Firth. — Deep Sinking in the Lava Beds of Mount Eden. 463 



fresh-water lake I am assuming to have occupied at this period the ancient 

 crater. Almost every particle of the wood had decayed, except patches of bark 

 adhering to portions of the cylindrical holes or matrices I have already des- 

 cribed. So closely had the mud rock taken the impress of the trees, that 

 I observed wherever a branch had been broken the most exact impress 

 remained in the mud rock. Strata &, c, d represent the bottom of the ancient 

 lake, at the lowest point of which will probably be found the stream which 

 discharges into the Waitemata at Messrs. Low and Motion's mills, and known 

 as the "Western Springs. At some future date I may perhaps put down what 

 miners call a " winze" on the dip of strata 6, c, d, with the twofold view of 

 obtaining more information regarding the waters of Mount Eden, and of 

 bringing to light some of the plants and denizens of older times. 



To return. Upon this mud rock there lay a stratum or lava stream of hard 

 close-grained blue volcanic rock; and upon this again a stratum two feet 

 thick of hard red scoria rock much honeycombed, followed by six inches of 

 fine equal-sized scoria gravel. 



These latter strata probably represent the first eruption of Mount Eden 

 subsequent to the appearance of the more ancient crater above sea level, 

 filling up the crater lake, and causing the superposed lava streams to dip at an 

 angle of 25° from the mountain to N., or in the opposite direction to the dip of 

 the lava stream below. 



Lying on this I found a stratum (a) dipping at about 25° to N., one foot 

 thick, of a reddish yellow clay, perforated with holes from ^ inch to f inch, 

 perfectly round, smooth, and slightly taper; in some instances containing 

 a woody fibrous-like matter, doubtless remains of the stringy filaments of 

 fern root. On being touched these filaments fell away to a white ash. The 

 fern roots growing on the surface exactly fitted these holes. All traces of the 

 plants had disappeared, leaving only the impress of their roots in the baked 



Upon this lay a two-feet stratum of hard blue close-grained 



clayey soil. 



and 



red scoria. It will not be necessary to continue to trace upward the various 



the 



durin 



befo 



From the 



total absence of vegetable matter, or of any traces of decomposition of ash or 



these five eruptions 



intervals. At 176 feet, as will 

 volcanic mud, or possibly a dec 



eruption and the first 



five subsequent ones. This eruption, occurring at a depth of about 180 feet 

 from the present surface, probably filled up the lake occupying the crater of a 



