THE SARDIS METEORITE—HENDERSON AND COOKE 147 
tive speculation; it might have penetrated deeper, and, if so, the geo- 
logical evidence of a scar would definitely be eroded by now. This 
part of the Coastal Plain has little relief, and Beaverdam Creek, the 
principal drainage system of the immediate vicinity, has a gradient 
of only 10 feet in a mile. Thus erosion is extremely slow, and to 
remove 48 inches or more of surface might require several thousand 
years. 
It is likewise possible that the Sardis meteorite fell into the sea in 
Miocene times and had its impact cushioned by striking the water, 
in which it gently settled to the bottom and was buried by the slowly 
accumulating Hawthorne formation. If this were true, corrosion 
would be active for a while, but the thickening oxide crust would 
offer increased protection as time elapsed. Furthermore, the sedi- 
ments would, in all probability, soon cover it, thereby decreasing the 
circulation of water and retarding the rate of alteration. If the Sardis 
iron was incorporated in the Miocene beds at the time of their forma- 
tion, the meteorite would not have become exposed to rapidly circu- 
lating water or air until late Pleistocene time or possibly until the 
Recent epoch, by which time a considerable thickness of upper Miocene 
and Pliocene sediments had been removed, and the level of permanent 
saturation had fallen below the meteorite. 
Relation to depressions and elliptical bays.—As there are many de- 
pressions of various shapes and sizes within a few miles of the place 
where the Sardis meteorite was recovered, we considered the possi- 
bility that some of them might be meteorite scars. For reasons given 
earlier in this paper, we are inclined to believe that the Sardis mete- 
orite fell in the far distant past, probably in Miocene time, and that 
any scar in the rocks made by it has long since been obliterated. 
There are many depressions of various sizes between Spring Mill 
Branch and Little Buckhead Creek, 5 to 10 miles southwest of the 
place where the Sardis iron was found. A depression about one- 
eighth of a mile long and nearly as wide lies about three-quarters of 
a mile southwest of Perkins, 7 miles away. There is another bay 
northwest of Perkins. A bay about one-half mile long by three- 
eighths mile wide lies about one and one-quarter miles east by north 
of Magnolia Spring and 6 miles southwest of the spot. 
About 10 miles west-northwest of the site of the Sardis find there 
are several parallel depressions about three-eighths of a mile long 
by about one-quarter of a mile wide extending a few degrees east 
of south. 
These depressions or bays are considered by C. W. Cooke to be sinks 
made by solution of the Cooper marl, which crops out at Magnolia 
Spring on Spring Mill Branch. 
