IIT-Kgp, PRL team decodes moon’s titanium-rich rocks, Pg13

Key Highlights:

• IIT-Kharagpur and Physical Research Laboratory (PRL) team decodes the mystery of titanium-rich rocks on the moon.
• Lunar basalts contain up to 18% titanium dioxide, unlike volcanic rocks on Earth, which rarely exceed 2%.
• The study offers insights for ISRO’s Chandrayaan-4 mission to select landing sites with chemical fingerprints of the moon's interior.
• The research findings were published in Geochimica et Cosmochimica Acta.

Detailed Insights:

• The moon, around 4.3 billion years ago, was cooling from a global ocean of molten rock, leading to the crystallization of minerals like olivine, orthopyroxene, plagioclase, and the titanium-rich ilmenite-bearing cumulate (IBC) layer.
• The dense IBC layer sank through the moon's magnesium-rich mantle, heated up, and melted, resulting in titanium-rich partial melts, believed to be the source of the moon’s titanium-rich basalts.
• High-resolution microscopic cameras, X-ray fluorescence, and X-ray diffraction can identify minerals and determine their chemical composition in lunar rocks before collection.
• Spectroscopic tools like Raman and visible-near infrared spectroscopy can confirm the mineral phases in rocks before they are collected.
• The team's experiments suggest that basalts high in titanium were created through reactions and mixing, with some molten rocks erupting with moderate amounts of titanium and others becoming trapped inside the moon.
• Fresh magma rising from below could have mixed with these trapped pockets, and the combined mass could have erupted as titanium-rich lava.

Scientific/Technical Concepts Involved:

• Olivine: A magnesium iron silicate mineral.
• Orthopyroxene: A mineral belonging to the pyroxene group, composed of magnesium, iron, and silica.
• Plagioclase: A series of tectosilicate minerals.
• Ilmenite: A titanium-iron oxide mineral.