Moodys Branch Formation Research Articles

The Town Creek locale of Jackson, Mississippi, USA: Charles Lyell (1797–1875), exemplary fossils and a subsurface volcano

Abstract The Town Creek locale in Jackson, Mississippi exposes fossiliferous strata through stream erosion and provides evidence for stratal doming atop an extinct volcano. Charles Lyell (1797–1875) investigated the locale on his second visit to North America (1845–46) and concluded that Town Creek fossils were older than Vicksburg fossils, and that strata dipped westward from Jackson. In the 1850s, Mississippi's state geologist Eugene Hilgard (1833–1916) recognized the first volcanic doming evidence and correctly concluded that a ‘local upheaval’ had elevated the Jackson area. Subsequent research revealed an extinct volcano as Jackson Dome's source, explaining the strata dip and Lyell's observation that Jackson's Eocene fossils were older than Vicksburg fossils, later identified as Oligocene. The Jackson fossiliferous strata, known today as the Moodys Branch Formation, exquisitely preserves fossils that have contributed to numerous scientific investigations. The Town Creek locale was threatened in 2003 when a proposed flood control project would have inundated it. Scientists rallied for the preservation of the geologically and historically important Town Creek, and today it remains as a geoheritage site available to scientists and the public, with a state historical marker noting its geological importance. Long-term preservation of the locale is needed but not guaranteed.

Xiphiorhynchus cf. X. eocaenicus (Woodward, 1901), (Scombroidei: Xiphiidae: Xiphiorhynchinae) from the Middle Eocene of Mississippi, the first transatlantic distribution of a species of Xiphiorhynchus

ABSTRACT An anterior (distal) rostrum (MMNS 2957) from the Moodys Branch Formation (late middle Eocene), Tesheva Creek, Yazoo County, Mississippi, U.S.A., is described and identified as Xiphiorhynchus cf. X. eocaenicus. The specimen is compared to various species of Xiphiorhynchus, especially the holotype of X. eocaenicus (BMNH 25744), Bracklesham Group, early middle Eocene, England. This represents the first record of a species of Xiphiorhynchus in deposits on both sides of the North Atlantic Ocean. Xiphiorhynchus eocaenicus is thought to have had similar environmental preferences and habits as the extant swordfish, Xiphias gladius. Since the swordfish prefers oceanic water and makes transatlantic movements, then distribution of a xiphiorhynchin on both sides of the Atlantic is not unexpected. The environment at Tesheva Creek and the type locality in England were both shallow, nearshore, tropical to subtropical habitats. The holotype was probably transported into shallow water either as stomach contents or by ocean currents, whereas the Tesheva Creek specimen was either the remains of a stranded individual or of an animal that died in shallow water after being impaled.

The oxygen isotopic record of seasonality in Conus shells and its application to understanding late middle Eocene (38 Ma) climate

To better understand Eocene climate and the isotopic record of paleotemperature preserved in shells of the gastropod Conus, we serially sampled and analyzed four modern and two Eocene shells from the U.S. Gulf Coast and the Gulf of Mexico. The modern shells are from nearshore Mexico off Veracruz, off-shore Texas (Stetson Bank), and nearshore Florida (Alligator Point). The fossil shells are of late middle Eocene (ca. 38 Ma) age from the Moodys Branch Formation in Mississippi (U.S.A.). The four modern shells yield three different oxygen-isotopic patterns of seasonality (asymmetrical saw-tooth, cuspate, and irregular) representing different seasonal growth patterns and environments. The asymmetrical sawtooth pattern occurs in the middle shelf specimen (Stetson Bank) and indicates rapid spring and declining autumn growth, presumably in response to increased nutrient supply and productivity associated with spring upwelling. The cuspate pattern indicates winter shutdown and occurs in the most northern specimen. The irregular pattern reflects seasonal freshwater input in a nearshore environment. The Eocene shells yield an asymmetrical sawtooth pattern suggestive of enhanced spring growth during upwelling.Assuming a constant seawater δ18O of 0.24‰ (Lear et al., 2000), including correction for latitude (Zachos et al., 1994), oxygen isotope data yield a mean annual range of temperature (MART) for the late middle Eocene of 4–5°C, and a mean annual temperature (MAT) of 23°C. Taking the depth estimation (20–100 m) into consideration, sea surface temperatures are estimated to be >25°C for summer, ∼21°C for winter, and MAT of >23°C. Compared with modern temperatures and isotopic paleotemperatures of modern shells, the late middle Eocene Gulf Coast experienced warmer winter temperatures. The difference between modern and late middle Eocene climate can partly be attributed to the development of a continental cold front during the modern winter, and to the increased marine influence during the middle Eocene caused by the warmer water mass of the ocean.

