• journal_title：Rocky Mountain Geology
• Contributor：Daniel K. Holm
• Publisher：University of Wyoming
• Date：1999-
• Format：text/html
• Language：en
• Identifier：10.2113/34.2.183
• journal_abbrev：Rocky Mountain Geology
• issn：1555-7332
• volume：34
• issue：2
• firstpage：183
• section：Articles

Previous attempts to explain Paleoproterozoic post-tectonic magmatism in the Penokean and southern Trans-Hudson orogens inadequately account for the entire tectonic setting and geologic history of these areas. Key characteristics of post-tectonic plutonism in both orogens include the similar time-lag of emplacement after orogenesis (50–60 m.y.), the close association in both time and space between post-orogenic uplift and intrusion, the depth of emplacement, and the long-lived tectonic quiescence (crustal stabilization) that followed magma emplacement. Post-tectonic magmatism appears closely associated with post-orogenic uplift (collapse) and crustal stabilization. I propose that convective removal of the mantle lithospheric root may best explain post-tectonic magma genesis. Such a model suggests that there is a simple and related evolutionary history that began with construction of the Penokean and southern Trans-Hudson orogens (crustal thickening, metamorphism, plutonism, etc.) and ended with their destruction (crustal thinning, widespread uplift/cooling, plutonism, etc.), thus stabilizing the crust. Post-tectonic plutons may be an indelible mark of orogenic demise, not the culmination of terminal collision. Delamination-magmatism probably played a key role in the differentiation and stabilization of crust after orogenesis and may have promoted its transformation into craton.