GEOLOGICAL SURVEY CIRCULAR 314

GEOLOGY OF THE WESTERN EVERGLADES AREA SOUTHERN FLORIDA

Prepared in cooperation with the Florida Geological Survey

UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary

GEOLOGICAL SURVEY W. E. Wrather, Director

GEOLOGICAL SURVEY CIRCULAR 314

GEOLOGY OF THE WESTERN EVERGLADES AREA, SOUTHERN FLORIDA

By Melvin C. Schroeder and Howard Klein

Prepared in cooperation with the Florida Geological Survey

Washington, D. C., 1954 Free on application to the Geological Survey, Washington 25, D. C.

CONTENTS

Page Page Introduction ...... 1 Geology Continued Purpose and scope of investigation 1 Pleistocene deposits ..... 5 Acknowledgments ...... 1 Fort Thompson formation . 5 Previous investigations ...... 1 Anastasia formation .... 5 Topographic-ecologic divisions . . . 1 Pamlico sand ...... 5 General features ...... 1 Recent deposits ...... 6 The Everglades ...... 1 Structural interpretation . . . 6 Big Cypress Swamp ...... 1 General features ...... 6 Sandy Flatlands ...... 4 Folding and faulting .... 6 Geology ...... 4 Solution and erosion .... 6 General features ...... 4 Ground-water occurrence . . . 7 Miocene deposits ...... 4 Correlation studies ...... 7 Tamiami formation ...... 4 General statement ..... 7 Pliocene deposits ...... 5 Logs of wells 1 to 43 ... 8 Caloosahatchee marl ...... 5 Fauna found in wells 1 to 43 19 Selected references ...... 25

ILLUSTRATIONS

Page Figure 1. Map of southern-Florida showing location of test wells and geologic cross sections ..... Facing 1 2. Geologic cross section along the sandy flatlands southeast of Lake Hicpochee ...... 2 3. Geologic cross section along the common margin of Big Cypress Swamp and the Everglades . . 3 mim. -^g_Jy - ^SEJU. -.- £n=r"» | *^5ialB T =^SSS D «^F^ C,

EXPLANATION

O TEST WELL

_ TEST WELL WITH

SCALE IN MILES 20 30

Figure 1. --Map of southern Florida showing location of test wells and geologic cross sections. GEOLOGY OF THE WESTERN EVERGLADES AREA, SOUTHERN FLORIDA

By Melvin C. Schroeder and Howard Klein

INTRODUCTION TOPOGRAPHIC-ECOLOGIC DIVISIONS Purpose and Scope of Investigation General Features During 1950, a series of 43 test wells 30 feet deep The line of tes*wells (see figure 1) crosses were drilled by the United States Corps of Engineers three relatively distinct topographic subdivisions. The along the western edge of the Everglades from the Tami- southern part of the line closely approximates the ami Canal northward to the Caloosahatchee River (see boundary between the Everglades and the Big Cypress figure 1). The cores obtained from the wells afford Swamp in western Dade and Broward Counties. In east­ geologic data along a line from the lower Everglades ern Hendry County, from the latitude of the Broward- of Dade County, where both the geology and water re­ Palm Beach County boundary, the line of test wells sources have been investigated, to the Caloosahatchee bears northward for about 20 miles along the western River area, where the surface geology has been stud­ edge of the Everglades, then northwestward across the ied. sandy flatlands to the western edge of Lake Hicpochee. Parker and Cooke (1944, p. 38-53) discuss these topo- This report has been prepared chiefly to record and graphic-ecologic divisions in detail, hence only a brief interpret the information obtained from the test wells. discussion is included in this report. It is one of a series prepared on ground-water investi­ gations by the United States Geological Survey, in co­ operation with the Florida Geological Survey. When The Everglades ground-water data become available they will be corre­ lated with the geology of this report and will be pre­ The Everglades is a region covered by black organic sented in a later report on the Glades-Hendry Counties soils. Although somewhat indefinite, the boundary be­ area. A few generalized inferences concerning ground tween the Everglades and the areas to the east and west water are made. is generally placed where the saw grass (sedges) of the Everglades is replaced by true grasses or cypress. The investigation was under the general supervision According to Parker and Cooke (1944, p. 48), the lime­ of A. N. Sayre, Chief, Ground Water Branch, U. S. stone which floors the Everglades is highest in the Geological Survey, Washington, D. C., and Herman vicinity of the Miami Canal, 4 miles east of well 24, Gunter, Director, Florida Geological Survey, and under and slopes gently to the southern mar gin and northward the direct supervision of Nevin D. Hoy, District Geolo­ toward LakeOkeechobee. The rock floor is composed gist, U. S. Geological Survey, Miami, Fla. of fresh-water and marine lime stone sand partially in­ durated marl of the Fort Thompson formation. Although the Miami oolite was not observed in any of the test Acknowledgments wells, it occurs as a thin layer overlying the Fort Thompson formation in the southern part of the Ever­ The U. S. Corps of Engineers granted permission glades. to examine cored material from test wells. Garald G. Parker, C. Wythe Cooke, and F. Stearns MacNeil of the U. S. Geological Survey, and R. O. Vernon of the Big Cypress Swamp Florida Geological Survey, assisted in interpreting the geology at the various formation type localities and in To the west, the Everglades merges with the Big identifying fossils. Cypress Swamp, which is a poorly defined region of al­ ternating swamp and hammock areas. The elevation in general is slightly higher than the Everglades, but Previous Investigations lower than the sandy flatlands on the north. The higher portions, where soils are aerated, support the growth Numerous geological studies have been made in the of palmettos, pines, and bunch grasses, but the lower areas which terminate the line of test wells. The area areas are marked with typical swamp growth of small covered in this report is included in the investigations cypress and sedges. In contrast with the Everglades, by Parker and Cooke (1944) who presented geologic the surface material is mainly limestone and sandstone, descriptions and correlations with a discussion of but there are numerous small areas where thin marly ground-water resources. In a later paper, Parker deposits lie at the surface. The geology, as interpret­ (1951) revised the stratigraphic correlations of the for­ ed from the well cores, pertains only to the eastern mations. edge of the Big Cypress Swamp. B

o o f o o

& ~ 20 13

RECENT SOILS

FORT THOMPSON^) FORMATION

FORT THOMPSON!?) FORMATION

TAMIAMI FORMATION \ TAMIAMI^-

Figure 2. --Geologic cross section along the sandy flatlands southeast of Lake Hicpochee. T18 D

FORT THOMPSONS) FORMATION

o o s oi o o so oI I d

THOMPSON*?) FORMATION 5V CO

UNOIFFERENTIATEO PLIOCENE OR PLEISTOCENE TAMIAMI FORMATION

\

TAMIAMI FORMATION

Figure 3. --Geologic cross section along the common margin of Big Cypress Swamp and the Everglades. GEOLOGY OF THE WESTERN EVERGLADES AREA Sandy Flatlands At Sunniland, Collier County, and Buckingham, Lee County, the Tamiami formation is about 50 feet thick. The northern extremity of the line of test wells In Dade County, according to Parker (1954r), the forma­ crosses the sandy flatlands, which is slightly higher tion has a relatively uniform thickness of about 100 feet. than the Everglades and the Big Cypress Swamp but does not exceed 25 feet. The sands were deposited as Lithology. --The Tamiami formation changes later­ part of the marine Pamlico sand of Pleistocene age and ally from shelly marl, as typified at Buckingham, to are dotted with small shallow ponds and poorly defined soft silty limestone at Sunniland, to the silty sand and marshy areas, one of which is the Devil's Garden. clayey marl that underlies Dade County. The hard Drainage is chiefly underground through the permeable sandy limestones of Mansfield's (1930, p. 8) type lo­ sand with very little, if any, surface runoff. calities along the Tamiami Trail were not encountered among the subsurface materials of the core line. The lithologic characteristics of the Tamiami formation as GEOLOGY noted in the cores are as diversified as the lithology between the areas of its known distribution. Cream to General Features white soft limestone and clayey marl are the common constituents, but shell marl and silty sand are also The materials penetrated by the test wells range in present in colors ranging from white and cream to age from late Miocene through Recent; the oldest forma­ green. tion is the Tamiami formation of late Miocene age. Organic soils are still being formed in parts of the Age. --The Tamiami formation overlies the Haw­ Everglades area. The Miami oolite of Pleistocene age thorn formation at every locality where the Hawthorn occurs as a thin discontinuous veneer near the south end has been penetrated in this area. Hoy and Schroeder of the line but apparently was not penetrated by any of (1953, personal communication) reported that the the wells. The late Miocene to Recent geologic forma­ Tamiami formation is overlain unconformably by the tions in the area of the report are listed in the table Caloosahatchee marl of Pliocene age along Alligator below. Creek in Charlotte County. The Buckingham and Tami­ ami limestones, referred by Mansfield (1939, p. 8-16) to the late Miocene and Pliocene, respectively, were Miocene Deposits tentatively placed by Parker and Cooke (1944, p. 59-65) in the Pliocene, equivalent in age to the Caloosahatchee Tamiami Formation marl. Parker (1951, p. 822-823) subsequently recog­ nized the Buckingham marl and the Tamiami limestone Definition. --The Tamiami formation, as redefined to be different facies of the same formation of late Mio­ by Parker (1951, p. 823), includes all deposits of the cene age, for which he retained the name Tamiami. upper Miocene in southern Florida. Thus, it includes the Tamiami and Buckingham limestones of Mansfield The faunal assemblage of the Tamiami formation (1939, p. 8-16) and the upper part of the material as­ commonly contains the mollusks Ostrea disparilis, signed to the Hawthorn formation by Parker and Cooke Chione ulocyma, and Turritella pontoni, which, F. (1944, p. 98-112). Stearns MacNeil(1951, personal communication)states, "..... are not only characteristic upper Miocene spe­ Development. --The Tamiami is the only Miocene cies, but they represent groups that have no known post- formation penetrated by the test wells. The top of the Miocene relatives, at least in this part of the world. " Tamiami formation (see figs. 2, 3) is an undulating The echinoid Encope macrophora tamiamiensis, ac­ surface which varies as much as 25 feet in elevation cording to Cooke (1942, p. 20-21), is not known in any within a distance of Smiles. Thisunevenness indicates other beds except what are now called the Tamiami that the upper part has been subjected to erosion. The formation. deposition of the Caloosahatchee marl on top of and along the flanks of erosional remnants indicates that the A specimen of Ecphora quadricostata umbilicata Tamiami was dissected prior to Pliocene deposition (Wagner) found in the marl along the Caloosahatchee and again during the Pleistocene. Apparently the deeper River at Banana Creek also indicates that the Tamiami valleys were developed during the Pleistocene. formation is of late Miocene age.

Formations Penetrated by Test Wells

Thickness Age Formations (feet) Character

Recent and Pleistocene Organic soils and Lake Flirt marl. 0 9 Undifferentiated peat, muck, and fresh-water marl. Pleistocene Pamlico sand (shore at +25 feet). 0 9 Gray to brown sand. Fort Thompson formation. ' 3 9 Alternating marine and fresh- water limestone and marl. Anastasia formation. 0 - 25? Marine sand, coquina, and sandy limestone. Pliocene Caloosahatchee marl. 0 - 20 Shells, sand, and marl.

