A fossiliferous spherule-rich bed at the Cretaceous–Paleogene (K–Pg) boundary in Mississippi, USA: Implications for the K–Pg mass extinction event in the Mississippi Embayment and Eastern Gulf Coastal Plain

James D. Witts, Neil H. Landman, Matthew P. Garb, Caitlin Boas, Ekaterina Larina, Remy Rovelli, Lucy E. Edwards, Robert Sherrell, J. Kirk Cochran

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

We describe an outcrop of the Cretaceous–Paleogene (K–Pg) boundary exposed due to construction near New Albany, Union County, Mississippi. It consists of the Owl Creek Formation and overlying Clayton Formation. The Owl Creek Formation is rich in the ammonites Discoscaphites iris and Eubaculites carinatus, which, along with biostratigraphically important dinoflagellate cysts and calcareous nannofossils, indicate deposition occurred within the last 1 million years, most likely last 500 kyrs, of the Cretaceous. The base of the overlying Clayton Formation marks the K–Pg boundary, and consists of a 15–30 cm thick muddy, poorly sorted quartz sand containing abundant spherules representing ejecta derived from the Chicxulub impact event. Impact spherules range in size from 0.5 mm to 1 mm in diameter and are hollow and well preserved, with details such as smaller vesicular spherules enclosed within. The spherules are altered to clay minerals such as smectite and are typical of those found at K–Pg boundary sites in the Gulf of Mexico and beyond. Spherules are scattered throughout the bed, and surface counts suggest an average of 4 spherules per cm2. Macrofossils within the spherule bed represent a rich fauna of ammonites, benthic molluscs (bivalves and gastropods), echinoids, as well as crabs and sharks. Macrofossil preservation ranges from whole to fragmentary, with most fossils preserved as internal moulds. The infill of the fossils is lithologically identical to the matrix of the spherule bed, including impact ejecta preserved within phragmocones and body chambers of ammonites, and differs from the underlying Owl Creek Formation. This suggests that the animals were either alive or loosely scattered on the sea floor at the time of deposition. Grain size changes indicate multiple events were responsible for deposition, and together with taphonomic evidence are consistent with dynamic high energy post-impact processes. Later sea level change during the Paleocene is responsible for a sharp contact at the top of the spherule bed. Geochemical evidence from the Owl Creek and Clayton Formations at this locality indicate numerous local paleoenvironmental changes affected the Mississippi Embayment at the time of the K–Pg boundary and mass extinction event.

Original languageEnglish (US)
Pages (from-to)147-167
Number of pages21
JournalCretaceous Research
Volume91
DOIs
StatePublished - Nov 1 2018

Fingerprint

spherule
mass extinction
coastal plain
ejecta
fossil
gulf
dinoflagellate cyst
nanofossil
infill
shark
sea level change
Paleocene
smectite
mollusc
gastropod
clay mineral
bivalve
crab
outcrop
seafloor

All Science Journal Classification (ASJC) codes

  • Palaeontology

Keywords

  • Ammonite
  • Chicxulub
  • Cretaceous
  • Impact spherule
  • Mass extinction
  • Paleogene

