METEORITES OF NORTH AMERICA. 173 



ELM CREEK. 



Lyon County, Kansas. 



Latitude 38° 40' N., longitude 96° 5' W. 



Stone. Ornansite (CcO), of Brezina. 



Found 1906; described 1907. 



Weight 7,075 gr. 7 kgs. (15 lbs.). 



This meteorite was described by Howard ' as follows: 



Another aerolite from Kansas has just been obtained by Ward's Natural Science Establishment, of Rochester, 

 New York. It is of especial interest as having been found near Admire, Lyon County, where the Admire pallasite 

 was found in 1902. 



About May 10, 1906, J. R. Waters ploughed up the meteorite some three miles north-northeast of Admire. It 

 was buried about eight inches deep in a field that up to that time had never been cultivated to any depth. Mr. 

 Waters also says that "it was on a slope where the soil would wash off of it instead of burying it up deeper." The 

 exterior of the stone exhibits considerable oxidation, so that it has evidently lain in the ground for a number of years. 

 There have been so many aerolites found in Kansas that at first there was a question as to whether this one constituted 

 a distinct fall or if it were merely one of a shower. An examination of a polished surface, however, showed that it is 

 entirely different from other Kansas stones. 



Elm Creek, a branch of the Marais des Cygnes River, flows about three-fourths of a mile from where the stone was 

 found, and as one meteorite has already been named after Admire this one will be called the Elm Creek aerolite. 



Its weight is 7,075 grams. It measures approximately 22 by 19 by 12 centimeters. The stone is highly oriented, 

 the pittings radiating from a point a little below the cenfer. Any markings that may have been on the reverse side 

 have been obliterated by oxidation. The stone is very firm and excepting where a few small chips have scaled off 

 shows no signs of fracture. 



Dr. Geo. P. Merrill, of the United States National Museum, has made a microscopic examination of the aerolite 

 and describes it as follows: "The stone on a polished surface is of a dark gray, nearly black color, thickly studded with 

 metallic iron and with numerous indistinct chondrules which break in large part with the groundmass. Under the 

 microscope the silicate portion is found to consist essentially of olivine and enstatite with a twinned monoclinic 

 pyroxene. The olivine occurs in the usual clear, colorless forms quite free from inclosures; in minute fragments and 

 splinters and in chondrules of the barred and porphyritic type common to meteorites. A part of the porphyritic 

 forms show a base of yellowish glass, while others seem noncrystalline. Occasional forms are met with in which 

 the entire chondrule is composed of a single individual, in which case the central portion is clear and colorless, while 

 the borders are of alight smoky-brown color and show a fibrous structure. All portions are, however, optically a unit. 



"The enstatites like the olivines occur in scattered fragmental particles and in chondrules, the latter of the com- 

 mon cryptocrystalline and radiate type, and in porphyritic forms. In the latter the crystal outlines are at times very 

 well developed. The cryptocrystalline forms are often remarkably spherical, or at least circular in outline in the 

 section. As such they rarely polarize as a single individual, but as is commonly the case the field breaks up into 

 sectors, as the stage is revolved between crossed Nicols. It is of course possible that not all of these cryptocrystalline 

 forms are of enstatite; some may be of augite or possibly olivine. An optical determination is impossible, and the 

 determination is based on their resemblance to others which have been tested chemically. 



"The monoclinic pyroxene is of interest on account of the beautifully developed polysynthetic twinning which 

 it presents when either in chondrules or in fragments in the groundmass. In this respect it would seem to be fully 

 comparable with the meteorite of Renazzo, Italy, as figured by Tschermak on Plate 15 of his Mikroskopische Beschaff- 

 enheit der Meteoriten. Crystal outlines are rare and the mineral is a trifle less limpid than the enstatite. A pris- 

 matic cleavage is fairly well developed. No feldspars or other silicates than those mentioned were detected. 



"The most striking feature of the stone is the spherical perfection of many of the chondrules and the perfection 

 of the twinning in the pyroxene. As a whole the stone is plainly fragmental — is composed of a moderately firm mass of 

 angular fragments in which are embedded the chondrules. I am disposed to class it with those of Allegan, Michigan, 

 San Emigdio, California, and Warrenton, Missouri. This, following Brezina, would throw it in the group of Ornansite 

 (CcO), from which it differs only in its firm character. I confess, however, that I fail to see the necessity of attempting 

 to name rocks according to their degree of compactness or friability." 



BIBLIOGRAPHY. 



1. 1907: Howard. The Elm Creek aerolite. Amer. Journ. Sci.. 4th ser., vol. 23, pp. 379-381. 



Emmett County. See Estherville. 



EMMITSBURG. 



Frederick County, Maryland . 



Latitude 39° 42' N., longitude 77° 19' W. 



Iron. Medium octahedrite (Om), of Brezina. 



Found 1854; described 1885. 



Weight (assignable), 177 grams (7 ounces). 



Nothing seems to have been published regarding the history of this meteorite. The first 

 mention of it seems to be in the Vienna catalogue of 1885 1 , where it stands as the representative 