Miocene (late) Tamiami formation. 50 - 100 Silty sand and marl. GEOLOGY Pliocene Deposits are the predominant constituents along the line of test wells. The occurrence of limestone in the Fort Thomp­ Caloosahatchee Marl son and Tamiami formations appears to be related to fluctuations of the water table accompanied by cementa­ Definition. --The shell beds exposed along the upper tion with calcium carbonate. reaches of the Caloosahatchee River were recognized in 1887 as Pliocene, but it was not until 1909 that Matson Age. Parker and Cooke (1944, p. 94-96) correlated and Clapp (1909, p. 123) adopted the name Caloosa­ the beds at old Fort Thompson with the inferred fluc­ hatchee marl for the beds. The Matson and Clapp defi­ tuations of sea level during the Pleistocene epoch. nition has since been generally used. Fresh-water beds have not bee"n reported in the Pliocene of the Atlantic Coastal Plain, land they do not occur in Development. --The Caloosahatchee marl apparently the Caloosahatchee marl (Pliocene) in the outer op are a, is present in southern Florida as discontinuous erosion although fresh-water shells are found, in places, mixed remnants. The most continuous exposures occur as with the marine forms. Any sequence of marine and thin beds along the Caloosahatchee and other rivers fresh-water beds,or fresh-water beds, older than the along the southwest Florida coast. The formation is at Lake Flirt marl is considered as representing the Fort least 10 feet thick along the Caloosahatchee River and Thompson formation. may be as much as 20 feet thick near Lake Hicpochee.

Lithology. --The Caloosahatchee marl consists pre­ Anastasia Formation dominantly of shells, sand, and silt. Freshunweathered exposures are generally pale cream-colored to light Definition. --The Anastasia formation was named by gray, although green clay marls near LaBelle have been Sellards (1912) from outcrops of coquina on Anastasia included in the formation. Green silty sands or sandy Island, near St. Augustine, Fla. Cooke and Mossom marls included in the Caloosahatchee along the line of (1929, p. 199) expanded this definition to include all the the test wells appear to be restricted to the flanks of marine deposits of Pleistocene age underlying the low­ the hills of the Tamiami formation. Probably the est plain bordering the east coast of Florida, excluding greenish elastics are redeposited green clay marls of the Key Largo limestone and the Miami oolite. Parker the Tamiami formation. The sand and shell variations and Cooke (1944, p. 66) defined the formation as fol­ of the Caloosahatchee marl can be separated from the lows: "The Anastasia formation as here defined in­ marine formations of Pleistocene age only by identifi­ cludes the coquina, sand, sandy limestone, and shelly cation of the mollusk faunas. marl of pre-Pamlico Pleistocene age that lies along both the Florida east and west coasts. " Age. --Dall (1890-1903) recognized 639 species of mollusks, of which, according to Cooke(1945, p. 216), Development. -- The pre-Pamlico deposits at the half are not yet extinct. Mansfield (1939, p. 27-28) north and south ends of the line of test wells are defi­ lists 40 of the more characteristic species which he nitely assigned to the Fort Thompson formation. The collected from the marl. Both Mansfield and Dall ac­ deposits of Pleistocene age between wells 10 and 33 cepted the original designation of the age of the marl as have been questionably identified as the Fort Thompson Pliocene. formation. Thin marine sandstones of the Anastasia formation, which are present along the southwest coast, extend as a tongue into Collier and Hendry Counties. Pleistocene Deposits In northeast Collier County and southeast Hendry County this marine sandstone has been found within 4 to 6 miles Fort Thompson Formation of the line of testwells. The strata of Pleistocene age between wells 10 and 33, tentatively assigned to the Definition. --The alternating fresh-water and marine Fort Thompson formation, apparently are transitional marls and limestones exposed at Fort Thompson were between the Fort Thompson and Anastasia tormations. initially named the Fort Thompson beds by Sellards (1919, p. 71-72). Cooke and Mossom (1929, p. 211- Lithology. --The typical coquina of the Anastasia 215) later named this sequence the Fort Thompson for­ formation in the type locality does not occur -in the mation and indicated that the beds lie unconformably on western part of southern Florida. Sand, shell beds, the Caloosahatchee marl and are overlain by the Lake marl, and calcareous sandstone are the most common Flirt marl of Pleistocene and Recent age. materials. Development. --The Fort Thompson formation at the Age. --Fossil evidence is not adequate for deter­ type locality is about 6 feet thick. In the Miami area it mining the age of the materials in the test wells that attains a maximum thickness of 80feet and constitutes may be Anastasia but are assigned to the Fort Thomp­ the major part of the Biscayne aquifer as described by son. The geologic cross sections, however, suggest Parker (1951, p. 820-823). The southern 18 miles of that the deposits are of Pleistocene age. Elsewhere in the line of test wells is approximately the western southern Florida, molluscan faunas establish a Pleis­ boundary of the Biscayne aquifer. In this area the Fort tocene age for the Anastasia formation. Thompson formation ranges from 3 to 9 feet in thick­ ness. The strata of Pleistocene age between wells 10 and 33 possibly are transitional beds between the Fort Pamlico Sand Thompson and Anastasia formations. Definition. --The Pamlico sand was extended from Lithology. --The Fort Thompson formation is com­ the typical locality in North Carolina by Parker and posed of sand, marl, shell marl, sandstone, and lime­ Cooke (1944, p. 74-75). They include in it all the ma­ stone of fresh-water and marine origin. Marl and sand rine deposits of Pleistocene age younger than the 6 GEOLOGY OF THE WESTERN EVERGLADES AREA Anastasia formation. These deposits are referable to solution and slumping, and erosion. In interpreting terrace materials deposited during a+25-foot stand of the cross sections, all these items are considered and the sea during the Pleistocene. therefore, even though they are diverse, they are grouped together in this discussion. Development. --The Pamlico sand occurs along the test-well line only in the sandy flatlands of Hendry County, where its maximum thickness is about 9 feet. Folding and Faulting

Lithology. The Pamlico sand is generally gray or Most surface structural interpretations are based brown. It is composed of quartz. upon the identification and attitude of sedimentary structures such as bedding, ripple marks, swash Age. --The sand that is referred to the Pamlico in marks, rill marks, and mud cracks in recognizable southern Florida lies unconformably upon the Miami beds. However, of these features only bedding has been oolite and Fort Thompson and Anastasia formations, found in the sediments in southern Florida. Bedding all of Pleistocene age, and upon the Caloosahatchee is not common in exposures of the Tamiami formation marl of Pliocene age and the Tamiami formation of or the Caloosahatchee marl, though locally it can be late Miocene age. The Lake Flirt marl and deposits recognized by thealinementof fossils. In some places of Recent age of peat and muck overlie the Pamlico indivii ual beds of the Pleistocene formations can be sand. Cooke (1952, p. 43) refers the Pamlico to a identif ad. Surface observations of the beds and indi­ marine shoreline at 25 feet above sea level, which he cations of stratification suggest that the beds of the (1952, p. 51) correlates with the third interglacial formations ranging from late Miocene to Pleistocene stage (Sangamon). are horizontal or dip so slightly, that the attitudes are determinable only by detailed plane-table or spirit- level surveying. Recent Deposits Subsurface structural determinations are based The deposits that have accumulated since the end of upon identification of formations and contacts by differ­ the Wisconsin glacial stage are Recent. These include ences of lithology or fossils. It is preferable to base organic soils of the Everglades and the Lake Flirt structural maps upon conformable contacts rather than marl, though their development may have started in erosion surfaces. All the contacts shown in the cross late Wisconsin time. The marl and the parent material sections of this report appear to be unconformable. of most of the soils accumulated in fresh water. The contacts between the formations observed in sur­ face exposures in Charlotte, Glades, Hendry, and Lee The test-well line follows the western margin of the Counties are all unconformable. Stratigraphic zones Everglades and in many places the peat and muck are that can be used as markers are not recognizable by sandy. The gray Lake Flirt marl is penetrated by only means of either lithology or fossils. a few wells, although its occurrence in the Everglades is common. The conditions of deposition are similar The data neither prove nor disprove that any of the to those that existed in the Everglades area prior to the beds are folded or faulted. If the beds shown in the digging of the drainage canals. cross sections are folded, the flexures are very slight. Faulting, if it is present, involves minor displacement. Parker and Cooke (1944, p. 20) supposed that the The major subsurface structure of Florida, the Pen­ Lake Flirt marl was deposited during late Wisconsin insular arch, was formed during theMesozoic, accord­ (fourth glacial stage) and Recent time, starting after ing to Applin (1951, p. 3-5), and the Ocala uplift, a the recession of the sea from the level of +25 feet to a surface feature cresting in Citrus and Levy Counties, level below the present sea level. Cooke (1952, p. 43) was formed during the early Miocene, according to infers that sea level in the third glacial epoch was be­ Vernon (1951, p. 53). Vernon (1951, pis. 3, 4) indi­ low the present level, rose to +25 feet in Pamlico time, cates by cross sections in central and northern Florida dropped to +6 feet during formation of the Silver Bluff that there has been no faulting in post-Hawthorn time. terrace, and then regressed to below present sea level Major structural disturbances therefore antedate the during the Wisconsin ice advance. F. Stearns MacNeil Tamiami formation and so could not have deformed the (1950, p. 104) tentatively correlates the Silver Bluff younger deposits of southern Florida. shoreline with the peak of the Recent interglacial stage. Obviously, it is difficult to determine which parts of E. W. Bishop (1953, personal communication), the Lake Flirt marl were deposited in the late Wiscon­ however, believes that topographic and geomorphologic sin and which in the Recent. However, most of the ma­ evidence indicates faulting and tilting of the Pleistocene terial was deposited in the Recent, and all post-Pamlico marine terraces in Highlands County. The authors' fresh-water marl deposits are included in the Lake opinion, based upon the available data, is that the late Flirt marl. All fresh-water limestones or marls older Miocene to Recent deposits discussed in.this report than the Pamlico sand are included in the Fort Thomp­ have not been folded or faulted. Parker and Cooke son formation. (1944, p. 19) suggest that there may have been a late Pliocene westward tilting of the Floridian Plateau.

