230 Notes, chiefly Geological, [No. 171. 



The outline of the ghauts in the back ground is bold and pictur- 

 esque. A little to the north, the mountains of overlying trap attain 

 their maximum elevation, which never approaches that of the peaks 

 of granite and hypogene schist farther south, although they sometimes 

 attain 4,500 feet of altitude above the sea's level. 



They usually rise from the low maritime tracts of the Concan in bold 

 escarpments, broken by steps or terraces, to the table land of the Deccan. 



The Concan. — The foregoing observations from Goa were made 

 as I was sailing up the coast from Sedashegur in a native pattamar, 

 with a foul wind to Bombay. After leaving Fort Victoria the wind 

 became fair, and consequently I had no longer any opportunity of 

 going ashore and examining the Concan between Bombay and Ban- 

 coot. The ghauts in this region, we know, are of trap from the obser- 

 vations of Colonel Sykes. Their long horizontal outline, varied occa- 

 sionally by truncated conoidal peaks, are characters in which their na- 

 ture is plainly written. 



The rock composing the Concan is chiefly trap. My lamented friend 

 Malcolmson found beds of sandstone at Atchera, dipping at a consi- 

 derable angle to the NW. 



As the existence of fossiliferous deposits is by no means improbable 

 on this low maritime tract, through the rocky fissures of which many 

 hot springs find vent, and which have not yet been fully examined, 

 I should strongly recommend its minute geological exploration. 



Bombay. — The geology of this and the neighbouring beautiful islets 

 of Elephanta, Salsette, &c. has been so well and minutely described 

 by Or. Thomson, that I shall content myself with observing that they 

 are all of the overlying trap formation, and the rocks composing them 

 embrace every variety from dark basalt to light coloured amygdaloids 

 and wackes, from compact to crystalline and porphyritic. 



I must not however omit to mention a curious variety termed 

 white basalt, of which -the base of Sir John Malcolm's statue at 

 Bombay, if I recollect right, is composed. Externally it often re- 

 sembles a soft felspathic granular sandstone, white, with a slight shade 

 of yellow, but it is clearly seen passing into a true, rough, crystalline 

 trachyte. 



It is dug at the quarries of Salsette, and composes a large part of 

 the island ; some of the granular varieties are extremely hard, and 



