302 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



stones and gypsums. The infra-Lias holds intercalated ill 

 marine strata a series of estuarine beds with thin coal-seams, 

 and the succeeding members of the Jurassic series show 

 many evidences of having been deposited in shallow waters 

 and near the shore. The whole Jurassic group has an ag- 

 gregate thickness of over 3000 feet, and is succeeded uncon- 

 formably by the Cretaceous, which, though not over 200 feet 

 thick, is of great interest to American geologists. Above the 

 Upper Greensand beds are sandstones with small coal-seams, 

 succeeded by a thin layer of white chalk with flints and vari- 

 ous silicified organisms. These are overlaid by argillaceous 

 beds with coal-seams and plant-remains, which, according to 

 Judd, are the remains of Cretaceous beds newer than anything 

 hitherto found in Great Britain, or else are to be regarded 

 as beds of passage between the Cretaceous and Tertiary. He 

 points out the resemblances in the conditions of deposition 

 between these and the Cretaceous of North America, and 

 shows that the great estuarine deposits of the Hebrides de- 

 monstrate the former presence of land in the present North 

 Atlantic area. He concludes that not only the Highlands, 

 but the larger part of the remainder of the British Islands, 

 were once overlaid by great deposits of secondary strata, 

 which have been subjected at different times to enormous 

 denudation, and that the principal surface-features of the 

 Highlands were produced in Pliocene times. 



TERTIARY STRATA. 



We have noticed the great thickness of the Tertiary stra- 

 ta in India, amounting to four or Ave miles. It would ap- 

 pear that they are not less in the Mediterranean region. The 

 Eocene is here but imperfectly developed, but the united 

 thickness of the Italian Miocene and Pliocene is, according 

 to Carl Meyer, between 22,000 and 23,000 feet. The great 

 importance and duration of the Tertiary age in geology is 

 becoming better understood. 



Late borings at the Citadel at Charleston, S. C, have 

 sriven us further information regarding the Tertiaries of the 

 Atlantic coast. The Cretaceous beds were reached at 950 

 feet, and were still found at 1870, at which depth the pres- 

 ence of debris of decomposing granite indicates probably 

 the base of the Cretaceous. It is there overlaid by 250 feet 



