It's actually fairly easy to do it yourself. If you are logged in, you can edit the location fairly easily.
On the edit page, there is a map. Hit the satellite view button in the location to display a satellite view. You will probably have to drag the view down a bit to see the quarry (click on the mouse - holding it down to drag the map to the south). When you position the mouse over the red marker - a box with with drag me appears. Click on the red marker with the left mouse button and drag the pointer to where the quarry is.
Once it is positioned where you want, you can go down to the bottom of the page and submit the edit.