Minnesota

@article{berg1954franconia,
    author = "BERG, ROBERT R.",
    title = "FRANCONIA FORMATION OF MINNESOTA AND WISCONSIN",
    year = "1954",
    journal = "Geological Society of America Bulletin",
    url = "https://doi.org/10.1130/0016-7606(1954)65[857:ffomaw]2.0.co;2",
    doi = "10.1130/0016-7606(1954)65[857:ffomaw]2.0.co;2",
    number = "9",
    openalex = "W2036940177",
    pages = "857",
    volume = "65"
}

9 Introduction 9 Terminology used in this report 14 Acknowledgments 14 Precambrian basement complex 14 St. Croixan series (Upper Cambrian) 19 Red Clastics 19 Mt. Simon sandstone 22 Lithology and thickness in Indiana 22 Lithology and thickness in surrounding region 22 Outcrop region 22 Illinois 24 Michigan 25 Ohio 25 Kentucky 25 Correlation of the Mt. Simon sandstone 26 Eau Claire formation 27 Lithology and thickness in Indiana 27 Lithology and thickness in surrounding region 28 Outcrop region 28 Illinois 28 Michigan 30 Ohio 30 Kentucky 30 Correlation of the Eau Claire formation 31 Galesville sandstone 32 Lithology and thickness in Indiana 32 Lithology and thickness in surrounding region 34 Correlation of the Galesville sandstone 34 Knox dolomite (Upper Cambrian and Lower Ordovician) 35 Methods of subdivision 35 Lithology and thickness in Indiana 39 Lithology and thickness of equivalents of the Knox dolomite in surrounding region 42 Upper Mississippi Valley region 42 Illinois 43 Michigan 47 Ohio 48 Missouri 49 Kentucky 51 Problems of Knox stratigraphy 52

@article{openalexw580072650,
    author = "Gutstadt, Allan M.",
    title = "Cambrian and Ordovician Stratigraphy and Oil and Gas Possibilities in Indiana",
    year = "1958",
    journal = "IUScholarWorks (Indiana University)",
    abstract = "9 Introduction 9 Terminology used in this report 14 Acknowledgments 14 Precambrian basement complex 14 St. Croixan series (Upper Cambrian) 19 Red Clastics 19 Mt. Simon sandstone 22 Lithology and thickness in Indiana 22 Lithology and thickness in surrounding region 22 Outcrop region 22 Illinois 24 Michigan 25 Ohio 25 Kentucky 25 Correlation of the Mt. Simon sandstone 26 Eau Claire formation 27 Lithology and thickness in Indiana 27 Lithology and thickness in surrounding region 28 Outcrop region 28 Illinois 28 Michigan 30 Ohio 30 Kentucky 30 Correlation of the Eau Claire formation 31 Galesville sandstone 32 Lithology and thickness in Indiana 32 Lithology and thickness in surrounding region 34 Correlation of the Galesville sandstone 34 Knox dolomite (Upper Cambrian and Lower Ordovician) 35 Methods of subdivision 35 Lithology and thickness in Indiana 39 Lithology and thickness of equivalents of the Knox dolomite in surrounding region 42 Upper Mississippi Valley region 42 Illinois 43 Michigan 47 Ohio 48 Missouri 49 Kentucky 51 Problems of Knox stratigraphy 52",
    url = "https://openalex.org/W580072650",
    openalex = "W580072650",
    references = "doi10113000167606195465299cotofo20co2, doi101130gsab461687, doi101130gsab46559, doi101130gsab55993, doi1013063d9337fe16b111d78645000102c1865d, doi1013063d933bf916b111d78645000102c1865d, doi1013063d933bff16b111d78645000102c1865d, doi1013065ceadd9d16bb11d78645000102c1865d, doi1013065ceae16016bb11d78645000102c1865d, openalexw1752684099"
}

@article{farkas1960crosslamination,
    author = "Farkas, Steven E.",
    title = "Cross-Lamination Analysis in the Upper Cambrian Franconia Formation of Wisconsin",
    year = "1960",
    journal = "SEPM Journal of Sedimentary Research",
    url = "https://doi.org/10.1306/74d70a5b-2b21-11d7-8648000102c1865d",
    doi = "10.1306/74d70a5b-2b21-11d7-8648000102c1865d",
    openalex = "W2155374581",
    volume = "Vol. 30"
}

@article{grant1962trilobite1,
    author = "Grant, R. E",
    title = "Trilobite distribution, upper Franconia Formation (Upper Cambrian), southeastern Minnesota",
    year = "1962",
    journal = "Journal of Paleontology, v. 36, p. 965- 998",
    note = "talkorigins\_source = {true}; raw\_reference = {Grant, R. E., 1962, Trilobite distribution, upper Franconia Formation (Upper Cambrian), southeastern Minnesota: Journal of Paleontology, v. 36, p. 965- 998.}"
}

Trilobites collected during the past 20 years from the Morgan Creek, Point Peak, and San Saba Members of the Wilberns Formation comprise 89 species assigned to 45 genera belonging to zones of the upper Franconian and Trempealeauan Stages of the Upper Cambrian Croixan Series. New zonal names are proposed in the interest of a regionally applicable nomenclature. Although none of the zonal nomenclature is identical to that of the 1944 Cambrian Correlation Chart of Howell et al., the four zones recognized in central Texas are equivalent to the eight highest zones on the Chart. Stratigraphically lowest is the Franconian Taenicephalus Zone, with a locally recognized Parabolinoides Subzone at its base; this zone is equivalent to the Conaspis Zone of the Correlation Chart. The Franconian Idahoia Zone, with a locally recognized Idahoia lirae Subzone at its base, is equivalent to the Ptychaspis Subzone of the Ptychaspis-Prosaukia Zone of the Correlation Chart. The sparsely fossiliferous Ellipsocephaloides Zone corresponds to the Prosaukia Subzone of the Ptychaspis-Prosaukia Zone on the Chart. Almost two-thirds of the trilobite species described occur in the Trempealeauan Saukia Zone, which corresponds to the five highest zones of the Correlation Chart; local subzones, in ascending order, are the Saukiella pyrene Subzone, the Saukiella junta Subzone, the Saukiella serotina Subzone, and the Corbinia apopsis Subzone. The succession of ptychoparioid trilobite faunas within these zones characterizes the Ptychaspid Biomere. The base of the biomere is at the base of the Taenicephalus Zone; the top coincides with the lowest occurrence of an Ordovician trilobite fauna. Trilobite families that characterize the Ptychaspid Biomere are the Ptychaspididae and the Parabolinoididae. Systematic descriptions include two new subfamilies, Drumaspidinae and Ptychaspidinae, and eight new species, Conaspis leptoholcis, Idiomesus infimus, Euptychaspis frontalis, Keithiella scapane, Saukiella serotina, Prosaukia remora, Calvinella prethoparia, and Westonaspis? texana.

@article{doi101017s002233600006128x,
    author = "LONGACRE, SUSAN A.",
    title = "Trilobites of the Upper Cambrian Ptychaspid Biomere Wilberns Formation, Central Texas",
    year = "1970",
    journal = "Journal of Paleontology",
    abstract = "Trilobites collected during the past 20 years from the Morgan Creek, Point Peak, and San Saba Members of the Wilberns Formation comprise 89 species assigned to 45 genera belonging to zones of the upper Franconian and Trempealeauan Stages of the Upper Cambrian Croixan Series. New zonal names are proposed in the interest of a regionally applicable nomenclature. Although none of the zonal nomenclature is identical to that of the 1944 Cambrian Correlation Chart of Howell et al., the four zones recognized in central Texas are equivalent to the eight highest zones on the Chart. Stratigraphically lowest is the Franconian Taenicephalus Zone, with a locally recognized Parabolinoides Subzone at its base; this zone is equivalent to the Conaspis Zone of the Correlation Chart. The Franconian Idahoia Zone, with a locally recognized Idahoia lirae Subzone at its base, is equivalent to the Ptychaspis Subzone of the Ptychaspis-Prosaukia Zone of the Correlation Chart. The sparsely fossiliferous Ellipsocephaloides Zone corresponds to the Prosaukia Subzone of the Ptychaspis-Prosaukia Zone on the Chart. Almost two-thirds of the trilobite species described occur in the Trempealeauan Saukia Zone, which corresponds to the five highest zones of the Correlation Chart; local subzones, in ascending order, are the Saukiella pyrene Subzone, the Saukiella junta Subzone, the Saukiella serotina Subzone, and the Corbinia apopsis Subzone. The succession of ptychoparioid trilobite faunas within these zones characterizes the Ptychaspid Biomere. The base of the biomere is at the base of the Taenicephalus Zone; the top coincides with the lowest occurrence of an Ordovician trilobite fauna. Trilobite families that characterize the Ptychaspid Biomere are the Ptychaspididae and the Parabolinoididae. Systematic descriptions include two new subfamilies, Drumaspidinae and Ptychaspidinae, and eight new species, Conaspis leptoholcis, Idiomesus infimus, Euptychaspis frontalis, Keithiella scapane, Saukiella serotina, Prosaukia remora, Calvinella prethoparia, and Westonaspis? texana.",
    url = "https://doi.org/10.1017/s002233600006128x",
    doi = "10.1017/s002233600006128x",
    openalex = "W1912065905",
    references = "berg1954franconia, doi1010160012825272900724, doi101130gsab461687, doi101130gsab481079, doi101130spe32, doi103133pp374f, doi105281zenodo16048491, doi105479si0096380113820267, doi105962bhltitle38399, openalexw2593310263, openalexw2594536661"
}

