Keywords: Bulletin 426 Plate VI B Guilford and Waltersville Granite Company Quarry.jpg Guilford MD <br>Guilford is now within the village of Kings Contrivance Columbia Maryland The quarried rock is now called the Guilford Quartz Monzonite <br>Text from the volume referring to this figure <br> The horizontal joints prominent in all the larger quarries separate the granite into sheetlike masses which usually have their strongest development near the surface but in some quarries extend to the entire depth of working Nowhere is this better shown among the Maryland granites than in the old Guilford and Waltersville Granite Company's quarry in the Woodstock area Pls IV B; VI B The sheets may vary from a few inches in thickness at or near the surface to 2 to 10 feet at some distance below the surface In the quarries on the Baltimore County side of Patapsco River at Ellicott City sheeting extends to the depth of working more than 90 feet and the sheets range in thickness from 2 to 4 feet In the quarries of the Woodstock area the sheets are from 2 to 6 feet thick and in the quarries of the Guilford area from 3 to 10 feet thick Approximately the same range in thickness is shown in the Port Deposit quarries one of which has been worked to the extreme depth of 230 feet 1910 Granites of the Southeastern Atlantic States Bulletin 426 United States Geological Survey Government Printing Office Washington 1910 Watson Thomas Leonard other versions PD-USGov Geology Quarrying |