Kate Whidden
Research Geologist with the Central Energy Resources Science Center.
Science and Products
Gulf Coast Geologic Energy Research
The Gulf Coast Geologic Energy Assessments and Research (GEAR) project also conducts research on the properties and processes relevant to the Gulf Coast Jurassic-Cretaceous-Tertiary composite total petroleum system (TPS). This research aims to improve ongoing and future undiscovered, technically recoverable hydrocarbon resources assessments on the onshore and State waters portion of the Gulf Coast...
Controls on Unconventional Oil and Gas Production
This scoping task incorporates insights from new approaches to production of unconventional resources and currently focuses on conducting a pilot assessment of biogenic natural gas resources in the Permian Basin. For the pilot assessment to occur, we are developing a database that will host geochemical parameters known to be suggestive of microbial methanogenesis mined to the reservoir level for...
Gulf Coast Geologic Energy Assessments
One of the main goals of the Gulf Coast Geologic Energy Assessments and Research (GEAR) project is to conduct assessments of undiscovered, technically recoverable petroleum resources of the U.S. Gulf Coast region. This goal is in accordance with the Energy Policy and Conservation Act (EPCA) and is performed in collaboration with the USGS National Oil and Gas Assessment project. These high-quality...
Carbon Isotopes, Total Organic Carbon, Programmed Pyrolysis, Volcanic Zircon U-Pb, and Geochemistry Data from the Hue Shale, Arctic Alaska - 2024
This dataset contains results from a stratigraphic section of the Hue Shale located along the Jago River in the Arctic National Wildlife Refuge at 69.9099, -143.3947 (WGS84). Sample heights were measured with a tape measure in a continuous succession. Zircon grains from volcanic ashes were analyzed via laser ablation at either the University of California, Santa Barbara (UCSB) or the University of
Geochemical Data from Selected Triassic Rock Samples in Northeastern Alaska
This set of data files contains analyses of samples representing Triassic units (Shublik and Ivishak Formations and Karen Creek Sandstone) in Alaska. The samples were collected from 20 outcrop localities in northeastern Alaska. The data set includes total organic carbon (TOC) and geochemical data from inductively coupled plasma-optical emission spectroscopy-mass spectroscopy (ICP-OES-MS) and porta
USGS Gulf Coast Geologic Energy Assessments and Research Project-Upper Jurassic Smackover Formation Continuous Resources: Assessment Unit Boundaries, Assessment Input Data, and Fact Sheet Data Tables
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered continuous oil and gas resources in the Smackover formation in the U.S. Gulf Coast. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the highe
Geochemical, Geochronologic, Rock-Eval, and Spectral Gamma Ray Data for Selected Triassic Rocks in Northwestern Alaska
This set of data files contains analyses of samples representing the Triassic Shublik and Otuk Formations in Alaska. The samples were collected from the Brontosaurus 1 well and measured stratigraphic sections at Surprise Creek and Cape Lisburne. The data set includes total organic carbon (TOC), Rock-Eval (Tmax) data, geochemical data from inductively coupled plasma-optical emission spectroscopy-ma
Subsurface stratigraphic picks of the Middle-Upper Triassic Shublik Formation, Alaska North Slope
The Middle-Upper Triassic Shublik Formation is the main source rock for Arctic Alaska oil and gas accumulations, including the supergiant Prudhoe Bay field. A revised stratigraphic framework recently has been developed in outcrop for the Shublik and related strata that delineates three large-scale stratigraphic units: 1) the lower clastic (LC) unit, 2) the middle carbonate-chert (MCC) unit, and 3)
Filter Total Items: 47
Facies variation within outcrops of the Triassic Shublik Formation, northeastern Alaska
The Shublik Formation (Middle to Upper Triassic) is a heterogeneous unit that is a major hydrocarbon source rock in northern Alaska and the largest known Triassic phosphate accumulation in the world. This formation, which occurs in the subsurface and crops out within the Arctic Alaska basin, was deposited on a gently sloping ramp along the northwestern Laurentian margin. In this study, we document
Authors
Julie A. Dumoulin, Katherine J. Whidden, William A. Rouse, Christina A. DeVera
Examining water and proppant demand, and produced water production, associated with petroleum resource development in the Eagle Ford Group, Texas
More than 20,000 horizontal wells have been drilled and hydraulically fractured in the Eagle Ford Group since the discovery well in 2008, but a considerable amount of undiscovered petroleum remains. Recently, drilled wells have been hydraulically fractured with an average of nearly 13 million gallons of water and 16 million lb of sand, yielding a million or more gallons of produced water. To infor
Authors
Nicholas J. Gianoutsos, Seth S. Haines, Brian A. Varela, Katherine J. Whidden
Assessment of undiscovered, technically recoverable conventional oil and gas resources in the Upper Jurassic Smackover Formation, U.S. Gulf Coast, 2022
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 143 million barrels of oil and 1,084 billion cubic feet of natural gas in conventional accumulations for the Upper Jurassic Smackover Formation in the onshore U.S. Gulf Coast region.
Authors
Justin E. Birdwell, Katherine J. Whidden, Stanley T. Paxton, Scott A. Kinney, Rand D. Gardner, Janet K. Pitman, Katherine L. French, Tracey J. Mercier, Cheryl A. Woodall, Heidi M. Leathers-Miller, Christopher J. Schenk
Assessment of continuous oil and gas resources in the Upper Jurassic Smackover Formation of the onshore U.S. Gulf Coast, 2022
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean continuous resources of 0.8 billion barrels of oil and 16 trillion cubic feet of gas in the Upper Jurassic Smackover Formation of the onshore U.S. Gulf Coast region.
Authors
Katherine J. Whidden, Justin E. Birdwell, Rand D. Gardner, Scott A. Kinney, Stanley T. Paxton, Janet K. Pitman, Christopher J. Schenk
Biosiliceous, organic-rich, and phosphatic facies of Triassic strata of northwest Alaska: Transect across a high-latitude, low-angle continental margin
The Shublik Formation (Middle and Upper Triassic) is a mixed siliciclastic-carbonate-phosphatic unit in northern Alaska. It generated oil found in Prudhoe Bay and other accumulations and is a prospective self-sourced resource play on Alaska’s North Slope. Its distal, deeper-water equivalent—the Otuk Formation—consists largely of radiolarian chert, mudstone, and limestone and contains potential gas
Authors
Julie A. Dumoulin, Katherine J. Whidden, William A. Rouse, Richard O. Lease, Adam Boehlke, Paul O'Sullivan
Assessment of undiscovered gas resources in Upper Devonian to Lower Cretaceous strata of the western North Slope, Alaska, 2021
Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 1,407 billion (1.4 trillion) cubic feet of gas in conventional accumulations in Upper Devonian to Lower Cretaceous strata of the western North Slope, Alaska.
Authors
David W. Houseknecht, Tracey J. Mercier, Christopher J. Schenk, Thomas E. Moore, William A. Rouse, Julie A. Dumoulin, William H. Craddock, Richard O. Lease, Palma J. Botterell, Margaret M. Sanders, Rebecca A. Smith, Christopher D. Connors, Christopher P. Garrity, Katherine J. Whidden, Jared T. Gooley, John W. Counts, Joshua H. Long, Christina A. DeVera
Energy and minerals division tight oil and gas committee: Activities and commodity report for 2019-2020
In 2019, total daily tight oil and gas production increased in the United States month over month, with annualized growth of 14% for oil and 12% for gas. Those gains leveled off in the first quarter of 2020 due to aggressive price competition and increases in international production. Then came the pandemic with a substantially larger dose of economic turmoil, driving down demand due in part to sh
Authors
Justin E. Birdwell, Kent Bowker, Ben Burke, Thomas Chidsey, Ursula Hammes, Bo Henk, Zachary Hollon, Shu Jiang, Peng Li, Kristen R. Marra, Jock McCracken, Richard Nyahay, Abbas Seyedolali, Katie Schmid, Beau Tinnin, Katherine J. Whidden
Assessment of undiscovered oil and gas resources in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations, U.S. Gulf Coast, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 6.9 billion barrels of oil and 41.5 trillion cubic feet of natural gas in conventional and continuous accumulations in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations onshore and in State waters of the U.S. Gulf Coast region.
