Sarcopside and low crystallization temperatures of clasts in Martian regolith breccia meteorite: implications for evolved melts on early Mars

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Formation of the earliest evolved rocks on terrestrial planets remains poorly understood. The ancient Martian regolith breccia meteorite (MRB) contains feldspar-rich clasts, which could be evolved. Here, we report the first discovery of Martian sarcopside within an igneous clast (CS) of MRB. The mineral assemblage, the presence of sarcopside included in chlorapatite, and the equilibrium temperature of 774 ± 20 °C for plagioclase and alkali feldspar in clast CS collectively demonstrate that this clast crystallized from an evolved magma. A new U-Pb zircon age of 4525 ± 66 Ma places crystallization of these feldspar-bearing clasts within the first ∼100 Myr of Martian crust evolution. Furthermore, the equilibrium temperatures of all 16 two-feldspar-bearing clasts observed in small chips of MRB are < 1000 °C, and half are < 800 °C. The low equilibrium temperatures and mineral assemblages of different clasts are consistent with the interpretation that diverse evolved magmatism could have been present on early Mars. These ancient clasts provide a unique window into the timing and thermal regimes of evolved magmatism within the early Martian crust. More importantly, taken together with evidence from evolved lunar samples and asteroidal meteorites, the evolved lithologies on early Mars inferred from MRB indicate that evolved magmatism may have played an important role in the early Solar system.
Funding Information
  • National Natural Science Foundation of China (42125303)
  • National Natural Science Foundation of China (42530210)
  • National Natural Science Foundation of China (42542019)
  • National Natural Science Foundation of China (42503028)

This publication has 82 references indexed in Scilit: