May 24, 1907] 



SCIENCE 



833 



practical engineers, the study of hygiene and 

 of scientific agriculture, and, last but not 

 least, for the adequate equipment and endow- 

 ment of that greatest of Oxford's academical 

 institutions, the ancient and world-renowned 

 library of Thomas Bodley's foundation. — The 

 London Times. 



CURRENT NOTES ON LAND FORMS 

 NARROW COASTAL PLAINS 



Well-defined land forms have an im- 

 portance in systematic physiography that is 

 not yet fully enough recognized by travellers. 

 Hence all the more satisfaction is felt when 

 an article gives so definite an account of such 

 a feature as a narrow coastal plain that it can 

 be easily appreciated by the reader. Such is 

 the case in the ' Notes on the Raised Beaches 

 of Taltal (Northern Chile),' by O. H. Evans 

 (Quart. Journ. Geol. Soc, LXIH., 1907, 64r- 

 68). 



The coastal plain at Taltal has a gently in- 

 clined surface, fringing the coastal ranges and 

 extending up the broader valleys to a con- 

 siderable altitude and distance from the pres- 

 ent shore. There is local variation in the 

 width of the plain, and in the altitude of its 

 inner border (200 feet, back of Taltal) along 

 the base of the moimtains. The surface of 

 the plain is thinly covered with angular frag- 

 ments from the hills ; but where sections reveal 

 its structure, it is seen to consist of stratified 

 sand and gravel, containing recent shells 

 which are sometimes plentiful enough to form 

 distinct beds. Here and there the subjacent 

 rocks rise thrftugh the plain in curiously 

 weathered remnants of former islets and 

 stacks. Evidence of intermittent uplift is 

 found in several terraces, three of which are 

 relatively well defined at altitudes of about 15, 

 80 and 200 feet above sea-level; two more ob- 

 scure terraces are seen at intermediate heights. 

 Where the mountains approach the sea and 

 the plain narrows, the terraces are replaced by 

 lines of boulders; at other points a rock 

 shelf and again a series of shallow caverns 

 marks the former shore line. Sudden uplifts 

 are inferred from the well-preserved condition 

 of the shells. Although no explicit statement 

 is made as to the relation of the larger in- 



land valleys to the plain, it may be inferred 

 from certain phrases that the valley floors are 

 now well opened somewhat below the plain sur- 

 face. Regarding the smaller ravines of the 

 old-land hills, it is said that their beds " sud- 

 denly alter in inclination and become pre- 

 cipitous as they approach the sea. Were 

 streams suddenly to start running in these 

 old gorges, they would terminate in water- 

 falls." Whether this sudden steepening is at 

 the former or at the present shore line, does 

 not clearly appear. 



Another narrow coastal plain is described 

 by W. D. Smith as forming an interrupted 

 rim around the mountainous island of Cebu, 

 and containing nine tenths of its large popula- 

 tion (' Contributions to the Physiography of 

 the Philippine Islands: I., Cebu Island,' 

 Philippine Journ. Sci., I., 1906, 1043-1059). 

 The basis of the plain is of coral rock, over 

 which alluvial deposits have been spread by 

 the streams and rivers from the interior val- 

 leys. 



Brief description of what appear? to be a 

 small and undissected coastal plain on which 

 Sidon is situated on the Mediterranean border 

 of Palestine, is given by Libbey and Hoskins 

 in their account of a journey to ' The Jordan 

 valley and Petra' (2 vols.. New York, Put- 

 nams, 1905). Its low and well-watered sur- 

 face has a ' carpet of green ' in strong con- 

 trast to the gray foot-hills which rise from its 

 inner border. A similar coastal or littoral 

 plain extends southward from the hills by 

 Beirut (see p. 66, frontispiece, and plate on 

 p. 41). I. B. AND W. M. D. 



GLACIAL TROUGHS AND HANGING LATERAL 

 VALLEYS 



In view of the ever-increasing volume of 

 evidence to the effect that every glaciated 

 mountain range in the world thus far studied 

 shows a systematic association of peculiar 

 features, such as valley-head cirques often 

 holding rock-basin tarns, over-deepened main- 

 valley troughs with floors of a considerable 

 width, hanging lateral valleys, and Piedmont 

 morainic amphitheaters, it is interesting to 

 scrutinize the statements of certain geologists 

 who still maintain that glaciers are ineffect- 



