70155 (3) High-Ti Mare Basalt
We would like to thank the following for the use of this sample:
70155 is a medium grey, subangular basalt, containing miarolitic cavities that was collected from a basaltic boulder named the "Geophone Rock". It has a plagioclase-poikilitic texture, with interstitial, blocky, and anhedral ilmenite set in pyroxene and plagioclase. Plagioclase also contains pyroxene, olivine and armalcolite inclusions. Ilmenite exhibits both rutile and spinel exsolution lamellae and rare, discrete spinel occurs, usually in pyroxene. Interstitial phases present are silica, metallic iron and troilite. 70155 contains olivine which is usually unzoned. Plagioclase is moderately zoned, and also exhibits inter-grain variations. Pyroxene compositions range from titanaugite to pigeonite, with pigeonite crystallizing only after significant olivine resorption. Rotation 1 shows twinning in pyroxene.
The sample weighed 0.77 grams before analysis and has not been dated.
Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/
Ma = Millions of years ago
Rock forming mineral:
- metallic iron,