Connecting external drive via USB-C to older iMac with Thunderbolt 1?

[jointfilms.com]

Hi, I have an older iMac (2011) and just bought a new external HD. I wanted to hook it up using the Thunderbolt 1 (I'm assuming it's Thunderbolt 1) port. The drive I bought only has a USB-C port. I bought the adapter Apple sells thinking thatmight work. But that is only good for going the opposite way (connecting a Thunderbolt 1 to USB-C port). I'm wondering if there is a cable or adapter that will allow me to do this?

Thanks....

 

[MacsBug]

If the drive is USB 3 up to 1000MB/s then the only way to hook the drive up to the thunderbolt port on the iMac is to find an older Thunderbolt 1 dock that has a USB 3 port on it, and plug the drive into the USB 3 port on the dock. Just note that the drive will only be able to be used for storage. The older thunderbolt docks do not allow for booting from USB 3.

If the new drive is thunderbolt 3, then this wont work at all.