Glacier NP

@article{martin1913glacier,
    author = "Martin, Lawrence",
    title = "Glacier National Park",
    year = "1913",
    journal = "Journal of Geography",
    url = "https://doi.org/10.1080/00221341308985843",
    doi = "10.1080/00221341308985843",
    number = "10",
    openalex = "W4255960065",
    pages = "324-326",
    volume = "11"
}

@techreport{campbell1914the1,
    author = "Campbell, M. R",
    title = "THe Glacier National Park",
    year = "1914",
    howpublished = "United States Geological Survey Bulletin, v. 600, p. 1-54",
    note = "talkorigins\_source = {true}; raw\_reference = {Campbell, M. R., 1914, THe Glacier National Park: United States Geological Survey Bulletin, v. 600, p. 1-54.}"
}

@article{johnson1915the,
    author = "Johnson, D. W. and Campbell, Marius R.",
    title = "The Glacier National Park",
    year = "1915",
    journal = "Bulletin of the American Geographical Society",
    url = "https://doi.org/10.2307/201163",
    doi = "10.2307/201163",
    number = "8",
    openalex = "W2798295660",
    pages = "614",
    volume = "47"
}

Rocks of the Belt series in Glacier National Park present evidence of repeated sedimentary cycles closely associated with changes in level, sedimentation apparently being marine. Conforming to stages in these cycles several new formations are described and others are redefined. At several horizons beds of fossil algae occur, containing both new and previously described species of Collenia, and species of Newlandia, Weedia, and Beltina. Algal life-forms are closely correlated with sedimentary types, remaining uniform over wide areas.

@article{doi101086623894,
    author = "Fenton, Carroll Lane and Fenton, Mildred Adams",
    title = "Algae and Algal Beds in the Belt Series of Glacier National Park",
    year = "1931",
    journal = "The Journal of Geology",
    abstract = "Rocks of the Belt series in Glacier National Park present evidence of repeated sedimentary cycles closely associated with changes in level, sedimentation apparently being marine. Conforming to stages in these cycles several new formations are described and others are redefined. At several horizons beds of fossil algae occur, containing both new and previously described species of Collenia, and species of Newlandia, Weedia, and Beltina. Algal life-forms are closely correlated with sedimentary types, remaining uniform over wide areas.",
    url = "https://doi.org/10.1086/623894",
    doi = "10.1086/623894",
    openalex = "W1971958109"
}

@article{gibson1939grinnell,
    author = "GIBSON, G. R. and DYSON, J. L.",
    title = "Grinnell Glacier, Glacier National Park, Montana",
    year = "1939",
    journal = "Geological Society of America Bulletin",
    url = "https://doi.org/10.1130/gsab-50-681",
    doi = "10.1130/gsab-50-681",
    number = "5",
    openalex = "W2323413393",
    pages = "681-696",
    volume = "50"
}

@article{doi101127zdgg1081956455,
    author = "Schindewolf, Otto H.",
    title = "On precambrian fossils",
    year = "1956",
    journal = "Zeitschrift der Deutschen Geologischen Gesellschaft",
    url = "https://doi.org/10.1127/zdgg/108/1956/455",
    doi = "10.1127/zdgg/108/1956/455",
    openalex = "W2914228975"
}

ceous. These rocks are intensely disturbed inasmuch as they lie below or near the Lewis overthrust fault (Precambrian over Cretaceous). The Colorado shale forms most of the outcrops along U. S. Highway 2 be­ tween East Glacier and the Continental Divide (Marias Pass) at Summit. The writer (1951a) has shown that the rocks on the Sweetgrass arch lying east and southeast of Glacier National Park, the Colorado shale, are divisible into many persistent lithologic units which can be correlated with named units elsewhere. Reconnaissance work along the southeast margin of Glacier Park reveals the presence of some of these subdivisions. The purpose of this report is to draw at­ tention to the better identified outcrops along U. S. Highway 2 between East Glacier and Summit. Geologists visiting or working in the area may find the dated and identified outcrops of value in interpreting the complex structure and in lithofacies studies. The mileage readings begin at the bridge over Midvale Creek at the south edge of East Glacier. Where fossils are mentioned, references are given for good illustrations. OUTCROPS ALONG U. S. HIGHWAY 2

@article{doi1013065ceae47e16bb11d78645000102c1865d,
    author = "Cobban, W. A.",
    title = "Cretaceous Rocks Along Part of Southeast Boundary of Glacier National Park, Montana: GEOLOGICAL NOTES",
    year = "1956",
    journal = "AAPG Bulletin",
    abstract = "ceous. These rocks are intensely disturbed inasmuch as they lie below or near the Lewis overthrust fault (Precambrian over Cretaceous). The Colorado shale forms most of the outcrops along U. S. Highway 2 be­ tween East Glacier and the Continental Divide (Marias Pass) at Summit. The writer (1951a) has shown that the rocks on the Sweetgrass arch lying east and southeast of Glacier National Park, the Colorado shale, are divisible into many persistent lithologic units which can be correlated with named units elsewhere. Reconnaissance work along the southeast margin of Glacier Park reveals the presence of some of these subdivisions. The purpose of this report is to draw at­ tention to the better identified outcrops along U. S. Highway 2 between East Glacier and Summit. Geologists visiting or working in the area may find the dated and identified outcrops of value in interpreting the complex structure and in lithofacies studies. The mileage readings begin at the bridge over Midvale Creek at the south edge of East Glacier. Where fossils are mentioned, references are given for good illustrations. OUTCROPS ALONG U. S. HIGHWAY 2",
    url = "https://doi.org/10.1306/5ceae47e-16bb-11d7-8645000102c1865d",
    doi = "10.1306/5ceae47e-16bb-11d7-8645000102c1865d",
    openalex = "W1976287864",
    references = "doi103133b691e"
}

