Emplacement age and thermal footprint of the diamondiferous Ellendale E9 lamproite pipe, Western Australia

The exhumation history of collision-related mineralizing systems in Tibet: Insights from thermal studies of the Sharang and Yaguila deposits, central Lhasa

“…9B). Based on the work of Evans et al (2013), where the emplacement of a large (20 m) mafic dyke was found not to have reset ZHe ages of the country rock at the contact with the dyke, it is highly unlikely that the emplacement of the thin (~1 m) Miocene dykes at Sharang would have thermally reset the helium ages of the granite intrusions ( Fig. 2A and B).…”

An in situ technique for (U–Th–Sm)/He and U–Pb double dating

“…RESOchron pairwise double dated Ellendale lamproitic zircon (grey diamonds) and country rock (grey squares) plotted with zircon from the same samples, previously dated using conventional (U-Th)/He and SHRIMP methods (black diamonds and squares; fromEvans et al, 2013). Pairwise in situ ages reproduce age distribution patterns identified by traditional analysis.…”

“…9,20 Recent work 21 has introduced the notion of a 'pairwise' approach where standards of known age are compared to samples of interest using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) for U, Th and He abundance. 18,19 The increased productivity (less time required to generate an age relative to conventional methods), ability to circumvent the multiple-handling steps previously required for double dating (SHRIMP/LA-ICP-MS U-Pb and conventional (U-Th-Sm)/He), 22,23 and improved worker safety (does not require grain dissolution, thereby avoiding the use of acids) are added advantages. 18,19 The increased productivity (less time required to generate an age relative to conventional methods), ability to circumvent the multiple-handling steps previously required for double dating (SHRIMP/LA-ICP-MS U-Pb and conventional (U-Th-Sm)/He), 22,23 and improved worker safety (does not require grain dissolution, thereby avoiding the use of acids) are added advantages.…”

“…However, none of these approaches have integrated in situ (U-Th-Sm)/He and U-Pb dating on single crystals to obtain double dates. 23,26 These types of studies require large datasets (preferably >100 ages) for proper statistical evaluation. 23,26 These types of studies require large datasets (preferably >100 ages) for proper statistical evaluation.…”

“…Uncertainty on AFM pit volume was 2.4% as described in the text.Evans, et al23 study.Fig. Uncertainty on AFM pit volume was 2.4% as described in the text.Evans, et al23 study.Fig.…”