Ah saying Mars has "always been cold and was rarely above freezing" based on a meteor sample "ejection from Mars, 11 to 15 million years ago."?..
By definition the meteor sample is only valid for data on Mars up till the time they were ejection from Mars...
you have a, 11 to 15 million years till now, data drop out there...
really puts a damper on making overall blanket assertion on the total Mars geo.history...don't you think?
OTOH, ten million years is only two or three one-thousandth of four billion years. So we have to be careful about saying it's not a representative look at Martian history... It'd be a little like saying we don't have a good understanding of American history if we don't know anything about the last six or seven months of it.