No. 15. — Notes on the Geology of the Island of Cuha, based vpon 

 a Eeconnoissance made for Alexander Agassiz. By Egbert 

 T. Hill. 



PAGE 



Letter of Transmittal 243 



Introduction 243 



I. Elementary Geologic Structure . . 24G 

 The Pre-Tertiar}', Metamorphic, 



and Igneous Foundation . 246 



The Pre-Tertiary Sedimentaries . 247 



The Tertiary Subsidence ... 248 



The Post-Tertiary Folding . . 253 



The Post-Tertiary Formations . 254 

 II. Geologic History recorded by the 



Topography 258 



General Topograph}" .... 258 



Topography of the Inland . . . 259 



The Topography of the Coasts . 264 



Terraces and Benches .... 267 

 The Soboruco or Elevated Reef 



Level 268 



Beach and Cliff Terraces . . 268 



The Cuchillas of Baracoa . . 269 

 Older Higher Levels of the 



Yunque Type .... 269 

 The Havana Levels .... 270 

 The ]\Ioro and Cantera Lev- 

 els ... 271 



The Matanzas Levels ... 271 



The Santiago Levels .... 274 

 Comparison and Correlation of 



various Levels 275 



Two Great Periods of Pleisto- 

 cene Regional Elevation . 275 

 The older Yunque Elevation 

 and succeeding Period 

 of Base Levelling . . 276 



PAGE 



The Modern or Tripartite Bench 

 Elevation and the Elevated 



Reef 276 



Inquiry into Evidences of Alter- 

 nating Subsidence .... 277 

 Absence of Upland Deposition 278 

 The Testimony of the Harbors 279 

 Absence of Fiords and Estu- 

 aries 280 



Absence of Terraced and Re- 

 vived Stream Valleys . . 280 

 III. Resume^ and Conclusion .... 282 

 History of the Island reviewed 282 

 Obscureness of Pre-Tertiary 



History 282 



Evidence of Jeep Marine 



Waters to North and 



South of Cuba during the 



two Cretaceous Epochs . 283 



Tertiary Subsidence regional . 284 



The Continental Shore during 



this Epoch 284 



The Orogenic Movement at 

 Close of Tertiary Time not 

 indicated in North Amer- 

 ican History 285 



Reflections on the Character of 

 the pleistocene Regional 



Uplifts 285 



Absence of known Evidence of 

 any former Union of the 

 Island with Continents . . 285 

 Description of Plates 287 



LETTER OP TRANSMITTAL. 



Washington, D. C, May 1, 1894. 



Dear Sir : — I beg to submit the following report upon my recent 

 studies in Cuha, undertaken at your expense and under your direction. 



I left Washington, D. C, Sunday, February 11, arriving at Havana 

 on the following Wednesday. A day was spent in Havana to ascer- 



VOI.. XVI. — NO. 15. 



