Mega Lithic Reduction, Mega Blades

Other stage analyses have focused on specific end products or specific knapping strategies. Biface reduction was analyzed by Errett Callahan (1979)  in terms of seven stages: obtaining the blank, initial edging, primary thinning, secondary thinning, shaping to preform, finishing, and reworking/rejuvenation. Diagnostics for the stages were based on the cross-sectional shape of the tool, its width-to-thickness ratio, and its flake scar pattern. Less detailed stage distinctions were proposed for the associated debitage: indicators of relatively early-stage work included cortex, simple dorsal scar morphology, remnants of ventral flake bulbs on dorsal surfaces, and single-faceted platforms."

"Stage 1- obtaining the blank: Obtaining the raw lithic material

Obtain a blank {unmodified} piece of raw material. A blank -may be a spall-, irregular chunk, or any other form suitable for the end product. Action may vary from simply picking up a suitable piece to systematic flaking of a suitable spall from a core. Edges may vary from thin and sharp to thick and squared.

 Edging. Shape is irrelevant.

Stage 2 rough out: Create a circumferential, roughly centered edge which is neither too sharp nor too blunt {ideally between about 55-75}. Work should focus on the zone with little or no attention being paid to the central zone, cross-section, or shape. Shape and width-thickness ratios may vary in the extreme.  The edge should end up being roughly centered and bi-convex, without such concavities, convexities, steps, squared edges, or other irregularities as would hinder successful execution in the next stage.

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Stage 3- primary thinning preform:  Create a symmetrical hand axe-like outline with generous ' lenticular cross-sections and a straight and  centered , bi-convex edge. Width-thickness ratios should fall between roughly 3.00 and 4.00 while edge-angles should fall between  about 40- 60 degrees.  Focus on the middle zone without losing control of the outer zone . Principal flakes should generally just contact or  overlap in the middle zone, except on thin pieces, and be without such concavities, convexities , steps, or other irregularities as would hinder  successful execution in the next stage.

Stage 4- secondary thinning preform: Create a symmetrical outline with flattened, lenticular cross-sections and a straight and centered, bi-convex edge. Thickness should gradually diminish during reduction so that width-thickness ratios end up falling between roughly 4.00 and 5.00 or more. Edge-angles should fall between about  25 and 45 degrees. Focus on the middle zone without losing control of the outer zone.  Principle flakes should generally overlap, often considerably, in the middle zone. Generalization of the final shape may start now and pattern flake removals may be implemented. The resultant piece should be without significant concavities, steps, or irregularities as would hinder successful execution in the next stage.

Stage 5- shaping: Final preform: Create a symmetrical, more-or-less parallel-sided outline (if final shape is to be parallel-sided) of specific shape, with appropriately flattened, lenticular cross-sections, and a straight and centered, bi-convex edge. The outline and thickness should be within one set of principal flake removals from the final product (i.e., with about 2-4 mm at either edge.) Pattern flake removals may be employed, with flake terminations being feathered. Principal flake scars in the middle zone may or may not overlap those of the previous stage. Width-thickness ratios and edge-angles should be about the same as on the final product, which may (or may not) be greater than the secondary preform.  Focus on the middle zone while giving special attention to outer zone regularity. The resultant piece should be without such concavities, convexity, steps, or irregularities as would hinder successful execution in the next stage.

Stage 6- flaked implement: Create an implement of specific, symmetrical shape, cross-sections, width-thickness ratios, thickness, and contours with a particular flake removal sequence and flake scar appearance, as appropriate to the type or anticipated function.  The edge should be more or less straight but without final retouch and alignment, if needed. The focus should be upon the outer zone, with the flake scars penetrating into the middle zone as appropriate to the type or function. Fluting,  if applicable, is done at this time.

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Stage 7- Create a finished implement, with edges and hafting elements being retouched as appropriate to the type or anticipated function. Focus on the outer zone only so as to create a sharp, very straight and centered edge, not prepared in anticipation of another set of flake removals but for function. Execute basal hafting or finishing elements such as notching, shouldering stitching, ect. Lateral notching sequences if applicable, are applied at this time. Basal abrasion may also be done now, as appropriate."

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