@article{florin1970lateglacial,
    author = "Florin, Maj-Britt",
    title = "Late-Glacial Diatoms of Kirchner Marsh, Southeastern Minnesota",
    year = "1970",
    journal = "Nova Hedwigia, Beihefte",
    url = "https://doi.org/10.1127/nova.beihefte/31/1970/667",
    doi = "10.1127/nova.beihefte/31/1970/667",
    openalex = "W4210701362",
    pages = "667-756",
    volume = "31"
}

Abstract The composite Cambrian sequence of the Lower Peninsula of Michigan consists, in ascending order, of the Mt. Simon Sandstone; Munising Group, composed of the Eau Claire Formation, Galesville Sandstone, and Franconia Formation; St. Lawrence Formation; Lodi Formation (a minor unit); and the Jordan Sandstone. They compose an estimated 3,000 ft (915 m) of section at the approximate depocenter, near or possibly in Ogemaw County. These rocks long have been an enigma to Michigan geologists because of a lack of both drilling information and outcrops. When viewed against the broad, regional stratigraphic framework and defined rigorously in terms of lithology, they are clearly identifiable as representing sedimentary facies deposited in or near the margins of a transgressive-regressive sea. The Mt. Simon Sandstone represents the high-energy shoreline facies of the northerly transgressing Cambrian sea. The glauconitic Eau Claire and Franconia Formations of the Munising Group are composed of sandstone, siltstone, and minor dolomite and shale interbeds which reflect a lower energy, near-shore marine environment. These two units can be distinguished from one another only where separated by the Galesville Sandstone, a regressive unit restricted to southern and western Michigan. Outside the depositional limits of the Galesville, there is present within the Munising Formation interbedded sandstone, dolomite, shale, and nodular anhydrite which, taken together, strongly suggest a shallow to supratidal environment of deposition. Known only in central Michigan, the areal extent of this facies is undetermined. Essentially a dolomite unit, the St. Lawrence Formation contains many chert and cherty sandstone interbeds in southwestern and western Michigan. The term St. Lawrence includes those stratigraphic elements called Trempealeau and Prairie du Chien in previous investigations. The St. Lawrence grades upward into the Jordan Sandstone, a regressive sandstone unit that documents the gradual infilling of the Michigan basin area. The Jordan Sandstone has been identified erroneously in prior reports as the St. Peter Sandstone of the Mid-Continent region, but the St. Peter was not recognized anywhere within the area of study. The top of the section is bounded by an erosional unconformity of regional extent on which rocks of the Glenwood Formation (Middle Ordovician) were deposited. The Mt. Simon through Jordan rocks form an essentially continuous sequence of deposition beginning with marine transgression probably in the Late Cambrian and ending with regression and regional uplift in the Early Ordovician. The sedimentary record clearly places the formation of the Michigan basin back at least to Late Cambrian time. In the light of the growing energy crisis in the United States, the clarification of the stratigraphic relations of these rocks should lead to increased interest in their petroleum potential.

@article{doi10130683d9132b16c711d78645000102c1865d,
    author = "Catacosinos, Paul A.",
    title = "Cambrian Lithostratigraphy of Michigan Basin",
    year = "1973",
    journal = "AAPG Bulletin",
    abstract = "Abstract The composite Cambrian sequence of the Lower Peninsula of Michigan consists, in ascending order, of the Mt. Simon Sandstone; Munising Group, composed of the Eau Claire Formation, Galesville Sandstone, and Franconia Formation; St. Lawrence Formation; Lodi Formation (a minor unit); and the Jordan Sandstone. They compose an estimated 3,000 ft (915 m) of section at the approximate depocenter, near or possibly in Ogemaw County. These rocks long have been an enigma to Michigan geologists because of a lack of both drilling information and outcrops. When viewed against the broad, regional stratigraphic framework and defined rigorously in terms of lithology, they are clearly identifiable as representing sedimentary facies deposited in or near the margins of a transgressive-regressive sea. The Mt. Simon Sandstone represents the high-energy shoreline facies of the northerly transgressing Cambrian sea. The glauconitic Eau Claire and Franconia Formations of the Munising Group are composed of sandstone, siltstone, and minor dolomite and shale interbeds which reflect a lower energy, near-shore marine environment. These two units can be distinguished from one another only where separated by the Galesville Sandstone, a regressive unit restricted to southern and western Michigan. Outside the depositional limits of the Galesville, there is present within the Munising Formation interbedded sandstone, dolomite, shale, and nodular anhydrite which, taken together, strongly suggest a shallow to supratidal environment of deposition. Known only in central Michigan, the areal extent of this facies is undetermined. Essentially a dolomite unit, the St. Lawrence Formation contains many chert and cherty sandstone interbeds in southwestern and western Michigan. The term St. Lawrence includes those stratigraphic elements called Trempealeau and Prairie du Chien in previous investigations. The St. Lawrence grades upward into the Jordan Sandstone, a regressive sandstone unit that documents the gradual infilling of the Michigan basin area. The Jordan Sandstone has been identified erroneously in prior reports as the St. Peter Sandstone of the Mid-Continent region, but the St. Peter was not recognized anywhere within the area of study. The top of the section is bounded by an erosional unconformity of regional extent on which rocks of the Glenwood Formation (Middle Ordovician) were deposited. The Mt. Simon through Jordan rocks form an essentially continuous sequence of deposition beginning with marine transgression probably in the Late Cambrian and ending with regression and regional uplift in the Early Ordovician. The sedimentary record clearly places the formation of the Michigan basin back at least to Late Cambrian time. In the light of the growing energy crisis in the United States, the clarification of the stratigraphic relations of these rocks should lead to increased interest in their petroleum potential.",
    url = "https://doi.org/10.1306/83d9132b-16c7-11d7-8645000102c1865d",
    doi = "10.1306/83d9132b-16c7-11d7-8645000102c1865d",
    openalex = "W1965563401",
    references = "berg1954franconia, doi101086622910, doi10113000167606195668165ucsumv20co2, doi101130001676061961721peotls20co2, doi101130gsab461687, doi1013065ceadd9d16bb11d78645000102c1865d, doi1013065ceae16016bb11d78645000102c1865d, doi101306bc74371516be11d78645000102c1865d, openalexw1138009292, openalexw580072650"
}

@article{lively1983late,
    author = "Lively, R. S.",
    title = "Late Quaternary U-series speleothem growth record from southeastern Minnesota",
    year = "1983",
    journal = "Geology",
    url = "https://doi.org/10.1130/0091-7613(1983)11<259:lqusgr>2.0.co;2",
    doi = "10.1130/0091-7613(1983)11<259:lqusgr>2.0.co;2",
    number = "5",
    openalex = "W2027685573",
    pages = "259",
    volume = "11"
}

@misc{lively1983late2,
    author = "Lively, R. S",
    title = "Late Quaternary U-series speleothem record from southeastern Minnesota",
    year = "1983",
    howpublished = "Geology, v. 11, p. 259-262",
    note = "talkorigins\_source = {true}; raw\_reference = {Lively, R. S., 1983, Late Quaternary U-series speleothem record from southeastern Minnesota: Geology, v. 11, p. 259-262.}"
}

