No. 2306. CUMBERLAND FALLS METEORITE— MERRILL. 103 



The 56.58 per cent insoluble silicates yielded : 



Silica (SiOj) 58.341 



Alumina (ALO,) 2. 705 



Ferrous oxide (FeO) 3. 528 



Nickel oxide (NiO) 295 



Cobalt oxide (CoO) trace 



Manganous oxide (MnO) 562 



Lime (CaO) 5. 073 



Magnesia (MgO) 29. 496 



100. 000 



This bears out the somewhat unsatisfactory determination of the 

 prevailing orthorhombic nature of the pyroxenic constituent, but the 

 high (5.073) per cent of hme (CaO) is difficult to account for. 



The 13.022 per cent metallic portion yielded: 



Iron (Fe) 92.982 



Nickel (Ni) 5.735 



Cobalt (Co) 599 



Manganese (Mn) 676 



Copper (Cu) 008 



Chromium (Cr) trace 



100. 000 



The mineralogical composition of the dark inclusion as calculated 

 from the foregoing is as below: 



Metal 13.022 



Troilite 6.760 



Lawrencite 080 



Chromite 869 



Soluble silicates mainly oUAdne 22. 582 



Insoluble silicates mainly pyroxenes 56. 580 



Carbon , mainly amorphous 449 



Calcium phosphate trace 



Water, hygroscopic 210 



100. 552 



The most striking features of the stone, aside from its coarse brec- 

 ciated structure, are the marked evidences of compression manifested 

 in the numerous small slickensided surfaces and the crushed and 

 optically distorted condition of the pyroxenes, as shown both in the 

 hand specimens and in thin sections. It is to be noted that while 

 the original shattering which resulted in the production of the frag- 

 ments may have been due to impact or explosive action, the mass has 

 since been subjected to pressure under a heavy load whereby the parti- 

 cles have been further crushed and distorted and once more welded 

 into a firm, rock-like mass. These are characteristics of deep seated 

 terrestrial rocks that have been subjected to dynamic metamoi-phism. 



The question naturally arises, is not the distortion so conspicuous in 

 so much of the enstatite due to the crushing which resulted in the 

 disintegration of the original meteorite rather than to any subsequent 

 pressure ? This question, I think, may be answered in the negative, 



