Taurus-Littrow TiO2-rich basalts: opaque mineralogy and geochemistry.
Abstract
The mineralogy and chemistry are reported for the opaque phases in numerous TiO2-rich basalts from the Apollo-17 landing site. Two distinct major rock types are recognized which have different crystallization paths. It is shown that tan armalcolite is encountered only in type I rocks while gray armalcolite is confined to type II rocks. Processes which form secondary ilmenite rims around the armalcolite are described, and it is shown that the majority of secondary ilmenites formed by reactions between basaltic liquid and armalcolite or between armalcolite and ulvospinel can be distinguished from coexisting primary ilmenites by the higher Cr2O3 concentrations in the secondaries. A unique rock fragment is described which consists of 60% iron, 30% chromite + ilmenite, and 10% silicates.
- Publication:
-
Lunar and Planetary Science Conference Proceedings
- Pub Date:
- 1974
- Bibcode:
- 1974LPSC....5..627E
- Keywords:
-
- Basalt;
- Chemical Composition;
- Crystallization;
- Lunar Rocks;
- Mineralogy;
- Titanium Oxides;
- Apollo 17 Flight;
- Geochemistry;
- Lunar Composition;
- Opacity;
- Lunar and Planetary Exploration