Curie temperature of weakly shocked target basalts at the Lonar impact crater, India

Abstract

The study investigates Curie temperature (T C), bulk magnetic susceptibility, hysteresis, and X-ray diffraction pattern of in situ target basalts of Lonar impact crater, India. The main magnetic phase in the target basalt is low-Ti titanomagnetite. This study reveals an increase in T C and decrease in magnetic susceptibility and in full width at half maxima of the 311 peaks of titanomagnetite with distance from the crater center. Changes in crystal lattice of titanomagnetite, such as straining of 311 peaks, decrease in apparent crystallite size, and grain fragmentation may be among the possible reasons for the observed trends in T C and magnetic susceptibility. However, they both do not show any correlation between each other, indicating that different shock-induced processes affect them.

Nature inspired synthesis of magnetite nanoparticle aggregates from natural berthierine

“…Secondly, the reference material presents a Tc of 580 °C, which agrees with the published Curie point for pure magnetite. 30 Whereas, Tc of the MNAs is >650 °C, which may due to hematite.…”

Evidence for shock provides insight into the formation of the central elevated area in the Dhala impact structure, India

“…Terrestrial impact combined with dry, semiarid conditions leads to pristine ejecta blanket, as is the case with the Lonar Crater, India (Maloof et al. 2010; Agarwal and Alva‐Valdivia 2019). However, marine or shallow water conditions lead to massive reworking and redepositing of the ejecta by gravity flows, tsunamis, and resurge, as is the case with Lockne crater, Sweden (Ormö et al.…”

“…Generally, the ejecta blanket forms as a result of ballistic sedimentation of loose ejected material comprising primary ejecta excavated from the initial transient cavity and local material (H€ orz et al 1983). Terrestrial impact combined with dry, semiarid conditions leads to pristine ejecta blanket, as is the case with the Lonar Crater, India (Maloof et al 2010;Agarwal and Alva-Valdivia 2019). However, marine or shallow water conditions lead to massive reworking and redepositing of the ejecta by gravity flows, tsunamis, and resurge, as is the case with Lockne crater, Sweden (Orm€ o et al 2007).…”

Astrobiology as a Driver to Connect India's Public, Scientists, and Space Missions

“…To further expand the field of astrobiology in India, there are planned research expeditions to other analogue sites across India, like the Lonar crater in central India and the Rann of Kutch located in the border regions of Gujarat and Pakistan. Both these sites are considered Mars analogue sites specific to different regions of Mars, with Lonar crater, a hyper alkaline soda lake that is the only meteorite impact crater in the world situated in basalt rocks, considered as an analogue site for Jezero crater 23 , the recent landing site for the NASA Perseverance. The delta basin formed by the Lonar crater has amassed organic sediments over its period of existence and therefore also represents an appropriate site for the testing of sample collection missions by rovers and drones with relevance to future lifedetection missions.…”