Cite this

Witts, James D. ; Landman, Neil H. ; Garb, Matthew P. ; Boas, Caitlin ; Larina, Ekaterina ; Rovelli, Remy ; Edwards, Lucy E. ; Sherrell, Robert ; Cochran, J. Kirk. / A fossiliferous spherule-rich bed at the Cretaceous–Paleogene (K–Pg) boundary in Mississippi, USA : Implications for the K–Pg mass extinction event in the Mississippi Embayment and Eastern Gulf Coastal Plain. In: Cretaceous Research. 2018 ; Vol. 91. pp. 147-167.
@article{915056c1f8e943c6ba4da49a157c5df8,
title = "A fossiliferous spherule-rich bed at the Cretaceous–Paleogene (K–Pg) boundary in Mississippi, USA: Implications for the K–Pg mass extinction event in the Mississippi Embayment and Eastern Gulf Coastal Plain",
abstract = "We describe an outcrop of the Cretaceous–Paleogene (K–Pg) boundary exposed due to construction near New Albany, Union County, Mississippi. It consists of the Owl Creek Formation and overlying Clayton Formation. The Owl Creek Formation is rich in the ammonites Discoscaphites iris and Eubaculites carinatus, which, along with biostratigraphically important dinoflagellate cysts and calcareous nannofossils, indicate deposition occurred within the last 1 million years, most likely last 500 kyrs, of the Cretaceous. The base of the overlying Clayton Formation marks the K–Pg boundary, and consists of a 15–30 cm thick muddy, poorly sorted quartz sand containing abundant spherules representing ejecta derived from the Chicxulub impact event. Impact spherules range in size from 0.5 mm to 1 mm in diameter and are hollow and well preserved, with details such as smaller vesicular spherules enclosed within. The spherules are altered to clay minerals such as smectite and are typical of those found at K–Pg boundary sites in the Gulf of Mexico and beyond. Spherules are scattered throughout the bed, and surface counts suggest an average of 4 spherules per cm2. Macrofossils within the spherule bed represent a rich fauna of ammonites, benthic molluscs (bivalves and gastropods), echinoids, as well as crabs and sharks. Macrofossil preservation ranges from whole to fragmentary, with most fossils preserved as internal moulds. The infill of the fossils is lithologically identical to the matrix of the spherule bed, including impact ejecta preserved within phragmocones and body chambers of ammonites, and differs from the underlying Owl Creek Formation. This suggests that the animals were either alive or loosely scattered on the sea floor at the time of deposition. Grain size changes indicate multiple events were responsible for deposition, and together with taphonomic evidence are consistent with dynamic high energy post-impact processes. Later sea level change during the Paleocene is responsible for a sharp contact at the top of the spherule bed. Geochemical evidence from the Owl Creek and Clayton Formations at this locality indicate numerous local paleoenvironmental changes affected the Mississippi Embayment at the time of the K–Pg boundary and mass extinction event.",
keywords = "Ammonite, Chicxulub, Cretaceous, Impact spherule, Mass extinction, Paleogene",
author = "Witts, {James D.} and Landman, {Neil H.} and Garb, {Matthew P.} and Caitlin Boas and Ekaterina Larina and Remy Rovelli and Edwards, {Lucy E.} and Robert Sherrell and Cochran, {J. Kirk}",
year = "2018",
month = "11",
day = "1",
doi = "10.1016/j.cretres.2018.06.002",
language = "English (US)",
volume = "91",
pages = "147--167",
journal = "Cretaceous Research",
issn = "0195-6671",
publisher = "Academic Press Inc.",

}

A fossiliferous spherule-rich bed at the Cretaceous–Paleogene (K–Pg) boundary in Mississippi, USA : Implications for the K–Pg mass extinction event in the Mississippi Embayment and Eastern Gulf Coastal Plain. / Witts, James D.; Landman, Neil H.; Garb, Matthew P.; Boas, Caitlin; Larina, Ekaterina; Rovelli, Remy; Edwards, Lucy E.; Sherrell, Robert; Cochran, J. Kirk.

In: Cretaceous Research, Vol. 91, 01.11.2018, p. 147-167.

Research output: Contribution to journalArticle

TY - JOUR

T1 - A fossiliferous spherule-rich bed at the Cretaceous–Paleogene (K–Pg) boundary in Mississippi, USA

T2 - Implications for the K–Pg mass extinction event in the Mississippi Embayment and Eastern Gulf Coastal Plain

AU - Witts, James D.

AU - Landman, Neil H.

AU - Garb, Matthew P.

AU - Boas, Caitlin

AU - Larina, Ekaterina

AU - Rovelli, Remy

AU - Edwards, Lucy E.