Timing of Latest Eocene Molluscan Extinction Patterns in Mississippi

Molluscs removed from 12 bulk samples of the Yazoo Formation (upper Eocene), exposed in a quarry at Cynthia, Mississippi, are similar in composition and diversity to those found in the underlying upper Eocene Moodys Branch Formation, when differences in outcrop area are considered (74% of the Yazoo species are also found in the Moodys Branch). This suggests there was no significant extinction during the late Eocene (at the P15/P16 biozone boundary) as has been reported for planktic foraminifera. Only 11.4% of the species from the Yazoo extend into the Oligocene Red Bluff Formation, suggesting a large molluscan extinction at or near the Eocene-Oligocene boundary. The presence in the lowermost Red Bluff of an assemblage with a relatively high diversity dominated by suspension-feeding bivalves suggests that the molluscan fauna had recovered from the extinction by the earliest Oligocene.

Paleoecology of a Late Eocene (Bartonian) Vertebrate Fauna, Moodys Branch Formation, Techeva Creek, Mississippi

ABSTRACT A paleoecological study of the late Eocene (Bartonian) marine strata of the Moodys Branch Formation at Techeva Creek, Yazoo County, Mississippi, describes a vertebrate fauna of 21 species, at least 15 not previously recorded from the Jackson Group of this state. The fauna consists of 9 sharks, 3 rays, 8 teleosts and a small cetacean, the Eocene whale, Zygorhiza kochii. The four most common vertebrate taxa are Negaprion gibbesi (lemon shark), Galeocerdo clarkensis (tiger shark), Myliobatis sp. (eagle ray), and Jefitchia claybornesis (croaker). Vertebrate paleoecology places this fauna within a shallow, nearshore setting; open, deeper marine conditions south of the late Eocene shoreline are suggested by the rarer occurrences of more open water vertebrates, such as Carcharodon, Isurus, Scyliorhinus and Galeorhinus. Associated invertebrates, dominated by a low diversity clam assemblage (especially Glycymeris idonea), Ophimorpha burrows, and beds of the echinoid, Periarchus lyelli, indicate a shallow, high energy marine environment in the 1 to 10 m depth range, typically shallower (5 m or less). Previously described estuarine and nearshore vertebrate faunas of the late Eocene in the Gulf Coast trend toward a lower diversity of taxa when compared to deeper shelf or more offshore settings. The very nearshore setting of Techeva Creek suggests that further vertebrate discoveries, even of terrestrial mammals, may be possible.

RbSr glauconite ages, Sabinian, Claibornian and Jacksonian units, southeastern Atlantic Coastal Plain, U.S.A

Hand-picked, disordered to ordered authigenic glauconite from the Nanjemoy Formation (Virginia), the Santee Limestone (restricted) and Cross Formation (South Carolina), and the Castle Hayne Limestone (North Carolina) yield RbSr isochron ages ( λ 87Rb = 1.42 × 10 −11 yr −1) for Eocene units in the southeastern Atlantic Coastal Plain. The units, zonal assignment of their contained nannofossil floras and radiometric age, are: 3 Unit Nannofossil zone Age (m.y.) Castle Hayne Limestone NP 19–20 34.9 ± 1.1 Cross Formation NP 18, NP 19, NP 20 34.1 ± 1.5 Santee Limestone (upper part) NP 16–17 36.7 ± 0.6 Nanjemoy Formation NP 13 46.7 ± 3.0 These ages, and their nannofossil assemblages, provide means of correlating southeastern Atlantic Coastal Plain units with Gulf Coastal Plain and European stratoypes. Correlation to Gulf Coast stratotypes, based on nannofossil zones, indicates that the Nanjemoy Formation (in part) is equivalent to the Hatchetigbee Formation; the upper part of the Santee Limestone (restricted) is equivalent to the upper Lisbon Formation, the Gosport Sand, and the Moodys Branch Formation (upper Claibornian-lower Jacksonian); and the Cross Formation and the Castle Hayne Limestone are equivalent to the Yazoo Group (Jacksonian). Previously reported KAr glauconite ages for the Gulf Coast units are different from the RbSr ages determined in this study. As the RbSr age determinations show internal consistency when compared to their contained nannofossil zones, whereas the KAr ages do not, it is suggested that the previously reported KAr ages for the Gulf Coast Claibornian and Jacksonian are in error. Correlation of the southeastern Atlantic Coastal Plain units to European stratoypes based on nannofossil zones indicates that the Nanjemoy Formation (in part) is equivalent to the type Lutetian; the upper part of the Santee Limestone (restricted) is equivalent to the Upper Bracklesham and Barton Beds; and the Cross Formation and Castle Hayne Limestone are equivalent to the Lower and Middle Headon Beds. Previously determined KAr and RbSr radiometric ages for the type Lutetian, the Bracklesham and Barton Beds are identical to the ages determined in this study. As a result, it is suggested that Rb-Sr glauconite isochron ages can be used for regional and inter-regional correlation and that the Eocene/Oligocene boundary is younger than 34 m.y.

