1 88 1. 21 Trans. N. V. Ac. Sci. 



forming as nodules about some nuclei. The aggregate quantity of 

 copper in this formation was enormous, but, except where by the erosion 

 of the beds it accumulated at the surface and could be picked up with- 

 out any expense in mining, it would hardly pay to attempt to obtain it 

 by ordinary mining processes. 



The wood replaced by copper, Dr. Newberry said, was undoubtedly 

 all coniferous, and different from any now living The beds which 

 contained the cuprified wood also contained much that was silicified. 

 Of this he had examined many specimens under the microscope and 

 had found the peculiar dotted cells which are characteristic of the con- 

 iferae, and these grouped in such a way as to prove the trees to have 

 belonged to the Araucarian group of conifers. So far as yet known, 

 the angiosperrris, or higher order of plants, did not make their appear- 

 ance on the earth's surface until after the copper bearing rocks of the 

 southwest had been deposited. 



November 7, 1881. 

 Regular Business Meeting. 



The President, Dr. J. S. Newberry, in the Chair. 

 Twenty-nine persons present. 



A paper by Prof. P. T. Cleve, University of Upsala, Sweden, 

 was read by Prof D. S. Martin, entitled 



Outlines of the Geology of the Northeastern West India 



Islands. 



(Abstract.) 



Prof, Cleve's paper contained a resume of his observations made 

 during 1868-9, in and around the Virgin Islands, and published in the 

 Swedish language in the Trans. R. Acad. Set. of Stockholm, in 1871. 

 He regards the whole group as of Cretaceous and Tertiary age, with 

 the exception of Anegada, which, like the Bahamas, is Post-pliocene. 



The strike of the rocks, and the trend of the entire group, are 

 approximately east and west. The rocks are various, largely eruptive 

 and metamorphic. Of these, Prof. Cleve discussed somewhat fully the 

 character and distribution of the following kinds : — i, Dioryte; 2, Fel- 

 syte ; 3, " Blue-beach" (a peculiar volcanic breccia, locally so-called); 

 4, Diabase. 



All these rocks have great thickness, and indicate long-continued vol- 

 canic activity. As in modern lavas, they present two types, basic and 

 acidic. 



Metamorphic slates are next described ; and then a partly metamor- 



