Air Carrier Captain reported a fume event during descent which dissipated briefly thereafter. Upon gate arrival Maintenance was requested and logbook entry was submitted

Narrative

During descent at 11000 detected an odor like crayons or wax. It was brief and cleared up on its own. I queried Flight Attendants (FAs) if they smelled anything. They replied not really; perhaps a brief musty smell. I inquired if it was like dirty socks or a gym bag. They said not really. We continued to landing and on gate arrival we detected the odor again. First Officer (FO) and I opened cockpit windows and figured we had experienced a fume event. We notified maintenance and made a write up in logbook. We discussed with local ZZZ maintenance folks. I again spoke with FAs after deplaning more about it. They noticed it more on landing and arrival and agreed more with the crayon like smell. They each said they felt fine as well as FO and each left as it was end of sequence. The smell was definitely notable in the entry was even with jetway attached and door open. I then followed fumes protocols in FOM and Safety website. I filled out the fumes form and called duty pilot and had an additional phone conversation with Maintenance Control. Fumes events should be brought more to the forefront in recurrent training as there is a lot of concerning issues that can present them selves post event.