chap. xiv. Upright Silicified Trees. 527 



sea, in a broken escarpment of thin strata, composed of 

 compact green gritstone passing into a fine mudstone, 

 and alternating with layers of coarser, brownish, very 

 heavy mudstone including broken crystals and particles 

 of rock almost blended together, I counted the stumps 

 of fifty-two trees. They projected between two and 

 five feet above the ground, and stood at exactly right 

 angles to the strata, which were here inclined at an 

 angle of about 25° to the west. Eleven of these trees 

 were silicified and well preserved : Mr. R. Brown has 

 been so kind as to examine the wood when sliced and 

 polished; he says it is coniferous, partaking of the 

 characters of the Araucarian tribe, with some curious 

 points of affinity with the Yew. The bark round the 

 trunks must have been circularly furrowed with irregu- 

 lar lines, for the mudstone round them is thus plainly 

 marked. One cast consisted of dark argillaceous lime- 

 stone ; and forty of them of coarsely crystallised car- 

 bonate of lime, with cavities lined by quartz crystals : 

 these latter white calcareous columns do not retain any 

 internal structure, but their external form plainly shows 

 their origin. All the stumps have nearly the same 

 diameter, varying from one foot to eighteen inches; 

 some of them stand within a yard of each other ; they 

 are grouped in a clump within a space of about sixty 

 yards across, with a few scattered round at the distance 

 of 150 yards. They all stand at about the same level. 

 The longest stump stood seven feet out of the ground : 

 the roots, if they are still preserved, are buried and 

 concealed. No one layer of the mudstone appeared 

 much darker than the others, as if it had formerly ex- 

 isted as soil, nor could this be expected, for the same 

 agents which replaced with silex and lime the wood of 

 the trees, would naturally have removed all vegetable 

 matter from the soil. Besides the fifty-two upright 



