Investigating low dispersion isotope dissolution Lu-Hf garnet dates via in situ Lu-Hf geochronology,Kanchenjunga Himal  

作　　者：Kyle P.Larson John M.Cottle Mark Button Brendan Dyck Iva Lihter Sudip Shrestha 

机构地区：[1]Department of Earth,Environmental and Geographic Sciences,University of British Columbia,Okanagan,Kelowna,Canada [2]Department of Earth Science,University of California,Santa Barbara,USA [3]Fipke Laboratory for Trace Element Research,University of British Columbia,Okanagan,Kelowna,Canada

出　　处：《Geoscience Frontiers》2024年第3期137-145,共9页地学前缘（英文版）

摘　　要：Re-examination of three specimens from the Kanchenjunga Himal of Nepal via in situ Lu-Hf garnet geochronology yields evidence of multiple garnet growth events.Spot analyses from grain cores in two specimens define Paleozoic regressions whereas analyses from grain rims in the same specimens define low-precision regressions consistent with the timing of Himalayan orogenesis.These dates contrast with previously published low dispersion,ca.290 Ma isotope dissolution(ID)Lu-Hf garnet dates for the same rocks.Modelling of Lu and spot age distribution in representative grains from the specimens examined yields calculated dates that approximate the Permian-age regressions through the original ID data.These findings demonstrate that it is possible to generate low dispersion ID Lu-Hf data from multigenerational garnet with significantly different-age growth events when approximately equal proportions of the different age reservoirs are included in multi-component aliquots.

关 键 词：Lu-Hf geochronology In situ Lu-Hf geochronology Kanchenjunga Himal 

分 类 号：P597[天文地球—地球化学]