HAJMAH (A)

Ureilite
Monomict/Unbrecciated
Olivine–pigeonite

standby for hajmah (a) photo
Found ~1958
19° 55′ N., 56° 15′ E. A single stone weighing 596 g was found during oil prospecting in the Hajmah area (formerly known as the Haima oil bore) in Oman before 1958. This ureilite is distinct from two L chondrites found in the same area at that time designated Hajmah (b) and (c). Current models of ureilite formation are presented on the Kenna page.

In an attempt to identify possible common ejection events among the ureilites, Beard and Swindle (2017) conducted a comparative study of 39 different samples utilizing three parameters: CRE age, Fo content in olivine (Mg#), and Δ17O value. They resolved ten potential clusters, several of which show concordance in their CRE age and Mg# but not in Δ17O value (heterogeneous), and three that are concordant in all three parameters (homogeneous). One of the seven potential heterogeneous clusters reflects an ejection event that occurred 1.3 (±0.3) m.y. ago and comprises Hajmah (a) and ALH 82130.

Infrared spectra of Hajmah (a) is similar to that observed by NASA’s Spitzer Space Telescope of the debris disk surrounding the evolving young star HD 179218, just as the ureilite Sahara 99201 is a good match to the debris disk surrounding the 16 m.y. old star HD 113766 (Morlok et al., 2007)—the onset of impact processing within these stars’ disks might be inferred. The specimen of Hajmah (a) shown above is a 2.2 g cut fragment with fusion crust on one end.


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