Lodran meteorite, Multan, Punjab, Pakistan

Stony-Iron Achondrite Prototype (Lodranite, S1)
Fell 1 Oct 1868; 970 g

After an afternoon fall the Lodran meteorite — a small, friable, and mildly-shocked mixture consisting mostly of meteoritic iron (~25 vol%), olivine (~37 vol%) and pyroxene (~36 vol%) — was soon recognized as a somewhat unusual meteorite. The Fe-Ni metal (~9 wt% Ni), the largely unzoned orthopyroxene (Fs~17), and somewhat variable olivine (Fa~9-15) are in themselves unexceptional components of many meteorites. However, this particular combination in a single stony-iron meteorite was and remains somewhat anomalous and, for over a century, Lodran was recognized as a unique meteorite. Accessory phases include troilite, Ca-rich clinopyroxenes, schreibersite, chromite, apatite, and a K-rich phase. Gradually, it was realized that Lodran appeared unusual simply because most of the stony-iron meteorites in our collections had been derived from more differentiated homeworlds. Lodran is now recognized as the prototype for ~ 60 similar largely undifferentiated meteorites. Two of the newly discovered lodranites are slightly more massive, but as the single witnessed and unweathered lodranite fall Lodran continues to occupy a central role in lodranite studies. Cosmic-ray exposure ages suggest that several of the Lodranites were involved in a common break-up ~ 5 million years ago.

The lodranites are closely related to the primitive acapulcoite achondrites and together they constitute the Acapulcoite-Lodranite Geochemical Group characterized by shared isotopic ratios and other geochemical affinities. In addition there are several meteorites with intermediate characteristics deemed 'acapulcoite/lodranites' also derived, presumably, from a single original parent body (OPB). Many of the acapulcoites and lodranites are quite small (over 60% < 100 g) and may actually be unrecognized fragments of a significantly smaller number of individual falls.

Most of the original Lodran mass (690 g) is held by the Geological Survey of India (Calcutta) with several small pieces stored elsewhere.

Mineral List

10 entries listed. 6 valid minerals.

References

External Links