Structural Interpretation Solution and Erosion General Features There are several places along the core line, such Structural interpretation of the geologic cross sec­ as at well 7, where sinkhole development is a possible tions.in this report seems to be restricted to the pos­ explanation of the structure indicated by the formation sible alternatives and combinations of folding, faulting, contacts. Parker and Cooke (1944, p. 29-33) report GEOLOGY on three sinkhole lakes: Deep Lake in Collier County, large areas are inundated and surface flow to the south Rocky Lake in Hendry County, and Still Lake in Lee occurs in both the Big Cypress Swamp and the Ever­ County. The diameters of these lakes range from 300 glades. Generally, the greatest surface flow into and to about 1, 000 feet. The greatest depth of Still Lake is across the Tamiami Canal occurs near Monroe Station about 213 feet below the land surface, in an elliptical (14 miles west of the Dade-Collier County line) during chimney 20 to 40 feet in diameter. The chimney prob­ September and October. The concentration of the'run- ably extends down through limestones of the Tamiami off commonly migrates eastward and by midwinter it formation into the Hawthorn formation. Deep Lake, is within 10 miles of the coastal ridge. The main fac­ midway between Sunniland and Everglades, is in lime­ tors related to this migration are rainfall and the vari­ stone of the Tamiami formation, the greatest depth ation and difference in storage of ground and surface being 97 feet below the land surface. Rocky Lake, water. The Everglades area is underlain by the very which is about 11 miles west of well 20, is about 50 feet permeable Biscayne aquifer, whereas the Big Cypress deep, although there may be a chimney which was not Swamp is floored by materials of low permeability. detected by the preliminary sounding. A driller's log Therefore, ground-water flow to the south is less in from a nearby well suggests that soft limestone of the the Big Cypress Swamp than in the Everglades. The Tamiami formation extends to about 65 feet in depth. water table in the Big Cypress Swamp is generally The limestone does not appear to be a major constituent nearer to land surface than in the Everglades, and, of the Tamiami formation along the core line, and it because of the small ground-water storage capacity, seems probable that the limestone section that predomi­ surface flow starts in the swamp soon after the rainy nates at Sunniland andlmmokalee makes up less of the season begins. Also, because of the slightly greater Tamiami formation as one progresses eastward. The slope of the land surface, the capacity for the storage absence of sinkholes along the core line may be attrib­ of surface water in the swamp is less than that in the uted to the thinness of the limestone there. Everglades. As ground-water storage increases in the glades area, the water table rises above land surface The top of the Tamiami formation varies as much as and flow increases with the concentration of the flow 25 feet in elevation within a distance of 8 miles. This moving eastward. unevenness was probably produced by erosion rather than by deformation. The Caloosahatchee marl and Fort Thompson and Anastasia formations were deposit­ Correlation Studies ed on this preexisting erosion surface, and erosion followed the deposition. The Pamlico sand was deposit­ General Statement ed on an eroded surface. The correlations illustrated in the cross sections The position and shape of the beds shown in the cross (figs. 2, 3) are based chiefly on lithologic similarity sections of this report appear to be the result of depo­ of the sediments. Vertical changes in lithology, al­ sition and erosion. Folding and faulting are believed though usually gradational, take place rapidly. There not to be the cause of the configuration of the beds. is almost no horizontal continuity of the beds, which makes exact correlation impracticable. Exposures of all of the formations along and near the western edge Ground-Water Occurrence of the Everglades are scarce and therefore are of little use in substantiating the correlations. The southern part of the line of test wells is near the western edge of the Biscayne aquifer (Parker, 1951, The section which follows contains the logs of the 43 p. 820-823); the Fort Thompson formation and younger test wells drilled by the U. S. Engineers. Each test deposits of Pleistocene age constitute the Biscayne aq­ well was drilled to a depth of 30 feet; thus the bottoms uifer over much of Dade County. About 25 miles west of the wells range from 8.5 feet below mean sea level of the line of test wells, near Sunniland and east of in well 3 in northern Hendry County to 22 feet below Immokalee, the Tamiami formation becomes highly mean sea level in well 41 near the Tamiami Canal. permeable and is an excellent aquifer. In that general Also included is a list of macrofossils collected at area, soft fossiliferous limestones predominate over various depths throughout the 30-foot core sections. the silty sands of the formation. The highly permeable The lists were prepared by F. S. MacNeil of the U. S. limestones of the Fort Thompson formation thin out or Geological Survey. Collections were made wherever are missing, except possibly as solution-hole fillings a relatively large assemblage occurred; not all core in the Tamiami formation, in the vicinity of the Collie r- holes are represented because the arealdistribution of Dade County line. Although in many places boundaries shelly material was very inconsistent. If diagnostic of the Biscayne aquifer cut across geologic formations, fossils were noted, then that portion of the section was there appears to be little, if any, continuity in permea­ assigned to the indicated geologic age. Many of the bility between the Biscayne aquifer and the fossiliferous species listed are of long stratigraphic range and were limestones of the Tamiami formation in northern Col­ of little use in differentiating formations. Several lier County. forms occur in great numbers in both Pliocene and Pleistocene deposits; thus the boundary between the The available data concerning ground-water levels Caloosahatchee marl and the formations of Pleistocene in the area across which the test wells were drilled are age is usually indefinite unless a lithologic break or an very limited; however, a few general inferences can be unconformity is evident. Scarcity of these fossil forms made. Water levels in southeastern Hendry County and in certain assemblages from the lower parts of the northeastern Collier County rise during the autumn and holes may be considered negative evidence of Miocene are commonly highest in October. Similar fluctuations age. Unfortunately, identifiable specimens were not of water level occur in the Everglades, corresponding found in the cores in some critical areas. Boundaries to rainfall, which commonly is the greatest from June between formations are tentative, for the writers be­ through October. During periods of high water levels, lieve that other interpretations are possible. GEOLOGY OF THE WESTERN EVERGLADES AREA

LOGS OF WELLS 1 TO 43

Well 1 Well 3

Location and description Depth (feet I/) Location and description Depth (feet I/)

NWiNWi sec. 31, T. 42 S., NWiNWi sec. 16, T. 43 S., R. 32 E., Glades County. R. 32 E., Hendry County. Top of measured section (land Top of measured section (land surface) ...... +12.6 surface) ...... +21.5

Pamlico sand: Pamlico sand: Sand, fine to medium quartz, Sand, fine to medium quartz, carbonaceous, rust-brown . +12.0 gray ...... +17.3 Sand, fine to medium quartz, Sand, fine to medium quartz, slightly marly, dark brown . +8.2 dark brown ...... +16.7 Fort Thompson formation: Fort Thompson formation: Sand, fine to medium quartz, Sandstone, friable, calcareous, shelly, marly, tan (mainly case hardened, fossiliferous Chione cancellata) ...... +4.6 (mainly Chione cancellata), Limestone, fresh-water, hard, cream, top 0. 3 foot ...... +14.5 tan, shelly, tan to brown . . . +3.5 Sand, fine to medium quartz, Limestone, sandy, shelly slightly marly, cream..... +13.5 (mainly Chione cancellata), Sand, fine quartz, marly, shelly, cream ...... +2.6 cream; somewhat indurated Limestone, fresh-water, hard, to sandstone in lower part. . . +5.5 tan to brown; in part, a de­ Sand, fine quartz, silty, very posit filling a solution hole marly, shelly (Chione can­ in sandy, shelly lime stone of cellata), cream ...... +4.0 the Caloosahatchee marl . . . -2.4 Sand, fresh-water, quartz, very Caloosahatchee marl: marly, silty, fine, shelly, Marl, sandy, very shelly (mainly cream ...... +1.5 Chione cancellata), cream . . -6.6 Marl, sandy, fossiliferous, Shell marl, silty, sandy, gray . . -15.4 shelly (Chione cancellata with a few fresh-water gastropods), cream ...... -1.5 Well 2 Marl, sandy, shelly (fresh-water gastropods), cream ...... -3.5 Center of sec. 6, T. 43 S., Caloosahatchee marl: R. 32 E., Hendry County. Marl, clayey, shelly, brown . . . -8.5 Top of measured section (land surface) ...... +18.4 Well 4 Pamlico sand: Sand, fine to medium, shelly NWiNWi sec. 22, T. 43 S., (mainly Chione cancellata), R. 32 E., Hendry County. brown ...... +10.0 Top of measured section (land Fort Thompson formation: surface) ...... +21.5 Sand, fine to medium quartz, slightly marly, very shelly Pamlico sand: in top 0. 5 foot, tan to buff . +8.0 Sand, fine to medium quartz, Marl, very shelly, very sandy, gray ...... +20.0 tan to cream; in part indu­ Sand, fine to medium quartz, rated to sandstone ...... +4.9 dark brown ...... +13.0 Sandstone, hard, porous, fos- Fort Thompson formation: siliferous, marine(?), tan . +3.4 Sand, medium to coarse quartz, Limestone, fresh-water(?), tan to cream ...... +10.0 dense, hard, shelly, tan . . +2.0 Sand, fine quartz, silty, shelly, Caloosahatchee marl: cream ...... +7.5 Sand, silty, marly, very Sandstone, fine, silty, cal­ shelly (Chione cancellata careous, fossiliferous, abundant), cream to tan . . .. -11.6 cream ...... +6.5 Sand, fine quartz, shelly, slightly silty, cream to tan . -5.5 I/ Datum is mean sea level. Sand, coarse quartz, some quartz granules ...... -8.5 LOGS OF WELLS Well 5 Well 7

Location and description Depth (feet I/) Location and description Depth (feet I/)

NW^NWi sec. 24, T. 43 S., SE^SEi sec. 36, T. 43 S., R. 32 E., Hendry County. R. 32 E., Hendry County. Top of measured section (land Top of measured section (land surface)...... +19.4 surface) ...... +19.4

Pamlico sand: Recent organic soils: Sand, carbonaceous, dark Muck, sandy, black ..... +18.5 gray ...... +18.2 Sand, mucky, black ..... +16.0 Sand, slightly marly, shelly, Pamlico sand: dark brown, locally cream . +14.4 Sand, fine to medium quartz, Fort Thompson formation: gray to tan ...... +14.0 Marl, sandy, indurated, Sand, fine to medium quartz, shelly, cream ...... +13.0 white ...... +12.0 Sand, fine quartz, silty, marly, Sand, fine quartz, white to shelly, tan ...... +8.8 cream ...... +9.4 Sandstone, friable, silty, very Fort Thompson (?) formation: shelly, cream ...... +6.7 Sand, fine quartz, silty, Sand, fine to medium quartz, slightly marly, slightly shelly, tan ...... +4.4 shelly, tan ...... +7.3 Sand, fine quartz, slightly Sand, fine to medium quartz, shelly, granules of quartz, very silty, very shelly, in lower part, cream .... -.6 tan ...... +4.4 Limestone, with coarse grains Sand, fine quartz, slightly and granules of quartz and shelly, tan to cream . . . -5.6 some pebbles; shelly and Shell marl (shells are worn some friable sandstone in and smooth), sandy, silty, lower part, cream...... -5.6 grayish-cream...... -7.0 Sand, fine to coarse quartz, Sand, fine to coarse quartz, marly, slightly shelly, some quartz granules, cream ...... -10.6 shelly, cream to white . . -10.6

Well 6 Well 8

SW^SWi sec. 25, T. 43 S., NEiNE? sec. 7, T. 44 S., R. 32 E., Hendry County. R. 33 E., Hendry County. Top of measured section (land Top of measured section (land surface) ...... +20.9 surface) ...... +20.6

Pamlico sand: Pamlico sand: Sand, fine to medium, light Sand, fine to medium quartz, gray ...... +19.0 tan ...... +17.5 Sand, fine to medium, tan . . +17.0 Sand, fine to medium quartz, Fort Thompson formation: rust ...... +15.8 Sand, fine to medium quartz, Fort Thompson formation: slightly marly, shelly, Marl, sandy, somewhat in­ cream to light gray .... +16.2 durated, tan ...... +14.4 Sand, fine quartz, marly, Limestone, fossiliferous cream ...... +15.9 (many Chione cancellata Sand, fine to medium quartz, preserved as molds), tan shelly (Chione cancellata), to brown ...... +13.5 light gray ...... +15.0 Marl, sandy, shelly (Chione Marl, clayey, sandy, gray cancellata), gray to tan . . +12.6 and cream ...... +14.0 Sand, fine quartz, very shelly Limestone, sandy, soft, fos- (Chione cancellata), silty, siliferous, gray ...... +12.3 gray ...... +7.5 Marl, clayey, sandy, shelly, Caloosahatchee marl: cream ...... +11.7 Sand, fine quartz, slightly Sand, fine to coarse quartz, shelly, silty, tan, orange marly, cream to tan . . . +10.9 to light gray ...... +1.5 Sand, fine to medium quartz, Tamiami formation: tan ...... +.9 Marl, clayey, slightly sandy, Sandstone, friable, very cal­ shelly, greenish-tan to careous, fossiliferous, cream ...... -5.6 white to cream...... -9.1 I/ Datum is mean sea level. 10 GEOLOGY OF THE WESTERN EVERGLADES AREA Well 8--Continued. Well 10--Continued.