Cirriped assemblage zones of the eocene claibornian and jacksonian stages, southeastern Atlantic and Gulf Coastal Plains

Two Eocene cirriped assemblage zones are recognized in the Gulf Coastal Plain of Alabama and Mississippi. The Arcoscalpellum subquadratum Zone is characterized by A. subquadratum (Meyer and Aldrich), Aporolepas americana (Withers), Euscalpellum eocenense (Meyer), and Solidobalanus antiquus (Meyer), and ranges through the upper Claibornian Stage. The Arcoscalpellum jacksonense Zone is characterized by A. jacksonense Withers, A. choctawensis Weisbord, Aporolepas howei Cheetham, and Solidobalanus sp. aff. S. antiquus (Meyer), and ranges through the Jacksonian Stage. Representative species of one or both of these cirriped zones are found also in Texas, Georgia, South Carolina, and North Carolina, and afford an additional means for correlating Claibornian and Jacksonian marine units between the Atlantic and Gulf Coastal Plains. The Arcoscalpellum subquadratum Zone is represented in the Cook Mountain Formation of Texas and Mississippi, the upper Lisbon Formation and overlying Gosport Sand of Alabama, the McBean Formation of Georgia, and the Cubitostrea sellaeformis beds of the restricted Santee Limestone of South Carolina. The A. jacksonense Zone is represented in the Moodys Branch Formation of Mississippi and Alabama, the Cocoa Sand of Alabama, the Pachuta Marl of either Mississippi or Alabama, the Shubuta Clay equivalents in Alabama, the Clinchfield Sand and Dry Branch Formation of Georgia, the Cross Formation of South Carolina, and the biosparrudite and biomicrudite members of the Castle Hayne Limestone in North Carolina. Some cirriped species found in these zones in the southeastern Atlantic Coastal Plain are not represented in the Gulf Coastal Plain. Solidobalanus n. sp. 1, a species unrelated to the S. antiquus group, occurs in the McBean Formation of Georgia ( Arcoscalpellum subquadratum Zone). Kathpalmeria georgiana Ross is found in the Griffins Landing Member of the Dry Branch Formation of Georgia and has tentatively been identified from the Inglis Formation of northern Florida ( Arcoscalpellum jacksonense Zone). Euscalpellum carolinensis Zullo and Baum and Solidobalanus n. sp. 2 (related to Solidobalanus n. sp. 1) are found in the Cross Formation of South Carolina and the Castle Hayne Limestone of North Carolina ( Arcoscalpellum jacksonense Zone). Recognition of the A. jacksonense Zone in the Cross Formation and the Castle Hayne Limestone supports recent conclusions based on calcareous nannofossil zonation and radiometric determinations that these units are Jacksonian rather than Claibornian in age.

Eocene biostratigraphy of South Carolina and its relationship to Gulf Coastal Plain zonations and global changes of coastal onlap

