386 NOTES ON THE GEOLOGY 



might not improbably be supposed to be the relics of some ani- 

 mals allied to the encrinites. So rapid does this deposition take 

 place, that pipes, such as the above, are sometimes filled in a few 

 years. On this account they are often made more than a foot in 

 diameter. 



No. 322, is a beautiful example of that pulverulent variety of 

 carbonate of lime, called ag-aric mineral, from a cavern near 

 Smyrna.* 



The region around the city of Broosa, in the vicinity of Mount 

 Olympus, next claims our attention. Most of my specimens from 

 that place were sent by Mr. Schneider ; though some have been 

 added by Mr, Homes and Mr. Van Lennep. 



Hot springs are very abundant at the foot of Olympus, not far 

 from the city. The consequence is, that tufaceous deposits are 

 common. They are mostly calcEireous, though No. 294, from the 

 foot of Olympus, is siliceous, and was probably an aqueous de- 

 posit. Baked clay is used in the city for aqueducts, as at Smyrna, 

 and they soon become filled with calcareous matter. " In the 

 box," says Mr. Schneider, " you will find a specimen (Nos. 172, 

 173) of the earthen aqueducts of Broosa, filled up, or partly filled, 

 by the sediment of the water. Where these pipes are in a leval 

 position, in three or four years they are completely filled. When 

 they lie more inclined, or stand upright, it requires a longer time. 

 The elevated platform on which the old part of the city of Broosa 

 stands, was probably gradually formed by the numerous fountains 

 gushing from the foot of the mountains, and leaving this deposit. 

 On examination it is found, that the rock beneath the city, and the 

 substance in the pipes, are of the same nature." 



Nos. 187, 188, are specimens of the common rock at Broosa, 

 and are a tufaceous, though hard and nearly compact limestone. 

 No. 155, which is also said to be the common rock, is decided 

 tufa. Nos. 194, 323, are calcareous tufa, broken from the curb of 



* Since the preparation of tlie text, I have seen, in Dr. Bucklantl's Anniversary Address 

 before the London Geological Society in 1S41, an abstract of a paper by l\Ir. W. Hamil- 

 ton, read before that Society, on the Geolog-y of Smyrna and vicinity. The rocks which 

 he describes, correspond essentially to those mentioned in the text. Mr. Strickland 

 describes a cretaceous limestone near SmjTna with hippurites. {Address, p. 42.) 



