MacAlpine Hills 88136 meteorite, Transantarctic Mountains, Eastern Antarctica, Antarcticai

Regional Level Types
MacAlpine Hills 88136 meteorite	Meteorite Fall Location
Transantarctic Mountains	Mountain Range
Eastern Antarctica	Region
Antarctica	Continent

Enstatite Chondrite, low iron (EL3)
Find, 1988; 74.4 g, slightly weathered


Among the small and large meteorites recovered from Antarctica there are a large number of ordinary chondrites as well as a smaller, but still impressive number of rare carbonaceous chondrites, unusual irons, and even Mars rocks… Sometimes, however, one comes upon something quite new and unexpected — even when, like MacAlpine Hills 88136, the stone is only as large as a somewhat squashed golf ball. MacAlpine Hills 88136 (or MAC 88136) is a type EL3 Enstatite chondrite filled with a small trove of unusual lithologies. The predominant mineral is enstatite, displayed in conspicuous chondrules, and the enstatite is accompanied by the usual complement of iron, troilite, and other rare, utterly reduced sulfides which characterize the Enstatite clan. (Microscopically) obvious alabandite (MnS) reveals that it is a member of the EL chemical group of Enstatite chondrites. Within the confines of this small rock are a number of minerals that are quite out of equilibrium with each other (silica and olivine, for example). Indeed, MAC 88136 was the first type EL3 chondrite to be discovered. Other EL3s have since been discovered, but MAC 88136 still seems a little unusual — perhaps because its is less weathered than many other EL3 finds.

Most EL Chondrites are type EL6 and have experienced significant metamorphism. Some of the components of MAC 88136 may have experienced significant shocks and other melting events before its components took on their current modes. But the present assemblage is quite diverse - a diverse medley that has remained largely unchanged for 4.5 billion years.

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