Unexpected Archeology: so white quartz arrow heads?

Digging drain holes to carry rain into the clay soil. Got two feet down and hit quartz objects.
Two arrowheads of white quartz in varying degrees of work. The bottom is two inches long, nocked at the rear, thin and blade-like tapering to the edges with a symmetrical taper towards the point. The second is thicker in shape though taper is good. Just in need of a flat and smooth polish.

The long piece is mostly a long square quartz block. Ideal for shaping and wearing the arrowheads. Its three and a half inches long.

Only bow and arrow users are the indonesian hobbits with the dj phonetic. That would make this podj-podj archeology. An unexpected find in red gravel clay two feet below a bluemetal garden path. A long way from their point of origin given the high iron content in the red clay the city of Darwin is built on.

Update (2 May 2019): 

Apparently these small arrowheads are 'mid paleo sub-phase' of the fluted point phase with a length to width ratio of 1.26-2.0 putting them at 10,550BC - 10,850BC, but they come with the arrow vice notch at the base of the Arrow characteristic of Clovis sub-phase. Does this indicate a transition period putting them at the older end of the scale? Its fascinating that these White Quartz people whose white quartz arrow-heads in North America are at twenty nine percent of arrowhead types found, and here in Australia with the first two arrows its at one hundred percent and can only decline.