The Upper Mississippi River Basin is diverse in ways that can control the areal distribution and flow of water and the distribution and concentration of constituents that affect water quality. A review of the environmental setting of the Upper Mississippi River Basin study unit of the National Water-Quality Assessment Program is intended to put water quality in perspective with the geology, soils, climate, hydrology, ecology and historical uses of the land and provides a basis for the sampling design of the study. The Upper Mississippi River Basin study unit encompasses about 47,000 square miles and includes all of the basin upstream from Lake Pepin. The climate of the study unit is subhumid continental with cold dry winters and warm, moist summers. Average annual precipitation ranges from 22 inches in the western part of the study unit to 32 inches in the east. Annual runoff ranges from less than 2 inches in the west to 14 inches in the northeast. The physiography of the study unit includes the Superior Upland and the Central Lowland Provinces. The Wisconsin Driftless Area and the Dissected Till Plains are unique physiographic sections of the Central Lowland Province. Hydrogeologic units in glacial deposits include surficial and buried sand and gravel aquifers and confining units. Bedrock aquifers and confining units are part of a thick sequence of sedimentary rocks that can be divided into major aquifers separated by confining units. The population of the study unit was about 3,640,000 as of 1990 and increased 16 percent between 1970 and 1990. Seventy-five percent of the population lives in the Twin Cities metropolitan area. An average of 413 million gallons of water per day was used 59 percent from ground water and 41 percent from surface water. Land use and land cover in the study unit consists of forested, agricultural, and urban areas. About 63 percent of the land area is agricultural. The quality of water in streams and ground water are affected by both natural and anthropogenic factors. The quality of water is generally satisfactory for most domestic, public, industrial, and irrigation uses. Most water is of the calcium-magnesium-bicarbonate type. The initial six-year phase of the Upper Mississippi River Basin National Water-Quality Assessment, lasting from 1994 to 1999, focuses on data collection and analysis in a 19,500 square-mile area in Minnesota and Wisconsin that includes the Twin Cities metropolitan area. The study design focuses on factors that have an influence on or a potential influence on the water quality in that area. The most significant contaminants include nutrients, pesticides, synthetic-organic compounds, and trace metals. Environmental stratification consists of dividing the study unit into subareas with homogeneous characteristics to assess natural and anthropogenic factors affecting water quality. The assessment of water quality in streams and in aquifers is based on the sampling design that compares water quality within homogeneous subareas defined by subbasins or aquifer boundaries. The study unit is stratified at four levels for the surface-water component: glacial deposit composition, surficial geology, general land use and land cover, and secondary land use. Ground-water studies emphasize shallow ground water where quality is most likely influenced by overlying land use and land cover. Stratification for ground-water sampling is superimposed on the distribution of shallow aquifers. For each aquifer and surface-water basin this stratification forms the basis for the proposed sampling design used in the Upper Mississippi River Basin National Water-Quality Assessment.

@misc{doi103133wri964098,
    author = "Stark, J.R. and Andrews, William and Fallon, James D. and Fong, A.L. and Goldstein, Robert M. and Hanson, Paul and Kroening, Sharon E. and Lee, K.E.",
    title = "Water-quality assessment of part of the Upper Mississippi River basin, Minnesota and Wisconsin: Environmental setting and study design",
    year = "1996",
    abstract = "The Upper Mississippi River Basin is diverse in ways that can control the areal distribution and flow of water and the distribution and concentration of constituents that affect water quality. A review of the environmental setting of the Upper Mississippi River Basin study unit of the National Water-Quality Assessment Program is intended to put water quality in perspective with the geology, soils, climate, hydrology, ecology and historical uses of the land and provides a basis for the sampling design of the study. The Upper Mississippi River Basin study unit encompasses about 47,000 square miles and includes all of the basin upstream from Lake Pepin. The climate of the study unit is subhumid continental with cold dry winters and warm, moist summers. Average annual precipitation ranges from 22 inches in the western part of the study unit to 32 inches in the east. Annual runoff ranges from less than 2 inches in the west to 14 inches in the northeast. The physiography of the study unit includes the Superior Upland and the Central Lowland Provinces. The Wisconsin Driftless Area and the Dissected Till Plains are unique physiographic sections of the Central Lowland Province. Hydrogeologic units in glacial deposits include surficial and buried sand and gravel aquifers and confining units. Bedrock aquifers and confining units are part of a thick sequence of sedimentary rocks that can be divided into major aquifers separated by confining units. The population of the study unit was about 3,640,000 as of 1990 and increased 16 percent between 1970 and 1990. Seventy-five percent of the population lives in the Twin Cities metropolitan area. An average of 413 million gallons of water per day was used 59 percent from ground water and 41 percent from surface water. Land use and land cover in the study unit consists of forested, agricultural, and urban areas. About 63 percent of the land area is agricultural. The quality of water in streams and ground water are affected by both natural and anthropogenic factors. The quality of water is generally satisfactory for most domestic, public, industrial, and irrigation uses. Most water is of the calcium-magnesium-bicarbonate type. The initial six-year phase of the Upper Mississippi River Basin National Water-Quality Assessment, lasting from 1994 to 1999, focuses on data collection and analysis in a 19,500 square-mile area in Minnesota and Wisconsin that includes the Twin Cities metropolitan area. The study design focuses on factors that have an influence on or a potential influence on the water quality in that area. The most significant contaminants include nutrients, pesticides, synthetic-organic compounds, and trace metals. Environmental stratification consists of dividing the study unit into subareas with homogeneous characteristics to assess natural and anthropogenic factors affecting water quality. The assessment of water quality in streams and in aquifers is based on the sampling design that compares water quality within homogeneous subareas defined by subbasins or aquifer boundaries. The study unit is stratified at four levels for the surface-water component: glacial deposit composition, surficial geology, general land use and land cover, and secondary land use. Ground-water studies emphasize shallow ground water where quality is most likely influenced by overlying land use and land cover. Stratification for ground-water sampling is superimposed on the distribution of shallow aquifers. For each aquifer and surface-water basin this stratification forms the basis for the proposed sampling design used in the Upper Mississippi River Basin National Water-Quality Assessment.",
    url = "https://doi.org/10.3133/wri964098",
    doi = "10.3133/wri964098",
    openalex = "W1916092359",
    references = "doi101007bf03041202, doi1010970001069419600900000018, doi101126science2575071784, doi101130dnaggnao1159, doi1023071788077, doi105962bhltitle6528, openalexw2280564438, openalexw2400329996, openalexw2410254495, openalexw657807096"
}

@article{hughes2000late,
    author = "HUGHES, NIGEL C. and GUNDERSON, GERALD O. and WEEDON, MICHAEL J.",
    title = "LATE CAMBRIAN CONULARIIDS FROM WISCONSIN AND MINNESOTA",
    year = "2000",
    journal = "Journal of Paleontology",
    url = "https://doi.org/10.1666/0022-3360(2000)074<0828:lccfwa>2.0.co;2",
    doi = "10.1666/0022-3360(2000)074<0828:lccfwa>2.0.co;2",
    number = "5",
    openalex = "W2173253834",
    pages = "828-838",
    volume = "74",
    references = "doi101017s0022336000033953, doi101111j150239311999tb00538x, doi101126science9231776, doi101306212f8cba2b2411d78648000102c1865d, doi1023072992562, doi105962bhltitle38399, doi105962bhltitle82327, openalexw1561458740, openalexw587905045, openalexw616683076"
}

Carbon isotope data from Upper Cambrian sections in three Laurentian basins in northern Utah, central Iowa, and western Newfoundland record a large positive d 13 C excursion (SPICE event) of up to 1 5‰. Peak d 13 C ratios are well dated by trilobite collections to the middle of the Steptoean Stage (Dunderbergia Zone) and occur during maximum regression associated with formation of the Sauk II- Sauk III subsequence boundary on the North American craton. Max- imum regression was marked by an influx of quartz sand into carbon- ate-platform settings in all three widely separated basins. In northern Utah, this quartz sand formed a thick sequence known as the Worm Creek Quartzite, which marks a conspicuous interruption of carbonate deposition during the Middle to Late Cambrian in the region. In west- ern Newfoundland, the thickness of the quartz sand unit is much re- duced but still marks a brief shutdown of the carbonate factory that is unique to the Cambrian shelf succession of the area. In the central Iowa area of the cratonic interior, an upward-shallowing carbonate succession culminates in cross-stratified trilobite grainstones at the peak of the SPICE in Dunderbergia Zone time, and the lowest point on the relative-sea-level curve is associated with the occurrence of coarse quartz sand derived from the encroaching shoreface. Although it is difficult to determine precisely the departure from baseline d 13 C that marks the beginning of the SPICE excursion in the stratigraphic successions analyzed, our results are consistent with a rise and subsequent fall in d 13 C tracking a major regressive-transgressive event recorded across northern Laurentia. The correlation of a major d 13 C excursion with regression is similar to that described for the Late Ordovician, for which the pattern has been attributed to either in- creased carbonate relative to terrigenous weathering rates as ice sheets covered up organic-matter-containing silicates at high latitudes or high productivity and organic-carbon burial driven by oceanic overturn. The lack of known Steptoean-age ice sheets that could have affected the ratio of carbonate to silicate weathering rates suggests that organic- carbon burial was the likely cause of the SPICE event. We suggest that increased weathering and erosion rates during relative sea-level fall (Sauk II-III) increased the burial fraction of organic carbon in an expanded region of fine-grained siliciclastic deposits in shelf and upper slope environments during the Steptoean.

