Development and Application of New Technologies of Trace Element Testing for Carbonate Minerals

Trace elements are widely used in tracing diagenetic fluids and reconstructing diagenetic environments. The wet method is a mature and commonly used measurement method, but the method encounters difficulties: high demand for powder samples, complex chemical processing procedures, and lower accuracy, which restrict the promotion and application of this technology.

We developed new technologies for testing trace elements in carbonate minerals and achieved three results. (1) The upgrade of wet method of trace element testing technology for carbonate mineral and optimization of chemical treatment process have reduced the demand for powder samples from 50mg to 10mg, meeting the requirements of microstructure sampling and testing. The acid consumption reduced from 10mL to 2mL, and the relative error of data has been reduced from 5% -10% to 2% -5%; (2) A new technology for trace element laser ablation imaging has been developed based on the RESOlution laser ablation system, iCAP TQ triple quadrupole inductively coupled plasma mass spectrometer, and QuadLock device. The detection limit has been reduced from 5-10 ppb to sub-ppb, the spatial resolution of the image has been increased from ≥ 5µm to ≤ 1µm, and the processing time has been improved by 10 times; (3) The new technology of trace element laser ablation imaging has expanded its application fields. In addition to micro-area fluid tracing and diagenetic environment reconstruction, it can also be used for laser U-Pb isotope age determination to improve the success rate and accuracy of dating. It is used for the study of the coupling relationship between trace element concentration (or ratio) and mineral cathodoluminescence characteristics, clarifying new cathodoluminescence control elements other than Fe and Mn.

The development of new testing technologies for trace element provides a powerful tool for the study of carbonate reservoir formation.