This report summarizes available data on two adjacent and partly overlapping regions in northwestern Montana. The first of these is Glacier National Park plus small areas east and west of the park. The second is here called, for convenience, the Flathead region; it embraces the mountains from the southern tip of Glacier Park to latitude 48 deg north and between the Great Plains on the east and Flathead Valley on the west. The fieldwork under the direction of the writer was done in 1948, 1949, 1950, and 1951, with some work in 1952 and 1953. The two regions together include parts of the Swan, Flathead, Livingstone, and Lewis Ranges. They are drained largely by branches of the Flathead River. On the east and north, however, they are penetrated by tributaries of the Missouri River and in addition by streams that flow into Canada. Roads and highways reach the borders of the regions; but there are few roads in the regions and only two highways cross them. The principal economic value of the assemblage of mountains described in the present report is as a collecting ground for snow to furnish the water used in the surrounding lowlands and as a scenic and wildlife recreation area. A few metallic deposits and lignitic coal beds are known, but these have not proved to be important and cannot, as far as can now be judged, be expected to become so. No oil except minor seeps has yet been found, and most parts of the two regions covered do not appear geologically favorable to the presence of oil in commercial quantities. The high, Hungry Horse Dam on which construction was in progress during the fieldwork now floods part of the Flathead region and will greatly influence the future of that region. The rocks range in age from Precambrian to Recent. The thickest units belong to the Belt series of Precambrian age, and special attention was paid to them. As a result, it is clear that at least the upper part of the series shows marked lateral changes within short distances. This fact introduces complexities into stratigraphic correlation and should be remembered wherever the series is studied. The stromatolites, or fossil algae, in the Belt series, although still imperfectly understood, give clues with respect to problems of ecology and stratigraphy. The subdivisions of the Belt series within the areas covered by the present report are, in ascending order, Altyn limestone, Appekunny argillite, Grinnell argillite, Siyeh limestone, and Missoula group. Local subdivisions of the Missoula group are possible in certain areas, and all the units just named are expected to be subdivided when detailed studies are undertaken. In the Glacier National Park and Flathead regions together, it is probable that between 25,000 and 30,000 feet of beds belonging to the Belt series, possibly more, are present. These consist largely of quartzitic argillite, quartzite, and carbonate rocks, mostly dolomitic. Small gabbroic and diabasic intrusive bodies and, at one horizon, basaltic lava are associated with the Belt series. Above the Belt series is a thick sequence of Cambrian, Devonian, and Carboniferous strata, in which limestone is dominant, followed by strata of Jurassic and Cretaceous age, largely limestone and shale and partly of terrestrial origin. Slightly consolidated gravel, sand, and silt of Tertiary age are preserved in some valleys and as erosional remnants on the plains close to the mountain border. Pleistocene and Recent glacial and fluviatile deposits are plentiful in mountain valleys and on the plains east of the mountains. Sufficient crustal movements took place during the latter part of Belt time to produce tension cracks that permitted some intrusion and related extrusion to occur. Broad crustal warping probably took place at intervals during the Paleozoic era, but these successive movements left little record other than the absence of sedimentary rock units that might otherwise have been deposited. The same can be said of much of the Me

@article{doi103133pp296,
    author = "Ross, Clyde Polhemus",
    title = "Geology of Glacier National Park and the Flathead Region, Northwestern Montana",
    year = "1959",
    journal = "USGS professional paper",
    abstract = "This report summarizes available data on two adjacent and partly overlapping regions in northwestern Montana. The first of these is Glacier National Park plus small areas east and west of the park. The second is here called, for convenience, the Flathead region; it embraces the mountains from the southern tip of Glacier Park to latitude 48 deg north and between the Great Plains on the east and Flathead Valley on the west. The fieldwork under the direction of the writer was done in 1948, 1949, 1950, and 1951, with some work in 1952 and 1953. The two regions together include parts of the Swan, Flathead, Livingstone, and Lewis Ranges. They are drained largely by branches of the Flathead River. On the east and north, however, they are penetrated by tributaries of the Missouri River and in addition by streams that flow into Canada. Roads and highways reach the borders of the regions; but there are few roads in the regions and only two highways cross them. The principal economic value of the assemblage of mountains described in the present report is as a collecting ground for snow to furnish the water used in the surrounding lowlands and as a scenic and wildlife recreation area. A few metallic deposits and lignitic coal beds are known, but these have not proved to be important and cannot, as far as can now be judged, be expected to become so. No oil except minor seeps has yet been found, and most parts of the two regions covered do not appear geologically favorable to the presence of oil in commercial quantities. The high, Hungry Horse Dam on which construction was in progress during the fieldwork now floods part of the Flathead region and will greatly influence the future of that region. The rocks range in age from Precambrian to Recent. The thickest units belong to the Belt series of Precambrian age, and special attention was paid to them. As a result, it is clear that at least the upper part of the series shows marked lateral changes within short distances. This fact introduces complexities into stratigraphic correlation and should be remembered wherever the series is studied. The stromatolites, or fossil algae, in the Belt series, although still imperfectly understood, give clues with respect to problems of ecology and stratigraphy. The subdivisions of the Belt series within the areas covered by the present report are, in ascending order, Altyn limestone, Appekunny argillite, Grinnell argillite, Siyeh limestone, and Missoula group. Local subdivisions of the Missoula group are possible in certain areas, and all the units just named are expected to be subdivided when detailed studies are undertaken. In the Glacier National Park and Flathead regions together, it is probable that between 25,000 and 30,000 feet of beds belonging to the Belt series, possibly more, are present. These consist largely of quartzitic argillite, quartzite, and carbonate rocks, mostly dolomitic. Small gabbroic and diabasic intrusive bodies and, at one horizon, basaltic lava are associated with the Belt series. Above the Belt series is a thick sequence of Cambrian, Devonian, and Carboniferous strata, in which limestone is dominant, followed by strata of Jurassic and Cretaceous age, largely limestone and shale and partly of terrestrial origin. Slightly consolidated gravel, sand, and silt of Tertiary age are preserved in some valleys and as erosional remnants on the plains close to the mountain border. Pleistocene and Recent glacial and fluviatile deposits are plentiful in mountain valleys and on the plains east of the mountains. Sufficient crustal movements took place during the latter part of Belt time to produce tension cracks that permitted some intrusion and related extrusion to occur. Broad crustal warping probably took place at intervals during the Paleozoic era, but these successive movements left little record other than the absence of sedimentary rock units that might otherwise have been deposited. The same can be said of much of the Me",
    url = "https://doi.org/10.3133/pp296",
    doi = "10.3133/pp296",
    openalex = "W1536465487"
}

@misc{ross1959rocks2,
    author = "Ross, C. P. and Rezak, R",
    title = "Rocks and Fossils of Glacier National Park",
    year = "1959",
    howpublished = "United States Geological Survey, Professional Paper, v. 294-K, p. 401-439",
    note = "talkorigins\_source = {true}; raw\_reference = {Ross, C. P., and Rezak, R., 1959, Rocks and Fossils of Glacier National Park: United States Geological Survey, Professional Paper, v. 294-K, p. 401-439.}"
}

@misc{ross1959the,
    author = "Ross, Clyde P. and Rezak, Richard",
    title = "The rocks and fossils of Glacier National Park: The story of their origin and history",
    year = "1959",
    booktitle = "Professional Paper",
    url = "https://doi.org/10.3133/pp294k",
    doi = "10.3133/pp294k",
    openalex = "W1554921367",
    pages = "401-439",
    references = "doi101126science1193097658, doi101130gsab10199, doi101130gsab171, doi101130gsab441135, doi101130gsab481873, doi103133b691e, doi103133pp140, doi103133pp174, doi103133pp50, doi104095100513"
}

@misc{johnson1960glacier,
    author = "Johnson, Arthur",
    title = "Glacier observations, Glacier National Park, Montana, 1959",
    year = "1960",
    booktitle = "Open-File Report",
    url = "https://doi.org/10.3133/ofr6081",
    doi = "10.3133/ofr6081",
    openalex = "W4232113654"
}

