102 PRINCIPLES OF STRATIGRAPHY 



d. Prolongations of the basins or trough, comprising: 



(i) Embayment (G. Bucht, Fr. golfe). Semicircular 

 to triangular indentations of the land or of sub- 

 marine elevations. 

 (2) Gully (G. Rinnc, Fr. chcnal). Elongated indenta- 

 tions of like character. 



3. Sub-oceanic elevations, either independent, or submarine pro- 



longations of the land. 



a. Rise (G. Schzvellen, Fr. seuii). With very gradually as- 



cending sides. 



b. Ridge (G. Riicken, Fr. crcte). Prolonged elevations with 



steep sides. 



c. Plateau (G. Plateau, Fr. plateau). Elevations with steep 



sides and longitudinal and transverse dimensions of sim- 

 ilar extent. 



4. Deep (G. Tief, Fr. fosse). Abrupt depressions of the sea 



floor, e. g., Nero deep. 



5. Height (G. H'dh, Fr. haut). Abrupt elevations, generally on 



rises, ridges, or plateaus. 



//. Minor Features, or Those of Limited Extent. 



1. Elevations. 



a. Ridge (G. Riicken, Fr. crcte). Long ridges of minor 



character, generally with an irregular surface, rising and 

 falling. 



b. Submarine hill or peak. 



(i) Dome (G. Kuppe, Fr. dome). Small, steep-sided 

 elevations in depths of more than 200 meters. 



(2) Bank (G. Bank, Fr. banc). Elevations above 200 



meters but below 11 meters, e. g.. Porcupine Bank 

 west of Ireland ; Grand Bank south of Newfound- 

 land. 



(3) Reef or Shoal (G. Riff, Fr. rccif or haut fond). 

 » Elevations to within 11 meters or less of the 



surface. 



2. Depressions. 



a. Caldron (G. Kessel, Fr. caldeira). Steep-sided depres- 



sions of slight extent. 



b. Fiirroiv (G. Fur die, Fr. sillon). Canal-like depressions 



in the continental shelf, and more or less transverse to it, 

 e. g., Ganges furrow. 



