Selector .selector_input_interaction .selector_input. Selector .selector_input_interaction .selector_spinner.
At present, Chemostrat can determine U-Pb ages for zircon and apatite crystals.
Concordia ages of 2,051 ± 9 Ma (2σ, MSWD = 0.1) and 2,056 ± 5 Ma (2σ, MSWD = 0.05) for zircons from the Merensky Reef and the Upper Platreef located equally near the top of the Critical Zone are in agreement with published ages for the Merensky Reef.
Zircon from the deeper-seated Lower Group, Middle Group and Lower Platreef chromitites yields younger concordia ages that may reflect prolonged late-stage volatile activity.
The most common dating method involves the use of minerals like zircon and monazite that are relatively common in granitic rocks.
Zircon is especially useful because it frequently contains uranium in substitution for zirconium, but does not incorporate lead (as shown by the absence of Lead-204).
During zircon analysis, oxygen gas is leaked through a valve into the ims1270 sample chamber. Note: in order to open EP10, EP11 or to vent the door, the leak valve has to be closed (1.5 turns clockwise).
At the beginning of an analytical session or when analytical parameters such as primary beam intensity or spot size were changed, energy offsets for all measured ion species must be determined.In addition there is another stable isotope, lead 204, that is entirely primordial and does not form via radioactive decay at all.Thus any of the radioactive isotopes and its lead daughter product can be used for dating, or a combination may be used.Thus all the lead in the zircon can be assumed to be radiogenic.The layered Bushveld Complex hosts a number of chromitite layers, which were found to contain significant amounts of zircon grains compared with adjacent silicate rocks.*Both EPMA and CL services would be carried out by Dr.