LaPaz Ice Field 02225 meteorite, LaPaz Ice Field, Pecora Escarpment, Eastern Antarctica, Antarcticai

Regional Level Types
LaPaz Ice Field 02225 meteorite	Meteorite Fall Location
LaPaz Ice Field	Ice Field
Pecora Escarpment	- not defined -
Eastern Antarctica	Region
Antarctica	Continent

EH-impact melt; S1
2002 find; 314 g

LAP 02225 is an enstatite-rich meteorite dominated by small and large pyroxene laths accompanied by accessory interstitial plagioclase (usually anorthitic), Fe-Ni metal, and troilite. Minor amounts of tridymite, perryite, daubréelite, and other sulfides are also found. LAP 02225 has the composition of an EH Enstatite Chondrite, but lacks chondrules or any chondrule relics (presumably due to extensive impact heating). An Argon-argon isochron age of 4.53 billion years suggests that the meteorite’s most severe impact may have occurred 10-15 million years after formation of the putative EH Chondrite parent body. Only relatively mild shocks (level S1: Pmax < 5 GPa) were experienced after shock melting had erased the effects of any earlier impacts. Since reaching the earth, moderate weathering has produced small amounts of rust and various evaporites along fractures (e.g., gypsum and goethite).

LAP 02225 is another enstatite-rich meteorite providing evidence that ancient enstatite chondrites and achondrites may have been exposed to collisional impacts at an even higher rate than the ordinary and carbonaceous chondrites. These collisional events have complicated efforts to construct a clear and consistent chronology of the formation and subsequent dispersal of some Enstatite Chondrites and Aubrites as radioactive decay and collisional disruption may have involved coeval or overlapping influences.

Other Regions, Features and Areas containing this locality

References