Location and description Depth (feet I/) Location and description Depth (feet I/)

Tamiami formation--Continued. Tamiami formation: Sand, very marly, shelly, Marl, clayey, very shelly, light greenish-tan .... -8.0 tannish-green ..... -4.0 Marl, very sandy, shelly, Marl, clayey, sandy, very greenish-gray ...... -9.4 shelly, greenish-gray . -6.7 Marl, very sandy, clayey, shelly, cream ..... -8.7 Well 9 Sand, fine quartz, clayey, light greenish-gray . . -9.9 NW^NWl sec. 10, T. 44 S., R. 33 E., Hendry County. Top of measured section (land Well 11 surface) ...... +19.0 SWiSWi sec. 7, T. 44 S., Pamlico sand: R. 34 E., Hendry County. Sand, fine to medium quartz, Top of measured section (land tan ...... +15.0 surface) ...... +17.4 Caloosahatchee marl: Sand, fine to medium quartz, Pamlico sand: shelly, rust ...... +12.3 Sand, fine to medium quartz, Sand, fine quartz, marly, gray ...... +12.4 silty, shelly, cream..... +8.0 Fort Thompson (?) formation, Marl, clayey, slightly sandy, and Caloosahatchee marl (un- phosphatic, shelly, cream . +5.0 differentiated): Marl, clayey, very shelly, Sand, fine quartz, very marly, cream ...... +2.0 slightly shelly, tan to rust . +7.4 Tamiami formation: Sand, fine quartz, silty, Marl, sandy, clayey, slightly slightly marly, very shelly, shelly, cream to light tan ...... +2.4 grayish-green ...... -1.0 Sand, fine quartz, silty, marly, Marl, very sandy, phosphatic, very shelly, greenish-brown -1.3 very shelly, gray ...... -4.0 Tamiami (?) formation: Marl, very sandy, very shelly Sand, fine quartz, silty, marly, (mainly fragments), grayish- clayey, light tannish-green . -3.3 tan ...... -11.0 Sand, fine quartz, clayey, silty, marly, light olive- green...... -7.0 Well 10 Sand, fine to medium quartz, silty, greenish-gray..... -12.6 NWiNWi sec. 14, T. 44 S., R. 33 E., Hendry County. Top of measured section (land Well 12 surface) ...... +18.6 SWiSWi sec. 9, T. 44 S., Pamlico sand: R. 34 E., Hendry County. Sand, fine to medium, organic, Top of measured section (land dark brown ...... +16.6 surface) ...... +16.4 Fort Thompson (?) formation: Sandstone, friable, silty, Recent organic soils: shelly (Chione cancellata), Peat, dark brown ...... +9.4 rust-yellow ...... +15.1 Pamlico sand: Limestone, very sandy, fos- Sand, fine to medium quartz, siliferous (pectens and carbonaceous, black .... +8.4 Chione cancellata), tan . . . +12.6 Fort Thompson (?) formation: Sandstone, fine, calcareous, Sandstone, calcareous, friable, friable, slightly fossilifer- shelly, gray ...... +5.9 ous, cream ...... +12.1 Undif f e rentiated: Caloosahatchee marl: Sand, fine to medium quartz, Marl, sandy, very shelly silty, cream to white .... +4.5 (oysters), cream ...... +5.1 Sand, fine to medium quartz, Shell marl, sandy, cream . . . +4.0 rust-yellow ...... +3.4 Sand, fine quartz, very Sand, fine to medium quartz, silty, marly, shelly, cream- white ...... -13.6 gray ...... +. 1 I/ Datum is mean sea level. LOGS OF WELLS 11 Well 13 Well 15--Continued.

Location and description Depth (feet I/) Location and description Depth (feet I/)

SWiSW| sec. 21, T. 44 S., Pamlico sand: R. 34 E., Hendry County. Sand, medium, light gray Top of measured section (land to brown ...... +16. 4 surface) ...... +17.3 Fort Thompson (?) formation: Sand, fine to medium quartz, Recent organic soils: white ...... +15.7 Peat, dark brown ...... +13.9 Sand, dark brown; "hardpan"..... +14. 4 Pamlico sand: Sand, fine to medium quartz, Sand, fine to medium quartz, rust-brown...... +13.7 tannish-gray ...... +13.5 Sand, fine to medium quartz, Sand, fine to medium quartz, brown ...... +10.2 dark brown...... +11.6 Sand, medium to coarse quartz, Fort Thompson (?) formation: brown ...... +6.7 Sand, fine to medium quartz, Sand, fine quartz, slightly tan; locally indurated to marly, silty, tan ...... -1.7 friable sandstone ...... +10.4 Sand, fine quartz, silty, Sand, fine, silty, tan to buff . . +1.0 brown ...... -3.6 Tamiami formation: Sand, fine quartz, grayish- Sand, fine quartz, silty, shelly, tan ...... -11.3 cream; some fine phosphatic Sand, fine to medium quartz, grains ...... -2.7 silty; cream to light gray ..... -12.7 Sand, fine quartz, silty, tan to greenish-gray ...... -9.0 Sand, fine to medium quartz, Well 16 silty, very shelly, brown to green; lower part indurated NW{NWi sec. 4, T. 46 S., to greenish-gray sandstone, R. 34 E., Hendry County. containing a few small peb­ Top of measured section (land bles of phosphate ...... -12.7 surface) ...... +18.3 Recent organic soils: Well 14 Sand, quartz, carbonaceous, black ...... +16.3 SE{SEi sec. 8, T. 45 S., Fort Thompson (?) formation: R. 34 E., Hendry County. Sand, quartz, carbonaceous, Top of measured section (land dark brown...... +14.9 surface) ...... +17.9 Sand, fine to medium quartz, rust-brown ...... +11.3 Pamlico sand: Sand, fine quartz, marly, Sand, fine to medium quartz, silty, light gray to cream . . +7.3 brown ...... +15.9 Marl, clayey, light cream to Fort Thompson (?) formation: white ...... -2.0 Limestone, sandy, hard, Marl, very sandy, shelly, tan to brown ...... +15.0 white to light cream . . . . . -3.0 Marl, very sandy, cream . . +14.2 Tamiami formation: Sand, fine to medium quartz, Sand, fine quartz, very marly, very marly, silty, cream . +10.2 shelly, green-brown. . . . . -5.6 Sand, fine quartz, silty, rust- Sand, as above, except very yellow ...... +8.7 shelly, green-tan; phosphate Sand, fine quartz, silty, buff +7.2 granules at -6. 0 mean sea Sand, fine to medium quartz, level ...... -8.9 light gray ...... -12.1 Sand, fine to medium quartz, marly, shelly, green-brown -11.7

Well 15 Well 17 SWiSWi sec. 21, T. 45 S., R. 34 E., Hendry County. SWiSWi sec. 9, T. 46 S., Top of measured section (land R. 34 E., Hendry County. surface) ...... +17.7 Top of measured section (land surface) ...... +16.2

\J Datum is mean sea level. Recent organic soils and marls: Peat, brown...... +15.3 Marl, sandy, gray ...... +13.2 12 GEOLOGY OF THE WESTERN EVERGLADES AREA Well 17 Continued. Well 19 Continued.

Location and description Depth (feet I/) Location and description Depth (feet I/)

Fort Thompson (?) formation: Fort Thompson (?) formation: Marl (Chione cancellata), Sand, fine to medium quartz, yellow; indurated, sandy tan to brown ...... +11.1 in part ...... +10. 2 Sand, fine to medium quartz, Limestone, dense, hard, marly, shelly, brown ...... +8.5 rust-yellow ...... +8.6 Sandstone, fine quartz, cal­ Sand, fine to coarse quartz, careous, fossiliferous shelly (Chione cancellata), (casts and molds), cream ..... +1.0 marly, cream ...... +7.4 Tamiami formation: Marl, clayey, sandy, shelly, Sand, fine quartz, marly, white to cream...... +3.3 silty, phosphatic, cream ..... -4.0 Tamiami formation: Sandstone, fossiliferous (casts), Marl, clay, shelly, tan to porous, calcareous, tan...... -4.8 cream ...... +1.0 Marl, very sandy, silty, shelly, Sand, very marly, tan to cream ...... -6.4 greenish-tan; some granules Marl, very sandy, shelly, tan .... -8.5 and small pebbles of black Sand, fine to medium quartz, phosphate ...... -10.0 marly, brown ...... -11.5 Marl, sandy, fine quartz, Sand, slightly marly, silty, silty, slightly shelly, green greenish-brown ...... -14.5 to brown ...... -14.4

Well 20 Well 18 SWiSWi sec. 9, T. 47 S., SWiSWi sec. 21, T. 46 S., R. 34 E., Hendry County. R. 34 E., Hendry County. Top of measured section (land Top of measured section (land surface) ...... +15.5 surface) ...... +15.8 Recent organic soils: Recent organic soils: Sand, carbonaceous, brown Peat, dark brown ...... +14. 8 to black ...... +12.5 Sand, mucky, black ...... +11.5 Fort Thompson (?) formation: Fort Thompson (?) formation: Sand, coarse to medium quartz, Marl, sandy, yellow; in part rust-brown...... +10.7 indurated, cream ...... +9.8 Sand, fine to medium quartz, Sandstone, coarse to very shelly, silty, tan to cream .... +9.7 coarse quartz, friable, Sand, coarse quartz, very shelly silty, slightly shelly, (Chione cancellata), tan; some cream to white ...... +8. 8 small quartz pebbles ...... +8.5 Sand, fine to medium quartz, Sand, medium to coarse quartz, marly, cream ...... +3. 8 tan to cream ...... +6. 0 Tamiami formation: Sand, medium to coarse quartz, Sandstone, calcareous, fos- slightly shelly, white ...... +2.1 siliferous, friable, silty, Sand, fine to medium quartz, cream to white ...... -.2 marly, silty, slightly shelly, Sand, very marly, fossilif- light gray to cream ...... -6. 4 erous, cream to white; in Sand, fine quartz, very silty, part indurated to friable phosphatic, brown ...... -9. 5 sandstone ...... -10.5 Sand, shelly, fine to medium Sand, fine to medium quartz, quartz, tan...... -11.3 shelly, tan ...... -13.5 Sand, fine quartz, shelly, phos­ Marl, sandy, brown ...... -14.4 phatic, marly, silty, tan ..... -14.5

Well 19 Well 21

SWiSWi sec. 33, T. 46 S., NE'iSWi sec. 22. T. 47 S., R. 34 E., Hendry County. R. 34 E., Hendry County. Top of measured section (land Top of measured section (land surface) ...... +15.5 surface) ...... +14.6 Recent organic soils: Recent organic soils: Peat, dark brown . +13.5 Sand, brown; top part con­ tains organic material. +12.1 Jt/ Datum is mean sea level. Sand, carbonaceous, black +11.1 LOGS OF WELLS 13

Well 21--Continued. Well 23--Continued.