Authors
Janet K. Pitman, Stanley T. Paxton, Scott A. Kinney, Katherine J. Whidden, Seth S. Haines, Brian A. Varela, Tracey J. Mercier, Cheryl A. Woodall, Christopher J. Schenk, Heidi M. Leathers-Miller, Ofori N. Pearson, Lauri A. Burke, Phuong A. Le, Justin E. Birdwell, Nicholas J. Gianoutsos, Katherine L. French, Ronald M. Drake, Thomas M. Finn, Geoffrey S. Ellis, Stephanie B. Gaswirth, Kristen R. Marra, Marilyn E. Tennyson, Chilisa M. Shorten
Surface to subsurface correlation of the Middle-Upper Triassic Shublik Formation within a revised sequence stratigraphic framework
Recent work on cores and outcrops of the Middle-Upper Triassic Shublik Formation has facilitated surface to subsurface correlation of depositional sequences across the Alaska North Slope. Five transgressive-regressive depositional sequences have been defined within three large-scale stratigraphic units. Outcrop spectral gamma-ray (GR) profiles were used to correlate observed stacking patterns with
Authors
William A. Rouse, Katherine J. Whidden, Julie A. Dumoulin, David W. Houseknecht
Assessment of undiscovered oil and gas resources in the Central North Slope of Alaska, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 3.6 billion barrels of oil and 8.9 trillion cubic feet of natural gas (associated and nonassociated) in conventional accumulations in Mississippian through Paleogene strata in the central North Slope of Alaska.
Authors
David W. Houseknecht, Katherine J. Whidden, Christopher D. Connors, Richard O. Lease, Christopher J. Schenk, Tracey J. Mercier, William A. Rouse, Palma J. Botterell, Rebecca A. Smith, Margaret M. Sanders, William H. Craddock, Christina A. DeVera, Christopher P. Garrity, Marc L. Buursink, C. Özgen Karacan, Samuel J. Heller, Thomas E. Moore, Julie A. Dumoulin, Marilyn E. Tennyson, Katherine L. French, Cheryl A. Woodall, Ronald M. Drake, Kristen R. Marra, Thomas M. Finn, Scott A. Kinney, Chilisa M. Shorten
Assessment of water and proppant quantities associated with petroleum production from the Eagle Ford Group, Gulf Coast, Texas, 2019
Building on a geology-based assessment of undiscovered, technically recoverable petroleum resources in the Eagle Ford Group in south Texas, the U.S. Geological Survey has estimated the required water and proppant demands and formation water production volumes associated with possible future development of these petroleum resources. The results of the water and proppant assessment are presented her
Authors
Nicholas J. Gianoutsos, Seth S. Haines, Brian A. Varela, Katherine J. Whidden, Justin E. Birdwell, Lauri A. Burke, Ronald M. Drake, Thomas M. Finn, Katherine L. French, Karen E. Jenni, Scott A. Kinney, Phuong A. Le, Heidi M. Leathers-Miller, Kristen R. Marra, Tracey J. Mercier, Stanley T. Paxton, Janet K. Pitman, Christopher J. Schenk, Brian N. Shaffer, Chilisa M. Shorten, Marilyn E. Tennyson, Cheryl A. Woodall
Element cycling in the Middle-Late Triassic Shublik Formation: Mineralization vs. recycling of biolimiting nutrients in an unconventional resource play
The Triassic Shublik Formation in northern Alaska is one of the major source rocks in North America, having generated much of the petroleum in Prudhoe Bay and associated fields. The middle Shublik Formation, the focus of this study, is a highly phosphatic, organic-rich carbonate mudstone interval. Apatite cements can occur as phosphatic peloids, steinkerns, elongate or angular nodules, and shells
Authors
Katherine J. Whidden, Julie A. Dumoulin, James Macquaker, Justin E. Birdwell, Adam Boehlke, Katherine L. French
Science and Products
Gulf Coast Geologic Energy Research
The Gulf Coast Geologic Energy Assessments and Research (GEAR) project also conducts research on the properties and processes relevant to the Gulf Coast Jurassic-Cretaceous-Tertiary composite total petroleum system (TPS). This research aims to improve ongoing and future undiscovered, technically recoverable hydrocarbon resources assessments on the onshore and State waters portion of the Gulf Coast...