@misc{johnson1961glacier,
    author = "Johnson, Arthur",
    title = "Glacier observations, Glacier National Park, Montana, 1960",
    year = "1961",
    booktitle = "Open-File Report",
    url = "https://doi.org/10.3133/ofr6178",
    doi = "10.3133/ofr6178",
    openalex = "W4241744100"
}

@article{doi101111j1469185x1962tb01331x,
    author = "Glaessner, Martin F.",
    title = "PRE‐CAMBRIAN FOSSILS",
    year = "1962",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    url = "https://doi.org/10.1111/j.1469-185x.1962.tb01331.x",
    doi = "10.1111/j.1469-185x.1962.tb01331.x",
    openalex = "W2021151522",
    references = "rutten1957origin"
}

@misc{johnson1962glacier,
    author = "Johnson, Arthur",
    title = "Glacier observations, Glacier National Park, Montana, 1961",
    year = "1962",
    booktitle = "Open-File Report",
    url = "https://doi.org/10.3133/ofr6269",
    doi = "10.3133/ofr6269",
    openalex = "W4230738666"
}

@misc{johnson1964glacier,
    author = "Johnson, Arthur",
    title = "Glacier Observations, Glacier National Park, Montana, 1963",
    year = "1964",
    booktitle = "Open-File Report",
    url = "https://doi.org/10.3133/ofr6490",
    doi = "10.3133/ofr6490",
    openalex = "W4232671337"
}

@article{doi1010382231226a0,
    author = "Nagy, Bartholomew and Nagy, Lois Anne",
    title = "Early Pre-Cambrian Onverwacht Microstructures: Possibly the Oldest Fossils on Earth?",
    year = "1969",
    journal = "Nature",
    url = "https://doi.org/10.1038/2231226a0",
    doi = "10.1038/2231226a0",
    openalex = "W2005044715",
    references = "doi101007bf02993256"
}

Certain worm-like configurations on rocks are recognized as shrinkage-crack infillings. Some genuine Precambrian trace fossils are briefly described. The early Cambrian contains a richer assemblage, including some distinctive and widespread form genera. The study of early trace fossils leads to conclusions not only on facies, but also on the evolution of behaviour and functional morphology in soft-bodied organisms.

@article{doi101111j150239311969tb01258x,
    author = "Glaessner, Martin F.",
    title = "TRACE FOSSILS FROM THE PRECAMBRIAN AND BASAL CAMBRIAN",
    year = "1969",
    journal = "Lethaia",
    abstract = "Certain worm-like configurations on rocks are recognized as shrinkage-crack infillings. Some genuine Precambrian trace fossils are briefly described. The early Cambrian contains a richer assemblage, including some distinctive and widespread form genera. The study of early trace fossils leads to conclusions not only on facies, but also on the evolution of behaviour and functional morphology in soft-bodied organisms.",
    url = "https://doi.org/10.1111/j.1502-3931.1969.tb01258.x",
    doi = "10.1111/j.1502-3931.1969.tb01258.x",
    openalex = "W1975727583",
    references = "doi1010160031018266900113, doi101038scientificamerican036172, doi10108011035896509448903, doi101086626811, doi101111j1469185x1962tb01331x, doi101111j150239311968tb01740x, doi101126science1543750766, doi101130gsab481873, doi101144gsljgs1890046010439, openalexw2170541304, openalexw2586923183"
}

Seven trace-fossil species are described from the upper part of the Torrowangee Group (Upper Proterozoic) of western New South Wales, and a variety of other traces are illustrated. A few forms occur in the Fowlers Gap Beds, and a more diverse and abundant fauna is recorded from the stratigraphically higher Lintiss Vale Beds. Virtually all the traces are preserved in the plane of bedding, as semi-reliefs. The named trace fossils all come from the Lintiss Vale Beds, and are as follows: Planolites ballandus sp. nov., Planolites? sp., Cochlichnus serpens sp. nov., Gordia? sp., Torrowangea rosei gen. et sp. nov., Phycodes? antecedent sp. nov., and Curvolithus? davidis sp. nov. Three of these species are regarded as feeding burrows (endogene), and are thought to represent the activity of infaunal, worm-like deposit feeders. Others may be either feeding burrows or crawling trails. There are also a few impressions which seem to be rest marks. A discussion of the significance of the trace-fossil occurrences is presented.

@article{doi101111j150239311970tb01265x,
    author = "Webby, B. D.",
    title = "LATE PRECAMBRIAN TRACE FOSSILS FROM NEW SOUTH WALES",
    year = "1970",
    journal = "Lethaia",
    abstract = "Seven trace-fossil species are described from the upper part of the Torrowangee Group (Upper Proterozoic) of western New South Wales, and a variety of other traces are illustrated. A few forms occur in the Fowlers Gap Beds, and a more diverse and abundant fauna is recorded from the stratigraphically higher Lintiss Vale Beds. Virtually all the traces are preserved in the plane of bedding, as semi-reliefs. The named trace fossils all come from the Lintiss Vale Beds, and are as follows: Planolites ballandus sp. nov., Planolites? sp., Cochlichnus serpens sp. nov., Gordia? sp., Torrowangea rosei gen. et sp. nov., Phycodes? antecedent sp. nov., and Curvolithus? davidis sp. nov. Three of these species are regarded as feeding burrows (endogene), and are thought to represent the activity of infaunal, worm-like deposit feeders. Others may be either feeding burrows or crawling trails. There are also a few impressions which seem to be rest marks. A discussion of the significance of the trace-fossil occurrences is presented.",
    url = "https://doi.org/10.1111/j.1502-3931.1970.tb01265.x",
    doi = "10.1111/j.1502-3931.1970.tb01265.x",
    openalex = "W2090045887",
    references = "doi101130gsab481873, doi101144gslsp19670020104"
}

@article{openalexw560220492,
    author = "Häntzschel, Walter",
    title = "Trace fossils and problematica",
    year = "1975",
    journal = "Medical Entomology and Zoology",
    openalex = "W560220492"
}

@incollection{doi10100797836426651651,
    author = "Golubic, S. and Barghoorn, Elso S.",
    title = "Interpretation of Microbial Fossils with Special Reference to the Precambrian",
    year = "1977",
    url = "https://doi.org/10.1007/978-3-642-66516-5\_1",
    doi = "10.1007/978-3-642-66516-5\_1",
    openalex = "W37756438",
    references = "doi101007bf02993256"
}

@article{fritz1980reinterpretation,
    author = "Fritz, William J.",
    title = "Reinterpretation of the depositional environment of the Yellowstone “fossil forests”",
    year = "1980",
    journal = "Geology",
    url = "https://doi.org/10.1130/0091-7613(1980)8<309:rotdeo>2.0.co;2",
    doi = "10.1130/0091-7613(1980)8<309:rotdeo>2.0.co;2",
    number = "7",
    openalex = "W2060151626",
    pages = "309",
    volume = "8"
}