@article{doi101306120203740366,
    author = "Saltzman, Matthew R. and Cowan, Clinton A. and Runkel, Anthony C. and Runnegar, Bruce and Stewart, Mathew and Palmer, Allison R.",
    title = "The Late Cambrian Spice (13C) Event and the Sauk II-SAUK III Regression: New Evidence from Laurentian Basins in Utah, Iowa, and Newfoundland",
    year = "2004",
    journal = "Journal of Sedimentary Research",
    abstract = "Carbon isotope data from Upper Cambrian sections in three Laurentian basins in northern Utah, central Iowa, and western Newfoundland record a large positive d 13 C excursion (SPICE event) of up to 1 5‰. Peak d 13 C ratios are well dated by trilobite collections to the middle of the Steptoean Stage (Dunderbergia Zone) and occur during maximum regression associated with formation of the Sauk II- Sauk III subsequence boundary on the North American craton. Max- imum regression was marked by an influx of quartz sand into carbon- ate-platform settings in all three widely separated basins. In northern Utah, this quartz sand formed a thick sequence known as the Worm Creek Quartzite, which marks a conspicuous interruption of carbonate deposition during the Middle to Late Cambrian in the region. In west- ern Newfoundland, the thickness of the quartz sand unit is much re- duced but still marks a brief shutdown of the carbonate factory that is unique to the Cambrian shelf succession of the area. In the central Iowa area of the cratonic interior, an upward-shallowing carbonate succession culminates in cross-stratified trilobite grainstones at the peak of the SPICE in Dunderbergia Zone time, and the lowest point on the relative-sea-level curve is associated with the occurrence of coarse quartz sand derived from the encroaching shoreface. Although it is difficult to determine precisely the departure from baseline d 13 C that marks the beginning of the SPICE excursion in the stratigraphic successions analyzed, our results are consistent with a rise and subsequent fall in d 13 C tracking a major regressive-transgressive event recorded across northern Laurentia. The correlation of a major d 13 C excursion with regression is similar to that described for the Late Ordovician, for which the pattern has been attributed to either in- creased carbonate relative to terrigenous weathering rates as ice sheets covered up organic-matter-containing silicates at high latitudes or high productivity and organic-carbon burial driven by oceanic overturn. The lack of known Steptoean-age ice sheets that could have affected the ratio of carbonate to silicate weathering rates suggests that organic- carbon burial was the likely cause of the SPICE event. We suggest that increased weathering and erosion rates during relative sea-level fall (Sauk II-III) increased the burial fraction of organic carbon in an expanded region of fine-grained siliciclastic deposits in shelf and upper slope environments during the Steptoean.",
    url = "https://doi.org/10.1306/120203740366",
    doi = "10.1306/120203740366",
    openalex = "W2143615063",
    references = "doi1011300091761319920201039scicis23co2"
}

Southeastern Minnesota's karst lands support numerous trout streams. These trout streams are formed by springs discharging from Paleozoic bedrock. Dye tracing has been the tool of choice for mapping the springsheds (karst groundwater basins) that feed these springs. Previous work was focused on the Galena limestone karst. In order to accelerate springshed mapping, a two-year study was funded by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR). Across southeastern Minnesota, numerous springs discharge from the Cambrian St. Lawrence formation. The St. Lawrence is considered to be a confining unit under the Minnesota well code. A dye trace was initiated when a stream sink was discovered in the upper St. Lawrence Formation. The sampling points included springs, stream crossings, and a municipal well that may be at risk for surface contamination. Dye was recovered at one spring in less than two weeks and at two other springs in less than three weeks. This translates into travel times of 200–300 meters/day. The springs all discharge from the lower St. Lawrence Formation. The St. Lawrence contains beds of dolostone; the dye trace demonstrates that there is a karst conduit flow component in this formation. This is evidence that these springs are significantly more susceptible to degradation than previously thought.

@article{doi1010614100332745,
    author = "Green, Jeffrey A. and Luhmann, Andrew J. and Peters, Andrew J. and Runkel, Anthony C. and Alexander, E. Calvin and Alexander, Scott C.",
    title = "Dye Tracing within the St. Lawrence Confining Unit in Southeastern Minnesota",
    year = "2008",
    journal = "Sinkholes and the Engineering and Environmental Impacts of Karst",
    abstract = "Southeastern Minnesota's karst lands support numerous trout streams. These trout streams are formed by springs discharging from Paleozoic bedrock. Dye tracing has been the tool of choice for mapping the springsheds (karst groundwater basins) that feed these springs. Previous work was focused on the Galena limestone karst. In order to accelerate springshed mapping, a two-year study was funded by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR). Across southeastern Minnesota, numerous springs discharge from the Cambrian St. Lawrence formation. The St. Lawrence is considered to be a confining unit under the Minnesota well code. A dye trace was initiated when a stream sink was discovered in the upper St. Lawrence Formation. The sampling points included springs, stream crossings, and a municipal well that may be at risk for surface contamination. Dye was recovered at one spring in less than two weeks and at two other springs in less than three weeks. This translates into travel times of 200–300 meters/day. The springs all discharge from the lower St. Lawrence Formation. The St. Lawrence contains beds of dolostone; the dye trace demonstrates that there is a karst conduit flow component in this formation. This is evidence that these springs are significantly more susceptible to degradation than previously thought.",
    url = "https://doi.org/10.1061/41003(327)45",
    doi = "10.1061/41003(327)45",
    openalex = "W2335522293",
    references = "doi1010614079617743, doi1010614079617747, openalexw1513056859, openalexw1583262885"
}

ABSTRACT The Eau Claire Formation of the midwestern United States was evaluated for its potential use as a confining unit (seal) overlying a sandstone reservoir to securely store injected CO2. This evaluation included: (1) lithofacies composition and distribution, (2) capillary entry pressure analysis, and (3) fluid- and fracture-pressure analysis. The regional distribution of lithofacies in the Eau Claire was evaluated by examination of core and log data from selected wells across the study area. Log data were used to define electro-lithofacies, which are spatially variable and represent a mixture of shale, siltstone, sandstone, limestone, and dolomite. Because of the significant variation in lithofacies and the complex spatial distribution, the entire interval should be considered in evaluating the seal capacity of the unit at a given locality. Mercury-injection capillary pressure (MICP) data were obtained on 17 samples of Eau Claire lithofacies ranging from muddy shale to sand/silt to evaluate the potential for capillary entry of fluids into the pore system of the lithofacies of the unit. Interpretation of these data indicated capillary failure of the muddy shale lithofacies is unlikely. However, many of the MICP samples contain millimeter-scale silt/sand interbeds, which would probably allow CO2 entry but, because these beds commonly have very limited lateral continuity, they are very unlikely to provide pathways for large-scale CO2 leakage through the interval. Evaluation of structural settings, lithostatic and existing formation aquifer pressures in the Eau Claire, in conjunction with the height of CO2 columns stored in the underlying Mount Simon Sandstone (Cambrian), suggest that fluid pressures induced by a static buoyant CO2 plume are unlikely to induce fractures in the formation. However, elevation of the aquifer pressure during injection may be capable of creating fractures within the unit.

@article{doi101306eg05011414003,
    author = "Lahann, Richard W. and Rupp, John A. and Medina, Cristian R.",
    title = "An evaluation of the seal capacity and CO2 retention properties of the Eau Claire Formation (Cambrian)",
    year = "2014",
    journal = "Environmental Geosciences",
    abstract = "ABSTRACT The Eau Claire Formation of the midwestern United States was evaluated for its potential use as a confining unit (seal) overlying a sandstone reservoir to securely store injected CO2. This evaluation included: (1) lithofacies composition and distribution, (2) capillary entry pressure analysis, and (3) fluid- and fracture-pressure analysis. The regional distribution of lithofacies in the Eau Claire was evaluated by examination of core and log data from selected wells across the study area. Log data were used to define electro-lithofacies, which are spatially variable and represent a mixture of shale, siltstone, sandstone, limestone, and dolomite. Because of the significant variation in lithofacies and the complex spatial distribution, the entire interval should be considered in evaluating the seal capacity of the unit at a given locality. Mercury-injection capillary pressure (MICP) data were obtained on 17 samples of Eau Claire lithofacies ranging from muddy shale to sand/silt to evaluate the potential for capillary entry of fluids into the pore system of the lithofacies of the unit. Interpretation of these data indicated capillary failure of the muddy shale lithofacies is unlikely. However, many of the MICP samples contain millimeter-scale silt/sand interbeds, which would probably allow CO2 entry but, because these beds commonly have very limited lateral continuity, they are very unlikely to provide pathways for large-scale CO2 leakage through the interval. Evaluation of structural settings, lithostatic and existing formation aquifer pressures in the Eau Claire, in conjunction with the height of CO2 columns stored in the underlying Mount Simon Sandstone (Cambrian), suggest that fluid pressures induced by a static buoyant CO2 plume are unlikely to induce fractures in the formation. However, elevation of the aquifer pressure during injection may be capable of creating fractures within the unit.",
    url = "https://doi.org/10.1306/eg.05011414003",
    doi = "10.1306/eg.05011414003",
    openalex = "W2122999390",
    references = "openalexw580072650"
}

