600 



J. E. MAEE ON TEE PEEDEVONIAN 



intrusive eclogite. The eclogite itself, near Chlumicek, is of a dark 

 olive-green colour, Near the small village of Krems, south of 

 Chlumicek (not the Krems above mentioned), it is of a reddish hue ; 

 south of Slavis, to the east of Chlumicek, it is of an amher-hrovs^n ; 

 whilst near Holobau it is black. In each locality it is very hard. 

 The last-mentioned place yields a very interesting section (fig. 4), in 

 which the eclogite is clearly seen to be intrusive. The section is to 

 the north of the road, just before it crosses a stream to the east of 

 the village of Holobau. 



Fig. 4. — Section by Bridge east of Holohan. (Height about 10 feet.) 



G. White quartzose foliated rock with amber-coloured garnets. 



E. Hard black eclogite. X X . Joint (and fault ?). 



Wear Srnin, between this place and Krumau, occurs another mass 

 of eclogite, probably connected with the former at no great distance 

 below the surface, and altogether similar to it. It is of a brown 

 colour*. 



§ 4. COMPAEISON" OE THE StRATA WITH ENGLISH DEPOSITS. 



In Salter's Catalogue of Cambrian and Silurian fossils of the Uni- 

 versity of Cambridge some of the Bohemian beds are correlated 

 with English deposits. A more detailed correlation is given by 

 Dr. Hicks (Geol. Mag. dec. ii. vol. iii. table opposite p. 156; 

 cf. also Hicks, Q. J. G. S. vol. xxxi. p. 552). Professor Krejci also, 

 in his work on the Geology of Bohemia (pp. 461 et seqq.), gives a com- 

 parison of the Cambrian and Silurian rocks of the two countries. 

 Sir R. I. Murchison (Siluria, p. 375), on the other hand, says, " Eor 

 my own part, however, I have always thought that geologists should 



* Professor Bonney has kindly examined a slide of this rock from Chlumicek, 

 and given me the following note : — 



"Your rock from Chlumicek has no claim whatever to be called a 

 serpentine. The chief mineral is omphacite, with perhaps, as is commonly 

 the case, some smaragdite. The other prevailing mineral is a decomposition 

 product after garnet .... It has a peculiar fibrous structure and acts upon 

 polarized light, the fibres radiating irregularly from a centre outwards. 1 have 

 seen something like it in an alteration product of Oordierite .... That it is 

 after garnet is shown not only by its mode of occurrence, but also by one or 

 two bits of unaltered garnet remaining in the centre. There are a few brown 

 microliths, in part probably only stains. The rock therefore is an eclogite, with 

 most of the garnets replaced by a decomposition product. The great difierence 

 in the condition of the two principal minerals is rather curious, though not 

 without parallel in the felspar and augite of some dolerites."— T. G. B. 



