Готові списки джерел за темами / Geology, Stratigraphic Cambrian

Добірка наукової літератури з теми "Geology, Stratigraphic Cambrian"

Автор: Grafiati

Опубліковано: 4 червня 2021

Оновлено: 4 березня 2023

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Статті в журналах з теми "Geology, Stratigraphic Cambrian":

Mel’nikov, N. V. "The Vendian–Cambrian Cyclometric Stratigraphic Scale for the Southern and Central Siberian Platform." Russian Geology and Geophysics 62, no. 08 (August 1, 2021): 904–13. http://dx.doi.org/10.2113/rgg20214339.

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Abstract —The general Vendian stratigraphic scale of Siberia, with the uncertain age of the Vendian base ranging from 600 to 630– 640 Ma in most of recent publications, remains worse constrained than the Cambrian scale, in which the boundaries of epochs and stages have been well defined. However, the imperfect classical stratigraphic division has been compensated by data on the cyclicity of the Vendian–Cambrian sedimentary section. The Vendian stratigraphy of the Siberian Platform and the related deposition history with cycles of sedimentation and gaps, as well as the hierarchy of sedimentation processes, can be inferred from the succession of alternating clastic, carbonate, and salt units. The cyclicity of geologic processes and their recurrence are attributed to periodic oscillatory motions of the crust. The ranks of these motions correlate with the cyclicity of sedimentary strata, including regocyclites, nexocyclites, and halcyclites separated by gaps. Each Vendian long-period oscillatory motion begins with a regocyclite and ends with a regional-scale gap. The Cambrian section includes one pre-Mayan regional gap at the end of the early Cambrian long-period cycle. Cambrian regocyclites are composed of carbonate subformations and formations in the lower part and alternating salt and carbonate beds in the upper part.

Idrissi, Assia, Mohamed Saadi, Yassir Astati, Ali Bouayachi, and Kawtar Benyas. "Mapping of Genetic Sequences of the Cambrian Series in the Jbel Saghro Massif, Eastern Anti-Atlas, Morocco: Implications for Eustatic and Tectonic Controls." Iraqi Geological Journal 55, no. 1D (April 30, 2022): 1–20. http://dx.doi.org/10.46717/igj.55.1d.1ms-2022-04-17.

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In this paper, a sedimentological and sequence stratigraphy analysis was performed on Lower and Middle Cambrian deposits of Jbel Saghro, Eastern Anti-Atlas. The field data analysis and the application of sequence stratigraphy concepts were used to classify sedimentary processes and depositional environment, and to define the Lower to Middle Cambrian basin’s detailed geometry. The Cambrian sedimentation of northeastern Saghro indicates a deltaic environment, which is composed of two depositional sequences. These sequences are made of a transgressive system-tract with retrograding sediments and a highstand system tract with prograding sediments. In response to sea-level change, these system-tracts were formed by several genetic units, and limited by various stratigraphic surfaces. The genetic unit stacking-patterns combined with the study of synsedimentary tectonics enabled to follow the sedimentary record’s Spatio-temporal evolution and its three-dimensional geometry. The study area deposits display significant dissimilarities in thickness. The western part shows a Lower Cambrian hiatus and an important reduction of the thickness in the Middle Cambrian deposits. However, the marine trend (progradation/retrogradation) remains similar in the study area. This suggests the same eustatic origin of all genetic sequences and variations in their preservation rate. This configuration is the result of differential subsidence that affected the Anti-Atlas during the Cambrian.

Myrow, P. M., N. C. Hughes, and N. R. McKenzie. "Reconstructing the Himalayan margin prior to collision with Asia: Proterozoic and lower Paleozoic geology and its implications for Cenozoic tectonics." Geological Society, London, Special Publications 483, no. 1 (November 21, 2018): 39–64. http://dx.doi.org/10.1144/sp483.10.

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AbstractReconstructing the stratigraphic architecture of deposits prior to Cenozoic Himalayan uplift is critical for unravelling the structural, metamorphic, depositional and erosional history of the orogen. The nature and distribution of Proterozoic and lower Paleozoic strata have helped elucidate the relationship between lithotectonic zones, as well as the geometries of major bounding faults. Stratigraphic and geochronological work has revealed a uniform and widespread pattern of Paleoproterozoic strata >1.6 Ga that are unconformably overlain by <1.1 Ga rocks. The overlying Neoproterozoic strata record marine sedimentation, including a Cryogenian diamictite, a well-developed carbonate platform succession and condensed fossiliferous Precambrian–Cambrian boundary strata. Palaeontological study of Cambrian units permits correlation from the Indian craton through three Himalayan lithotectonic zones to a precision of within a few million years. Detailed sedimentological and stratigraphic analysis shows the differentiation of a proximal realm of relatively condensed, nearshore, evaporite-rich units to the south and a distal realm of thick, deltaic deposits to the north. Thus, Neoproterozoic and Cambrian strata blanketed the northern Indian craton with an extensive, northward-deepening, succession. Today, these rocks are absent from parts of the inner Lesser Himalaya, and the uplift and erosion of these proximal facies explains a marked change in global seawater isotopic chemistry at 16 Ma.

Anderson, Donna, and Mark Longman. "Subsurface Reinterpretation of Ordovician and Devonian Strata in Southwest Wyoming with Implications for Upwarping Across the Transcontinental Arch." Mountain Geologist 55, no. 3 (July 2018): 91–118. http://dx.doi.org/10.31582/rmag.mg.55.3.91.

