Nininger Moment #12 A Classification of the Meteoritic Additions to the Earth

It is evident that the materials composing a meteorite are widely distributive during the process of its fall to Earth. Some of the material is reduced to the finest powder and probably a considerable portion is transformed into gases. Certainly some of this disintegration begins in some cases, as high up as one hundred miles above sea level and apparently continues within a few miles of the soil. The distribution of the surviving fragments may be considered both from the standpoint of the area over which they are scattered, and from a standpoint of the depths to which they penetrate the ground. So far as is known to this writer, no attempt has been made to deal systematically with the penetrative distribution of meteorites. It is only fair to state that in this writers opinion, our knowledge in this field is too meager for any attempt at final conclusion.

A study of 102 witnessed falls reveals the fact that from these falls 50 individuals were recovered from below plough depth. The average weight of these 50 stones and irons were 84..7 lbs. (38.5 kilos) The average depth buried was 22 inches (55 cm) Thirty two of the fifty had weights of less than 50 lbs (22.7 kg) and an average weight for these were 20.3 lbs. (9.2kg) The average depth of burial for these 32 were 20.3 inches (50.8 cm)

Six individuals weighed between 50 lbs and 100 lbs (22.7 and 45.4 kg) with and average weight of 63 lbs. (28.6 kg) for these the average depth of burial was 32 inches or (80 cm) Seven individuals weighed between 100 lbs and 200 lbs. or (45.4 kg and 90.8 kg) with and average weight of 139 lbs (63.2 kg) for these the average depth of burial was 43 inches or ( 107.5 cm) Two individuals weighed between 200 and 400 lbs. (90.8 and 181.6 kg) and the average weight for these was 230 lbs. (104.5 kg) and the average depth of burial was 48 inches (120 cm) Three individuals weighed more than 400 lbs (181.6 kg) each; and these were buried at an average depth of 122 inches (305 cm)

Generally speaking it may be said that the depth of burial increases with the diameter of the meteorite, though of course there are several factors which greatly modify this relationship. The shape and specific gravity, the angle and velocity at which it falls, and the nature of the soil (soft/hard etc.) As far as we know the majority of stony meteorites of less than 300 grams do not bury themselves completely in the soil. Many stones as massive as one kilogram (2.2 lbs) have been found freshly fallen on the surface of the soil and in some cases as heavy as five or six kilograms (11 to 13.2 lbs) have come to rest on ordinary soil without sinking into it even half their own diameter. Irons have buried themselves usually about 50 percent deeper than stones. In a few rare instances as in the Lumpkin stone weighing 12.5 Oz (354 g) buried itself rather deeply in hard ground at a depth of 10
inches (25 cm)

Source: The Published Papers Of H.H. Nininger
By the Center for Meteorite Studies Arizona State University, Tempe, AZ

Published originally in Popular Astronomy 1935

The Nininger Moments are articles or books written originally by Harvey Nininger and put into a consolidated form by Al Mitterling. Some of the items written in the moments might be old out dated material and the reader is advised to keep this in mind.

–AL Mitterling

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