Let's see if -57 can handle this simple page.
http://adsabs.harvard.edu/abs/1984usgs.nasa...82S
>> Primitive strontium-isotopic composition and overall bimodal distribution of silica in
upper Paleocene and Eocene subalkalic tholeiitic to calc-alkaline basalt and low-potassium rhyolite of the Matanuska Valley and southern Talkeetna Mountains suggest that these rocks were derived from the mantle with little contamination by continental crust. The volcanic rocks consist of rhyolite tuff and ash flows, as well as basalt flows and dikes, in the
nonmarine Arkose Ridge Formation of the southwestern Talkeetna Mountains; of subaerial basalt and andesite flows, tuff, and mafic intrusions in the southeastern Talkeetna Mountains; and of felsic and mafic dikes, sills, and small plutons in the Matanuska Valley. <<
There's your citation. Now let's see if your substance can match your bluff and bluster.