Location and description Depth (feet I/) Location and description Depth (feet I/)

Fort Thompson (?) formation: Fort Thompson (?) forma­ Sand, coarse quartz, rust- tion--Continued. brown ...... +9.6 Sand, medium to coarse Sand, fine to medium quartz, quartz, slightly silty, marly, light gray ...... +5.2 shelly, cream to Sandstone, calcareous, porous, white; some phos­ fossiliferous, light gray to phate granules ..... +.7 cream; in part friable ..... +3.3 Sand, fine to medium Sand, fine to coarse quartz, quartz, marly, slightly very marly, cream ...... +1.5 shelly, tan ...... -4.0 Sandstone, calcareous, fossil­ Sand, fine quartz, silty, iferous, friable, cream .... -1.1 slightly marly, brown . -5.6 Sand, fine quartz, silty, marly, Sand, fine quartz, slightly cream; contains very small silty, tan to brown , . -16.6 phosphate specks ...... -3.5 Marl, very sandy, cream .... -5.1 Sand, fine quartz, marly, very Well 24 shelly, cream ...... -7.5 Sand, fine to medium quartz, NW^NWi sec. 10, T. 48 S., marly, light gray ...... -9.4 R. 35 E., Broward County. Sand, fine to medium quartz, Top of measured section (land marly, silty, cream to tan . . -15.4 surface)...... +13.9 Recent organic soils and marls: Well 22 Peat, mucky, dark brown . . . +9.6 Marl, slightly sandy, gray . . . +9.0 SWiNEi sec. 35, T. 47 S., Fort Thompson (?) formation: R. 34 E., Hendry County. Marl, sandy, shelly, cream . . +5.9 Top of measured section (land Limestone, sandy, fossilif­ surface) ...... +14.0 erous, porous, tan to gray . +3.9 Marl, sandy, shelly, white to Recent organic soils: cream; some pieces of in­ Peat, brown...... +13.0 durated marl...... +.1 Sand, fine to coarse quartz, Limestone, soft, fossilifer­ carbonaceous, dark brown . +10.5 ous, white ...... -2.7 Fort Thompson (?) formation: Caloosahatchee marl: Sand, fine to coarse quartz, Marl, very sandy, shelly, brown ...... +9.7 with grains of black phos­ Marl, sandy, clayey, brown . +7.3 phate, cream ...... -3.7 Marl, sandy, cream ..... +4.5 Sand, fine to medium quartz, Sand, fine quartz, very marly, marly, very shelly, phos- cream ...... -3.5 phatic, cream to tan .... -8.0 Marl, sandy, shelly, cream Marl, very sandy, shelly, to light gray; in part indu­ cream to tan ...... -9.6 rated ...... -10.0 Sand, fine to medium quartz, Limestone, very sandy, fos­ marly, shelly, gray ..... -11.5 siliferous, porous, friable, Sand, fine quartz, very marly, tan to brown ...... -16.0 slightly shelly, tan to cream -18.1

Well 23 Well 25 NEiNEi sec. 12, T. 48 S., SW{SWi sec. 15, T. 48 S., R. 34 E., Hendry County. R. 35 E., Broward County. Top of measured section (land Top of measured section (land surface) ...... +13.4 surface) ...... +13.0

Recent organic soils: Recent organic soils and marls: Peat, dark brown ...... +12.4 Muck and peat, dark brown. +9.6 Peat and muck, sandy, Marl, brownish-gray .... +9.0 dark brown ...... +10.4 Fort Thompson (?) formation: Fort Thompson (?) formation: Limestone, sandy, fossilif­ Limestone, sandy, hard, cream erous, tan ...... +8.0 to brown; perforated by solu­ Marl, sandy, shelly, cream tion holes ...... +6.7 to white; in places indu­ I/ Datum is mean sea level. rated to limestone .... -5.2 14 GEOLOGY OF THE WESTERN EVERGLADES AREA Well 25--Continued. Well 27 Continued.

Location and description Depth (feet I/) Location and description Depth (feet I/) Caloosahatchee marl: Fort Thompson(?) formation-­ Marl, very sandy, and very Continued. marly sand, shelly, Marl, slightly shelly (casts greenish-brown to green -11.0 of shells, some Chione Sand, fine to medium quartz, cancellata), light gray- silty, marly, very shelly cream to white...... +2.3 (some Chione cancellata), Marl, very sandy, light cream ...... -17.0 cream-gray ...... +1.7 Marl, very sandy, shelly, cream; with some phos­ Well 26 phate granules ...... +.1 Caloosahatchee marl: SWiSWi sec. 27, T. 48 S., Sand, fine to very fine quartz, R. 35 E., Broward County. slightly silty, shelly (Chione Top of measured section (land cancellata), cream to light surface) ...... +12.5 tan ...... -12.3 Tamiami formation: Recent organic soils and marls: Sand, fine quartz, slightly Peat, brown ...... +7.1 shelly, marly, tan...... -12.9 Muck, sandy, black ..... +6.3 Marl, shelly, dark greenish- Marl, sandy, clayey, gray tan ...... -17.9 to tan...... +3.5 Fort Thompson (?) formation: Limestone, sandy, fossilif- Well 28 erous, porous, light cream to gray ...... +2.5 SW{SWi sec. 15, T. 49 S., Marl, sandy, shelly, light R. 35 E., Broward County. gray ...... +1.0 Top of measured section (land Caloosahatchee marl: surface) ...... +11.4 Sand, fine quartz, with some larger quartz granules, Recent organic soils: marly, shelly (some Chione Sand, mucky, carbonaceous, cancellata), buff ...... -4.7 dark brown to black .... +9.2 Tamiami formation: Fort Thompson (?) formation: Sand, fine to medium quartz, Marl, sandy, brown to tan . . +3.4 very marly, very shelly, Sand, very fine to fine brownish-gray; with quartz, slightly shelly, granules of phosphate, marly, silty, light brown black; at -5.0 feet mean to white ...... -2.6 sea level ...... -6.5 Caloosahatchee marl: Sand, fine to medium quartz, Sandstone, fossiliferous very marly, white to light (some molds of Chione cream, shelly; pebbles cancellata), calcareous, and granules of phosphate . -13.7 in part friable, tan to Marl, clayey, sandy, shelly, cream ...... -3.0 brownish-green ...... -17.5 Sand, marly, shelly, cream to white ...... -8.6 Sand, fine quartz, silty, tan . -11.6 Well 27 Tamiami formation: Marl, sandy, greenish-brown -18.6 SWiSWi sec. 3, T. 49 S., R. 35 E., Broward County. Top of measured section (land Well 29 surface) ...... +12.1 SW{SW{ sec. 27, T. 49 S., Recent organic soils: R. 35 E., Broward County. Peat, sandy, brown. . . . +10.6 Top of measured section (land Fort Thompson (?) formation: surface) ...... +11.1 Sandstone, calcareous, tan to brown ...... +9.1 Recent organic soils: Marl, slightly shelly, Peat, sandy, brown. . . . . +8.6 cream-tan ...... +7.6 Fort Thompson (?) formation: Sand, dark brown ...... +7.5 Marl, sandy, silty, cream . +4.0 I/ Datum is mean sea level. Sand, fine to medium quartz, very marly, cream ... +2.1 LOGS OF WELLS 15 Well 29--Continued. Well 31--Continued.

Location and description Depth (feet I/) Location and description Depth (feet I/)

Fort Thompson (?) formation-- Fort Thompson (?) formation: Continued. Sandstone, calcareous, Sand, fine to very fine quartz, fairly hard, tan ...... +8.0 silty, tan...... -2.9 Marl, very sandy, shelly, Sand, marly, cream ...... -6.2 cream ...... +5.5 Tamiami formation: Sandstone, calcareous, in Marl, sandy, fossiliferous, part friable, cream ...... +5.0 white; indurated to a fos­ Sand, fine, very silty, siliferous sandy lime­ marly, light cream; with stone in places...... -7.9 some concretions ...... -11.5 Sand, fine to very fine quartz, Tamiami formation: silty, cream ...... -13.7 Sandstone, calcareous, in Marl, silty, slightly shelly, part friable, slightly cream ...... -18.9 porous, fossiliferous, silty, light gray to cream gray ...... -20.0 Well 30

Western Broward County, 3 miles Well 32 east of the Collier County line and 12. 4 miles north of the Western Broward County, 2. 2 Dade County line. miles east of the Collier Top of measured section (land County line and 8. 6 miles surface) ...... +11.4 north of the Dade County line. Recent organic soils and marls: Top of measured section (land Soil, sandy, brown ...... +11.0 surface)...... +10.2 Marl, sandy, gray ...... +10.1 Fort Thompson (?) formation: Recent organic soils and marls: Sandstone, shelly, calcareous, Peat, muck, dark brown . . . +8.6 hard, rust-yellow ..... +9.9 Sand, carbonaceous, black . . +7.8 Marl, slightly sandy, fossilif­ Marl, clayey, brown to erous, indurated, cream . +9.0 gray ...... +6.8 Marl, slightly sandy, slightly Fort Thompson (?) formation: shelly, cream; locally in­ Marl, sandy, partially in­ durated ...... -1.0 durated, cream ...... +5.5 Sand, fine quartz, very silty Sand, fine to medium quartz, and marly, slightly shelly marly, white...... +.7 (some Chione cancellata), Sand, fine quartz, very cream ...... -6.9 marly, white...... -4.7 Tamiami formation: Tamiami formation: Sand, very marly, clayey, Marl, sandy, slightly shelly, shelly, brown to tan .... -15.0 white to cream...... -8.8 Marl, clayey, sandy, shelly, Marl, very sandy, shelly, greenish-tan ...... -18.6 cream; in places indurated to sandstone ...... -13.5 Marl, sandy, silty, greenish- Well 31 brown ...... -21.2 Western Broward County, 3 miles east of the Collier County line Well 33 and 10. 4 miles north of the Dade County line. Western Broward County, 2.0 Top of measured section (land miles east of the Collier surface) ...... +10.0 County line and 6. 8 miles north of the Dade County Recent organic soils and Lake line. Flirt marl (undifferentiated): Top of measured section (land Peat, sandy, dark brown; surface)...... +9.7 dark brown at base . . . +9.0 Sand, clayey, dark gray; Recent organic soils: possibly fresh-water . . +8.5 Peat, brown...... +9.1 Fort Thompson formation: Sand, brown...... +8.9 1 I/ Datum is mean sea level. Sandstone, hard, dense, tan to cream . . . . . +7.3 16 GEOLOGY OF THE WESTERN EVERGLADES AREA Well 33 Continued. Well 35

Location and description Depth (feet I/) Location and description Depth (feet I/)

Fort Thompson formation-- SWiNWi sec. 21, T. 51 S., Continued. R. 35 E., Broward County. Sandstone, very silty, cal­ Top of measured section (land careous, very friable, surface) ...... +9.2 cream ...... +4.0 Tamiami formation: Recent organic soils: Limestone, very sandy, Peat, brown ...... +7.9 fossiliferous (preserved Fort Thompson formation: by molds), cream to Limestone, sandy, dense, white; in places a fri­ hard, cavernous, slightly able sandstone ...... -12.5 shelly, tan to brown .... +5.0 Limestone, very sandy, very Sandstone, calcareous, po­ fossiliferous, soft, white . -15.3 rous, in part friable, tan Sandstone, shelly, calcare­ to dark gray ...... +3.2 ous, brown ...... -15.5 Tamiami formation: Sand, fine quartz, marly, Marl, sandy, fossiliferous silty, brown ...... -20.8 (similar to limestone in Sunniland pits), white to cream; in part indurated Well 34 to a soft limestone .... .0 Marl, very sandy, white to SWiNWi sec. 9, T. 51 S., light gray ...... -2.0 R. 35 E., Broward County. Sand, fine to medium quartz, Top of measured section (land silty, marly, slightly surface) ...... +9.4 shelly, buff to tan ..... -5.0 Sand, fine to medium quartz, Recent organic soils: very silty, marly, white . -6.8 Peat, brown ...... +8.8 Sandstone, calcareous, silty, Fort Thompson formation: very fossiliferous, in part Marl, slightly indurated, friable, cream...... -11.0 cream ...... +8.4 Marl, sandy, shelly, cream; Sandstone, very calcareous, in part cemented to a fri­ slightly shelly, dense, able, calcareous, silty hard, brown ...... +7.6 sandstone...... -12.8 Tamiami formation: Marl, sandy, shelly, cream Marl, sandy, slightly shelly, to buff ...... -13.5 in part indurated, tan .... +5.7 Limestone, soft, silty, fossil­ Marl, sandy, cream to tan . . . +3.5 iferous ...... -14.4 Marl, sandy, fossiliferous, Marl, sandy, shelly, cream . -18.8 in part indurated to a soft Marl, sandy, slightly shelly, sandy limestone, cream . . . +1.3 tan ...... -20.8 Marl, sandy, cream; very shelly at top ...... -2.0 Sand, fine to medium quartz, Well 36 very shelly, buff to orange . -4.7 Marl, very sandy, shelly, SEiNWi sec. 33, T. 51 S., cream; in part cemented R. 35 E., Broward County. to calcareous sandstone . . . -8.4 Top of measured section (land Marl, sandy, cream; in part surface) ...... +8.9 shelly ...... -10.0 Marl, sandy, cream; in part Recent organic soils: cemented to sandy lime­ Peat, brown ...... +8.3 stone containing fossils Pamlico (?) sand: (mainly echinoids) ...... -12.6 Sand, marly, brown . . . . +7.2 Marl, slightly sandy, slightly Fort Thompson formation: shelly, cream ...... -15.7 Limestone, hard, sandy, Limestone, very soft, sandy, containing some gas­ silty, fossiliferous, porous, tropods (possibly fresh­ cream to white...... -19.6 water), light tan; possi­ Marl, sandy, shelly, cream . . -20.6 bly a deposit filling a cavity in underlying rock +6.7 Limestone, sandy, fossil­ _!/ Datum is mean sea level. iferous, marine, cream; in part friable ...... +.6 LOGS OF WELLS 17 Well 36--Continued. Well 38

