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Detrital zircon dating

The results of U-Pb Sensitive High Resolution Ion Micro-Probe (SHRIMP) dating of detrital zircons from the Lower Cretaceous section exposed in Israel indicate that they are dominated by detrital zircons of Neoproterozoic age, mainly concentrated in the 0Æ55 to 0Æ65 Ga interval, with various amounts of older (pre-Neoproterozoic) zircons (of 0Æ95 to 1Æ10, 1Æ7 to 2Æ0 and 2Æ6 to 2Æ65 Ga age groups).The overall age signal is similar to detrital zircon age spectra previously obtained from the Cambrian–Ordovician sections of Israel and Jordan.

Detailed studies of the variation of (U-Th)/He detrital mineral dates in sedimentary substrates, combined with thermal modeling, may be a valuable tool for physical volcanologists who wish to explore the temporal and spatial evolution of individual flows and lava fields. PY - 2011Y1 - 2011N2 - Simple numerical models suggest that many basaltic lava flows should sufficiently heat the sediments beneath them to reset (U-Th)/He systematics in detrital zircon and apatite.We analyzed a variety of samples including glaucophane-bearing pelitic schist from the Itsuki area in Kyushu and the Toba area on the Kii Peninsula, and quartzite from the Anan area in eastern Shikoku.The U-Pb age distributions reflect similar characteristics for all three areas, indicating significant peaks at 450-500 Ma and ̃ 600 Ma, with additional scattered ages of 800-1800 Ma, and ages older than 2000 Ma.The age spectrum of the detrital zircons indicates that the Zhaochigou Formation-complex shared the same provenance with the eastern edge of the Khondalite Series.Products of ancient magmatic activities within the Khondalite Belt may be the major source for the sedimentary materials that formed the Khondalite Series.Typically these ages correspond to crystallization and exhumation or eruption ages, and their combination can be used to more confidently resolve candidate source terrains, establish maximum depositional ages, and constrain the thermal histories of orogenic source regions.U/Pb dating is accomplished by laser-ablation ICP-MS in a small pit on the exterior of the crystal, and He dates are then determined on the bulk grain by conventional laser-heating and dissolution techniques.This work was supported by the Key Project of National Natural Science Foundation of China (41230206) and the project of China Geological Survey (1212011120552).Simple numerical models suggest that many basaltic lava flows should sufficiently heat the sediments beneath them to reset (U-Th)/He systematics in detrital zircon and apatite.Since first unroofed from above pan-African terranes closer to the secession of orogeny, the ensuing siliciclastics were recycled repeatedly throughout the Phanerozoic with little additional basement denudation.The Lower Cretaceous sandstone comprises quartz sand that was first eroded from above pan-African orogens ca 400 Myr prior to deposition.

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  1. Eastern Succession of the Mt Isa district. detrital zircon, event signature, Hf isotopes. significant amount of U–Pb zircon dating has been

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