Excess helium and argon in beryl and other minerals

摘要: All beryl crystals appear to contain a quantity of helium and argon in great excess over that which can be acccounted for from radioactive decay. Other magnetic minerals have structural sites suitable large nonessential atoms such as cordierite tourmaline also show this variable amount. It seems inert gas must represent sample the gases immediate environment forming crystal amd prowide useful information on conditions. Although there are considerable differences concentration even same crystal, these small compared one hundred-fold difference belween formed early Precambrian (--3.0 b.y.) Paleozoic eras. This strong age effect is interpreted suggesting more extensive history. (auth)