Location and description Depth (feet I/) Location and description Depth (feet I/)

Pliocene (?) or Pleistocene (?), NWiNEi sec. 16, T. 52 S., undifferentiated: R. 35 E., Dade County. Sand, fine quartz, very Top of measured section (land marly, silty, white to surface) ...... +8.2 cream ...... -3.7 Tamiami formation: Recent organic soils: Sandstone, silty, calcareous, Peat and muck, sandy, fossiliferous, light gray; dark brown...... +7.6 in part very friable .... -6.4 Fort Thompson formation: Sand, fine quartz, very Limestone, sandy, dense, marly, silty, white .... -7.5 cream to tan ...... +4.5 Sand, fine to coarse quartz, Sandstone, calcareous, fos­ very marly, silty, cream . -10.3 siliferous, in part fria­ Marl, very sandy, fossilif­ ble, cream...... +1.6 erous, light gray to cream; Pliocene (?) or Pleistocene (?), in places locally indurated undifferentiated: to a fossiliferous sandstone -16.7 Marl, very sandy, slightly Marl, sandy, tan ...... -18.2 shelly, light gray to cream . Sand, fine, marly, tan to Sandstone, silty, calcareous, brown ...... -21.2 very friable, fossiliferous, cream to white...... Sand, marly, silty, cream to Well 37 white, fossiliferous; and white, calcareous, fossil­ SWiNEi sec. 9, T. 52 S., iferous sandstone from -3. 8 R. 35 E., Dade County. to -4.5 ...... -5.3 Top of measured section (land Tamiami formation: surface) ...... +8.7 Marl, very sandy, shelly, cream to white; in places Recent organic soils: indurated to a sandy fos­ Peat, brown ...... +7.4 siliferous limestone ..... -21.9 Muck, black ...... +6.3 Fort Thompson formation: Sandstone, calcareous, hard, Well 39 dense, tan to cream ..... +4.6 Marl, very sandy, silty, cream; SW|NW{ sec. 33, T. 52 S., in part indurated...... +2.1 R. 35 E., Dade County. Sandstone, calcareous, brown Top of measured section (land to tan...... +1.2 surface) ...... +8.0 Pliocene (?) or Pleistocene (?), undifferentiated: Recent organic soils: Sand, fine quartz, very marly, Muck and peat, dark brown. . +7.2 - silty, cream ...... -8.0 Fort Thompson formation: Sand, marly, silty, fine to Sandstone, hard calcareous, medium, tan ...... -10.4 tan to brown ...... +6.7 Tamiami formation: Marl, partially indurated, Limestone, very sandy, very light cream ...... +4.8 soft, friable, fossiliferous, Sandstone, calcareous, silty, cream to tan ...... -14.3 white to light gray; fairly Sand, shelly, calcareous, hard from +4. 8 to +2. 6; silty, tan...... -15.4 friable from +2.6 to +1. 4 . +1.4 Marl, sandy, shelly, grayish- Pliocene (?) or Pleistocene (?), cream; indurated to a soft undifferentiated: sandy limestone around Sand, medium to coarse the shells ...... -18.5 quartz, rust to light cream -7.0 Marl, silty, sandy, fossilif­ Sand, medium to coarse erous, brown; in part in­ quartz, white ...... -22.0 durated...... -21.7 Well 40 I/ Datum is mean sea level. SEiNEi sec. 8, T. 53 S., R. 35 E., Dade County. Top of measured section (land surface) ...... +7.4 18 GEOLOGY OF THE WESTERN EVERGLADES AREA Well 40 Continued. Well 41--Continued.

Location and description Depth (feet I/) Location and description Depth (feet I/)

Recent organic soils and Tamiami formation: Lake Flirt marl: Limestone, sandy, fossilif­ Peat and muck, dark brown. . . +6.8 erous, friable, white . . -15.3 Marl, sandy, gray to cream . . +6.2 Marl, shelly, sandy, in part Fort Thompson formation: indurated, white to cream -17.6 Limestone, sandy, hard, Marl, sandy, shelly, light dense, cream to brown . . . +4.8 gray to white; some gray, Marl, silty, sandy, tan. .... +2.4 very shelly limestone . . -20.8 Pliocene (?) or Pleistocene (?), Marl, sandy, shelly, tan to undifferentiated: cream ...... -22.9 Sand, fine to medium quartz, very silty, marly, cream . , -.4 Sand, fine to medium quartz, Well 42 slightly silty, buff ...... -1.5 Sand, fine to medium quartz, NEiNWi sec. 32, T. 53 S., marly, light gray ...... -4.9 R. 35 E., Dade County. Marl, very sandy, fossilifer- Top of measured section (land ous, light gray; in part in­ surface) ...... +8.1 durated, calcareous, fos- siliferous sandstone ..... -6.3 Recent organic soils: Sand, fine to medium quartz, Peat, dark brown ...... +7.9 very silty, grayish-tan; in Fort Thompson formation: lower part fine to coarse Limestone, sandy, silty, quartz sand ...... -8.5 soft, fossiliferous, cream; Sand, fine to medium quartz, in places an indurated light orange to rust ..... -10.7 marl ...... +5.6 Sand, medium to coarse Limestone, marine, sandy, quartz, marly, white; some dense, hard, light tan . . . +4.7 friable fossiliferous sand­ Limestone, sandy, hard, stone from -14. 0 to -14-. 5 -17.0 dense, fresh-water (?), Sand, fine to medium quartz, dark gray ...... +4.0 slightly marly, shelly, Limestone, soft; indurated cream ...... - -19.2 marl, sandy, rust-yellow . +3.0 Tamiami formation: Limestone, fresh-water, Marl, very sandy, fossilifer­ sandy, hard, dense, tan. . +2.6 ous, white; in places indu­ Limestone, soft, sandy, rated to sandy limestone . -22.6 cream ...... -.8 Pliocene (?) or Pleistocene (?), undifferentiated: Well 41 Marl, sandy, cream to white . -3.0 Sand, fine quartz, marly, NWiNEi sec. 20, T. 53 S., tan to rust ...... -4.3 R. 35 E., Dade County. Sand, fine quartz, white to Top of measured section (land light gray ...... -6.9 surface) ...... +7.5 Sand, fine quartz, marly, very shelly (some Chione Recent organic soils and Lake cancellata), white ..... -9.2 Flirt marl: Tamiami formation: Muck and peat, dark brown. +7.1 Shell marl, silty, sandy, Marl, sandy, gray ..... +6.0 white ...... -10.4 Fort Thompson formation: Marl, sandy, shelly, cream Limestone, hard, slightly to tan ...... -21.9 shelly, tan ...... +5.0 Marl, sandy, tan to buff; a few concretions around Well 43 shell material ...... 0 Pliocene (?) or Pleistocene (?), SW|SWi sec. 5, T. 54 S., undifferentiated: R. 35 E., Dade County. Marl, sandy, shelly, white; Top of measured section (land lower part partially indu­ surface) ...... +7.7 rated ...... -12.5 Recent organic soils and Lake Flirt marl: I/ Datum is mean sea level. Muck and peat, dark brown, +7.1 Marl, clay, fresh-water, brown ...... +6.5 FAUNA FOUND IN WELLS 19 Well 43 Continued. Well 43 Continued. Location and description Depth (feet I/) Location and description Depth (feet I/) Fort Thompson formation: Pliocene (?) and Pleistocene (?), Sandstone, hard, calcareous, undif f e re ntiated: cream to brown; and lime­ Sand, fine to medium quartz, stone, hard fossiliferous, and friable sandstone, dark gray, as a cavity white to cream, both filling in sandstone (or the shelly ...... -4.7 reverse) from +5.5 to +5. 0 . . +4.1 Sandstone, calcareous, in Sandstone, calcareous, dense, part friable, silty, po­ fossiliferous, cream to rous, fossiliferous, gray ..... -7.5 tan ...... +3.7 Sand, silty, shelly, buff to Limestone, dense, hard, dark tan ...... -10.0 gray, as a cavity filling . . . . +3. 4 Tamiami formation: Sandstone, in part friable, Marl, sandy, silty, cream to cream ...... -1.1 white; in part indurated to sandstone; in places very _!/ Datum is mean sea level. shelly ...... -22.3

FAUNA FOUND IN WELLS 1 TO 43

Well 1 Well 1 Continued. Fossils and range Depth (feet I/) Fossils and range Depth (feet I/) Fresh-water limestone containing Unidentified fragments of a large Helisoma sp...... +4.2 oyster and other pelecypods. -12.0 Stratigraphic range: Fort Stratigraphic range: Formation Thompson formation. indeterminate. Serpula sp...... -1.0 "Vitrinellid". Well 2 Calyptraea centralis (Conrad). Turritella subannulata Heilprin. Natica canrena Linne. -3.0 Cerithium ornatissimum Heilprin. to -4.0 Mitra sp. Turritella subannulata Heilprin. Mitre lla sp. Cerithium sp. Marginella precursor Dall. Busycon pyrum (Dillwyn). Cancellaria conradiana Dall. Oliva sp. cf. O. carolinae Gardner. "Drillia" pogodula Dall. Terebra sp. aff. T. protexta Terebra concava Say. Conrad. Nuculana cf. N. acuta (Conrad). Acteocina. Arcopsis adamsi (Shuttleworth). Arcopsis adamsi (Shuttleworth). Anadara sp. (fragment). Anadara cf. A. transversa (Conrad). Ostrea cf. O. sculpturata Conrad Anomia sp. (fragment). Corbula sp. Phacoides (Parvilucina) multilin- Chione cf. (J. cribraria (Conrad). eatus Tuomey and Holmes. Chione cancellata Linne'. Phacoides (Bellucina) tuomeyi Cardita (Carditamera) floridana Dall. Gemma magna Dall. Venus sp. (fragment). Stratigraphic range: Caloosa- Chione cancellata Linne'. hatchee marl. Corbula sp. Stratigraphic range: Caloosa- hatchee marl.

