Stratigraphy and Tertiary Development of the Continental Margin East of Florida GEOLOGICAL SURVEY PROFESSIONAL PAPER581-F Prepared in cooperation with the Woods Hole Oceanographic Institution and the Joint Oceanographic Institutions' Deep Earth Sampling Program Stratigraphy and Tertiary Development of the Continental Margin East of Florida By JOHN SCHLEE DRILLING ON THE CONTINENTAL MARGIN OFF FLORIDA GEOLOGICAL SURVEY PROFESSIONAL PAPER 581-F Prepared in cooperation with the Woods Hole Oceanographic Institution and the Joint Oceanographic Institutions' Deep Earth Sampling Program UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1977 UNITED STATES DEPARTMENT OF THE INTERIOR CECIL D. ANDRUS, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress Cataloging in Publication Data Schlee, John Stevens, 1928- Stratigraphy and Tertiary development of the continental margin east of Florida. (Drilling on the continental margin off Florida) (Geological Survey professional paper; 581-F) Bibliography: p. 1. Geology, Stratigraphic-Tertiary. 2. Geology-Atlantic coast (United States) 3. Continental margins-Florida. I. Title. II. Series. III. Series: United States. Geological Survey. Professional paper; 581-F. QE691.S34 551.7'8'0916348 76-608370 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 Stock Number 024-001-02912-0 DRILLING ON THE CONTINENTAL MARGIN OFF FLORIDA Drilling on the continental margin off Jackson­ ville, Fla., in 1965 was the first project under­ taken by the Joint Oceanographic Institutions' Deep Earth Sampling (JOIDES) Program, sponsored by the National Science Foundation. The U.S. Geological Survey cooperated with the Oceanographic Institutions in this undertaking and is publishing the results of these investiga­ tions in a series of professional papers. CONTENTS Page Abstract ________________. Fl Introduction ______________________ 1 Descriptive stratigraphy __ ____ 5 Continental Shelf _____________ 5 Florida-Hatteras Slope _ _ 11 Blake Plateau ________________ 12 Paleontology _____________________ 16 Rate of sediment accumulation _ 16 Paleoecology _ ____________ 18 Tectonic setting and geologic history 19 References cited _________ 24 ILLUSTRATIONS Page PLATE 1. Stratigraphic profiles across the southeastern United States continental margin In pocket FIGURE 1. Index map of continental margin off eastern Florida __ F2 2. Map showing main tectonic features of the southern United States and bordering continental margin 3 3. Diagram showing interpretation of continuous seismic-reflection profiles collected across the continental mar­ gin along a line of four drill holes _________ 4 4. Stratigraphic sections to show the type of limestone and limy sediment of middle and late Eocene age cored in holes 1 and 2 _____________________ 6 5. Sketches of thin sections cut from rocks cored beneath the Continental Shelf 8 6. Sketches of the sedimentary structures in calcareous ooze of Oligocene age encountered in hole 5 11 7. Photomicrographs of thin sections from hole 4 and hole 3 13 8. Structure-contour map on the top of the Eocene Series _ 20 9. Schematic diagrams showing development of the Florida margin during the Cenozoic 24 TABLES Page TABLE 1. Estimates of the amounts of minerals in samples, based on X-ray diffraction by Hathaway (Hathaway and others, 1971, table IB) ________________________________ _ F9 2. Rates of sediment accumulation for selected biostratigraphic zones on the Blake Plateau and Florida-Hat­ teras slope __________________________ 17 3. List of calcareous nannoplankton indicative of nearshore shelf or basin milieu _ 18 VI CONTENTS METRIC-ENGLISH EQUIVALENTS Metric unit English equivalent Metric unit English equivalent Length Specific combinations Continued millimetre (mm) = 0.03937 inch (in) litre per second (1/s) = .0353 cubic foot per second metre (m) = 3.28 feet (ft) cubic metre per second kilometre (km) = .62 mile (mi) per square kilometre [(m3/s)/km2] Area square mile [(ft3/s)/mi2] metre per day (m/d) 3.28 feet per day (hydraulic square metre (m2) = 10.76 square feet (ft2) conductivity) (ft/d) square kilometre (km2 ) = .386 square mile (mi2) metre per kilometre hectare (ha) = 2.47 acres (m/km) = 5.28 feet per mile (ft/mi) kilometre per hour (km/h) = .9113 foot per second (ft/s) Volume metre per second (m/s) = ,'!.2S feet per second cubic centimetre (cm3 ) = 0.061 cubic inch (in3 ) metre squared per day litre (1) = 61.03 cubic inches (m2/d) = 10.764 feet squared per day (ft2/d) cubic metre (m3 ) = 35.31 cubic feet (ft3) (transmissivity) cubic metre = .00081 acre-foot (acre-ft) cubic metre per second cubic hectometre (hm3) r=S10.7 acre-feet (m3/s) = 22.826 million gallons per day litre = 2.113 pints (pt) (Mgal/d) litre = 1.06 quarts (qt) cubic metre per minute litre = .26 gallon (gal) (m3/min) = 264.2 gallons per minute (gal/min) cubic metre . .00026 million gallons (Mgal or litre per second (1/s) = 15.85 gallons per minute 106 gal) litre per second per cubic metre = 6.290 barrels (bbl) (1 bbl = 42 gal) metre [(1/s) /ml = 4.83 gallons per minute per foot [(gal/min) /ft] kilometre per hour Weight (km/h) .62 mile per hour (mi/h) gram (g) = 0.035 ounce, avoirdupois (oz avdp) metre per second (ni/s) = 2.237 miles per hour gram = .0022 pound, avoirdupois (Ib avdp) gram per cubic tonne (t) = 1.1 tons, short (2,000 Ib) centimetre (g/cm3) = 62.43 pounds per cubic foot (lb/ft3) tonne = .98 ton, long (2,240 Ib) gram per square centimetre (g/cm2) gram per square Specific combinations centimetre .0142 pound per square inch (lb/in2) kilogram per square centimetre (kg/cm2) = 0.96 atmosphere (atm) Temperature kilogram per square centimetre = .98 bar (0.9869 atm) degree Celsius (°C) = 1.8 degrees Fahrenheit (°F) cubic metre per second degrees Celsius (m3/s) = 35.3 cubic feet per second (ftD/s) (temperature) = [(l.SX°C)+32] degrees Fahrenheit DRILLING ON THE CONTINENTAL MARGIN OFF FLORIDA STRATIGRAPHY AND TERTIARY DEVELOPMENT OF THE CONTINENTAL MARGIN EAST OF FLORIDA By JOHN SCHLEE ABSTRACT dicated by a diminished rate of sedimentation (less than 1 Six holes drilled on the continental margin off eastern mm/1,000 years) in the lower Miocene and the excellent sort­ Florida reveal a continuity in age and a change in lithology ing of some of the deep-water oozes. between the rocks found offshore and those described from the Sediment-accumulation rates on the Blake Plateau and the Atlantic Coastal Plain. As on the land, pre^Miocene rocks are Florida-Hatteras Slope range from less than 1 mm/1,000 carbonate limestone and calcareous ooze. The ooze is a deep- years to 36 mm/1,000 years. The rate is highest on the slope water deposit found mainly under the Blake Plateau and (hole 5) and in the oldest rocks (Paleocene) cored on the Florida-Hatteras Slope; it is a clayey to sandy, faintly mottled Blake Plateau. The winnowing of younger sediment on the sediment composed of planktonic Foraminifera, coccoliths, Blake Plateau and the wide fluctuation of accumulation rates Radiolaria, fine-grained carbonate, and lesser amounts of clay, may indicate some shifting of the patterns of bottom cur­ ash, glauconite, and quartz. The limestone is a shallow-water rents over a period of time. The rates of sediment accumula­ grainstone and packstone under the shelf and siliceous car­ tion are similar to those noted by other investigators for deep- bonate mudstone under the Blake Plateau. Sediment of Mio­ water areas of carbonate sedimentation, and they are decided­ cene age grades from a mottled sandy silt and phosphatic ly less than those in noncarbonate depositional areas to the clay nearshore to a calcarenitic ooze under the Blake Plateau. north during the Quaternary. Nearshore, the Miocene Series appears to have accumulated in a restricted bay or lagoon; phosphate grains are concen­ INTRODUCTION trated in widespread distinct horizons and were transported In April and May 1965, six holes were drilled on prior to burial. On the Blake Plateau, a partially complete the continental margin off eastern Florida as the Miocene Series accumulated as a deep-water deposit, though the better sorting of the biogenetic debris suggests that the first project of the Joint Oceanographic Institutions' bottom was scoured by bottom currents perhaps the an­ Deep Earth Sampling Program (JOIDES) to sam­ cestral Florida Current. Post-Miocene sediment is 20-50 m ple the rock and sediment that compose the margin of shelly quartzose sand and silt on the shelf; seaward on (Emery and Zarudzki, 1967). The area (fig. 1) was the slope, it thickens to as much as 67 m of sandy to clayey selected because geophysical surveys indicated that calcareous ooze which unconformably overlies the Oligocene Series. significant parts of the stratigraphic section might Formations of Eocene and Miocene age beneath the Coastal be sampled and might expand our knowledge of the Plain continue seaward as recognizable units to the inner- geologic history of the margin. The purpose of this shelf hole (42 km offshore). Beyond, changes in lithology chapter is to discuss the lithology of the rocks pene­ make recognition of individual units difficult. trated in the six holes, in terms of the regional tec­ The stratigraphic sequence off eastern Florida is built over tonic framework as it evolved during the Tertiary. the Southeast Georgia embayment and the Blake Plateau trough. Except for minor warping on the inner part of the Topographically, the continental margin east of shelf during the Tertiary, the main structural framework Florida differs from the typical shelf-slope-rise (trough and basin) was already formed. The geologic record transition by the presence of a large deep-water preserved is mainly a complex pattern of sedimentation and plateau (Blake Plateau) that interrupts the Conti­ erosion over a gently subsiding margin. The broad outlines of bathymetry were already established by the beginning of nental Slope at a depth of 500-600 m (Uchupi, the Tertiary; that is, the present deep-water areas were 1968).