66. What is the difference between lacustrine and fluvio-marine deposits? What is a delta?
67. Describe the geological action of frost. Describe the geological action of river-ice.
68. What are glaciers? What thickness do they attain in the Alps? What is their rate of motion? What are crevasses, and how do they originate? What are superficial moraines? What are terminal moraines? What changes does a glacier effect upon its bed, and how are these modifications produced? What is the character of a glacial river? What is the origin of icebergs? How is the general absence of blocks and stones in Greenland icebergs to be explained? What is the nature of a submarine terminal moraine? What is the ice-foot? What is the chief agent in distributing erratic stones and blocks over the sea-bottom? What effect upon the sea-bed must stranding icebergs produce?
69. What are some of the chemical compounds held in solution in sea-water? Which of these go to form the shells and skeletons of marine animals?
70. Describe the action of breakers on a sea-coast. How does frost aid the wasting action of breakers? What effect has the nature of the rocks in the production of inequalities in a coast-line? Upon what part of the sea-bottom does the material derived by the action of the breakers chiefly accumulate? What effect have the tides and ocean currents in the distribution of sediment?
71. What is the general rule as regards fine-grained and coarse-grained deposits? Mention a partial exception to this rule. What effect have tidal currents in shallow seas?
72. How are rocks disintegrated through the action of plants? What is peat? What may be inferred from the occurrence of shell-marl underneath peat? What does the appearance of roots and trunks of trees, and of remains of land animals under peat, indicate?
73. What, generally, is the geological action of animal life?
74. What is coral? What is a fringing reef? What is the general character of a barrier reef? Give an example of one. What is an atoll? What is the nature of coral rock? What is Mr Darwin's theory of the formation of coral reefs?