INTEGRATING MULTISYSTEM GEO- AND THERMOCHRONOLOGY AND THERMOBAROMETRIC DATA TO DEVELOP EVOLUTIONARY TECTONIC MODELS FOR THE PALEOZOIC LAURENTIAN MARGIN: HONORING THE OUTSTANDING CAREER OF ROB STRACHAN

Orogenic studies along the Paleozoic Laurentian margin from the southern Appalachians to Scotland and the East Greenland Caledonides have provided many fundamental field-based observations and laboratory-based data sets that have subsequently guided our understanding of processes that have operated in a range of extinct (and also active) orogens. However, the Paleozoic assembly of the composite Appalachian-Caledonian system was complex and resulted from multiple collisional and accretionary events of various types (continent-continent, arc-continent, transpressional and transtensional, etc.). Because of this, the record preserved in these polymetamorphic and polydeformational terranes has traditionally been difficult to unravel. This challenge is compounded by a notable lack of widespread modern geo- and thermochronology data from many parts of this system, which is due in part to the broader view in the tectonics community that the important problems in these orogens have been addressed. Over the past two decades many of these “gaps” in our understanding of the Appalachian-Caledonian system are progressively being filled by new studies carried out by long standing Laurentian pioneers like Rob Strachan joined by a cadre of researchers that are new to these regions. This recent surge in data availability has provided the opportunity to begin developing more detailed constraints on source provenance and P-T-t evolution, and these in turn are allowing us to foster new ideas about the tectonic evolution of the Paleozoic Laurentian margin. This presentation will share preliminary results of ongoing studies from the southern Appalachians and northwest Scotland wherein multisystem geo- and thermochronology is being coupled with quantitative P-T-t data and numerical modeling of orogen thermodynamics to develop new evolutionary tectonic models.