Briggs, Reginald Peter <br/><br/>
Provisional geologic map of Puerto Rico and adjacent islands 
by Reginald P. Briggs ; prepared in cooperation with the Commonwealth of Puerto Rico, Economic Development Administration, Industrial Research Department. 
, Scale 1:240,000  (W 68⁰00'--W 65⁰15'/N 18⁰30'--N 17⁰55'). 
 - Washington, D.C.  U.S. Geological Survey  1964. 
 - 1 map  38 x 128 cm., on sheet 83 x 140 cm., folded in envelope 30 x 24 cm. 
 - Miscellaneous geologic investigations  map I-392 .
<br/><br/> Inset: Map showing relative accuracy of parts of the geologic map. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology--Maps.--Puerto Rico<br/>Maps--Puerto Rico--1964.
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Puerto Rico--Maps.