Research Article| November 01, 1982 Eocene biostratigraphy of South Carolina and its relationship to Gulf Coastal Plain zonations and global changes of coastal onlap RICHARD J. POWELL; RICHARD J. POWELL 1Department of Geology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina 27514 Search for other works by this author on: GSW Google Scholar GERALD R. BAUM GERALD R. BAUM 2Exxon Production Research Company, P.O. Box 2189, Houston, Texas 77001 Search for other works by this author on: GSW Google Scholar Author and Article Information RICHARD J. POWELL 1Department of Geology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina 27514 GERALD R. BAUM 2Exxon Production Research Company, P.O. Box 2189, Houston, Texas 77001 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1982) 93 (11): 1099–1108. https://doi.org/10.1130/0016-7606(1982)93<1099:EBOSCA>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation RICHARD J. POWELL, GERALD R. BAUM; Eocene biostratigraphy of South Carolina and its relationship to Gulf Coastal Plain zonations and global changes of coastal onlap. GSA Bulletin 1982;; 93 (11): 1099–1108. doi: https://doi.org/10.1130/0016-7606(1982)93<1099:EBOSCA>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract An assimilation of mega-invertebrate assemblages in South Carolina with Gulf Coast biozones allows for the subdivision of the middle and late Eocene into four regional zonations that can be compared with proposed global sequences controlled by eustatic changes of sea level. The middle Eocene can be divided, in ascending stratigraphic order, into the Cubitostrea perplicata zone, C. lisbonensis zone, and C. sellaeformis zone. The late Eocene is represented by the Crassatella alta–Chlamys cawcawensis zone. These zones are separated by Type 1 or Type 2 unconformities that bracket global sequence boundaries (unconformity types after Vail and Todd, 1981).The following sequences are proposed for the middle and upper Eocene: TE2.1, Cubitostrea perplicata zone, followed by a Type 2 unconformity; TE2.2, C. lisbonensis zone, followed by a Type 2 unconformity; TE2.3, C. sellaeformis zone, followed by a Type 1 unconformity; and TE3, Crassatella alta–Chlamys cawcawensis zone, followed by a Type 2 unconformity. Although not recognized in the downdip areas of South Carolina, the TE3 sequence can be further subdivided into a TE3.1 sequence and TE3.2 sequence, separated by a Type 2 unconformity. This regional break lies at the Gosport Sand-Lower Moodys Branch Formation/Upper Moodys Branch Formation contact in the Gulf Coastal Plain and at the base of the Tivola Tonque in Georgia. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Macrofossil Assemblages of Moodys Branch Formation (Upper Eocene), Louisiana and Mississippi: ABSTRACT

The Moodys Branch Formation (upper Eocene, Jackson Group) is a thin, fossiliferous, glauconitic sand which represents the destructive shelf phase of a transgressive sea. Computer cluster analysis of fossils taken from closely spaced samples reveals six distinct macrofossil assemblages: (A) open bay, (B) nearshore, (C) inner shelf, (D) western inner middle shelf, (E) eastern inner middle shelf, and (F) outer middle shelf. Quantitative trends are similar to Holocene trends for dead shell assemblages in that species dominance and numbers of individuals increase nearshore and diversity, as measured by the Shannon-Weiner index, increases offshore and in bays. However, there are conspicuous differences in the environmental preferences of some Eocene species and their closest li ing analogs. This suggests that care should be taken when making ecologic analogies between modern organisms and fossil remains. End_of_Article - Last_Page 1684------------

Upper Eocene-Lower Oligocene Stratigraphy and Paleontology in Alabama: ABSTRACT

ABSTRACT Southeastern Alabama, where the clastic upper Eocene and lower Oligocene beds from the west grade into and interfinger with the equivalent limestone beds toward the east, is an area of deep weathering. Exposure are lacking except along the rivers and major streams, where complete unweathered geologic sections can be studied by means of a small boat. Study of these sections where the two lithosomes and their distinctive fossils mingle has resulted in a better understanding of the stratigraphic relationships and correlation of upper Eocene and lower Oligocene strata between Mississippi and Florida. The Moodys Branch Formation can be divided into a lower and an upper member in southeastern Alabama, the lower member being the Periarchus lyelli Assemblage Zone. The lower member is correlated with the Inglis Formation in Florida and the upper member with the Williston Formation. The members of the Yazoo Clay can be traced eastward into southern Alabama, where they merge into the Crystal River Formation, the Ocala of early reports. The upper member of the Yazoo (Shubuta Clay Member) is correlated with the upper part of the Crystal River (Asterocyclina Assemblage Zone) exposed in the vicinity of Marianna, Florida. The Red Bluff Clay is correlated with the Bumpnose Limestone that overlies the Crystal River Formation in the Marianna area. Like the Bumpnose, it contains the guidefossil Lepidocyclina chaperi Lemoine and Douville in exposures near Perdue Hill, Alabama.

