Write protected error when mounting a loop device with a GPT and single partition

I'm trying to mount a loop device that I've created with the following steps but receive an error telling me that the fs is of an unknown type. If I don't add a partition to the fs it will mount as expected.

$ sudo dd if=/dev/zero of=secOps bs=1M count=512
512+0 records in
512+0 records out
536870912 bytes (537 MB) copied, 0.244399 s, 2.2 GB/s

$ sudo mkfs.ext4 secOps
mke2fs 1.42.9 (28-Dec-2013)
secOps is not a block special device.
Proceed anyway? (y,n) y
Discarding device blocks: done
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
32768 inodes, 131072 blocks
6553 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=134217728
4 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
    32768, 98304

Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

$ sudo gdisk secOps
GPT fdisk (gdisk) version 0.8.10

Partition table scan:
  MBR: not present
  BSD: not present
  APM: not present
  GPT: not present

Creating new GPT entries.

Command (? for help): o
This option deletes all partitions and creates a new protective MBR.
Proceed? (Y/N): Y

Command (? for help): n
Partition number (1-128, default 1):
First sector (34-1048542, default = 2048) or {+-}size{KMGTP}:
Last sector (2048-1048542, default = 1048542) or {+-}size{KMGTP}: +256M
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300):
Changed type of partition to 'Linux filesystem'

Command (? for help): p
Disk secOps: 1048576 sectors, 512.0 MiB
Logical sector size: 512 bytes
Disk identifier (GUID): 941146DD-99DB-4A90-B400-8D7D1534AF21
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1048542
Partitions will be aligned on 2048-sector boundaries
Total free space is 524221 sectors (256.0 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048          526335   256.0 MiB   8300  Linux filesystem

Command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!

Do you want to proceed? (Y/N): Y
OK; writing new GUID partition table (GPT) to secOps.
Warning: The kernel is still using the old partition table.
The new table will be used at the next reboot.
The operation has completed successfully.

$ sudo losetup /dev/loop0 secOps
$ sudo lsblk
NAME      MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda         8:0    0   20G  0 disk
├─sda1      8:1    0  200M  0 part /boot/efi
└─sda2      8:2    0 19.8G  0 part /
loop0       7:0    0  512M  0 loop
└─loop0p1 259:0    0  256M  0 loop

$ sudo blkid
/dev/sda1: SEC_TYPE="msdos" UUID="8939-51F5" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="c8b5c89a-17ed-480e-b9f6-0e811c16fee3"
/dev/sda2: LABEL="root" UUID="a8ee4848-df7a-4cc9-a9f0-07e423353d28" TYPE="xfs" PARTUUID="e8d78e3d-29f6-44f1-bd31-977ffd4b3d7d"
/dev/loop0: PTTYPE="gpt"
/dev/loop0p1: PARTLABEL="Linux filesystem" PARTUUID="b0ad9144-89bf-49ce-9038-f70d9d69d7ea"

I notice here that the partition does not have a UUID. Why might that be?

And then when attempting to mount the loop device.

$ sudo mount /dev/loop0 /secOpsMnt/
mount: /dev/loop0 is write-protected, mounting read-only
mount: unknown filesystem type '(null)'