DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR BULLETIN 604: THE PHOSPHATE DEPOSITS OF FLORIDA BY GEORGE CHAKLTON MATSON WASHINGTON GOVERNMENT PRINTING OFFICE 1915 CONTENTS. Page. Classes and general form and features................ ...................... 7 History and production.................................................... 7 Distribution of phosphate deposits. ........................................ 9 General conditions.................................................... 9 Rock phosphate...................................................... 9 Land-pebble phosphate............................................... 10 River-pebble phosphate................................................ 10 Soft phosphate....................................................... 10 Geology.................................................................. 11 Nomenclature and lithology of the formations........................... 11 Tertiary system....................................................... 11 Oligocene series. .........................--.- -.--- ------- - - 11 Vicksburg group........................................'....... 11 Definition and subdivisions................................ 11 Lithologic character....................................... 12 Distribution.............................................. 12 Apalachicola group............................................ 12 Subdivisions.............................................. J 2 Chattahoochee formation................................... 13 Tampa formation......................................... 13 Lithologic character................................... 13 Distribution.......................................... 13 Alum Bluff formation..................................... 13 General features...................................... 13 Lithologic character................................... 14 Distribution.......................................... 15 Miocene series..................................................... 15 Subdivisions.................................................. 15 Ch.octawliatch.ee marl......................................... 15 Lithologic character....................................... 15 Distribution.............................................. 16 Jacksonville formation........................................ 16 Lithologic character........................................ 16 Distribution................................................ 18 Pliocene series.................................................... 18 Subdivisions.................................'................. 18 Caloosahatchee marl and Nashua marl.......................... 19 Age....................................................... 19 Lithologic character....................................... 19 Distribution................ .................................... 19 Alachua clay................................................. 20 Age....................................................... 20 Lithologic character........................................ 20 Distribution.............................................. 21 Bone Valley gravel............................................ 21 Age....................................................... 21 Lithologic character......:........................'........ 21 Distribution ......,,...........................<............ 22 3 4 CON'TENTS. Geology Continued. Page. Quaternary system................................................................ 22 Pleistocene series................................................. 22 Subdivisions................:................................. 22 Lithologic character.................,...-.............'......... 22 Distribution.................................................. 22 Recent series...................................................... 23 Character and occurrence of the deposits. .................................. 23 Kock phosphate...................................................... 24 Form and general features.......................................... 24 Matrix.....................................................'...... 25 Flint and limestone............................................... 26 Overburden...................................................... 26 Deformation..................................................... 27 Size and shape of deposits.......................................... 28 Thickness......................................................... 28 Local details of rock-phosphate deposits...;........................... 29 Newberry district.............................................. 29 Dunnellon district............................................ 31 Hernando and vicinity........................................ 32 Phosphate of Alum Bluff formation ("bedrock")........................ 33 Phosphate of Bone Valley gravel or land-pebble phosphate............... 35 Distinctive features................................................ 35 Animal remains. ................................................. 36 Quartz and chert..'............................................'.... 37 Overburden...................................................... 37 Size and shape of the deposits. .................................... 37 Thickness......................................................... 38 Local details...................................................... 38 Northern part of region......................................... 38 Mulberry and vicinity. ...........'............................. 40 Fort Meade and vicinity....................................... 42 Phosphatic marl...................................................... 44 Character and uses................................................ 44 Development at Fort Meade........................................ 45 River-pebble phosphate............................................... 45 Origin and age of the phosphates............................................ 45 General conclusions................................................... 45 Rock phosphates of the Vicksburg group................................. 46 Theories of origin................................................. 46 Types of rock phosphate discriminated............................. 49 Rock phosphate formed in place................. ................ 49 Redeposited phosphate............................................ 52 Source of the phosphoric acid....................................... 53 Phosphate of Alum Bluff formation ("bedrock ")........................ 58 Marine phosphatic nodules........................................ 58 Source of the phosphoric acid....................................... 63 Phosphate of Bone Valley gravel (land-pebble phosphate)............... 65 River-pebble phosphate............................................... 67 Topographic position............................................... 67 Source of phosphate............................................... 67 Rock phosphate....................................................... 68 Phosphates of Apalachicola group....................................... 68 Bone Valley gravel (land-pebble phosphate)............................. 69 River-pebble phosphate...................................,.../.....,. 69 CONTENTS. Composition of the phosphates.............................................. G9 Commercial requirements-............................................. 69' Rock phosphate....................................................... 70 Waste from rock phosphate............................................ 75 Phosphates of the Alum Bluff formation................................. 77 . Land-pebble phosphate................................................ 79 Waste from land-pebble phosphate................................'...... 82 Phosphatic marl...................................................... 83 River-pebble phosphate............................................... 83 Mineralogy................................................................ 84 Phosphate mining.......................................................... 89 Classes of phosphates mined.:.......................................... 89 Rock phosphate...................................................... 90 Stripping.......................................................... 90 Excavating....................................................... 90 Raising and washing.............................................. 91 Sorting........................................................... 91 Drying............................................................ 92 Waste products..... v ............................................ 92 Pebble phosphate. ........................'. ........................... 92 Stripping.......................................................... 92 Excavating....................................................... 93 Washing .......................................................... 93 Sorting........................................................... 94 Drying............................................................ 94 Waste products................................................... 94 Bibliography of Florida phosphates......................................... 95 Index.................................................................... 99 ILLUSTRATIONS. PLATE I. Map showing geology of the peninsular portion of Florida....... In pocket. II. General view of rock-phosphate mine............................. 8 III. Map showing the phosphate deposits of Florida..................... 10 IV. A, Bowlders