470 MESOZOIC TIME. 



and are of concretionary origin. The exterior is frequently white, and 

 penetrated by chalk, proving that they are not introduced bowlders or 

 stones, but have originated where they lie. Moreover, many chalk 

 fossils are turned into flint ; and the flint nodules have often fossils as 

 nuclei. 



The Cretaceous beds of Europe have been divided into : — 



I. The Lower Cretaceous, including in England the Lower Green-sand, 800 to 900 

 feet thick, and in other regions beds of clay, and limestone sometimes chalky. 



II. The Middle Cretaceous, including in England (a) the clayey beds or marlytes, 

 called Gavlt, 150 feet thick, and (b) the Upper Green-sand, 100 feet. 



III. The Upper Cretaceous, including in England the beds of Chalk, in all about 

 1,200 feet: it consists of (a) the Lower or Gray Chalk, or Chalk Marl, Without flint; 

 (b) the White Chalk, containing flint; (c) the Maastricht beds, rough friable limestone, 

 at Maestricht in Denmark, 100 feet thick. 



The subdivisions of the Cretaceous are variously named, in different parts of Europe. 



Lower Cretaceous. — Superior Neocomian of D'Orbigny (the Wealden being the 

 Inferior); the Hils-conglomerat of Germany. 



Middle Cretaceous. — 1. Gault, lower part Aptian, of D'Orbigny; the upper, Albian 

 of D'Orbigny; 2. Upper Green-sand, Cenomanian of D'Orbigny; Lower Quadersand- 

 stein (or Unterquader) of the Germans; Lower Planerkalk of Saxony. 



Upper Cretaceous. — 1. Gray Chalk, or Chalk without flints, Turonian of D'Orbigny; 

 Hippurite Limestone of the Pyrenees; Middle and Upper Pliinerkalk of Saxony; Mit- 

 telquader of Germany. 2. White Chalk or Chalk with flints, Senonian of D'Orbigny; 

 Upper Quadersandstein (Oberquader) of the Germans; La Scaglia of the Italians. 3. 

 Maestricht beds, of Limburg; Danian of D'Orbigny; Faxoe Kalke of Denmark; Cal- 

 caire pisolitique near Paris. 



In mineral character, the beds of each division vary much over Europe, the Chalk 

 of England being synchronous with marlytes and solid limestones in Europe. 



•The Cretaceous of Great Britain is not found on any part of the Atlantic coast, ex- 

 cepting a small area in the vicinity of the Giants' Causeway. The beds of northern 

 France spread eastward over Belgium and Westphalia, but not to the Atlantic on the 

 west: farther south, they occur at the deep indentation of the Bay of Biscay. They 

 cover part of the Pyrenees, and reach into Spain, in what has been called the Pyrenean 

 basin, which in the Cretaceous period was a bay on the Atlantic. There is another ■ 

 sea-border deposit at Lisbon, in Spain. In southern France, over what is called the 

 Mediterranean basin, the beds extend from the Gulf of Lyons along the Mediterranean 

 coast, northeast to Switzerland, though with interruptions. The formation is found in 

 the Juras and Alps, in Italy, Savoy, Saxony, Westphalia, Moravia, Bohemia, northern 

 Germany, Poland, middle and southern Eussia, Greece, and other places in Europe. 



In Asia, it has been observed about Mount Lebanon and the Dead Sea, the Caucasus, 

 in Circassia and Georgia, and elsewhere; in northern and southern Africa; in South 

 America, along the Andes, and on the Pacific coast, occurring in Venezuela, in Peru, 

 at Concepcion in Chili, in the Chilian Andes at the passes of the Portillo and Rio Vol- 

 can, at an elevation of 9,000 to 14,000 feet, in the Straits of Magellan at Fort Famine 

 in Fuegia. 



The Cretaceous formation occurs also in Queensland (northeast Australia), and in 

 Victoria, west of Flinders river. It also exists in North Greenland, where some of the 

 fossil leaves are identical in species with European. 



II. Life. 



The Life of the Cretaceous period in Europe resembled that of 

 America, but was far more abundant. 



