Binda meteorite, Crookwell, King Co., New South Wales, Australiai

Regional Level Types
Binda meteorite	Meteorite Fall Location
Crookwell	- not defined -
King Co.	County
New South Wales	State
Australia	Country

Find, 1912; 5.4 kg.
Eucrite, Cumulate.

A few months after the appearance of a bright fireball, a moderately large stone — the Binda Eucrite cumulate — was found. The essential mineralogy - dominant orthopyroxene accompanied by anorthitic plagioclase - is representative of cumulate pyroxenes which were probably formed a few kilometers below the surface of their original asteroidal homeworld(s). Minor constituents include exolved augite, chromite, ilmenite, tridymite, and troilite. Very small amounts of Fe-rich, Ni-poor metal and an unidentified phosphate are also reported in the cited rarticles and texts. A few unrepresentative clasts contain plagioclase of bytownite composition and, rarely, significant amounts of tridymite.

Radiometric dating reveal an ancient rock, crystallizing ~4.55 billion years ago, which has more recently been near the surface of a small meteoroid before colliding with the earth (Cosmic ray ages ~20 million years). Both petrology and chronology indicated a shared history with a number of HED (Howardite-Eucrite-Diogenite) meteorites. Unless, high-precision laser fluoridation determination of O-isotope ratios and/or other new findings require reconsideration, it seems likely that Binda is a 'normal' member of the HED meteorite clan. It now seems even more clear that most — but not all — HED meteorites are fragments blasted off of the asteroid 4Vesta over the past 4 billion years. Terminology is evolving, but for now Binda appears to be a candidate for what may eventually be called the 'main group' of HED meteorites with a bona fide identified Original Parent Body.

Other Regions, Features and Areas containing this locality

References