474 PROCEEDINGS OF BALTIMORK MEETING. 



an inch in diameter, presumably of salt, replaced by calcite. The extreme delicacy 

 of the forms, the feathery outgrowths and the lack of broken specimens, indicate 

 that they were formed in place in the soft mud. They w^ere, I think, discovered 

 by Mr B. Hosford, of Springfield, and were much studied by him. They have been 

 called chiastolite, and are cited as spinel in Dana's Manual, 1892. The specimen 

 shown was a bowlder from Holyoke. Mr Hosford's specimens were from West 

 Springfield. 



PUCKERIXG OF CoRUNDUM CRYSTALS AKOUND AlLANITE 



The well known asbestus mine in Pelham, Massachusetts, is opened on a great 

 dike of black olivine-enstatite rock enclosed in gneiss. The metamorphism which 

 changed the Cambrian conglomerate into gneiss changed the olivine rock, along a 

 network of fissures, into anthophyllite, arranged in transverse fibers, meeting in 

 a suture — a macroscopic olivine network. 



A macroscopic *' reaction rim " was produced between the two rocks by the inter- 

 action of the very basic and the very acid members. Against the olivine rock is a 

 broad band, characterized by very basic minerals— thick bands of biotite, containing 

 apatite, and fine large corundum crystals. Then comes anorthite full of orthite, 

 rutile and tourmaline in large masses. Then the anorthite graduates into andesite, 

 and this, by the gradual appearance of quartz, microcline and biotite, into the 

 common, well bedded gneiss. 



A crystal of corundum was shown — largely fine blue sapphire, in which was a 

 crystal of allanite a half inch across, which had coerced the corundum into a fine 

 radiated puckering nearly an inch wide, outside of which the fine cleavage of the 

 corundum assorted itself. The same puckering surrounds the allanite in the mas- 

 sive anorthite. 



The section took a recess until 2.15 o'clock p m, at which hour a fur- 

 ther adjournment was taken until 4.30. At the latter hour the section 

 reconvened and the following paper was read : 



SPHERULITIC VOLGA NICS AT NORTH HAVEN, MAINE 

 BY W. S. BAYLEY 



It is not my intention to discuss the subject of spherulites or of the occurrence of 

 volcanic rocks on the coast of Maine. I desire simply to call attention to the 

 existence of large thicknesses of genuine volcanic products, in all probability of 

 Paleozoic age, in the neighborhood of the village of North Haven and in the north- 

 ern portion of Vinal Haven island, just west of Penobscot bay. 



The late Dr Williams announced the discovery of these rocks in a recent number 

 of the Journal of Geology.* They are found not only in the vicinity of the island 

 referred to, but the same or perhaps other areas of them extend eastwardly as far 

 as Little Deer island, on the west side of Penobscot bay. 



Mr W. W. Dodge, of Cambridge, Massachusetts, first called my attention to 

 them, and kindly presented me with a few specimens ; later Mr Pirsson loaned 

 me some thin-sections cut from rocks on Vinal Haven ; so that the discovery 

 of this interesting series of volcanics is due primarily to Messrs Dodge and 



* Vol. ii, p. 23. 