Controls on Unconventional Oil and Gas Production
This scoping task incorporates insights from new approaches to production of unconventional resources and currently focuses on conducting a pilot assessment of biogenic natural gas resources in the Permian Basin. For the pilot assessment to occur, we are developing a database that will host geochemical parameters known to be suggestive of microbial methanogenesis mined to the reservoir level for...
Gulf Coast Geologic Energy Assessments
One of the main goals of the Gulf Coast Geologic Energy Assessments and Research (GEAR) project is to conduct assessments of undiscovered, technically recoverable petroleum resources of the U.S. Gulf Coast region. This goal is in accordance with the Energy Policy and Conservation Act (EPCA) and is performed in collaboration with the USGS National Oil and Gas Assessment project. These high-quality...
Carbon Isotopes, Total Organic Carbon, Programmed Pyrolysis, Volcanic Zircon U-Pb, and Geochemistry Data from the Hue Shale, Arctic Alaska - 2024
This dataset contains results from a stratigraphic section of the Hue Shale located along the Jago River in the Arctic National Wildlife Refuge at 69.9099, -143.3947 (WGS84). Sample heights were measured with a tape measure in a continuous succession. Zircon grains from volcanic ashes were analyzed via laser ablation at either the University of California, Santa Barbara (UCSB) or the University of
Geochemical Data from Selected Triassic Rock Samples in Northeastern Alaska
This set of data files contains analyses of samples representing Triassic units (Shublik and Ivishak Formations and Karen Creek Sandstone) in Alaska. The samples were collected from 20 outcrop localities in northeastern Alaska. The data set includes total organic carbon (TOC) and geochemical data from inductively coupled plasma-optical emission spectroscopy-mass spectroscopy (ICP-OES-MS) and porta
USGS Gulf Coast Geologic Energy Assessments and Research Project-Upper Jurassic Smackover Formation Continuous Resources: Assessment Unit Boundaries, Assessment Input Data, and Fact Sheet Data Tables
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered continuous oil and gas resources in the Smackover formation in the U.S. Gulf Coast. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the highe
Geochemical, Geochronologic, Rock-Eval, and Spectral Gamma Ray Data for Selected Triassic Rocks in Northwestern Alaska
This set of data files contains analyses of samples representing the Triassic Shublik and Otuk Formations in Alaska. The samples were collected from the Brontosaurus 1 well and measured stratigraphic sections at Surprise Creek and Cape Lisburne. The data set includes total organic carbon (TOC), Rock-Eval (Tmax) data, geochemical data from inductively coupled plasma-optical emission spectroscopy-ma
Subsurface stratigraphic picks of the Middle-Upper Triassic Shublik Formation, Alaska North Slope
The Middle-Upper Triassic Shublik Formation is the main source rock for Arctic Alaska oil and gas accumulations, including the supergiant Prudhoe Bay field. A revised stratigraphic framework recently has been developed in outcrop for the Shublik and related strata that delineates three large-scale stratigraphic units: 1) the lower clastic (LC) unit, 2) the middle carbonate-chert (MCC) unit, and 3)
Filter Total Items: 47
Facies variation within outcrops of the Triassic Shublik Formation, northeastern Alaska
The Shublik Formation (Middle to Upper Triassic) is a heterogeneous unit that is a major hydrocarbon source rock in northern Alaska and the largest known Triassic phosphate accumulation in the world. This formation, which occurs in the subsurface and crops out within the Arctic Alaska basin, was deposited on a gently sloping ramp along the northwestern Laurentian margin. In this study, we document
Authors
Julie A. Dumoulin, Katherine J. Whidden, William A. Rouse, Christina A. DeVera
Examining water and proppant demand, and produced water production, associated with petroleum resource development in the Eagle Ford Group, Texas
More than 20,000 horizontal wells have been drilled and hydraulically fractured in the Eagle Ford Group since the discovery well in 2008, but a considerable amount of undiscovered petroleum remains. Recently, drilled wells have been hydraulically fractured with an average of nearly 13 million gallons of water and 16 million lb of sand, yielding a million or more gallons of produced water. To infor
Authors
Nicholas J. Gianoutsos, Seth S. Haines, Brian A. Varela, Katherine J. Whidden
Assessment of undiscovered, technically recoverable conventional oil and gas resources in the Upper Jurassic Smackover Formation, U.S. Gulf Coast, 2022
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 143 million barrels of oil and 1,084 billion cubic feet of natural gas in conventional accumulations for the Upper Jurassic Smackover Formation in the onshore U.S. Gulf Coast region.
