Pitfalls in using the geochronological information from the EarthChem Portal for Precambrian time-series analysis

•EarthChem Portal is the most comprehensive open access online database in Earth sciences.•Only 17% of the samples in the Earthchem Portal have age with relative age range less than 5%.•Only ∼3% of the sample can be used to investigate the Precambrian.•Our study show that careful filtering is mandatory before applying the data time-series analyses.