Because of fundamental differences between trace fossils and body fossils, ichnologic nomenclature is beset with difficulties. Foremost is inconsistent treatment by the International Commission on Zoological Nomenclature (lack of sanction for post-1930 names, confusion over the rule of priority) and inadequate curation of type specimens. However, ichnologists have contributed their own problems via inadequate diagnoses and descriptions, misconceptions of ichnologic and taxonomic principles, proliferation of names and failure to engage in true monographic revisions. All these difficulties are illustrated in a thorough reevaluation of the ichnogenera Planolites Nicholson and Palaeophycus Hall. Contrary to a popular but ill-founded scheme in which these ichnogenera are differentiated simply on the presence or absence of branches, Planolites is an unlined burrow infilled with sediments having textural and fabricational characters unlike those of the host rock, whereas Palaeophycus is a lined burrow filled with sediments typically identical to those of the surrounding matrix. Planolites represents active backfilling of sediment in an ephemeral burrow constructed by a mobile deposit feeder and Palaeophycus represents passive sedimentation within an open dwelling burrow constructed by a predaceous or suspension-feeding animal. In addition to ichnological nomenclature and ethology, the ramifications are important in paleoecology, sedimentology and diagenetic studies. Currently recognized ichnospecies of Planolites include P. montanus Richter, P. beverleyensis (Billings) and P. annularis Walcott. Those of Palaeophycus include P. heberti (Saporta), P. tubularis Hall, P. striatus Hall, P. sulcatus (Miller and Dyer) and P. alternatus n. ichnosp.

@article{openalexw2344228935,
    author = "Pemberton, S. George and Frey, Robert W.",
    title = "Trace fossil nomenclature and the Planolites-Palaeophycus dilemma",
    year = "1982",
    journal = "Journal of Paleontology",
    abstract = "Because of fundamental differences between trace fossils and body fossils, ichnologic nomenclature is beset with difficulties. Foremost is inconsistent treatment by the International Commission on Zoological Nomenclature (lack of sanction for post-1930 names, confusion over the rule of priority) and inadequate curation of type specimens. However, ichnologists have contributed their own problems via inadequate diagnoses and descriptions, misconceptions of ichnologic and taxonomic principles, proliferation of names and failure to engage in true monographic revisions. All these difficulties are illustrated in a thorough reevaluation of the ichnogenera Planolites Nicholson and Palaeophycus Hall. Contrary to a popular but ill-founded scheme in which these ichnogenera are differentiated simply on the presence or absence of branches, Planolites is an unlined burrow infilled with sediments having textural and fabricational characters unlike those of the host rock, whereas Palaeophycus is a lined burrow filled with sediments typically identical to those of the surrounding matrix. Planolites represents active backfilling of sediment in an ephemeral burrow constructed by a mobile deposit feeder and Palaeophycus represents passive sedimentation within an open dwelling burrow constructed by a predaceous or suspension-feeding animal. In addition to ichnological nomenclature and ethology, the ramifications are important in paleoecology, sedimentology and diagenetic studies. Currently recognized ichnospecies of Planolites include P. montanus Richter, P. beverleyensis (Billings) and P. annularis Walcott. Those of Palaeophycus include P. heberti (Saporta), P. tubularis Hall, P. striatus Hall, P. sulcatus (Miller and Dyer) and P. alternatus n. ichnosp.",
    openalex = "W2344228935",
    references = "doi1010079783642659232, doi101111j150239311980tb00632x, doi101130gsab10199, doi1023071485443, openalexw3127114020, openalexw574363047"
}

Abstract The distribution of Middle and Late Proterozoic sedimentary and metasedimentary cover that lies unconformably on Early Proterozoic and Archean crystalline basement has been known for decades, but recent work, employing techniques of paleomagnetic correlation, sedimentology, sequence stratigraphy, and analysis of tectonic subsidence has led to modifications of some long-accepted correlations and tectonic models. Within the context of both older classical studies and this new work, the stratigraphy, correlation, tectonic setting, fossil content, and mineral potential of Middle and Late Proterozoic rocks of parts of the Rocky Mountain, Colorado Plateau, and Basin and Range provinces of the United States are discussed. A problem common to interpretation of all Proterozoic strata is a widespread lack of fossil control on age and paleoecology, which makes correlations inherently uncertain and interpretation of depositional environments more difficult. We present current hypotheses about these topics and stress the uncertainty of some of our conclusions. The apparent polar wander path for the North American craton, as derived from the Middle and Late Proterozoic sedimentary cover, is central to our modifications of stratigraphie correlation, especially of Middle Proterozoic rocks. The reader is asked to view the work and summaries presented here in the light of ongoing scientific debate about strata that are chronically stubborn in yielding information. The authors of sections of this chapter include both those who have performed classical studies, which are the foundation of our present understanding, and younger geologists who have been busy refining and modifying early interpretations, using different methods of study. The treatment in this chapter is therefore variable depending on which generation of investigators is speaking.

@incollection{doi101130dnaggnac2463,
    author = "Christie‐Blick, Nicholas and Devlin, William J. and Elston, Donald P. and Horodyski, Robert J. and Levy, Marjorie and Miller, Julia M. G. and Pearson, Robert Carl and Prave, Anthony R. and Stewart, John H. and Winston, Don and Wright, Lauren and Wrucke, Chester T.",
    title = "Middle and Late Proterozoic stratified rocks of the western U.S. Cordillera, Colorado Plateau, and Basin and Range province",
    year = "1993",
    booktitle = "Geological Society of America eBooks",
    abstract = "Abstract The distribution of Middle and Late Proterozoic sedimentary and metasedimentary cover that lies unconformably on Early Proterozoic and Archean crystalline basement has been known for decades, but recent work, employing techniques of paleomagnetic correlation, sedimentology, sequence stratigraphy, and analysis of tectonic subsidence has led to modifications of some long-accepted correlations and tectonic models. Within the context of both older classical studies and this new work, the stratigraphy, correlation, tectonic setting, fossil content, and mineral potential of Middle and Late Proterozoic rocks of parts of the Rocky Mountain, Colorado Plateau, and Basin and Range provinces of the United States are discussed. A problem common to interpretation of all Proterozoic strata is a widespread lack of fossil control on age and paleoecology, which makes correlations inherently uncertain and interpretation of depositional environments more difficult. We present current hypotheses about these topics and stress the uncertainty of some of our conclusions. The apparent polar wander path for the North American craton, as derived from the Middle and Late Proterozoic sedimentary cover, is central to our modifications of stratigraphie correlation, especially of Middle Proterozoic rocks. The reader is asked to view the work and summaries presented here in the light of ongoing scientific debate about strata that are chronically stubborn in yielding information. The authors of sections of this chapter include both those who have performed classical studies, which are the foundation of our present understanding, and younger geologists who have been busy refining and modifying early interpretations, using different methods of study. The treatment in this chapter is therefore variable depending on which generation of investigators is speaking.",
    url = "https://doi.org/10.1130/dnag-gna-c2.463",
    doi = "10.1130/dnag-gna-c2.463",
    openalex = "W2495702502",
    references = "doi1010160012821x78900717, doi101016001282527990059x, doi101086627783, doi101086627882, doi101086628623, doi10113000167606196273139lcswmc20co2, doi1011300091761319910190425suseas23co2, doi1011300091761319910190598pmolae23co2, doi101130dnaggnaa447, doi101130gsab171, doi101130gsab441135, doi101306m26490, doi101306mth7510, karlstrom1986early, openalexw602333724, ross1959the"
}