@inproceedings{andbarry2015conduit,
    author = "Barry, John and Green, Jeffrey and Steenberg, Julia",
    title = "Conduit Flow in the Cambrian Lone Rock Formation, Southeast Minnesota, U.S.A.",
    year = "2015",
    booktitle = "Sinkholes and the Engineering and Environmental Impacts of Karst: Proceedings of the Fourteenth Multidisciplinary Conference",
    url = "https://doi.org/10.5038/9780991000951.1026",
    doi = "10.5038/9780991000951.1026",
    openalex = "W2175838350",
    pages = "31-42",
    references = "doi1010614100332745, doi101111j174565841998tb01099x, doi101111j17456584200500127x, doi1011302011002422, doi103133sir20115229, openalexw2889189703"
}

Abstract The common belief that organic-rich mudstones formed in quiescent, distal settings is further weakened by study of an upper Cambrian (Leptoplastus – lower Peltura superzones) succession in the Chesley Drive Group in Avalonian Cape Breton Island that is comparable to Alum Shale successions in Baltica. Dramatic sea-level (likely eustatic) changes are now recognized by punctuation of deposition of shallow, wave-influenced black mudstone with brachiopod (Orusia lenticularis) and olenid trilobite-bearing limestones by offlap and formation of a subaerially cemented calcrete-clast conglomerate. Subaerial exposure was followed by transgression and accumulation of clastic pyrite sand and phosphatic granules with Leptoplastus Superzone (L. ovatus Zone) trilobite sclerites. Dynamic processes are shown by wave ripples in the mudstone and limestone, sorting and winnowing of fossil rudstones, and pre-compactional fracture of the conglomerate and rudstones. Orusia rudstones in the succession below the conglomerate are regarded as analogues of Eoorthis and Billingsella rudstones in the ‘biomere’ extinction intervals of the Laurentian basal Sunwaptan. The lowest Orusia -rich beds are no older than the P. spinulosa Zone but, as elsewhere in Avalonia, they range into the higher Leptoplastus (Cape Breton) and even the Peltura (Britain, New Brunswick) superzones. Rare agnostoid sclerites in lower Peltura Superzone (Ctenopyge tumida Zone) olenid rudstone resemble those traditionally assigned to Lotagnostus trisectus in Avalonian Britain and Sweden, and are distinct from Laurentian L. americanus. An L. americanus Zone cannot be identified in Avalonia or Baltica, and the first appearance datum (FAD) of purported ‘ L. americanus ’ is not suitable as a standard for the base of the highest Cambrian stage.

@article{doi101017s001675681400079x,
    author = "Landing, Ed and Westrop, Stephen R.",
    title = "Late Cambrian (middle Furongian) shallow-marine dysoxic mudstone with calcrete and brachiopod–olenid– Lotagnostus faunas in Avalonian Cape Breton Island, Nova Scotia",
    year = "2015",
    journal = "Geological Magazine",
    abstract = "Abstract The common belief that organic-rich mudstones formed in quiescent, distal settings is further weakened by study of an upper Cambrian (Leptoplastus – lower Peltura superzones) succession in the Chesley Drive Group in Avalonian Cape Breton Island that is comparable to Alum Shale successions in Baltica. Dramatic sea-level (likely eustatic) changes are now recognized by punctuation of deposition of shallow, wave-influenced black mudstone with brachiopod (Orusia lenticularis) and olenid trilobite-bearing limestones by offlap and formation of a subaerially cemented calcrete-clast conglomerate. Subaerial exposure was followed by transgression and accumulation of clastic pyrite sand and phosphatic granules with Leptoplastus Superzone (L. ovatus Zone) trilobite sclerites. Dynamic processes are shown by wave ripples in the mudstone and limestone, sorting and winnowing of fossil rudstones, and pre-compactional fracture of the conglomerate and rudstones. Orusia rudstones in the succession below the conglomerate are regarded as analogues of Eoorthis and Billingsella rudstones in the ‘biomere’ extinction intervals of the Laurentian basal Sunwaptan. The lowest Orusia -rich beds are no older than the P. spinulosa Zone but, as elsewhere in Avalonia, they range into the higher Leptoplastus (Cape Breton) and even the Peltura (Britain, New Brunswick) superzones. Rare agnostoid sclerites in lower Peltura Superzone (Ctenopyge tumida Zone) olenid rudstone resemble those traditionally assigned to Lotagnostus trisectus in Avalonian Britain and Sweden, and are distinct from Laurentian L. americanus. An L. americanus Zone cannot be identified in Avalonia or Baltica, and the first appearance datum (FAD) of purported ‘ L. americanus ’ is not suitable as a standard for the base of the highest Cambrian stage.",
    url = "https://doi.org/10.1017/s001675681400079x",
    doi = "10.1017/s001675681400079x",
    openalex = "W2322914709",
    references = "berg1954franconia, doi101016s0070457108x70451, doi101038nature09700, doi1010970001069419650700000024, doi10113000917613198614535scaia20co2, doi101144gsjgs13720171, doi101306m33429, doi102110pec88010039, doi105860choice295709, openalexw1590447055, openalexw1599178669"
}

Abstract New and archival collections from the Chelsey Drive Group of the Avalon terrane of Cape Breton Island, Nova Scotia, Canada, yield late Cambrian trilobites and agnostoid arthropods with full convexity that contrast with compacted, often deformed material from shale and slate typical of Avalonian Britain. Four species of the agnostoid Lotagnostus form a stratigraphic succession in the upper Furongian (Ctenopyge tumida – Parabolina lobata zones). Two species, L. ponepunctus (Matthew, 1901) and L. germanus (Matthew, 1901) are previously named; L. salteri and L. matthewi are new. Lotagnostus trisectus (Salter, 1864), the type species of the genus, is restricted to compacted material from its type area in Malvern, England. Lotagnostus americanus (Billings, 1860) has been proposed as a globally appropriate index for the base of ‘Stage 10’ of the Cambrian. All four species from Avalonian Canada are differentiated clearly from L. americanus in its type area in Laurentian North America (i.e., from debris flow blocks in Taconian Quebec). In our view, putative occurrences of L. americanus from other Cambrian continents record very different species. Lotagnostus americanus cannot be recognized worldwide, and other taxa should be sought to define the base of Stage 10, such as the conodont Eoconodontus notchhpeakensis.

@article{doi101017s0016756816000571,
    author = "Westrop, Stephen R. and Landing, Ed",
    title = "The agnostoid arthropod Lotagnostus Whitehouse, 1936 (late Cambrian; Furongian) from Avalonian Cape Breton Island (Nova Scotia, Canada) and its significance for international correlation",
    year = "2016",
    journal = "Geological Magazine",
    abstract = "Abstract New and archival collections from the Chelsey Drive Group of the Avalon terrane of Cape Breton Island, Nova Scotia, Canada, yield late Cambrian trilobites and agnostoid arthropods with full convexity that contrast with compacted, often deformed material from shale and slate typical of Avalonian Britain. Four species of the agnostoid Lotagnostus form a stratigraphic succession in the upper Furongian (Ctenopyge tumida – Parabolina lobata zones). Two species, L. ponepunctus (Matthew, 1901) and L. germanus (Matthew, 1901) are previously named; L. salteri and L. matthewi are new. Lotagnostus trisectus (Salter, 1864), the type species of the genus, is restricted to compacted material from its type area in Malvern, England. Lotagnostus americanus (Billings, 1860) has been proposed as a globally appropriate index for the base of ‘Stage 10’ of the Cambrian. All four species from Avalonian Canada are differentiated clearly from L. americanus in its type area in Laurentian North America (i.e., from debris flow blocks in Taconian Quebec). In our view, putative occurrences of L. americanus from other Cambrian continents record very different species. Lotagnostus americanus cannot be recognized worldwide, and other taxa should be sought to define the base of Stage 10, such as the conodont Eoconodontus notchhpeakensis.",
    url = "https://doi.org/10.1017/s0016756816000571",
    doi = "10.1017/s0016756816000571",
    openalex = "W2475360221",
    references = "doi101017s001675681400079x"
}

