How ipv6 address is determined from 1pv4 address

I'm studying networking for my college exams.I read that arp protocol was responsible for mapping IP to Mac in a lan.so I used Wireshark to see how arp protocol works.

When I visited Google and saw an arp response telling Mac address of my router.the network traffic better my computer and Google server is based on ipv6 protocol.the IP address of my system and Google were shown in ipv6 format..

My doubt is that if my router uses arp to find my ipv4 address for delivering incoming packets,then how is it mapped to my ipv6 address.my arp cache doesn't show ipv6 addresses also. please help!!