The Bathurst Batholith west of Sydney, Australia, consists of an enormous pluton (the Bathurst Granite) and numerous smaller related satellite plutons and dikes. The major pluton cuts east-west across the prevailing north-south strike of the fossiliferous sedimentary strata, unequivocal evidence that the intrusion of the batholith structurally disrupted the regional fabric of the host strata sequence. Sedimentary rocks in the contact zone were metamorphosed by the hot magma. The major dike-like Evans Crown granite cuts across the Bathurst Granite and the surrounding host strata. This dike's central portions are coarse and even grained like the Bathurst Granite, but the margins are chilled, testimony to intrusion of the dike as hot granite magma. Many minor granite dikes cut across the margins of the Bathurst Granite and also across the Evans Crown dike out into the surrounding strata. Alteration zones marginal to the sharp contacts of the dikes with the wallrocks indicate the magma was still hot when injected. Abundant 238U and 210Po radiohalos are present in biotite flakes of all samples of the Bathurst Granite and Evans Crown dike. 214Po and 218Po radiohalos are present only in some samples of the Bathurst Granite. A few 210Po and 238U radiohalos are also present in biotite flakes within some samples of the dikes that cut across the Bathurst Granite or the Evans Crown dike. Field and textural data have established that these granite phases were sequentially intruded while still hot. That these granitic phases were intruded as hot magma is also confirmed by analytical and experimental data. All this had to occur within the Flood year, so these multiple granite phases were not created cold by fiat. Instead, the Po radiohalos indicate they were formed rapidly below 150°C via hydrothermal fluid transport of Rn and Po from the zircon grains embedded in the biotite flakes that are often the radiocenters of the U radiohalos. Furthermore, their presence in all three sequentially intruded granite phases is evidence that all this intrusive activity, and the cooling of all three granite phases to 150°C, must have occurred within a week or two so that these Po radiohalos in them formed subsequently within days to weeks.