I/ Datum is mean sea level. 20 GEOLOGY OF THE WESTERN EVERGLADES AREA Well 3 Well 9 Continued. Fossils and range Depth (feet I/) Fossils and range Depth (feet I/) Lunatia? sp...... +2.0 Marginella sp...... +4.0 Several genera of fresh-water Anadara transversa Say. gastropods. Mulinia cf. M. late rails (Say). Pecten sp. Stratigraphic range: Fort Ostrea sculpturata Conrad. Thompson formation and Phacoides (Belluclna) tuomeyi Caloosahatchee marl. Dall. Dosinia sp. Nuculana acuta (Conrad). .... -3.0 Cardium sp. Several genera of fresh-water gastropods. Stratigraphic range: Caloosa- hatchee marl. Stratigraphic range: Fort Thompson formation and, Natica cf. N. canrena (Linne). -2.0 possibly, Caloosahatchee Turritella cf. T. variabilis marl. Conrad. Cunearca cf. C>. scalaris (Conrad). Well? Anadara improcera (Conrad). Mulinia congesta (Conrad). Anadara improcera (Conrad). +6.0 Pecten sp. Mulinia congesta (Conrad). Chione (Lirophora) latilirata athleta Conrad. Stratigraphic range: Formation Chione cancellata Linne. indeterminate. Cardium sp. Turritella sp...... -6.5 Stratigraphic range: Tamiami Oliva cf. O. carolinae Gardner. formation. Arcopsis adamsi (Shuttleworth). Anadara sp. ''Solariella" sp...... -8.0 Mytilus. Arcopsis adamsi (Shuttleworth). Parastarte ? sp. Mytilus sp. Cardium sp. Ostrea sp. Cardita (Carditamera) sp. Stratigraphic range: Formation Venericardia (Pleuroineris) n. sp. ? indeterminate. Stratigraphic range: Tamiami formation. Well 8 Turritella subannulata Heilprin. . . +11.0 Well 11 Oliva cf. O. sayana Ravenel. Arneria. Epitonium sp...... +2.0 Dentalium. Cunearca sp. Anadara cf. A. transversa (Conrad). Anadara cf. A. delandensis Chione cancellata Linne" Mansfield. Dosinia sp. Mulinia lateralis (Say). Transenella? sp. Anomia sp. Ostrea sp. Stratigraphic range: Fresh-water Eontia variabilis MacNeil. and marine mixture of Fort Chione cancellata Linne*. Thompson formation and Ca­ loosahatchee (?) marl. Stratigraphic range: Caloosa­ hatchee (?) marl. Well 9 Well 13 Cerithium glaphyrea var. litha- rium Dall...... +12.5 Crepidula fornicata Say. .0 Marginella limatula Conrad. Turritella sp. (juvenile). Chione cancellata Linne\ Mitrella sp. Pleuroliria sp. (fragment). Stratigraphic range: Caloosahat­ Olivella sp. chee marl. Terebra dislocata Say. Acteon sp. I/ Datum is mean sea level. FAUNA FOUND IN WELLS 21 Well 13 Continued. Well 16--Continued. Fossils and range Depth (feet I/) Fossils and range Depth (feet I/) Ostrea sculpturata Conrad. Phacoides (Cardiolucina) mul- Phacoides (Lucinisca) cri- tistriatus (Conrad). brarius (Say). Chione cancellata Linne". Phacoides (Parvilucina) multilineatus (Tuomey Stratigraphic range: Tami- and Holmes). ami (?) formation. Chione cancellata Linne*. Stratigraphic range: Tami- Well 17 ami (?) formation. Tgrritella perattenuata Neverita cf. N. duplicata Heilprin...... -1.0 (Say)...... -10.0 Syrnola sp. Turritella sp. (juvenile). Opercula. Turritella variabilis Conrad. Nuculana acuta (Conrad). Serpula sp. Mulinia congesta (Conrad). trNassatr cf. N. consensa Phacoides (Bellucina) tuomeyi Ravenel. Dall. Marginella limatula Conrad. Gemma magna Dall. Marginella denticulata Conrad. Stratigraphic range: Formation Olive lla sp. indeterminate, possibly the *Cancellaria aff. (?. venusta Tamiami formation. Tuomey and Holmes. Conus sp. Drillia lunata (Lea). Well 18 Nuculana trochilia (Dall). Nuculana acuta (Conrad). Nothing identifiable +1,0 Anadara improcera (Conrad). Cunearca sp. Discinisca sp. ... -14.0 Mulinia congesta (Conrad). Mytilus sp. Stratigraphic range: Formation Pecten sp. cf. P. eboreus indeterminate. Conrad. Ostrea sculpturata Conrad. Dosinia sp. Well 22 Chione cancellata Linne*. Pecten sp...... -7.0 Stratigraphic range: Tamiami Arbacia sp. cf. _A. .waccamaw formation. Cooke (identified by C. W. Cooke). Stratigraphic range: Formation Well 16 indeterminate, though C. Wythe Cooke believes it is possibly Cerithium glaphyrea var. Pliocene. litharium Dall. .... -6.0 Marginella limatula Conrad. Oliva sp. Well 23 Opercula. Anadara improcera (Conrad). Cardita (Carditamera) sp. +2.0 Mulinia congesta (Conrad). Chione cancellata Linnd. Chione cancellata Linne. Stratigraphic range: Formation Stratigraphic range: Tami- indeterminate. ami (?) formation. Oliva cf. O. carolinae Well 25 Gardner...... -10.0 Anadara improcera (Conrad). Oliva sp...... -9.0 Mulinia congesta (Conrad). Abra aequalis (Say). Pecten eboreus Conrad var. ? Ostrea sp. Eucrassatella sp. Phacoides (Callucina) radians Conrad. Tellina sp. _!/ Datum is mean sea level. * More like specimens from Duplin marl at Stratigraphic range: Caloosa- Natural Well, N. C. hatchee (?) marl. 22 GEOLOGY OF THE WESTERN EVERGLADES AREA Well 25 Continued. Well 26 Continued. Fossils and range Depth (feet I/) Fossils and range Depth (feet I/) Helisoma sp. -12.0 Chione cancellata Linne. to -13.0 Bryozoa. Omphalius exoletus (Conrad). Turbonilla sp. Stratigraphic range: Caloosa­ Crepidula fornicata Say. hatchee (?) marl and Tami­ Calyptraea centralis (Conrad). ami (?) formation, possibly Polinices sp. a mixture. Turritella perattenuata Heilprin. Turritella cookei gladee*nsis Cerithium muscarum Say. Mansfield...... -5.0 Cerithium caloosae'nsis cf. Marginella sp. var. heilprini Dall. Nucula sp. Cerithium glaphyrea var. Nuculana acuta (Conrad). litharium Dall. Cardita TCarditamer a) arata Busycon sp. (juvenile). Conrad. Pyrazisinus scalatus Heilprin. Mulinia (juveniles). Urosalpinx perrugatus Chione sp. Conrad. Cardium sp. Nassa vibex Say. Mitrella n. sp. Stratigraphic range: Tami­ Operculum. ami formation. "Mitrella" sp. Marginella limatula Conrad. Turritella (juvenile). .... -7.0 Oliva sp. Cerithium (juveniles). Oliva cf. carolinae Gardner. Marginella limatula Conrad. ___7onus sp. (fragment). Oliva spT~(thick parietal Bulla striata BruguieVe. callus). Gemma sp. Mytilus sp. Anadara lienosa (Say). Anadara sp. Cardita (Carditamera) Pecten cf. P_. eboreus (juvenile). Conrad. Phacoides (Pseudomiltha) Venericardia (Pteromeris) anodonta (Say). pe rplana"7 Conrad). Chione (Lirophora) latilirata Gemma magna Dall. athleta Conrad. Chione (Athleta). Chione cancellata Linne*. Chione (Lirophora) latilirata Dosinia sp. (fragment). athleta Conrad. Cardium (Trachycardium) sp. Chione cancellata Linne'. Cardita (Carditamera) sp. Stratigraphic range: Probably a Dentalium sp. mixture of Caloosahatchee Barnacle. marl and Tamiami formation. Stratigraphic range: Tami­ ami (?) formation. Well 26 Nuculana trochilia(Dall)...... -17.0 Turritella sp. cf. T. perattenuata Heilprin...... 0 Stratigraphic ranger Tami­ Cerithium n. sp. aff. C. callisoma ami formation. Dall. Nassa ambigua Montagu var. antillarum d'Orbigny. Well 27 Olivella sp. Conus adversarius Conrad. Venus sp. +8.5 Acteocina sp. Nucula sp. Stratigraphic range: Formation Glycymeris pectinata (Gmelin). indeterminate. Phacoides (Bellucina) tuomeyi Dall. Epitonium sp...... +2.5 Gemma magna Dall. Pecten (Nodipecten?) sp. Phacoides (Parvilucina) cf. multilineatus (Tuomey and _!/ Datum is mean sea level. Holmes). Crassinella sp. FAUNA FOUNB IN WELLS 23 Well 27 Continued. Well 30 Continued. Fossils and range Bepth (feet I/) Fossils and range Bepth (feet I/) Venus sp. Acteocina sp. Chione ? sp. Pecten sp. Parastarte sp. Ostrea sp. Phacoides (Cardiolucina) cf. Stratigraphic range: Caloosa- trisulcatus multistriatus hatchee (?) marl. (Conrad). Transenella n. sp. Cerithium n. sp. aff . ca- Bosinia sp. loosaensis Ball...... +.1 Oliva sp. (thick parietal callus). Stratigraphic range: Formation Dentalium sp. indeterminate. Chione sp. (juvenile). Pecten sp. -5.0 Stratigraphic range: Caloosa- hatchee (?) marl. Stratigraphic range: Formation indeterminate. Turritella sp. cf. T. perat- tenuata Heilprin...... -4.0 Ostrea sculpturata Conrad...... -12.1 Cerithium n. sp. aff. C_. Phacoides (Cardiolucina) sp. caloosae'nsis Ball. Chione sp. Marginella limatula Conrad. Coral. *Oliva spT (thick parietal Barnacle. callus). Conus adversarius Conrad. Stratigraphic range: Tami- Operculum. ami (?) formation. Cunearca scalaris (Conrad). Parastarte sp. Dentalium sp...... -17.0 Phacoides (Parvilucina) cf. Nuculalp". crenulatus (Conrad). Pecten sp. Anomia sp. Corbula sp. Chione cancellata Linns'. Venericardia (Pleuromeris) Stratigraphic range: Formation decemcostata Conrad. indeterminate. Pelecypod sp. Atrina sp. Well 31 Stratigraphic range: Caloosa hatchee marl. Unidentifiable fragments of Pecten and barnacles. -9.5 Nuculana trochilia (Ball). -17.0 Pecten (Nodipecten?) sp. Stratigraphic range: Formation Venus? sp. indeterminate. Stratigraphic range: No definite Fragmental mold of large Cardita evidence that Miocene was cf. C_. arata Conrad...... -15.0 penetrated. Stratigraphic range: Tami- ami (?) formation. Well 29 Anomia sp...... -18.0 Well 33 Stratigraphic range: Formation Glycymeris sp. cf. subovata indeterminate. (Say)...... -1.0 Pecten cf. eboreus Conrad.

Well 30 Stratigraphic range: Tami- ami (?) formation. Turritella pontoni Mansfield. .0 Serpula sp. Olivella sp.

Datum is mean sea level. Same form occurs in Buplin marl at Natural Well, N. C. 24 GEOLOGY OF THE WESTERN EVERGLADES AREA Well 34 Well 36

Fossils and range Depth (feet I/) Fossils and range Depth (feet I/) Chione cf. (?. cancellata Turritella cookei gladee'nsis Linne*...... +5.5 Mansfield...... -11.0 Cardita (Carditamera) sp. Stratigraphic range: Tami- Stratigraphic range: Formation ami formation. indeterminate.