Abstract The Middle and Late Cambrian mixed carbonate–siliciclastic Abrigo Formation of southeastern Arizona was deposited during the Sauk transgression in the craton interior landward of the passive margin of Laurentia. It overlies shallow-marine sandstone of the Bolsa Quartzite, which mantled the Precambrian land surface. The Abrigo Formation consists of ten distinct rock types that comprise fifteen lithofacies, which are grouped into eight facies associations. The strata represent an array of shallow-marine environments that were dominated by wave and storm activity. The interpreted paleoenvironments include lower offshore, upper offshore, offshore transition, and lower, middle, and upper shoreface. These environments migrated laterally as a function of relative sea-level changes along with input of siliciclastic sediment and its effect on carbonate deposition. Stratigraphic distribution of facies indicates that there were two separate carbonate factories: one in the nearshore immediately seaward of the siliciclastic shoreface and the other in the distal offshore area. Correlation across 170 km of the study area suggests that these lithofacies were deposited in six temporally distinct phases involving two transgressive–highstand systems tract couplets during the Bolaspidela through Crepicephalus biozones, a falling-stage systems tract in the Aphelaspis Biozone, and a lowstand systems tract in the Elvinia Biozone following the Sauk II–Sauk III hiatus. In general, the mixed carbonate–siliciclastic depositional environment of the Abrigo Formation shows that fine-grained siliciclastic facies dominate the transgressive systems tract. By contrast, carbonate sedimentation was dominant mostly during the middle to late phase of the highstand. The upper part of the highstand systems tract records progradation of the sandy shoreface. Nevertheless, the ratio between siliciclastic and carbonate sediment in various bathymetric zones differs from previously described inner-detrital-belt examples of Cambrian age. In the Abrigo Formation, some bioclastic grainstone in shoreface deposits contains siliciclastic sand, indicating that the two were deposited together until sand was dominant. However, carbonate production and siliciclastic mud sedimentation were for the most part mutually exclusive, suggesting that the shallow-water carbonate factory during the Middle and Late Cambrian was vulnerable to poisoning from clay or nutrient input. Consequently, carbonate sedimentation in the offshore transition, located between sand-dominated shoreface and mixed carbonate–siliciclastic offshore facies, reflects the bypassing of siliciclastic mud.

@article{doi102110jsr201596,
    author = "Łabaj, Marcelina and Pratt, Brian R.",
    title = "Depositional Dynamics In A Mixed Carbonate–Siliciclastic System: Middle–Upper Cambrian Abrigo Formation, Southeastern Arizona, U.S.A.",
    year = "2016",
    journal = "Journal of Sedimentary Research",
    abstract = "Abstract The Middle and Late Cambrian mixed carbonate–siliciclastic Abrigo Formation of southeastern Arizona was deposited during the Sauk transgression in the craton interior landward of the passive margin of Laurentia. It overlies shallow-marine sandstone of the Bolsa Quartzite, which mantled the Precambrian land surface. The Abrigo Formation consists of ten distinct rock types that comprise fifteen lithofacies, which are grouped into eight facies associations. The strata represent an array of shallow-marine environments that were dominated by wave and storm activity. The interpreted paleoenvironments include lower offshore, upper offshore, offshore transition, and lower, middle, and upper shoreface. These environments migrated laterally as a function of relative sea-level changes along with input of siliciclastic sediment and its effect on carbonate deposition. Stratigraphic distribution of facies indicates that there were two separate carbonate factories: one in the nearshore immediately seaward of the siliciclastic shoreface and the other in the distal offshore area. Correlation across 170 km of the study area suggests that these lithofacies were deposited in six temporally distinct phases involving two transgressive–highstand systems tract couplets during the Bolaspidela through Crepicephalus biozones, a falling-stage systems tract in the Aphelaspis Biozone, and a lowstand systems tract in the Elvinia Biozone following the Sauk II–Sauk III hiatus. In general, the mixed carbonate–siliciclastic depositional environment of the Abrigo Formation shows that fine-grained siliciclastic facies dominate the transgressive systems tract. By contrast, carbonate sedimentation was dominant mostly during the middle to late phase of the highstand. The upper part of the highstand systems tract records progradation of the sandy shoreface. Nevertheless, the ratio between siliciclastic and carbonate sediment in various bathymetric zones differs from previously described inner-detrital-belt examples of Cambrian age. In the Abrigo Formation, some bioclastic grainstone in shoreface deposits contains siliciclastic sand, indicating that the two were deposited together until sand was dominant. However, carbonate production and siliciclastic mud sedimentation were for the most part mutually exclusive, suggesting that the shallow-water carbonate factory during the Middle and Late Cambrian was vulnerable to poisoning from clay or nutrient input. Consequently, carbonate sedimentation in the offshore transition, located between sand-dominated shoreface and mixed carbonate–siliciclastic offshore facies, reflects the bypassing of siliciclastic mud.",
    url = "https://doi.org/10.2110/jsr.2015.96",
    doi = "10.2110/jsr.2015.96",
    openalex = "W2295821911",
    references = "doi101016jsedgeo201309007, doi101016jsedgeo201309008, doi101016s089598110300097x"
}

The focus of this study is application of sequence stratigraphy and chemostratigraphy to the Sesong and Hwajeol formations (Taebaek area) and the Machari Formation (Yeongweol area), which are interpreted to have deposited in mixed carbonate-siliciclastic stable craton interior during the upper Cambrian Series 3 to Furongian.The Sesong and Hwajeol formations consist of nine lithofacies, and seven lithofacies are recognized in the Machari Fromation based on facies analysis.According to the facies stacking pattern and the recognition of bounding surface, the Sesong and Hwajeol formations are comprised of three stratigraphic sequences with two bounding surfaces, and the Machari Formation consists of two stratigraphic sequences with a sequence boundary.Trace elements suggestive of redox condition are analyzed in the Machari Formation.Stable carbon isotope values of whole rock sample, which imply relative sea-level fluctuation, are analyzed in the Sesong and the overlying Hwajeol formations.The Sesong and Hwajeol formations (Taebaek area) and Machari Formation (Yeongweol area) are well correlated based on sequence stratigraphy, chemostratigraphy, and biostratigraphy.Stratigraphic sequences and bounding surfaces are compared with those of Gushan and Chaomidian formations in Shandong region, China.Sequence stratigraphic correlation between the two regions suggests that a basin-scale correlation is possible with sequence-bounding surfaces developed in stable cratonic interior basins characterized by mixed carbonate-siliciclastic environment.Sequence stratigraphic interpretation of this region suggest that the interplayDSS-1 -1.85 -17.91 DSS-46 -0.26 -23.54 DSS-7 -2.74 -24.10 DSS-47 -2.26 -22.31DSS-9 -2.85 -19.66 DSS-48 -3.27 -21.73 DSS-10 -3.53 -20.51 DSS-50 -4.99 -22.96DSS-11 -3.79 -22.64 DSS-51 -5.04 -19.65 DSS-12 -3.74 -22.

@phdthesis{openalexw2770164719,
    author = "김윤종",
    title = "Sequence Stratigraphy and Chemostratigraphy of the Cambrian Sesong and Hwajeol formations (Taebaek area) and the Machari Formation (Yeongweol area), Gangweon Province, Korea: Implications for a Mixed Carbonate-siliciclastic Environment of Stable Cratonic Interior",
    year = "2017",
    booktitle = "Seoul National University Open Repository (Seoul National University)",
    abstract = "The focus of this study is application of sequence stratigraphy and chemostratigraphy to the Sesong and Hwajeol formations (Taebaek area) and the Machari Formation (Yeongweol area), which are interpreted to have deposited in mixed carbonate-siliciclastic stable craton interior during the upper Cambrian Series 3 to Furongian.The Sesong and Hwajeol formations consist of nine lithofacies, and seven lithofacies are recognized in the Machari Fromation based on facies analysis.According to the facies stacking pattern and the recognition of bounding surface, the Sesong and Hwajeol formations are comprised of three stratigraphic sequences with two bounding surfaces, and the Machari Formation consists of two stratigraphic sequences with a sequence boundary.Trace elements suggestive of redox condition are analyzed in the Machari Formation.Stable carbon isotope values of whole rock sample, which imply relative sea-level fluctuation, are analyzed in the Sesong and the overlying Hwajeol formations.The Sesong and Hwajeol formations (Taebaek area) and Machari Formation (Yeongweol area) are well correlated based on sequence stratigraphy, chemostratigraphy, and biostratigraphy.Stratigraphic sequences and bounding surfaces are compared with those of Gushan and Chaomidian formations in Shandong region, China.Sequence stratigraphic correlation between the two regions suggests that a basin-scale correlation is possible with sequence-bounding surfaces developed in stable cratonic interior basins characterized by mixed carbonate-siliciclastic environment.Sequence stratigraphic interpretation of this region suggest that the interplayDSS-1 -1.85 -17.91 DSS-46 -0.26 -23.54 DSS-7 -2.74 -24.10 DSS-47 -2.26 -22.31DSS-9 -2.85 -19.66 DSS-48 -3.27 -21.73 DSS-10 -3.53 -20.51 DSS-50 -4.99 -22.96DSS-11 -3.79 -22.64 DSS-51 -5.04 -19.65 DSS-12 -3.74 -22.",
    openalex = "W2770164719",
    references = "doi101016jsedgeo201309007"
}

