Dating antarcic meteorites
In comparison to terrestrial volcanoes (blue) those on Mars (red) have a greater volume and duration, but much lower eruption rates.Data and references in Supplementary Table 1 , an approach to estimating the age of a planetary surface based upon the size-frequency distribution of impact craters, indicate that Martian volcanoes have longer lifespans (up to 3500 Ma) but far lower eruption rates () (Fig. These crater-counting models are useful to resolve the relative ages of planetary surfaces, but are prone to uncertainty in terms of absolute age determination.And findings by the University of Manchester researchers, published in the journal Nature Communications, suggest they may be retrievable - unlocking information about other planetary bodies and their cosmic past.Although meteorites fall evenly across the Earth, more than two-thirds of the total number of collected meteorites has been recovered in Antarctica, partly due to the contrast between the white Antarctic surface and the dark meteorites resting on top.
b Relative characteristics of terrestrial and Martian plume volcanism.A non-radiogenic trapped , with most volcanoes being active along divergent and convergent plate boundaries.A small proportion of terrestrial volcanoes are fed by mantle plumes—highly localized upwellings of abnormally hot rock that ascend from deep within the mantle and undergo partial melting at relatively shallow depths) are located in the Tharsis and Elysium regions, with the largest volcano, the 600 km wide Olympus Mons, rising more than 21 km above the surrounding plains.As potassium and chlorine are both dominantly hosted in the mesostasis, the argon gas derived from radiogenic decay of potassium and chlorine gas from apatite will be closely associated in location and thermal behaviour during a We analysed unirradiated fragments of each of the six nakhlites, with our data yielding concordant cosmogenic exposure ages, and a weighted mean of 10.7 ± 0.8 Ma (2σ, 10% uncertainty on production rates; Fig. The indistinguishable cosmogenic exposure ages attest to the fact that the nakhlites can be launch-paired, indicating they were ejected from a single point source on the Martian surface by a single impact event. 3 and Supplementary Table 3) were used to correct the Ar cosmogenic exposure ages overlap within uncertainty, which is consistent with all of the nakhlites being sourced from the same impact.
Blue data points were analysed at Lawrence Livermore, and red data points were analysed at SUERC.
Blue ellipses denote plateau steps that were included in the isochron regression, white ellipses are outliers from the low-temperature steps that were excluded from the isochron analysis, and the red lines indicate the 2σ uncertainty envelope Ar (Fig. 2), indicating that the Ar-systematics have been relatively undisturbed.