How can I delete my email contacts from my iPhone 6

Hi

My data including contacts were transferred from my samsung to my iphone 6. I noticed that all my gmail contacts (over 500) were also transferred and now showing in my contacts. Is there a way of deleting these contacts but keep the ones with phone numbers? I tried to turn off Contacts, Calender and Notes from Settings/Mail, Contacts, Calenders/Gmail... but that didn't solve the problem. Any help would be appreciated.