A decade of dye tracing in southeastern Minnesota within shallow, buried Cambrian siliciclastic units has revealed groundwater flow characteristics more commonly associated with carbonate karst aquifers. To understand the hydrologic system, several characterization methods were used on a pair of dye traces in central Winona County in southeast Minnesota. South of the City of Stockton, Minnesota, a deeply incised north-south trending valley and its tributaries contain a number of large springs and several sinking streams. In the project area, streams sink into the lower part of the Cambrian siliciclastic Jordan Sandstone or the upper portion of the underlying Cambrian St. Lawrence Formation. The St. Lawrence Formation consists of interbedded well-cemented siltstone, very fine-grained sandstone, and very thin shale. Most of the large springs found in deeply incised valleys in southeastern Minnesota emanate from the basal St. Lawrence and upper Lone Rock Formations. The Lone Rock is a siliciclastic unit consisting of fine-grained sandstone and siltstone with minor beds of shale and dolostone. Passive charcoal detectors were used to calculate dye-breakthrough velocities that ranged between 58-203 meters/day at one location and 47-72 meters/day at another. These velocities are consistent with other trace velocities measured within siliciclastic units in southeastern Minnesota. Water samples collected at the sinking streams, springs, and a domestic well in the project area show elevated nitrate and chloride concentrations indicating the presence anthropogenic impacts likely related to application of fertilizers and road salt. Passive geophysical data were collected at the sinking stream locations and at transects within two valleys to characterize depth to bedrock. At the sinking stream above mapped Jordan Sandstone, the depth to bedrock was determined to be 6.4 meters. The depth at the location mapped above the St. Lawrence Formation was determined to be 5.2 meters. These data suggest colluvium and alluvium layers are thicker than what was previously conceptually modeled in this setting. The results of these dye traces are consistent with others in southeast Minnesota showing that the siliciclastic St. Lawrence and Lone Rock Formations have conduit-flow properties similar to those found in carbonate karst aquifers.

@article{doi10503897809910009821034,
    author = "Barry, John D and Green, Jeff A. and Rutelonis, J. Wes and Steenberg, Julia R. and Survey, Minnesota Geological and Alexander, E.",
    title = "Coupling Dye Tracing, Water Chemistry, and Passive Geophysics to Characterize a Siliciclastic Pseudokarst Aquifer, Southeast Minnesota, USA",
    year = "2018",
    abstract = "A decade of dye tracing in southeastern Minnesota within shallow, buried Cambrian siliciclastic units has revealed groundwater flow characteristics more commonly associated with carbonate karst aquifers. To understand the hydrologic system, several characterization methods were used on a pair of dye traces in central Winona County in southeast Minnesota. South of the City of Stockton, Minnesota, a deeply incised north-south trending valley and its tributaries contain a number of large springs and several sinking streams. In the project area, streams sink into the lower part of the Cambrian siliciclastic Jordan Sandstone or the upper portion of the underlying Cambrian St. Lawrence Formation. The St. Lawrence Formation consists of interbedded well-cemented siltstone, very fine-grained sandstone, and very thin shale. Most of the large springs found in deeply incised valleys in southeastern Minnesota emanate from the basal St. Lawrence and upper Lone Rock Formations. The Lone Rock is a siliciclastic unit consisting of fine-grained sandstone and siltstone with minor beds of shale and dolostone. Passive charcoal detectors were used to calculate dye-breakthrough velocities that ranged between 58-203 meters/day at one location and 47-72 meters/day at another. These velocities are consistent with other trace velocities measured within siliciclastic units in southeastern Minnesota. Water samples collected at the sinking streams, springs, and a domestic well in the project area show elevated nitrate and chloride concentrations indicating the presence anthropogenic impacts likely related to application of fertilizers and road salt. Passive geophysical data were collected at the sinking stream locations and at transects within two valleys to characterize depth to bedrock. At the sinking stream above mapped Jordan Sandstone, the depth to bedrock was determined to be 6.4 meters. The depth at the location mapped above the St. Lawrence Formation was determined to be 5.2 meters. These data suggest colluvium and alluvium layers are thicker than what was previously conceptually modeled in this setting. The results of these dye traces are consistent with others in southeast Minnesota showing that the siliciclastic St. Lawrence and Lone Rock Formations have conduit-flow properties similar to those found in carbonate karst aquifers.",
    url = "https://doi.org/10.5038/9780991000982.1034",
    doi = "10.5038/9780991000982.1034",
    openalex = "W2891573959",
    references = "doi1010614100332745"
}

Abstract The Steptoean Positive Carbon Isotope Excursion (SPICE) is globally distributed in late Cambrian sedimentary records but controversially heterogeneous in its magnitudes. Here we use multiple geochemical proxies to investigate the late Cambrian carbonates from the Tangwangzhai section in North China, which were deposited in a shallow coastal environment with three depositional sequences (S1–S3). Each sequence comprises a transgressive systems tract (TST) and a highstand systems tract (HST). The REE + Y and trace element records are consistent with the depositional condition and indicate that terrigenous influence was more significant in the TST than HST. δ 13 C carb and δ 34 S CAS are low in the TST relative to HST, consistent with the scenario that terrigenous inputs were profoundly aggressive to seawater by introducing 13 C-depleted and 34 S-depleted materials. Within the TST of S2, the SPICE excursion shows a scaled-down δ 13 C carb positive shift (∼1.7 ‰) relative to its general records (∼4–6 ‰); the corresponding δ 34 S CAS show no positive excursion. This ‘atypical’ SPICE record is attributed to enhanced 13 C-depleted and 34 S-depleted terrigenous influence during the TST, which would reduce the amplitude of δ 13 C carb excursion, and even obscure δ 34 S CAS excursion. Meanwhile the subaerial unconformity at the base of TST would also cause a partially missing and a ‘snapshot’ preservation. Our study confirms significant local influence to the SPICE records, and further supports the heterogeneity and low sulphate concentrations of the late Cambrian seawater, because of which the SPICE records may be vulnerable to specific depositional conditions (e.g. sea-level, terrigenous input).

@article{doi101017s0016756819000025,
    author = "Huang, Jing and Chen, Yali and Chu, Xuelei and Sun, Tao",
    title = "The geochemistry of the late Cambrian carbonate in North China: the Steptoean Positive Carbon Isotope Excursion (SPICE) record suppressed in a coastal condition?",
    year = "2019",
    journal = "Geological Magazine",
    abstract = "Abstract The Steptoean Positive Carbon Isotope Excursion (SPICE) is globally distributed in late Cambrian sedimentary records but controversially heterogeneous in its magnitudes. Here we use multiple geochemical proxies to investigate the late Cambrian carbonates from the Tangwangzhai section in North China, which were deposited in a shallow coastal environment with three depositional sequences (S1–S3). Each sequence comprises a transgressive systems tract (TST) and a highstand systems tract (HST). The REE + Y and trace element records are consistent with the depositional condition and indicate that terrigenous influence was more significant in the TST than HST. δ 13 C carb and δ 34 S CAS are low in the TST relative to HST, consistent with the scenario that terrigenous inputs were profoundly aggressive to seawater by introducing 13 C-depleted and 34 S-depleted materials. Within the TST of S2, the SPICE excursion shows a scaled-down δ 13 C carb positive shift (∼1.7 ‰) relative to its general records (∼4–6 ‰); the corresponding δ 34 S CAS show no positive excursion. This ‘atypical’ SPICE record is attributed to enhanced 13 C-depleted and 34 S-depleted terrigenous influence during the TST, which would reduce the amplitude of δ 13 C carb excursion, and even obscure δ 34 S CAS excursion. Meanwhile the subaerial unconformity at the base of TST would also cause a partially missing and a ‘snapshot’ preservation. Our study confirms significant local influence to the SPICE records, and further supports the heterogeneity and low sulphate concentrations of the late Cambrian seawater, because of which the SPICE records may be vulnerable to specific depositional conditions (e.g. sea-level, terrigenous input).",
    url = "https://doi.org/10.1017/s0016756819000025",
    doi = "10.1017/s0016756819000025",
    openalex = "W2982579472",
    references = "doi101130g21434ar1"
}

@inproceedings{andbradbury2021small,
    author = "Bradbury, Michael and Hegna, Thomas",
    title = "SMALL SHELLIES IN THE LATE CAMBRIAN?—ENIGMATIC SILICIFIED SHELLY FOSSILS FROM THE ST. CHARLES FORMATION, LATE CAMBRIAN (FURONGIAN) OF SOUTHEASTERN IDAHO, USA",
    year = "2021",
    booktitle = "Geological Society of America Abstracts with Programs",
    url = "https://doi.org/10.1130/abs/2021am-368039",
    doi = "10.1130/abs/2021am-368039",
    openalex = "W3208626533"
}

Abundant well‐preserved microbially induced sedimentary structures (MISS) are exposed in the Xinji Formation, the earliest Cambrian sedimentary unit in North China. The MISS herein are categorized into microbial mat growth structure (wrinkle structures and mat biolaminites) and microbial mat destruction structure (sand cracks and ‘ Manchuriophycus ’ structures). The MISS developed on the surface of thick quartz sandstones, as well as the lithologic interface between thin sandstone and mudstone. Most of the sand cracks lack the direct evidence of microbial activities, whereas the mat biolaminites that consist of filamentous mica, clay minerals, and quartz grains may record the in situ microbial mats. The Xinji Formation deposited along with the Cambrian explosion when biodiversity and abundance of metazoan stayed relatively low. Besides, the intermittently exposed tidal flats are not the ideal place for early life, which exacerbated the ecological vacuum therein. The massive occurrence of the MISS in the siliciclastic rocks of the Xinji Formation indicated that the tidal flat setting during this period was still beneficial for accumulations of microbial mat because of the deficient grazing metazoans and weak bioturbation.