Abstract The purpose of this paper is to provide a general, current overview of the Precambrian fossil occurrences in North America. This work, a sequel to earlier compilations for Canada (See Hofmann, 1971, 1972, 1981a), has been expanded to encompass the remainder of North America, for which similar compilations are not available (except for the western United States and northwestern Mexico: Horodyski, 1993a, b). On the other hand, several comprehensive monographs on the global Precambrian paleontological record (Schopf, 1983; Schopf and Klein, 1992; Bengtson, 1994) provide impressive detail with global coverage of all aspects of Precambrian paleobiology and evolution. Another topical volume that includes chapters on Precambrian stromatolite reef complexes is Geldsetzer et al. (1989). All the above references have extensive documentation and bibliographies. The present inventory is meant to complement this previous work by providing a synoptic view of North American occurrences in map form (Fig. 4.1, in pocket; Fig. 4.2–4.13), and some observations on the content of the database. This perspective allows a better continent-wide overview of geographic data than tabulated data dispersed in various publications; moreover, lateral relationships of areas where previous work has been concentrated, and those where data are not available, are more readily visualized. This continental overview should be helpful for those contemplating future paleontological work in the Precambrian sequences of North America. Fossils and possible fossils have been reported from at least 383 formations in North America attributed to the Precambrian. These 383 occurrences, known up to mid-1996 from Canada, Greenland, U.S.A., and Mexico,

@incollection{doi101130dnaggnac1271,
    author = "Hofmann, Hans",
    title = "Synopsis of Precambrian Fossil Occurrences in North America",
    year = "1998",
    booktitle = "Geological Society of America eBooks",
    abstract = "Abstract The purpose of this paper is to provide a general, current overview of the Precambrian fossil occurrences in North America. This work, a sequel to earlier compilations for Canada (See Hofmann, 1971, 1972, 1981a), has been expanded to encompass the remainder of North America, for which similar compilations are not available (except for the western United States and northwestern Mexico: Horodyski, 1993a, b). On the other hand, several comprehensive monographs on the global Precambrian paleontological record (Schopf, 1983; Schopf and Klein, 1992; Bengtson, 1994) provide impressive detail with global coverage of all aspects of Precambrian paleobiology and evolution. Another topical volume that includes chapters on Precambrian stromatolite reef complexes is Geldsetzer et al. (1989). All the above references have extensive documentation and bibliographies. The present inventory is meant to complement this previous work by providing a synoptic view of North American occurrences in map form (Fig. 4.1, in pocket; Fig. 4.2–4.13), and some observations on the content of the database. This perspective allows a better continent-wide overview of geographic data than tabulated data dispersed in various publications; moreover, lateral relationships of areas where previous work has been concentrated, and those where data are not available, are more readily visualized. This continental overview should be helpful for those contemplating future paleontological work in the Precambrian sequences of North America. Fossils and possible fossils have been reported from at least 383 formations in North America attributed to the Precambrian. These 383 occurrences, known up to mid-1996 from Canada, Greenland, U.S.A., and Mexico,",
    url = "https://doi.org/10.1130/dnag-gna-c1.271",
    doi = "10.1130/dnag-gna-c1.271",
    openalex = "W2488428454",
    references = "doi101038321832a0, doi101038384055a0, doi101086626965, doi101126science1473658563, doi101126science2735277924, doi102113gsecongeo493235, doi105962p295214, openalexw2026796374, openalexw3126336940, openalexw353142951, openalexw560220492, raymond1947prehistoric, ross1959the"
}

Aspidella terranovica Billings, 1872 was first described from the late Neoproterozoic Fermeuse Formation (St. John's Group) on the Avalon Peninsula of eastern Newfoundland, approximately 1km stratigraphically above the famous Ediacaran biota at Mistaken Point, and several kilometres below the base of the Cambrian. Aspidella has been reinterpreted perhaps more than any other Precambrian taxon, and has variously been regarded as a fossil mollusc or ‘medusoid’, a gas escape structure, a concretion, or a mechanical suction mark. Our studies indicate that Aspidella includes a wide variety of preservational morphs varying from negative hyporeliefs with a raised rim and ridges radiating from a slit (Aspidella ‐type preservation), to flat discs with a central boss and sharp outer ring (Spriggia preservation), to positive hyporeliefs with concentric ornamentation (Ediacaria preservation). Specimens occur in a continuum of sizes, with preservational styles dependent on the size of the specimen and the grain size of the host lithology; the elongation of specimens is tectonic. Aspidella is confirmed as a body fossil from observations of complex radial and concentric ornamentation, mutually deformed borders in clusters of specimens, and occurrence on the same bedding planes as certain distinctive Ediacaran taxa. Aspidella is indistinguishable from, and has priority over, several of the most common genera of late Neoproterozoic discoidal body fossils worldwide. Similar fossils from Australia are interpreted as holdfasts of frond‐like organisms. The density of specimens in the Aspidella beds suggests levels of benthic biomass in the Neoproterozoic that could rival those of modern marine communities. The serial growth forms, Palaeopascichnus Intrites, Neonereites renarius Yelovichnus, associated with Aspidella, are interpreted as body fossils of unknown affinities rather than trace fossils. A new, trilobed, Ediacaran body fossil, Triforillonia costellae gen. et sp. nov., is described from the Aspidella beds of the Fermeuse Formation.