Authors
Justin E. Birdwell, Katherine J. Whidden, Stanley T. Paxton, Scott A. Kinney, Rand D. Gardner, Janet K. Pitman, Katherine L. French, Tracey J. Mercier, Cheryl A. Woodall, Heidi M. Leathers-Miller, Christopher J. Schenk
Assessment of continuous oil and gas resources in the Upper Jurassic Smackover Formation of the onshore U.S. Gulf Coast, 2022
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean continuous resources of 0.8 billion barrels of oil and 16 trillion cubic feet of gas in the Upper Jurassic Smackover Formation of the onshore U.S. Gulf Coast region.
Authors
Katherine J. Whidden, Justin E. Birdwell, Rand D. Gardner, Scott A. Kinney, Stanley T. Paxton, Janet K. Pitman, Christopher J. Schenk
Biosiliceous, organic-rich, and phosphatic facies of Triassic strata of northwest Alaska: Transect across a high-latitude, low-angle continental margin
The Shublik Formation (Middle and Upper Triassic) is a mixed siliciclastic-carbonate-phosphatic unit in northern Alaska. It generated oil found in Prudhoe Bay and other accumulations and is a prospective self-sourced resource play on Alaska’s North Slope. Its distal, deeper-water equivalent—the Otuk Formation—consists largely of radiolarian chert, mudstone, and limestone and contains potential gas
Authors
Julie A. Dumoulin, Katherine J. Whidden, William A. Rouse, Richard O. Lease, Adam Boehlke, Paul O'Sullivan
Assessment of undiscovered gas resources in Upper Devonian to Lower Cretaceous strata of the western North Slope, Alaska, 2021
Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 1,407 billion (1.4 trillion) cubic feet of gas in conventional accumulations in Upper Devonian to Lower Cretaceous strata of the western North Slope, Alaska.
Authors
David W. Houseknecht, Tracey J. Mercier, Christopher J. Schenk, Thomas E. Moore, William A. Rouse, Julie A. Dumoulin, William H. Craddock, Richard O. Lease, Palma J. Botterell, Margaret M. Sanders, Rebecca A. Smith, Christopher D. Connors, Christopher P. Garrity, Katherine J. Whidden, Jared T. Gooley, John W. Counts, Joshua H. Long, Christina A. DeVera
Energy and minerals division tight oil and gas committee: Activities and commodity report for 2019-2020
In 2019, total daily tight oil and gas production increased in the United States month over month, with annualized growth of 14% for oil and 12% for gas. Those gains leveled off in the first quarter of 2020 due to aggressive price competition and increases in international production. Then came the pandemic with a substantially larger dose of economic turmoil, driving down demand due in part to sh
Authors
Justin E. Birdwell, Kent Bowker, Ben Burke, Thomas Chidsey, Ursula Hammes, Bo Henk, Zachary Hollon, Shu Jiang, Peng Li, Kristen R. Marra, Jock McCracken, Richard Nyahay, Abbas Seyedolali, Katie Schmid, Beau Tinnin, Katherine J. Whidden
Assessment of undiscovered oil and gas resources in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations, U.S. Gulf Coast, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 6.9 billion barrels of oil and 41.5 trillion cubic feet of natural gas in conventional and continuous accumulations in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations onshore and in State waters of the U.S. Gulf Coast region.