@article{doi101002gj4243,
    author = "Zheng, Wei and Dai, Mingyue and Qi, Yong‐An and Bai, Wan‐Bei and Yang, Wentao and Wang, Min and Xing, Zhifeng and Li, Da",
    title = "Microbially induced sedimentary structures from the Xinji Formation (Cambrian Series 2), Western Henan, North China",
    year = "2021",
    journal = "Geological Journal",
    abstract = "Abundant well‐preserved microbially induced sedimentary structures (MISS) are exposed in the Xinji Formation, the earliest Cambrian sedimentary unit in North China. The MISS herein are categorized into microbial mat growth structure (wrinkle structures and mat biolaminites) and microbial mat destruction structure (sand cracks and ‘ Manchuriophycus ’ structures). The MISS developed on the surface of thick quartz sandstones, as well as the lithologic interface between thin sandstone and mudstone. Most of the sand cracks lack the direct evidence of microbial activities, whereas the mat biolaminites that consist of filamentous mica, clay minerals, and quartz grains may record the in situ microbial mats. The Xinji Formation deposited along with the Cambrian explosion when biodiversity and abundance of metazoan stayed relatively low. Besides, the intermittently exposed tidal flats are not the ideal place for early life, which exacerbated the ecological vacuum therein. The massive occurrence of the MISS in the siliciclastic rocks of the Xinji Formation indicated that the tidal flat setting during this period was still beneficial for accumulations of microbial mat because of the deficient grazing metazoans and weak bioturbation.",
    url = "https://doi.org/10.1002/gj.4243",
    doi = "10.1002/gj.4243",
    openalex = "W3195455652",
    references = "doi101007s103470140400x"
}

Abstract Planamandibulus nevadensis n. gen n. sp. is a newly discovered exceptionally preserved Laurentian phosphatocopid crustacean described from the upper Windfall Formation (Furongian, Stage 10) in Nevada. Planamandibulus nevadensis has closest affinity with the Baltic and Avalonian taxon Cyclotron. Its occurrence in sedimentary facies associated with dysoxia on the Laurentian paleocontinent fills in a gap in the global distribution of phosphatocopid crustaceans, facilitating a paleoenvironmental synthesis of this Cambrian group. We assess 75 taxa from nine paleocontinental areas spanning Cambrian stages 3 to 10 (~521–486.9 Ma). Comparison of these data with paleoclimate model simulations suggests that phosphatocopid distribution is explained partly by biogeography and ocean temperature patterns. Dabashanella species (e.g., D. hemicyclica Huo et al., 1983) are found across the low paleolatitude (<35°) paleocontinents of East Gondwanan (Australia), South China, and the central Asian terranes, spanning marine shelf carbonates to deeper marine black shale lithofacies, but are absent from mid- and high-paleolatitude sites, suggesting a warmer water preference. A similar warm-water preference is inferred for endemic taxa (e.g., Ulopsis, Parashergoldopsis) of East Gondwana, and perhaps for the newly described Laurentian Planamandibulus. By contrast, the mid- to high-paleolatitude paleocontinents Baltica and Avalonia are characterized by Veldotron, Cyclotron, Bidimorpha, Waldoria, Vestrogothia, Falites, and Trapezilites species, which occur in deep-shelf, cooler-water settings, typically below storm wave base. Hesslandona species sensu lato occur in mid-depth (likely above storm-wave base) warm tropical marine waters but are more typically found in deeper shelf and cooler waters in mid to high paleolatitudes. Phosphatocopids are also associated with sedimentary deposits characteristic of low environmental oxygen concentrations; this is emphasized by a peak in occurrences in the Guzhangian (Miaolingian) and Paibian (Furongian) stages, around the interval of the Steptoean Positive Carbon Isotope Excursion (SPICE) and its associated expansion of anoxic water masses onto shallow marine shelves. Our data compilation and data–model comparison support the environmental preference of phosphatocopids for low-oxygen, but not anoxic, water masses, and the new occurrence of Planamandibulus is consistent with this pattern. UUID: http://zoobank.org/f136f8bf-1ccf-46b0-8980-b88be8f9603d

@article{doi101017jpa202510180,
    author = "Reynolds, Rebekah A. and Hearing, Thomas W. Wong and Williams, Mark and Harvey, Thomas H. P. and Yanagihara, Ayari and Murdock, Duncan and Repetski, John E. and Loch, James D. and Lunt, Daniel J. and Gostling, Neil J.",
    title = "A new exceptionally preserved phosphatocopid crustacean from the Furongian of Laurentia and a synthesis of Cambrian phosphatocopid distribution patterns",
    year = "2025",
    journal = "Journal of Paleontology",
    abstract = "Abstract Planamandibulus nevadensis n. gen n. sp. is a newly discovered exceptionally preserved Laurentian phosphatocopid crustacean described from the upper Windfall Formation (Furongian, Stage 10) in Nevada. Planamandibulus nevadensis has closest affinity with the Baltic and Avalonian taxon Cyclotron. Its occurrence in sedimentary facies associated with dysoxia on the Laurentian paleocontinent fills in a gap in the global distribution of phosphatocopid crustaceans, facilitating a paleoenvironmental synthesis of this Cambrian group. We assess 75 taxa from nine paleocontinental areas spanning Cambrian stages 3 to 10 (\textasciitilde 521–486.9 Ma). Comparison of these data with paleoclimate model simulations suggests that phosphatocopid distribution is explained partly by biogeography and ocean temperature patterns. Dabashanella species (e.g., D. hemicyclica Huo et al., 1983) are found across the low paleolatitude (<35°) paleocontinents of East Gondwanan (Australia), South China, and the central Asian terranes, spanning marine shelf carbonates to deeper marine black shale lithofacies, but are absent from mid- and high-paleolatitude sites, suggesting a warmer water preference. A similar warm-water preference is inferred for endemic taxa (e.g., Ulopsis, Parashergoldopsis) of East Gondwana, and perhaps for the newly described Laurentian Planamandibulus. By contrast, the mid- to high-paleolatitude paleocontinents Baltica and Avalonia are characterized by Veldotron, Cyclotron, Bidimorpha, Waldoria, Vestrogothia, Falites, and Trapezilites species, which occur in deep-shelf, cooler-water settings, typically below storm wave base. Hesslandona species sensu lato occur in mid-depth (likely above storm-wave base) warm tropical marine waters but are more typically found in deeper shelf and cooler waters in mid to high paleolatitudes. Phosphatocopids are also associated with sedimentary deposits characteristic of low environmental oxygen concentrations; this is emphasized by a peak in occurrences in the Guzhangian (Miaolingian) and Paibian (Furongian) stages, around the interval of the Steptoean Positive Carbon Isotope Excursion (SPICE) and its associated expansion of anoxic water masses onto shallow marine shelves. Our data compilation and data–model comparison support the environmental preference of phosphatocopids for low-oxygen, but not anoxic, water masses, and the new occurrence of Planamandibulus is consistent with this pattern. UUID: http://zoobank.org/f136f8bf-1ccf-46b0-8980-b88be8f9603d",
    url = "https://doi.org/10.1017/jpa.2025.10180",
    doi = "10.1017/jpa.2025.10180",
    openalex = "W4416334993",
    references = "doi101017s001675681400079x"
}

@misc{hegnaNonesystematics,
    author = "Hegna, Thomas Arthur",
    title = "Systematics of late Cambrian (Sunwaptian) trilobites from the St. Charles Formation, southeastern Idaho",
    year = "None",
    url = "https://doi.org/10.17077/etd.9er7zprz",
    doi = "10.17077/etd.9er7zprz",
    openalex = "W1603237072"
}