SONORA PALEOCHANNEL


and metavolcanics with up to four distinct suites of calc-alkaline meta- plutonic rocks extends throughout the region. Within this larger ter- rane, the Dawson Range extends from Mount Freegold (Nucleus- Revenue, Figure 3) northwest to


Alaska.


Metavolcanic sequenc- es in the Dawson Range of quartz-mica schist, gneiss and diorite are intruded by porphyritic granodiorite and quartz monzonite plutons of the mid-Cretaceous Dawson Range Batholith. The plutons are accompa- nied by smaller, high- level, felsic porphyry plugs and sills. Narrow, Upper Cretaceous(?) ultramafic dikes are common along major east-west and north- west faults. Volcanic rocks in this central part of the Dawson Range consist of sills, dikes and


12 TPG • Jul.Aug.Sep 2024 www.aipg.org


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56