Pecten sp...... +1.0 Well 37 Phacoides (Here) densatus (Conrad). Fragment of large oyster. . . -18.0 Phacoides (Cardiolucina) sp. Mulinia cf. M. congesta Stratigraphic range: Tami- (Conrad). ami (?) formation. Transenella n. sp. Chione sp. Cardita (Carditamera) sp. Well 38 Encope sp. Ostrea sp...... -2.0 Stratigraphic range: Tami- ami (?) formation. Stratigraphic range: Formation indeterminate. Phacoides (Cardiolucina) cf. trisulcatus multistriatus Pecten eboreus Conrad...... -7.0 (Conrad)...... -3.0 Ostrea sp. Transenella n. sp. Venericardia (Pleuromeris) Stratigraphic range: Tami- decemcostata Conrad. ami (?) formation. Bryozoa. Barnacle. Anomia sp...... -12.0 Pecten sp. Stratigraphic range: Tami- Encope sp. ami (?) formation. Stratigraphic range: Tami- Parastarte sp...... -7.0 ami (?) formation. Phacoides (Here) densatus Conrad. Pecten sp...... -16.0 Phacoides (Cardiolucina) cf. Echinoid fragments. trisulcatus multistriatus (Conrad). Stratigraphic range: Tami- Venericardia (Pleuromeris) ami (?) formation. decemcostata Conrad. Echinoid fragments...... -21.0 Barnacle fragments. Stratigraphic range: Tami- ami formation. Stratigraphic range: Tami- ami (?) formation. Unidentified gastropod...... -11.0 Pecten sp. Encope sp. Well 41

Stratigraphic range: Tami- Ostrea sculpturata Conrad. -3.0 ami formation. Chione aff. £. cancellata Linne'. Turritella sp. aff. T. variabilis Cardita (Carditamera) sp. Conrad...... -17.0 (juvenile). Pecten sp. (gibbus var. ?). Stratigraphic range: Forma­ tion indeterminate.

\J Datum is mean sea level. Cardita (Carditamera) sp...... -15. 0 Stratigraphic range: Forma­ tion indeterminate. SELECTED REFERENCES 25 Well 41--Continued. Well 43--Continued.

Fossils and range Depth (feet I/) Fossils and range Depth (feet I/)

Anadara sp...... -20.0 Pecten sp...... -15.0 Ostrea sculpturata Stratigraphic range: Forma­ Conrad. tion indeterminate. Donax fossor Say. Transenella n. sp. Venericardia (Pleuromeris) Well 42 decemcostata Conrad. Cardium cf. C. robustum Glycymeris sp...... -10.0 Solander. Ostrea sculpturata Conrad. Turritella cookei gladegnsis Transenella n. sp. Mansfield. Venericardia (Pleuromeris) Turritella pontoni Mansfield. decemcostata Conrad. Oliva mutica Say. Turritella pontoni Oliva sp. aff. sayana Mansfield. Ravenel. Turritella cookei gladeSnsis Mansfield. Stratigraphic range: Tami­ ami formation. Stratigraphic range: Tamiami formation. Ostrea sp...... -22.0 Venericardia (Pleurom- Glycymeris subovata (Say). -12.0 eris) decemcostata to -16.0 Conrad. Ostrea sculpturata Conrad. Turritella cookei gladee'nsis Phacoides (Cardiolucina) Mansfield. trisulcatus multistriatus Turritella pontoni (Conrad). Mansfield. Divaricella cf. D. quadri- Oliva mutica Say. sulcata '(d* Orbigny). Macrocallista sp. Stratigraphic range: Tami­ Transenella n. sp. ami formation. Cardium (Trachycardium) isocardia Linnet Venericardia (Pleuromeris) SELECTED REFERENCES decemcostata Conrad. Omphalius exoletus (Conrad). Applin, P. L., 1951, Preliminary report on buried Turritella cookei gladee"nsis pre-Mesozoic rocks in Florida and adjacent States: Mansfield. U. S. Geol. Survey Circ. 91, 28 p. Cooke, C. Wythe, 1942, Cenozoic irregular echinoids Stratigraphic range: Tamiami of eastern United States: Jour. Paleontology, v. 16, formation. no. 1, p. 1-62, 8 pis. ____ 1945, Geology of Florida: Florida Geol. Survey Bull. 29, 314 p., 47 figs., 1 pi., incl. geol. map. Well 43 ____ 1952, Sedimentary deposits of Prince Georges County (Maryland) and the District of Columbia: Ostrea sp. -1.5 Md. Dept. Geology, Mines, and Water Resources, Bull. 10, p. 1-53, Stratigraphic range: Forma­ ____ and Mossom, Stuart, 1929, Geology of Florida: tion indeterminate. Florida Geol. Survey 20th Ann. Rept., p. 29-227, 29 pis., incl. geol. map. Venericardia (Pleuromeris) Dall, W. H., 1890-1903, Contributions to the Tertiary decemcostata Conrad. . . . -5.0 fauna of Florida, with especial reference to the Miocene Silex beds of Tampa and the Pliocene beds Stratigraphic range: Forma­ of the Caloosahatchee River: Wagner Free Inst. Sci. tion indeterminate. Trans., v. 3, 1654 p., 60 pis., pt. 1, 189-0; pt. 2, 1892; pt. 3, 1895; pt. 4, 1898; pt. 5, 1900; pt. 6, Transenella n. sp...... -12.0 1903. Venericardia (Pleuromeris) Hoy, N. D., and Schroeder, M. C., 1952, Age of sub­ decemcostata Conrad. surface "Tamiami" formation near Miami, Florida: Turritella pontoni Mansfield. Jour. Geology, v. 60, no. 3, p. 283-286. MacNeil, F. Stearns, 1950, Pleistocene shore lines in Stratigraphic range: Tamiami Florida and Georgia: U. S. Geol. Survey Prof. formation. Paper 221, p. 95-107. Mansfield, W. C., 1939, Notes on the upper Tertiary and Pleistocene mollusks of peninsular Florida: I/ Datum is mean sea level. Florida Geol. Survey Bull. 18, 75 p., 4 pis., 2 figs. 26 GEOLOGY OF THE WESTERN EVERGLADES AREA Matson, C. G., and Clapp, F. G., 1909, A preliminary ______Ferguson, G. E., Love, S. K., and others, report on the geology of Florida, with special ref­ 1954, Water resources of southeastern Florida, with erence to the stratigraphy: Florida Geol. Survey special reference to the geology and ground water Ann. Rept. 2, p. 25-173, incl. geol. map. of the Miami area: U. S. Geol. Survey Water-Supply Parker, GaraldG., 1951, Geologic and hydrologicfac­ Paper 1255 (in preparation). tors in the perennial yield of the Biscayne aquifer: Sellards, E. H., 1912, The soils and other surface Jour. Am. Water Works Assoc., v. 43, no. 10, residual materials of Florida: Florida Geol. Survey p. 817-834, 7 figs. Ann. Rept. 4, p. 7-79. _____ and Cooke, C. W., 1944, Late Cenozoic geol­ Vernon, R. O., 1951, Geology of Citrus and Levy ogy of southern Florida, with a discussion of the Counties, Florida: Florida Geol. Survey Bull. 33, ground water: FloridaGeol. Survey Bull. 27, 119 p., 252 p., 40 figs., 2 pis. 4 figs., 26 pis.

INT.-DUP. SBC., WASH.. D.C«21S« SELECTED REFERENCES 25 Well 41 Continued. Well 43--Continued. Fossils and range Depth (feet I/) Fossils and range Depth (feet I/) Anadara sp...... -20.0 Pecten sp...... -15.0 Ostrea sculpturata Stratigraphic range: Forma­ Conrad. tion indeterminate. Donax fossor Say. Transenella n. sp. Venericardia (Pleuromeris) Well 42 decemcostata Conrad. Cardium cf. _C. robustum Glycymeris sp...... -10.0 Solander. Ostrea sculpturata Conrad. Turritella cookei gladegnsis Transenella n. sp. Mansfield. Venericardia (Pleuromeris) Turritella pontoni Mansfield. decemcostata Conrad. Oliva mutica Say. Turritella pontoni Oliva sp. aff. sayana Mansfield. Ravenel. Turritella cookei gladee*nsis Mansfield. Stratigraphic range: Tami­ ami formation. Stratigraphic range: Tamiami formation. Ostrea sp...... -22.0 Venericardia (Pleurom- Glycymeris subovata (Say). . . -12.0 eris) decemcostata to -16.0 Conrad. Ostrea sculpturata Conrad. Turritella cookei gladee'nsis Phacoides (Cardiolucina) Mansfield. trisulcatus multistriatus Turritella pontoni (Conrad). Mansfield. Divaricella cf. D. quadri- Oliva mutica Say. sulcata (d'Orbigny). Macrocallista sp. Stratigraphic range: Tami- Transenella n. sp. ami formation. Cardium (Trachycardium) isocardia Linnet Venericardia (Pleuromeris) SELECTED REFERENCES decemcostata Conrad. Omphalius exoletus (Conrad). Applin, P. L., 1951, Preliminary report on buried Turritella cookei gladefe'nsis pre-Mesozoic rocks in Florida and adjacent States: Mansfield. U. S. Geol. Survey Circ. 91, 28 p. Cooke, C. Wythe, 1942, Cenozoic irregular echinoids Stratigraphic range: Tamiami of eastern United States: Jour. Paleontology, v. 16, formation. no. 1, p. 1-62, 8 pis. ____ 1945, Geology of Florida: Florida Geol. Survey Bull. 29, 314 p., 47 figs., 1 pi., incl. geol. map. Well 43 ____ 1952, Sedimentary deposits of Prince Georges County (Maryland) and the District of Columbia: Ostrea sp. -1.5 Md. Dept. Geology, Mines, and Water Resources, Bull. 10, p. 1-53, Stratigraphic range: Forma­ ____ and Mossom, Stuart, 1929, Geology of Florida: tion indeterminate. Florida Geol. Survey 20th Ann. Rept., p. 29-227, 29 pis., incl. geol. map. Venericardia (Pleuromeris) Dall, W. H., 1890-1903, Contributions to the Tertiary decemcostata Conrad. .... -5.0 fauna of Florida, with especial reference to the Miocene Silex beds of Tampa and the Pliocene beds Stratigraphic range: Forma­ of the Caloosahatchee River: Wagner Free Inst. Sci. tion indeterminate. Trans., v. 3, 1654 p., 60 pis., pt. 1, 1890; pt. 2, 1892; pt. 3, 1895; pt. 4, 1898; pt. 5, 1900; pt. 6, Transenella n. sp. .... -12.0 1903. Venericardia (Pleuromeris) Hoy, N. D., and Schroeder, M. C., 1952, Age of sub­ decemcostata Conrad. surface "Tamiami" formation near Miami, Florida: Turritella pontoni Mansfield. Jour. Geology, v. 60, no. 3, p. 283-286. MacNeil, F. Stearns, 1950, Pleistocene shore lines in Stratigraphic range: Tamiami Florida and Georgia: U. S. Geol. Survey Prof. formation. Paper 221, p. 95-107. Mansfield, W. C., 1939, Notes on the upper Tertiary and Pleistocene mollusks of peninsular Florida: l/ Datum is mean sea level. Florida Geol. Survey Bull. 18, 75 p., 4pis., 2 figs. 26 GEOLOGY OF THE WESTERN EVERGLADES AREA Matson, C. G., and Clapp, F. G., 1909, A preliminary _____ Ferguson, G. E., Love, S. K., and others, report on the geology of Florida, with special ref­ 1954, Water resources of southeastern Florida, with erence to the stratigraphy: Florida Geol. Survey special reference to the geology and ground water Ann. Rept. 2, p. 25-173, incl. geol. map. of the Miami area: U. S. Geol. Survey Water-Supply Parker, GaraldG., 1951, Geologic and hydrologicfac­ Paper 1255 (in preparation). tors in the perennial yield of the Biscayne aquifer: Sellards, E. H., 1912, The soils and other surface Jour. Am. Water Works Assoc., v. 43, no. 10, residual materials of Florida: FloridaGeol. Survey p. 817-834, 7 figs. Ann. Rept. 4, p. 7-79. _____ and Cooke, C. W., 1944, Late Cenozoic geol­ Vernon, R. O., 1951, Geology of Citrus and Levy ogy of southern Florida, with a discussion of the Counties, Florida: Florida Geol. Survey Bull. 33, ground water: FloridaGeol. Survey Bull. 27, 119p., 252 p., 40 figs., 2 pis. 4 figs., 26 pis.

INT.-OOP. SEC., WASH., D.C42186