The composition of basaltic melts in equilibrium with the mantle can be determined for several Martian meteorites and in‐situ rover analyses. We use the melting model MAGMARS to reproduce these primary melts and estimate the bulk composition and temperature of the mantle regions from which they originated. We find that most mantle sources are depleted in CaO and Al2O3 relative to models of the bulk silicate Mars and likely represent melting residues or magma ocean cumulates. The concentrations of Na2O, K2O, P2O5, and TiO2 are variable and often less depleted, pointing to the re‐fertilization of the sources by fluids and low‐degree melts, or the incorporation of residual trapped melts during the crystallization of the magma ocean. The mantle potential temperatures of the sources are 1400–1500°C, regardless of the time at which they melted and within the range of the most recent predictions from thermochemical evolution models.
N2 - Plain Language Summary: Martian meteorites and rocks analyzed by rovers are witnesses of magmatic processes on Mars. Some of the basaltic specimens among them have been classified as “primitive” as they are closely related to the melts that form in the mantle and feature high MgO/FeO. They record important properties of the mantle of Mars. We use the mantle melting model MAGMARS to constrain the temperature and composition of the mantle source regions from which primitive basalts originated. We find that the mantle compositions were low in CaO and Al2O3, either because they melted on several occasions, or because these components were locked in deeper layers of the mantle when it solidified from the bottom up (early magma ocean). Several mantle sources are comparatively rich in Na2O, K2O, P2O5, and TiO2. These components were either subsequently added to the mantle sources by fluids and low‐degree melts or can be explained by the trapping of melts during the progressive crystallization of the magma ocean. The temperature of the mantle sources projected to surface conditions for easier comparison (potential temperature) was 1400–1500°C, regardless of the time at which they melted, and is within the range of recent predictions from planetary‐scale models of interior dynamics. N2 - Key Points: Basalts that sampled discrete mantle regions throughout Mars's history provide information about the mantle composition and temperature. The mantle potential temperature of primitive basalts appears constant (1400–1500ºC), yet is likely not representative of the average mantle. Incompatible element concentrations in the mantle vary due to magma ocean crystallization, partial melting, and metasomatism. UR - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10941 ER -