  Measuring the solar neutrino flux over gigayear timescales could provide a
new window to inform the Solar Standard Model as well as studies of the Earth's
long-term climate. We demonstrate the feasibility of measuring the
time-evolution of the $^8$B solar neutrino flux over gigayear timescales using
paleo detectors, naturally occurring minerals which record neutrino-induced
recoil tracks over geological times. We explore suitable minerals and identify
track lengths of 15--30 nm to be a practical window to detect the $^8$B solar
neutrino flux. A collection of ultra-radiopure minerals of different ages, each
some 0.1 kg by mass, can be used to probe the rise of the $^8$B solar neutrino
flux over the recent gigayear of the Sun's evolution. We also show that models
of the solar abundance problem can be distinguished based on the
time-integrated tracks induced by the $^8$B solar neutrino flux.