Faunal Zones of the Paleocene and Eocene Geologic Section Along Chattahoochee River, Alabama: ABSTRACT

The stratigraphic interval from the top of the Upper Cretaceous Providence Sand to the bottom of the upper Eocene Ocala Limestone, extending 49 miles along the Chattahoochee River, was studied and sampled. The section, more than 600 feet thick, can be correlated with the standard section in central and western Alabama by means of fossil zones. Each of the eight formations studied contains beds with distinctive guide fossils. The Paleocene Series is represented by a limestone facies that contains a more poorly preserved fauna than the equivalent argillaceous facies of western Alabama. The upper Paleocene (Naheola Formation) is absent in eastern Alabama. The lower Eocene Series is lithologically and faunally similar to its equivalent farther west. The middle Eocene Series is more calcareous than in western Alabama. The lower Lisbon (Winona equivalent) and the Gosport Sand are absent. The upper Eocene Series is represented by a limestone facies of the Moodys Branch Formation and Yazoo Clay of western Alabama. Foraminiferal zones established for the geologic section on the Chattahoochee River conform closely to the macrofossil zones. End_of_Article - Last_Page 355------------

Stratigraphy Along Chattahoochee River, Connecting Link Between Atlantic and the Gulf Coastal Plains

The geologic section along the Chattahoochee River is one of the best in the Coastal Plain of the United States. It is the only extensive unweathered section of beds of Cretaceous and Tertiary age in southeastern Alabama and southwestern Georgia, and is a connecting link between the well known standard section and type exposures on the west in Alabama and equivalent strata on the east in Georgia and South Carolina. It is important also because of its intermediate position between the clastic facies in the central and western Gulf Coastal Plain and the equivalent carbonate facies in the subsurface in Florida. A complete section of Upper Cretaceous, Paleocene, lower Eocene, middle Eocene, and some upper Eocene strata is exposed down the dip from the crystalline rocks at the Fall Line at Columbus, Georgia, to the place where upper Eocene exposures become discontinuous about 8 miles north of the Alabama-Florida boundary, a distance of 126 miles. This study of a part of that section supplies stratigraphic and structural information on rocks of Late Cretaceous and Tertiary age that are exposed southward from Thomas Mill Creek, 14 miles south of Eufaula, Alabama, near the Upper Cretaceous-Paleocene contact, to exposures of limestone of late Eocene age 15 miles south of Columbia, Alabama, a distance of 49 miles. The total thickness of the Paleocene and Eocene strata studied along this part of the river is more than 600 feet. The average dip is about 13 feet per mile toward the south. The Tertiary formations recognized in the river section are those in the standard Alabama stratigraphic section. They are, in ascending order, the Clayton Formation of Paleocene age, the Nanafalia Formation, Tuscahoma Sand, and Hatchetigbee Formation of early Eocene age, the Tallahatta and Lisbon Formations of middle Eocene age, and the Moodys Branch Formation and Ocala Limestone of late Eocene age. The Gosport Sand of late middle Eocene age is absent. Columnar diagrams of measured stratigraphic sections were combined into longitudinal profiles to show detailed lithologic character and structure along the river. Vertical control was from the river surface. The altitude of the river surface was determined from the stage of the river referenced to the thalweg and the corresponding profile of the mean low-water stage as plotted by the U. S. Corps of Engineers.

Moodys Branch-Cockfield Contact in Sabine Parish, Louisiana, and Adjacent Areas

Brackish or marginal-marine upper Cockfield sediments are exposed between the Red and Sabine rivers in western Louisiana. These clays, silts, and sands are complexly lenticular and interfinger with many deltaic fresh-water beds of similar composition. The Jacksonian Moodys Branch formation, overlying the Cockfield, consists of rather uniform, glauconitic, marine sands throughout its known outcrop in this area. Two sedimentary facies comprise the Cockfield directly below the Moodys Branch. In southwest Sabine Parish marginal-marine deposits (Creola member) predominate; elsewhere, fresh-water deltaic sediments underlie the marine beds of the Moodys Branch. Brackish deposits occur in places stratigraphically below these fresh-water deposits. In both occurrences the contact is sharp. However, borings, extending from the Moodys Branch several feet into the Cockfield, are commonly encountered. At one locality deltaic fresh-water Cockfield grades through several feet into the Moodys Branch. Analysis of the microfauna found in the Creola and Moodys Branch sediments shows that more than half of the species collected do not cross the Moodys Branch-Cockfield boundary. Furthermore, the Creola fauna is much less abundant. This change, although indicative of some break in deposition, is considered primarily ecologic. In this area there is small, but apparent, stratigraphic discontinuity between the Moodys Branch and Cockfield formations. The term diastem most nearly expresses this relationship when viewed locally. These strata and their contact relationships are favorably comparable with conditions in parts of the Louisiana coast where marine sands are encroaching on contemporaneous and slightly older brackish and limnic sediments.