THE RH^TIC ROCKS OP NOTTINGHAMSHIRE. 
193 
THE KHiETIC EOCKS OF NOTTINGHAMSHIRE.* 
BY E. WILSON, F.G.S. 
It is now more than twenty years since the term “Khaetic” was 
applied in this country by the late Mr. Charles Moore to a peculiar set 
of black and grey shales, sandstones, and impure limestones (first 
noticed in Britain by Strickland and Portlock) which occur imme¬ 
diately at the top of the Bed Marls of the Keuper series, and at the base 
of the Lower Lias (zone of Ammonites planorhis). The term “Penarth 
Beds” was assigned to this group by Sir Boderick Murchison, on account 
of their being so typically developed in the cliffs between Penarth and 
Lavernock, near Cardiff, and Dr. Wright gave the name Avicula 
contorta” zone to the same beds from the presence of a peculiar species 
of Avicula {Cassianella contorta). The term Bhsetic, however, is the 
best, as expressive of the great development of these rocks in the 
Bhaetian Alps bordering the northern plain of Lombardy, where, be¬ 
tween Como and Lake Garda, they attain a thickness of from 3,000 to 
4,000 feet, and occur as and constitute mountain ranges. 
Many years previous to their discovery in this country—viz., by 
Von Buch in 1828, and Alberti in 1834—an extensive and widely spread 
series of rocks, rich in organic remains, of contemporaneous age with our 
“ Penarth Beds,” had been noticed and described on the continent of 
Europe. In England, as in the Northern latitudes of Europe {e.g., 
Sweden, South Norway, the Islands of the Baltic, and also in Bohemia 
and Hungary) the Bhaetic series is only known as a thin but representa¬ 
tive zone, whereas in the South of Europe (France, Austria, Germany, 
and especially the Alps of Switzerland, Lombardy, and Savoy) it 
attains a great development, rich in organic remains, either molluscan 
or piscine, with occasionally plant remains, but everywhere containing 
the Avicula contorta, a shell which is cosmopolitan in the strictest 
sense. 
The distribution of the Bhaetic rocks over much of Europe is a very 
marked feature, both physically and palaeontologically. It marks the 
close of the Triassic sandstones and marls almost everywhere, and 
commences and exhibits in Britain new conditions of life through a 
fauna (according to Etheridge) closely allied to, and perhaps migratory 
or descendant from the Middle Trias or Muschelkalk of Germany, and 
the Kossener and St. Cassian beds of Central Europe. The relation¬ 
ship of the British with the Continental deposits is fully established 
by certain mollusca which ranged through the Bhaetic seas, and which, 
in Britain as in Lombardy, abound in the black shales, bone beds, and 
impure limestones of the group. In fact, in almost every essential 
feature the Bhaetics of Britain agree with the Continental deposits, 
enabling us to co-ordinate through its fauna the entire series in this 
country with those of Europe. 
* Read before the Nottingham Naturalists’ Society. March 20th, 1883. 
