Jack's Reef

Point Type:  Jack's Reef                 
Associated Date: 2000 - 1200 B.P.
Morphology:  Corner Notched


Length Point:        
Ave: [ 39 +/-  8 mm]  
Range: [ 25 to 57 mm] 
Example: [ 34 mm]

Width Point:         
Ave: [ 29 +/-  7 mm]  
Range: [ 20 to 47 mm] 
Example: [ 26 mm]

Point Ratio
 (Width / Length):  
Ave: [.75 +/- .16 ]

Length of Base:      
 (Shoulder to Base)
Ave: [ 8  +/- 2 mm]  
Range: [ 4 to 12 mm] 
Example: [ 10 mm]

Width of Base:      
  (Maximum)
Ave: [ 24 +/- 5 mm]  
Range: [ 16 to 40 mm] 
Example: [ 24 mm]

Depth of Notch:      
Ave: [5.2 +/- .04  mm] 

Base Length/Point Ratio:  
 (Length of Base  / Length Point)
Ave: [.21 +/- .04 ]

Base Width/Point Ratio:          
 (Width of Base  / Width Point)
Ave: [.82 +/- .14 ]
 
Base Ratio:        Ave: [.35 +/- .09 ] 		1. Short (<= 0.7)  
 (Base Length                                 		2. Proportionate (> 0.7 & < 1.3)  
   / Base Width)                            		3. Long (>= 1.3)

Base Form:           1. Convex   2. Straight   3. Concave   
 (Subjective) 

Notch Ratio:       Ave: [.18 +/- .03 ]
 (Depth Notch 
   / Width Point)

Blade Ratio:       Ave: [1.1 +/-  .2 ] 		1. Lanceolate (>= 2.0 mm)
 ([Length Point                                     		2. Isosceles (< 2.0 & > 1.2 mm)
    - Length Base] / Width)                        		3. Equilateral (<= 1.2 mm)
   
Blade Curvature:   Ave: [4.1 +/- 1.2 mm]  		1. Very Convex (>= 5 mm)
 (Cord height of curve                       		2. Convex (< 5 mm & >= 2 mm)
  from Shoulder to Tip)                      		3. Straight (< 2 mm & >= -2 mm)   
                                                   		4. Concave (< -2 mm)
                                                   		5. Mixed (< -2 mm & > 2 mm)
Shoulder Angle:    Ave: [ 60 +/- 11  o]
 (Angle of Shoulder from   
 Notch Center to Shoulder to Tip)

1993 - Tara Prindle