@article{doi101111j00310239200000134x,
    author = "Gehlîng, James G. and Narbonne, Guy M. and Anderson, Michael M.",
    title = "The first named Ediacaran body fossil, Aspidella Terranovica",
    year = "2000",
    journal = "Palaeontology",
    abstract = "Aspidella terranovica Billings, 1872 was first described from the late Neoproterozoic Fermeuse Formation (St. John's Group) on the Avalon Peninsula of eastern Newfoundland, approximately 1km stratigraphically above the famous Ediacaran biota at Mistaken Point, and several kilometres below the base of the Cambrian. Aspidella has been reinterpreted perhaps more than any other Precambrian taxon, and has variously been regarded as a fossil mollusc or ‘medusoid’, a gas escape structure, a concretion, or a mechanical suction mark. Our studies indicate that Aspidella includes a wide variety of preservational morphs varying from negative hyporeliefs with a raised rim and ridges radiating from a slit (Aspidella ‐type preservation), to flat discs with a central boss and sharp outer ring (Spriggia preservation), to positive hyporeliefs with concentric ornamentation (Ediacaria preservation). Specimens occur in a continuum of sizes, with preservational styles dependent on the size of the specimen and the grain size of the host lithology; the elongation of specimens is tectonic. Aspidella is confirmed as a body fossil from observations of complex radial and concentric ornamentation, mutually deformed borders in clusters of specimens, and occurrence on the same bedding planes as certain distinctive Ediacaran taxa. Aspidella is indistinguishable from, and has priority over, several of the most common genera of late Neoproterozoic discoidal body fossils worldwide. Similar fossils from Australia are interpreted as holdfasts of frond‐like organisms. The density of specimens in the Aspidella beds suggests levels of benthic biomass in the Neoproterozoic that could rival those of modern marine communities. The serial growth forms, Palaeopascichnus Intrites, Neonereites renarius Yelovichnus, associated with Aspidella, are interpreted as body fossils of unknown affinities rather than trace fossils. A new, trilobed, Ediacaran body fossil, Triforillonia costellae gen. et sp. nov., is described from the Aspidella beds of the Fermeuse Formation.",
    url = "https://doi.org/10.1111/j.0031-0239.2000.00134.x",
    doi = "10.1111/j.0031-0239.2000.00134.x",
    openalex = "W2089680322",
    references = "doi101111j150239311969tb01258x, doi101130gsab10199, doi101139e87124, doi101144pygs313211"
}

Abstract The glaciers in the Blackfoot–Jackson Glacier Basin of Glacier National Park, Montana, decreased in area from 21.6 square kilometers (km2) in 1850 to 7.4 km2 in 1979. Over this same period global temperatures increased by 0.45°C (± 0.15°C). We analyzed the climatic causes and ecological consequences of glacier retreat by creating spatially explicit models of the creation and ablation of glaciers and of the response of vegetation to climate change. We determined the melt rate and spatial distribution of glaciers under two possible future climate scenarios, one based on carbon dioxide–induced global warming and the other on a linear temperature extrapolation. Under the former scenario, all glaciers in the basin will disappear by the year 2030, despite predicted increases in precipitation; under the latter, melting is slower. Using a second model, we analyzed vegetation responses to variations in soil moisture and increasing temperature in a complex alpine landscape and predicted where plant communities are likely to be located as conditions change.

@article{doi1016410006356820030530131mcigci20co2,
    author = "Hall, Myrna and Fagre, Daniel B.",
    title = "Modeled Climate-Induced Glacier Change in Glacier National Park, 1850–2100",
    year = "2003",
    journal = "BioScience",
    abstract = "Abstract The glaciers in the Blackfoot–Jackson Glacier Basin of Glacier National Park, Montana, decreased in area from 21.6 square kilometers (km2) in 1850 to 7.4 km2 in 1979. Over this same period global temperatures increased by 0.45°C (± 0.15°C). We analyzed the climatic causes and ecological consequences of glacier retreat by creating spatially explicit models of the creation and ablation of glaciers and of the response of vegetation to climate change. We determined the melt rate and spatial distribution of glaciers under two possible future climate scenarios, one based on carbon dioxide–induced global warming and the other on a linear temperature extrapolation. Under the former scenario, all glaciers in the basin will disappear by the year 2030, despite predicted increases in precipitation; under the latter, melting is slower. Using a second model, we analyzed vegetation responses to variations in soil moisture and increasing temperature in a complex alpine landscape and predicted where plant communities are likely to be located as conditions change.",
    url = "https://doi.org/10.1641/0006-3568(2003)053[0131:mcigci]2.0.co;2",
    doi = "10.1641/0006-3568(2003)053[0131:mcigci]2.0.co;2",
    openalex = "W2099995575",
    references = "doi101126science22646811418, doi101126science2645156243, doi101126science2895477270, doi1011300091761319910190610hgacvi23co2, doi1023071930735, doi1023071971875, doi1023072257005, gibson1939grinnell, openalexw1515170858, openalexw1759145845, openalexw2068090847"
}

Abstract The spatial characteristics for all glaciers in the North Cascades National Park Complex, USA, were estimated in 1958 and again in 1998. The total glacier area in 1958 was 117.3 ± 1.1 km 2; by 1998 the glacier area had decreased to 109.1 ± 1.1 km2, a reduction of 8.2 ± 0.1 km2 (7%). Estimated volume loss during the 40 year period was 0.8 ± 0.1 km3 of ice. This volume loss contributes up to 6% of the August–September stream-flow and equals 16% of the August–September precipitation. No significant correlations were found between magnitude of glacier shrinkage and topographic characteristics of elevation, aspect or slope. However, the smaller glaciers lost proportionally more area than the larger glaciers and had a greater variability in fractional change than larger glaciers. Most of the well-studied alpine glaciers are much larger than the population median, so global estimates of glacier shrinkage, based on these well-studied glaciers, probably underestimate the true magnitude of regional glacier change.

@article{doi103189172756506781828782,
    author = "Granshaw, Frank D. and Fountain, Andrew G.",
    title = "Glacier change (1958–1998) in the North Cascades National Park Complex, Washington, USA",
    year = "2006",
    journal = "Journal of Glaciology",
    abstract = "Abstract The spatial characteristics for all glaciers in the North Cascades National Park Complex, USA, were estimated in 1958 and again in 1998. The total glacier area in 1958 was 117.3 ± 1.1 km 2; by 1998 the glacier area had decreased to 109.1 ± 1.1 km2, a reduction of 8.2 ± 0.1 km2 (7\%). Estimated volume loss during the 40 year period was 0.8 ± 0.1 km3 of ice. This volume loss contributes up to 6\% of the August–September stream-flow and equals 16\% of the August–September precipitation. No significant correlations were found between magnitude of glacier shrinkage and topographic characteristics of elevation, aspect or slope. However, the smaller glaciers lost proportionally more area than the larger glaciers and had a greater variability in fractional change than larger glaciers. Most of the well-studied alpine glaciers are much larger than the population median, so global estimates of glacier shrinkage, based on these well-studied glaciers, probably underestimate the true magnitude of regional glacier change.",
    url = "https://doi.org/10.3189/172756506781828782",
    doi = "10.3189/172756506781828782",
    openalex = "W1971400458",
    references = "doi1016410006356820030530131mcigci20co2"
}

Glacier National Park in northwestern Montana holds significant geological and paleontological re- sources. The Middle Proterozoic sedimentary rocks exposed by the Lewis Overthrust span over 2,100 m of stratigraphic thickness, representing 800 million years of deposition. The glacial carving of the mountains and valleys that began 1.6 Ma left outcrops that are strangely unaltered. While the geological resources of the park have been substantially researched, the paleontological studies have been more sporadic. Precambrian formations of the Belt Supergroup hold a record of abundant ancient life, such as stromatolites and eucaryotes. Stromatolites within the parks were first recognized by Walcott in 1906. They have subsequently been studied in detail by Fenton and Fenton in the 1930s, Rezak and Ross in the 1950s and to a great extent by Horodyski from the mid-1970s to the 1990s. Current research conducted on the eukaryote Horodyskia moniliformis, from the Precambrian Appekunny Formation, and on the cone- and branching-shaped stromatolites of the Precambrian Siyeh Formation. These works yielded a great deal of knowledge about the paleontological history of the park but many more questions exist. Future explorations lie in the morphometric attributes, macrostructures and environmental conditions of the local stromatolites. Detailed study of the separate units within the park could also prove useful in the further search for fossils.

