U–Pb geochronology and Sr/Nd isotope compositions of groundmass perovskite from the newly discovered Jurassic Chidliak kimberlite field, Baffin Island, Canada

Reconstructing deep‐time histories from integrated thermochronology: An example from southern Baffin Island, Canada

“…We do not impose any constraints on the Proterozoic t–T history other than requiring cooling through closure for the apatite U–Pb system. The independent geological constraints on the Phanerozoic t–T history are as follows: (a) Preserved Foxe Basin and Baffin Island sediments imply crystalline bedrock was near surface in the Late Ordovician (Zhang & Riva, ); (b) Early Palaeozoic xenoliths from the c. 156–138 Ma Chidliak kimberlites on Hall Peninsula (Heaman, Pell, Grütter, & Creaser, ; Zhang & Pell, ) demonstrate Palaeozoic strata were fully eroded to within ~200–300 m by the Late Jurassic; and (c) preserved sediment remnants near Cape Dyer (Figure ) locally suggest minor late Cretaceous–Palaeocene burial (Burden & Langille, ). We assume that the constraints are regional (at least for Cumberland and Hall Peninsula) because the oldest known sediments encountered in the offshore Baffin Island shelf (i.e.…”

Earth evolution and dynamics—a tribute to Kevin Burke

“…3b) with North American, NW African, South African and Australian kimberlites erupted over the TUZO margin. Late Jurassic kimberlites from Siberia, however, are not associated with the LLSVP margins (see also Heaman et al 2015). Three Late Jurassic LIPs, Argo (155 Ma) and Magellan (145 Ma) and Shatsky (147 Ma) -the oldest known in-situ Oceanic LIPs -plot directly above the TUZO and JASON plume generation zones.…”

U–Pb geochronology of calcite carbonatites and jacupirangite from the Guli alkaline complex, Polar Siberia, Russia

“…Owing to its capacity to concentrate U, Th, rare earth elements (REE), Sr and high-field-strength elements (in particular, Nb and Ta), this mineral has been used widely as a petrogenetic indicator and robust geochronological tool (e.g. Heaman, 1989; Kinny et al , 1997, Hamilton et al , 2003, Paton et al , 2007; Donnelly et al , 2012; Chakhmouradian et al , 2013; Heaman et al ., 2015; Stamm et al , 2018). Since the late 1980s, geochronological studies of perovskite have generally relied on mass-spectrometry techniques, which are capable of providing high-precision results for a small quantity of material (Stamm et al , 2018; Heaman et al , 2019).…”

“…Perovskite from the Ice River alkaline complex (Canada) has been proposed as a calibration standard for U–Pb radiometric age determination (Heaman, 2009). It is also noteworthy here that the overwhelming majority of the available geochronological data on perovskite are for groundmass crystals from kimberlites (Smith et al , 1989; Heaman et al ., 2015; Donnelly et al ., 2012; Stamm et al , 2018; Tappe et al , 2018, to name a few), whereas publications on other rock types – in particular, alkaline-ultramafic intrusions with carbonatites – are very limited (Srivastava et al , 2005; Cox and Wilton, 2006; Heaman, 2009; Reguir et al , 2010).…”