Authors
Janet K. Pitman, Stanley T. Paxton, Scott A. Kinney, Katherine J. Whidden, Seth S. Haines, Brian A. Varela, Tracey J. Mercier, Cheryl A. Woodall, Christopher J. Schenk, Heidi M. Leathers-Miller, Ofori N. Pearson, Lauri A. Burke, Phuong A. Le, Justin E. Birdwell, Nicholas J. Gianoutsos, Katherine L. French, Ronald M. Drake, Thomas M. Finn, Geoffrey S. Ellis, Stephanie B. Gaswirth, Kristen R. Marra, Marilyn E. Tennyson, Chilisa M. Shorten
Surface to subsurface correlation of the Middle-Upper Triassic Shublik Formation within a revised sequence stratigraphic framework
Recent work on cores and outcrops of the Middle-Upper Triassic Shublik Formation has facilitated surface to subsurface correlation of depositional sequences across the Alaska North Slope. Five transgressive-regressive depositional sequences have been defined within three large-scale stratigraphic units. Outcrop spectral gamma-ray (GR) profiles were used to correlate observed stacking patterns with
Authors
William A. Rouse, Katherine J. Whidden, Julie A. Dumoulin, David W. Houseknecht
Assessment of undiscovered oil and gas resources in the Central North Slope of Alaska, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 3.6 billion barrels of oil and 8.9 trillion cubic feet of natural gas (associated and nonassociated) in conventional accumulations in Mississippian through Paleogene strata in the central North Slope of Alaska.
Authors
David W. Houseknecht, Katherine J. Whidden, Christopher D. Connors, Richard O. Lease, Christopher J. Schenk, Tracey J. Mercier, William A. Rouse, Palma J. Botterell, Rebecca A. Smith, Margaret M. Sanders, William H. Craddock, Christina A. DeVera, Christopher P. Garrity, Marc L. Buursink, C. Özgen Karacan, Samuel J. Heller, Thomas E. Moore, Julie A. Dumoulin, Marilyn E. Tennyson, Katherine L. French, Cheryl A. Woodall, Ronald M. Drake, Kristen R. Marra, Thomas M. Finn, Scott A. Kinney, Chilisa M. Shorten
Assessment of water and proppant quantities associated with petroleum production from the Eagle Ford Group, Gulf Coast, Texas, 2019
Building on a geology-based assessment of undiscovered, technically recoverable petroleum resources in the Eagle Ford Group in south Texas, the U.S. Geological Survey has estimated the required water and proppant demands and formation water production volumes associated with possible future development of these petroleum resources. The results of the water and proppant assessment are presented her
Authors
Nicholas J. Gianoutsos, Seth S. Haines, Brian A. Varela, Katherine J. Whidden, Justin E. Birdwell, Lauri A. Burke, Ronald M. Drake, Thomas M. Finn, Katherine L. French, Karen E. Jenni, Scott A. Kinney, Phuong A. Le, Heidi M. Leathers-Miller, Kristen R. Marra, Tracey J. Mercier, Stanley T. Paxton, Janet K. Pitman, Christopher J. Schenk, Brian N. Shaffer, Chilisa M. Shorten, Marilyn E. Tennyson, Cheryl A. Woodall
Element cycling in the Middle-Late Triassic Shublik Formation: Mineralization vs. recycling of biolimiting nutrients in an unconventional resource play
The Triassic Shublik Formation in northern Alaska is one of the major source rocks in North America, having generated much of the petroleum in Prudhoe Bay and associated fields. The middle Shublik Formation, the focus of this study, is a highly phosphatic, organic-rich carbonate mudstone interval. Apatite cements can occur as phosphatic peloids, steinkerns, elongate or angular nodules, and shells
Authors
Katherine J. Whidden, Julie A. Dumoulin, James Macquaker, Justin E. Birdwell, Adam Boehlke, Katherine L. French