@article{openalexw2185480587,
    author = "Hunt-Foster, ReBecca",
    title = "MIDDLE PROTEROZOIC PALEONTOLOGY OF THE BELT SUPERGROUP, GLACIER NATIONAL PARK",
    year = "2006",
    abstract = "Glacier National Park in northwestern Montana holds significant geological and paleontological re- sources. The Middle Proterozoic sedimentary rocks exposed by the Lewis Overthrust span over 2,100 m of stratigraphic thickness, representing 800 million years of deposition. The glacial carving of the mountains and valleys that began 1.6 Ma left outcrops that are strangely unaltered. While the geological resources of the park have been substantially researched, the paleontological studies have been more sporadic. Precambrian formations of the Belt Supergroup hold a record of abundant ancient life, such as stromatolites and eucaryotes. Stromatolites within the parks were first recognized by Walcott in 1906. They have subsequently been studied in detail by Fenton and Fenton in the 1930s, Rezak and Ross in the 1950s and to a great extent by Horodyski from the mid-1970s to the 1990s. Current research conducted on the eukaryote Horodyskia moniliformis, from the Precambrian Appekunny Formation, and on the cone- and branching-shaped stromatolites of the Precambrian Siyeh Formation. These works yielded a great deal of knowledge about the paleontological history of the park but many more questions exist. Future explorations lie in the morphometric attributes, macrostructures and environmental conditions of the local stromatolites. Detailed study of the separate units within the park could also prove useful in the further search for fossils.",
    openalex = "W2185480587",
    references = "doi1010160301926876900164, doi1010160301926883900839, doi101016030192689390116j, doi101086627341, doi101086627783, doi101130gsab10199, doi101130gsab481873, doi105479si00810266941, doi105962bhltitle60642, openalexw3127114020, openalexw360029564, ross1959the"
}

@article{doi101016jprecamres200901003,
    author = "Schopf, J. William",
    title = "The hunt for Precambrian fossils: An abbreviated genealogy of the science",
    year = "2009",
    journal = "Precambrian Research",
    url = "https://doi.org/10.1016/j.precamres.2009.01.003",
    doi = "10.1016/j.precamres.2009.01.003",
    openalex = "W2043854582",
    references = "doi101073pnas97136947, doi101130gsab171"
}

Siliciclastic beds in the upper part of the Miette Group in southeastern British Columbia have yielded an assemblage of late Ediacaran soft-bodied macrofossils and trace fossils. The macrofossils comprise Aspidella, Bradgatia?, and Miettia salientensis gen. et sp. nov. The ichnofossils include Archaeonassa, Cochlichnus, Didymaulichnus?, Gordia, Halopoa, Helminthoidichnites, Helminthopsis, Planolites, and a large, unnamed crawling trace. In addition, two types of unidentified problematica are recorded, representing either tubular Vendotaenia -like body fossils, or trace fossils. The Bradgatia? constitutes the youngest occurrence of this type of fossil, and is the first to be recorded from Laurentia, having previously been noted only in Avalonia. With Cloudina and Namacalathus in associated shallow-water platform carbonates, the Miette biota in the study area contains a combination of Namibian-type and Avalonian-type elements.

@article{doi101139e10070,
    author = "Hofmann, Hans and Mountjoy, E W",
    title = "Ediacaran body and trace fossils in Miette Group (Windermere Supergroup) near Salient Mountain, British Columbia, CanadaRevision of the paper was carried out by Dr. Guy Narbonne following the passing away of both Hans Hofmann († deceased May 19, 2010) and Eric Mountjoy († deceased June 18, 2010) after manuscript submission.",
    year = "2010",
    journal = "Canadian Journal of Earth Sciences",
    abstract = "Siliciclastic beds in the upper part of the Miette Group in southeastern British Columbia have yielded an assemblage of late Ediacaran soft-bodied macrofossils and trace fossils. The macrofossils comprise Aspidella, Bradgatia?, and Miettia salientensis gen. et sp. nov. The ichnofossils include Archaeonassa, Cochlichnus, Didymaulichnus?, Gordia, Halopoa, Helminthoidichnites, Helminthopsis, Planolites, and a large, unnamed crawling trace. In addition, two types of unidentified problematica are recorded, representing either tubular Vendotaenia -like body fossils, or trace fossils. The Bradgatia? constitutes the youngest occurrence of this type of fossil, and is the first to be recorded from Laurentia, having previously been noted only in Avalonia. With Cloudina and Namacalathus in associated shallow-water platform carbonates, the Miette biota in the study area contains a combination of Namibian-type and Avalonian-type elements.",
    url = "https://doi.org/10.1139/e10-070",
    doi = "10.1139/e10-070",
    openalex = "W2606810677",
    references = "doi101130dnaggnac1271"
}

A compilation of all supra- and (infra-) specific taxa of extant and fossil Valvatidae, a group of freshwater operculate snails, is provided, including taxa initially described in this family and subsequently classified in other families, as well as names containing errors or misspellings. The extensive reference list is directly linked to the available electronic source (digital view or pdf-download) of the respective papers.

@article{doi103897zookeys3776032,
    author = "Haszprunar, Gerhard",
    title = "A nomenclator of extant and fossil taxa of the Valvatidae (Gastropoda, Ectobranchia)",
    year = "2014",
    journal = "ZooKeys",
    abstract = "A compilation of all supra- and (infra-) specific taxa of extant and fossil Valvatidae, a group of freshwater operculate snails, is provided, including taxa initially described in this family and subsequently classified in other families, as well as names containing errors or misspellings. The extensive reference list is directly linked to the available electronic source (digital view or pdf-download) of the respective papers.",
    url = "https://doi.org/10.3897/zookeys.377.6032",
    doi = "10.3897/zookeys.377.6032",
    openalex = "W2012640338",
    references = "doi103133pp140"
}

@incollection{williams2017glacier,
    author = "Williams, Terry Tempest",
    title = "GLACIER NATIONAL PARK, MONTANA",
    year = "2017",
    booktitle = "The Glacier Park Reader",
    url = "https://doi.org/10.2307/jj.33676880.44",
    doi = "10.2307/jj.33676880.44",
    pages = "300-311"
}

