Reviews— Gunns Geology of Norfolk. = — 275 
the lakes lie are almost horizontal and undisturbed. One of the 
lakes (Ontario) lies in a low anticlinal bend of soft strata, and Lake . 
Superior on a faint synclinal curve. E 
Professor Ramsay concludes with an inquiry—why it is ‘that not 
only drift- and moraine-dammed lakes, but striated rock-basins, of 
all sizes, occur in such prodigious numbers in America, Scandinavia, 
the Highlands, and in all other rocky temperate regions, high and 
low, that have been glaciated, while in tropical and subtropical 
regions they are so rare as to be quite exceptional elsewhere than in 
mountain-areas that now or once maintained their glaciers ?’ 
A Sxercn or THE GeoLioey or Norrotk. By the Rey. JoHn 
Gunn, F.G.S. Reprinted from White’s History and Directory of 
the County. Sheffield: W. Wurrr, 1864. 8vo. pp. 27. 
Ts this unpretending pamplet, which is of a class that might with 
advantage be more common, the author follows the usual 
arrangement, beginning with an account of the geography, especially 
_ of the rivers, followed by a list of the geological formations of the 
County, ranging from the Kimmeridge Clay to the peat and other 
recent deposits ; and he names the chief books and papers that have 
treated of Norfolk geologically. 
Norfolk affords examples of those ‘gaps’ to which Dr. Bigsby 
has lately drawn attention;* thus the Lower Greensand rests at 
once on the Kimmeridge Clay, the higher Oolitic and the Wealden 
formations being absent; and the Norwich Crag lies upon London 
Clay. In parts also the Chalk is but barely separated from the 
Lower Greensand, the thin bed of so-called ‘Red Chalk’ being all 
that comes between those formations at Hunstanton. This ‘Red 
Chalk’ Mr. Gunn seems to look upon, with Professor Sedgwick, as 
the representative of the Gault (p. 7), although he allows (p. 8) that 
Mr. Seeley had good reason for taking it to be the Upper Greensand : 
may it not represent both those formations, as we believe the Rev. 
T. Wiltshire has suggested ? It would perhaps have been better 
to have treated of the Red Chalk under a separate heading. 
Strange to say, fragments of so thin and local a bed have been 
found in the Drift just north of London, a very long way from any 
spot where it occurs in place. 
We must demur to the remark made at p. 7 as to ‘ fossil contents’ 
being ‘the only dependable basis’ on which one can trust to ‘estab- 
lish identity’ of beds. Were this the case, we fear there would soon 
be an end to field-geology (a branch of the science, by the way, not so 
well understood as it should be); fossils not being so ever-present as 
is often thought, and the lithological nature and relative position of 
beds being often of, at least, equal importance. What this doctrine of 
the all-powerfulness of fossils leads to may be seen at p. 8, where we are 
told that ‘it may be inferred that the Gault is principally represented 
in the Lower Greensand, and the Upper Greensand in the red lime- 
* Journ, Geol. Soc., vol. xx. p. 198, 
