Disaggregating meteorites by automated freeze thaw.

Area of Science:

• Planetary Science
• Materials Science
• Analytical Chemistry

Background:

• Meteorite disaggregation is crucial for studying their composition and origin.
• Traditional methods can be destructive or inefficient, leading to sample loss.

Purpose of the Study:

• To describe a novel automated freeze-thaw (AFT) instrument for meteorite disaggregation.
• To evaluate the efficiency of AFT in recovering valuable chondrules and fragments.

Main Methods:

• Meteorite samples were immersed in pure water and sealed in Teflon vials.
• Samples underwent repeated freeze-thaw cycles using liquid nitrogen and hot water baths.
• A dual-stepper motor system controlled by LabView automated the process.

Main Results:

• The AFT instrument successfully weakened phase boundaries in the CR2 chondrite NWA801.
• 500 chondrules and fragments (0.2-4.7 mm) were recovered after 243 cycles (103.3 h).
• Freeze-thaw experiments on a basalt analog indicated a potential time reduction factor of ~4.

Conclusions:

• The AFT instrument provides an effective and efficient method for meteorite disaggregation.
• This technique facilitates the recovery of numerous chondrules for further scientific analysis.
• Optimized AFT protocols may significantly reduce sample processing time.