AU - Sherrell, Robert

AU - Cochran, J. Kirk

PY - 2018/11/1

Y1 - 2018/11/1

N2 - We describe an outcrop of the Cretaceous–Paleogene (K–Pg) boundary exposed due to construction near New Albany, Union County, Mississippi. It consists of the Owl Creek Formation and overlying Clayton Formation. The Owl Creek Formation is rich in the ammonites Discoscaphites iris and Eubaculites carinatus, which, along with biostratigraphically important dinoflagellate cysts and calcareous nannofossils, indicate deposition occurred within the last 1 million years, most likely last 500 kyrs, of the Cretaceous. The base of the overlying Clayton Formation marks the K–Pg boundary, and consists of a 15–30 cm thick muddy, poorly sorted quartz sand containing abundant spherules representing ejecta derived from the Chicxulub impact event. Impact spherules range in size from 0.5 mm to 1 mm in diameter and are hollow and well preserved, with details such as smaller vesicular spherules enclosed within. The spherules are altered to clay minerals such as smectite and are typical of those found at K–Pg boundary sites in the Gulf of Mexico and beyond. Spherules are scattered throughout the bed, and surface counts suggest an average of 4 spherules per cm2. Macrofossils within the spherule bed represent a rich fauna of ammonites, benthic molluscs (bivalves and gastropods), echinoids, as well as crabs and sharks. Macrofossil preservation ranges from whole to fragmentary, with most fossils preserved as internal moulds. The infill of the fossils is lithologically identical to the matrix of the spherule bed, including impact ejecta preserved within phragmocones and body chambers of ammonites, and differs from the underlying Owl Creek Formation. This suggests that the animals were either alive or loosely scattered on the sea floor at the time of deposition. Grain size changes indicate multiple events were responsible for deposition, and together with taphonomic evidence are consistent with dynamic high energy post-impact processes. Later sea level change during the Paleocene is responsible for a sharp contact at the top of the spherule bed. Geochemical evidence from the Owl Creek and Clayton Formations at this locality indicate numerous local paleoenvironmental changes affected the Mississippi Embayment at the time of the K–Pg boundary and mass extinction event.

AB - We describe an outcrop of the Cretaceous–Paleogene (K–Pg) boundary exposed due to construction near New Albany, Union County, Mississippi. It consists of the Owl Creek Formation and overlying Clayton Formation. The Owl Creek Formation is rich in the ammonites Discoscaphites iris and Eubaculites carinatus, which, along with biostratigraphically important dinoflagellate cysts and calcareous nannofossils, indicate deposition occurred within the last 1 million years, most likely last 500 kyrs, of the Cretaceous. The base of the overlying Clayton Formation marks the K–Pg boundary, and consists of a 15–30 cm thick muddy, poorly sorted quartz sand containing abundant spherules representing ejecta derived from the Chicxulub impact event. Impact spherules range in size from 0.5 mm to 1 mm in diameter and are hollow and well preserved, with details such as smaller vesicular spherules enclosed within. The spherules are altered to clay minerals such as smectite and are typical of those found at K–Pg boundary sites in the Gulf of Mexico and beyond. Spherules are scattered throughout the bed, and surface counts suggest an average of 4 spherules per cm2. Macrofossils within the spherule bed represent a rich fauna of ammonites, benthic molluscs (bivalves and gastropods), echinoids, as well as crabs and sharks. Macrofossil preservation ranges from whole to fragmentary, with most fossils preserved as internal moulds. The infill of the fossils is lithologically identical to the matrix of the spherule bed, including impact ejecta preserved within phragmocones and body chambers of ammonites, and differs from the underlying Owl Creek Formation. This suggests that the animals were either alive or loosely scattered on the sea floor at the time of deposition. Grain size changes indicate multiple events were responsible for deposition, and together with taphonomic evidence are consistent with dynamic high energy post-impact processes. Later sea level change during the Paleocene is responsible for a sharp contact at the top of the spherule bed. Geochemical evidence from the Owl Creek and Clayton Formations at this locality indicate numerous local paleoenvironmental changes affected the Mississippi Embayment at the time of the K–Pg boundary and mass extinction event.

KW - Ammonite

KW - Chicxulub

KW - Cretaceous

KW - Impact spherule

KW - Mass extinction

KW - Paleogene

UR - http://www.scopus.com/inward/record.url?scp=85048410215&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85048410215&partnerID=8YFLogxK

U2 - 10.1016/j.cretres.2018.06.002

DO - 10.1016/j.cretres.2018.06.002

M3 - Article

AN - SCOPUS:85048410215

VL - 91

SP - 147

EP - 167

JO - Cretaceous Research

JF - Cretaceous Research

SN - 0195-6671

ER -