Although the use of nuclear energy is still viewed with caution due to various problems associated, such as the safe operation of 'aging' nuclear plants and the final disposal of nuclear waste, many countries in Europe are now increasingly considering nuclear energy as an alternative to reducing fossil fuel energy production. At the present stage primary sources of uranium are sufficient to meet uranium needs and secondary sources are becoming increasingly important in terms of their long-term availability and environmental friendliness. Mining/recovery of uranium from secondary sources (such as phosphate minerals) is considerably safer in terms of exposure to radiological radiation and therefore requires less stringent safety measures. Uranium is also present in waste produced from certain industrial processes such as fertilizer production industry (e.g. phoshogypsum) and in nuclear waste. This work refers to the extraction and recovery of uranium from phosphate rocks, which is directly related to the production of uranium-free phosphate fertilizers and aims to limit environmental pollution related to the use of phosphate fertilizers. Since the chemistry during the leaching step is critical to efficient uranium recovery, various investigations have been carried to study various parameters that play an important role in achieving an optimum uranium extraction from rocks. Uranium leaching is carried out under acidic or alkaline conditions and the choice of chemistry is determined by the mineralogy of the host rocks. Acid leaching yields a higher recovery than alkaline leaching because the matrix is often more resistant to alkali than to acid leaching. However, the alkaline leaching process has the advantage of leading to the precipitation of a comparatively purer product directly from the leaching liquid. In addition, the washing solutions can be regenerated for further use, making this method more environmentally friendly. Recently alternative methods have been proposed which make use of uranium complexing ligands (e.g. EDTA) to achieve more efficient and selective uranium recovery.

@article{doi101016jscenv2023100055,
    author = "Michael, Andria and Varnava, Neκtaria and Ioannidis, Ioannis and Pashalidis, Ioannis",
    title = "Uranium recovery from phosphate rocks/minerals – A comprehensive review",
    year = "2023",
    journal = "Sustainable Chemistry for the Environment",
    abstract = "Although the use of nuclear energy is still viewed with caution due to various problems associated, such as the safe operation of 'aging' nuclear plants and the final disposal of nuclear waste, many countries in Europe are now increasingly considering nuclear energy as an alternative to reducing fossil fuel energy production. At the present stage primary sources of uranium are sufficient to meet uranium needs and secondary sources are becoming increasingly important in terms of their long-term availability and environmental friendliness. Mining/recovery of uranium from secondary sources (such as phosphate minerals) is considerably safer in terms of exposure to radiological radiation and therefore requires less stringent safety measures. Uranium is also present in waste produced from certain industrial processes such as fertilizer production industry (e.g. phoshogypsum) and in nuclear waste. This work refers to the extraction and recovery of uranium from phosphate rocks, which is directly related to the production of uranium-free phosphate fertilizers and aims to limit environmental pollution related to the use of phosphate fertilizers. Since the chemistry during the leaching step is critical to efficient uranium recovery, various investigations have been carried to study various parameters that play an important role in achieving an optimum uranium extraction from rocks. Uranium leaching is carried out under acidic or alkaline conditions and the choice of chemistry is determined by the mineralogy of the host rocks. Acid leaching yields a higher recovery than alkaline leaching because the matrix is often more resistant to alkali than to acid leaching. However, the alkaline leaching process has the advantage of leading to the precipitation of a comparatively purer product directly from the leaching liquid. In addition, the washing solutions can be regenerated for further use, making this method more environmentally friendly. Recently alternative methods have been proposed which make use of uranium complexing ligands (e.g. EDTA) to achieve more efficient and selective uranium recovery.",
    url = "https://doi.org/10.1016/j.scenv.2023.100055",
    doi = "10.1016/j.scenv.2023.100055",
    openalex = "W4389210033",
    references = "doi103133pp140"
}

Glaciers are retreating, altering alpine ecosystems and creating new proglacial lakes. Compared to lakes fed by snowpack, glacial lakes are often enriched in nutrients and suspended solids that decrease light penetration. However, the microorganisms and biogeochemical conditions within these newly formed lakes are not well characterized. We describe the microbial communities in 14 glacial lakes in Glacier National Park, MT, USA using 16S rRNA gene amplicon sequencing and measurements of nutrient concentrations, water clarity, and other environmental properties. Microbial communities were distinct between lakes, including those connected to the same glacier, indicating the importance of site-specific biogeochemical and physical dynamics on these systems. Microbial community composition correlated with lake age (formation before or after the Little Ice Age) and conductivity but not with whether a lake was connected to a contemporaneous glacier > 0.1 km2. Heterotrophic lineages found in other glacial systems were abundant and widespread, while cyanobacteria only reached appreciable abundances in shallow lakes where light reached the benthos. Relative abundances of ammonia and nitrite oxidizers correlated with concentrations of nitrate and nitrite, suggesting nitrification may help control nitrogen forms and concentrations in glacial lakes. We show that as glaciers recede, unique glacial lake microbial communities will be formed and lost with them.

@article{doi101093femsecfiaf060,
    author = "Peoples, Logan M. and Giersch, J. Joseph and Tappenbeck, Tyler H. and Vanderwall, Joseph and Ranieri, John M and Vick‐Majors, Trista J. and Elser, James J. and Church, Matthew J.",
    title = "Microbial communities in glacial lakes of Glacier National Park, MT, USA",
    year = "2025",
    journal = "FEMS Microbiology Ecology",
    abstract = "Glaciers are retreating, altering alpine ecosystems and creating new proglacial lakes. Compared to lakes fed by snowpack, glacial lakes are often enriched in nutrients and suspended solids that decrease light penetration. However, the microorganisms and biogeochemical conditions within these newly formed lakes are not well characterized. We describe the microbial communities in 14 glacial lakes in Glacier National Park, MT, USA using 16S rRNA gene amplicon sequencing and measurements of nutrient concentrations, water clarity, and other environmental properties. Microbial communities were distinct between lakes, including those connected to the same glacier, indicating the importance of site-specific biogeochemical and physical dynamics on these systems. Microbial community composition correlated with lake age (formation before or after the Little Ice Age) and conductivity but not with whether a lake was connected to a contemporaneous glacier > 0.1 km2. Heterotrophic lineages found in other glacial systems were abundant and widespread, while cyanobacteria only reached appreciable abundances in shallow lakes where light reached the benthos. Relative abundances of ammonia and nitrite oxidizers correlated with concentrations of nitrate and nitrite, suggesting nitrification may help control nitrogen forms and concentrations in glacial lakes. We show that as glaciers recede, unique glacial lake microbial communities will be formed and lost with them.",
    url = "https://doi.org/10.1093/femsec/fiaf060",
    doi = "10.1093/femsec/fiaf060",
    openalex = "W4411046482",
    references = "doi101016s0022283605803602, doi10103835054051, doi101038nmeth3869, doi101038s4158701902099, doi101073pnas0606291103, doi101093nargks1219, doi1011111462292013023, doi101186s1305901405508, doi101371journalpcbi1003531, doi101371journalpone0061217, gibson1939grinnell"
}