U-Pb Zircon Geochronology of the Adirondack Mountains and Implications for Their Geologic Evolution
|Title||U-Pb Zircon Geochronology of the Adirondack Mountains and Implications for Their Geologic Evolution|
|Publication Type||Journal Article|
|Year of Publication||1988|
|Authors||McLelland, JM, Chiarenzelli, JR, Whitney, PR, Isachsen, YW|
U-Pb zircon studies of metamorphosed igneous rocks in the Adirondack Mountains have yielded preliminary ages within the range 1420-990 Ma. Several geochronologically and geochemically distinct episodes of igneous intrusion and at least one pre-granulite facies dynamothermal metamorphic event are documented. This information is consistent with recent field and geochronological studies throughout the Grenville province and suggests that a complex sequence of events occurred in the Adirondack Mountains prior to the widespread deformation and metamorphism commonly attributed to the ∼1100-1000 Ma Ottawan phase of the Grenvillian orogenic cycle.