CONTENTS 



Pago 



Pri I'atory notes 13 



Chapter I— Introductory 19 



The field of investigation 19 



The art remains studied 20 



Character of the stone implements 21 



Materials and their distribution 21 



Quarrying 23 



Manui.icture 24 



Initial stages 24 



Shaping ])roeesses 25 



Chapter II — Manufacture of flaked stoiie inii)lements . 29 



Introductory statement 29 



Qnarry-workshops of the District of Columbia 30 



History of the research 30 



Geology of the locality. 31 



Piny branch quarries 33 



Location of the quarries 33 



Operations on the site 35 



Discovery and reconnoissance 35 



The first trench 36 



The tree pit 44 



The second treu ch 45 



The third trench 45 



The fourth and fifth trenches 49 



The sixth trench 50 



Other Piny branch sites 51 



Piny branch shops 52 



General features 52 



Special features 53 



The quarry-shop product 53 



Tools used in flaking 58 



Processes of manufacture 58 



Destiny of the quarry blades 62 



The Dumbarton heights quarry-shops 62 



Location 62 



Geology of the site 63 



Distribution of quarry pits 64 



Trenching 64 



Other Rock creek sites 66 



Shop sites of the middle Potomac valley 66 



Falls section of the Potomac 66 



Auacostia valley 61' 



The tidewater Potomac 71 



Sites in James river valley 72 



5 



