the paired masses, weighing together 180.5 kg, have been accurately recorded. This work has provided the means to accurately map the dispersion ellipse of this rare meteorite. Its very long and narrow shape has dimensions of approximately 42 km by 3 km. Petrographic and geochemical details about the CO group can be found on the Colony and Isna pages.
As is typical of the CO group, there is a high density of very small chondrules compared to matrix. Comparisons among chondrules of different chondrite groups led Rubin (2010) to conclude that CO, CM, and E chondrites formed in a less dusty nebular region than that of OC chondrites. In turn, the OC chondrite formation region was less dusty than that of R chondrites; R chondrites and OC chondrites are considered to constitute a superclan. The nebular formation region of CV, CK, and CR chondrites was more dusty than that of all other chondrites.
Dar al Gani 005 has a shock stage of S2 and a weathering grade of W2. The photo above shows a 26.5 g partial end-section. The photo below shows the dark brown desert varnish on this specimen, evidence of its long residence in the arid Saharan Desert.