HENBUEY METEORITE CRATERS ALDERMAN 227 



where a watercourse had at one point broken through and washed away the 

 crater wall. 



No. 4. Very similar to No. 3. Circular, diameter about 45 yards, general height 

 of walls 10 to 20 feet. In the immediate neighborhood of No. 4 about 500 frag- 

 ments of various sizes were found. Of these nearly 400 were on the west side 

 of the crater. As noted below, about 100 of these were lying within an area 

 of 6 by 6 feet. 



No. 5. Circular, diameter 25 yards, low walls. Boring in the " clay-pan " 

 floor showed a depth of 8 feet of fine soil before coarse rock fragments pre- 

 vented further sinking. 



No. 6. The Water Crater. Roughly circular, with diameter of 80 yards. 

 Height of walls 12 to 25 feet, the highest part being that which divides this 

 crater from the Main Crater. A watercourse has broken through the wall on 

 the south side, water being preserved in the pan for some time after rain. This 

 crater contains mulga and other acacia trees, the latter reaching a height of 

 45 feet. 



No. 7. The Main Crater (pi. 1, fig. 2; pi. 2, fig. 1). Oval in shape, with its 

 principal axes 220 and 120 yards from rim to rim, and 170 and 70 yards across 

 the floor. The peculiarity of shape is possibly due to two large masses landing 

 simultaneously and in close proximity. Height of walls averages 40 to 50 feet. 

 Fragments of iron mostly on north side. 



No. 8. Well-defined, circular, diameter 55 to 60 yards. Height of walls varies 

 from 3 to 15 feet, being greatest where No. 8 is divided from the adjacent Main 

 and Water Craters. 



No. 9. Ill-defined and doubtful ; the topography, however, suggests a small 

 crater. 



No. 10. Like Nos. 11, 12, and 13, is situated on a low sandstone ridge to the 

 south of the main craters and to the north of the prominent ridge of siliceous 

 breccia previously mentioned as a spur of Bacons Range. No. 10 is circular, 

 with a diameter of about 20 yards ; low walls. It is about south-southwest of 

 the main group of craters. 



No. 11. On ridge, circular ; diameter about 15 yards. 



No. 12. On ridge. A very well-defined circular crater sunk into side of ridge, 

 the walls reaching 12 or more feet on the highest side ; diameter 20 yards. 

 (PI. 2, fig. 2.) 



No. 13. Rather indefinite, but there can be very little doubt that this is a 

 crater ; diameter about 10 yards. 



METEORITE FRAGMENTS 



A great number of metallic meteorite fragments are scattered over 

 a wide area (fig. 2). Those collected are of all shapes and vary 

 in weight from a fraction of an ounce up to 52i/^ pounds. The shape 

 of many of them suggests that they were fragments torn or scaled 

 off a large mass, whereas others seem to have fallen as complete 

 units. This, together with the fact that a number of craters were 

 located, suggests the extreme probability that many of the fragments 

 were torn off large masses immediately before or during impact with 

 the earth and that others fell at the same time but separately. It 

 was, of course, owing to the impact of the largest members of this 

 meteoric shower that the craters were formed. 

 149571—33 16 



