As long as we're looking into Mars during its Noachian we'd like to see what its crust and mantle were like, back then. Last year Lei Zhang, Jinhai Zhang, and Ross N. Mitchell (pdf) noted that the yuuge Hellas impact-crater is almost-but-not-quite the antipode of the Alba Patera volcano.
The offset is 119 km which wouldn't be much latitude on Earth but on Mars it's a significant 2°. Also Hellas has a daterange, from crater-count, if not a firm date: 4.1 to 3.8 Gya. The crust around Alba Patera will have done its Mercury thing around then. By similar crater-count methods the volcano formed 3.2 Gya, the boundary between Hesperian and Amazonian (it might even define that boundary). It couldn't form in the badlands so it formed 2° off it.
The triad believe these formations are related: the impact causing, Caloris-style, the geologic mess on (again: almost) the other side of the planet. The offset would, then, have summat to tell us about the state of the crust and mantle there and then. The conclusion: the northern-lowlands ~4 Gya were still soft compared to the badlands around what's now Tharsis.
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