Help ID my Great Grandfather's cap badge

[POFmilitaria]

Hello, this is my first post on this forum. I collect mainly American Militaria but I am part British so many of my ancestors fought in the British military. I was given this photograph of my Great Grandfather. His name was Christopher Clark and I was told he was killed in action only a few weeks before World War I ended. That is the only info I have on him. I notice there is insignia on his cap but have no idea what it may be. It is very blurry but I figured maybe someone on this forum could identify it. If anyone could identify the regiment I would be very grateful to find out my family's history.

Thanks,
Jacob Anderson