Ground base and stem question

[Sleestak]

Howdy folks
I'm just learning about arrowhead identification and keep coming across the terms "ground base" and "ground stem" yet I don't know what it means. Could y'all clue me in about what it looks like, and why it is done. Links or attached pictures would be appreciated.
Thanks, Sleestak

[Butch Wilson]

Here are couple of examples of grinding , not always to this extentt !
Two Big Sandy/Rowan points the black one shows heavy grinding, removing most of the flaking scars!



This little Palmer shows the base being ground almost flat, in most cases grinding will not be this extreme!



Grinding was done to aid in hafting to the shaft, an attempt to minimize splitting and cutting the hafting material !

[Sleestak]

Thanks Butch-
is the purpose of grinding to aid the hafting process?

[chase]

Sleestak wrote:

Thanks Butch-
is the purpose of grinding to aid the hafting process?

  I know your asking Butch, but I will put my two cents worth in.
Basil Grinding is more for the after effect, of what it did to aid in the stability of the sinue ( string, tie wrap) from being cut from the sharp edges of the stone. this was ground down to become dull. The base would be ground down to keep the shaft from splitting down the middle. So it did not aid the hafting process but was a end result.
Here is a base that shows basil grinding you can see where it is smooth and then you can see where the flakes go through the edge.

[Sleestak]

Gracias Chase-  it all makes sense now.