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A new interpretation of the subsurface geometries of the Ordovician Bighorn Dolomite and overlying Devonian strata across southwestern Wyoming arises from revising the stratigraphy in a core from the Mountain Fuel Supply UPRR #11–19–104–4 well drilled on the crest of the Rock Springs Uplift in 1962. One of only a few wells to penetrate all or part of the Lower Paleozoic succession in the subsurface of southwestern Wyoming, the well was almost continuously cored through the Devonian–Cambrian succession. From a reinterpretation of the stratigraphy in the core, 22 ft of Bighorn Dolomite is recognized based on the characteristic Thalassinoides bioturbation fabric in skeletal dolowackestone typical of Late Ordovician subtidal carbonate facies ranging from Nevada to Greenland along the western margin of the Great American Carbonate Bank. This lithology is in complete contrast with the alternating dolomitic flat-pebble conglomerate and dolomudstone of the underlying Cambrian Gallatin Limestone and the cyclical units of brecciated anhydritic dolomudstone and quartzose sandstone of the overlying Devonian Lower Member of the Jefferson Formation. Stratigraphic re-interpretation yields insights regarding Ordovician–Devonian stratal geometries across southwestern Wyoming. More widespread than previously portrayed, the Bighorn Dolomite pinches out on the eastern flank of the Rock Springs Uplift. Similar to past interpretations, Devonian strata pinch out east of the Rock Springs Uplift at Table Rock Field. A true-geometry multi-datumed stratigraphic cross section yields insights not obtainable by mapping. Regionally, top truncation of stratigraphic units below the base-Madison Limestone unconformity normally progresses stratigraphically deeper eastward. However, in southwestern Wyoming, the Devonian Lower Member of the Jefferson Formation overlaps the older Bighorn Dolomite by marked onlap across the Rock Springs Uplift and then pinches out by top truncation/onlap near Table Rock Field, forming an “abnormal” overlap relationship along the northern margin of the Transcontinental Arch. The underlying Bighorn Dolomite shows little to no onlap onto the underlying Cambrian section, but is markedly top truncated below the Lower Member of the Jefferson Formation. Comparing proportions of onlap versus top truncation for the two formations constrains the timing of two successive upwarping episodes along the northern margin of the Transcontinental Arch across southwestern Wyoming. The first is arguably Middle Devonian, and the second spans the Devonian–Mississippian boundary. Two subtle and different angular unconformities created by these two episodes imply a persistent fold or tilt axis that sequentially was reactivated along the northern margin of the Transcontinental Arch in southwestern Wyoming.

Elicki, Olaf, and Gerd Geyer. "The Cambrian trilobites of Jordan – taxonomy, systematic and stratigraphic significance." Acta Geologica Polonica 63, no. 1 (March 1, 2013): 1–56. http://dx.doi.org/10.2478/agp-2013-0001.

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Abstract Elicki, O. and Geyer, G. 2013. The Cambrian trilobites of Jordan - taxonomy, systematic and stratigraphic significance. Acta Geologica Polonica, 63(1), 1-56. Warszawa. Marine carbonates and siliciclastic rocks of the Burj Formation in Jordan include paucispecific trilobite associations of the (traditional) Lower-Middle Cambrian boundary interval. Comprehensive new material of these trilobites allows a review of their taxonomy and systematic positions as well as a refined morphological description and a reconsideration of previous interpretations of their stratigraphic position and thus the correlation of the fossiliferous beds. In addition to the classic species Kingaspis campbelli (King, 1923) and Redlichops blanckenhorni Richter and Richter, 1941, Timnaella? orientalis (Picard, 1942) and Hesa problematica Richter and Richter, 1941, the discussed trilobites include Issalia gen. nov. with Issalia scutalis gen. nov., sp. nov., Tayanaspis gen. nov. with Tayanaspis bulbosus gen. nov., sp. nov., Uhaymiria gen. nov. with Uhaymiria glabra gen. nov., sp. nov., Cambrunicornia ? jafnaensis sp. nov., Myopsolenites palmeri (Parnes, 1971), M. hyperion sp. nov., and Enixus cf. antiquus (Chernysheva, 1956). Myopsolenites boutiouiti Geyer and Landing, 2004 is now regarded as a junior synonym of Myopsolenites altus (Linan and Gozalo, 1986). A detailed discussion of the correlation with a focus on global aspects provides clues for the utility of potential index fossils for the global Cambrian Series 3 and Stage 5.

Kontorovich, A. E., A. I. Varlamov, A. S. Efimov, V. A. Kontorovich, I. V. Korovnikov, V. A. Krinin, S. V. Saraev, N. V. Sennikov, and Yu F. Filippov. "Stratigraphic Scheme of Cambrian Deposits, South of the Cis-Yenisei Area of West Siberia." Russian Geology and Geophysics 62, no. 03 (March 1, 2021): 357–76. http://dx.doi.org/10.2113/rgg20204317.

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Abstract ––In this paper we present a stratigraphic scheme for the subdivision and correlation of the Cambrian deposits in the south of the cis-Yenisei area of West Siberia, which was adopted as a current scheme by the decision of the Interdepartmental Stratigraphic Committee in 2018. This scheme is based on the data from stratigraphic test wells (Lemok-1, Averinskaya-150, Tyiskaya-1, Vostok-1, Vostok-3, Vostok-4, etс.). In the study area, two structure-facies zones were identified: Kas (Lemok-1, Averinskaya-150, Tyiskaya-1, Vostok-4, and Eloguiskaya-1 wells), where sedimentary complexes accumulated in a salt subbasin, and Ket’ (Vostok-1 and Vostok-3 wells) with the deposition in an open sea basin. The boundary between these structure-facies zones is drawn along the inferred N–S-trending barrier reef zone. The rubrication in this paper is compiled in accordance with the requirements of the Stratigraphic Code of Russia for explanatory notes for regional stratigraphic schemes. Local stratigraphic subdivisions (formations, strata) are described and compared with the adjacent Turukhansk–Irkutsk–Olekma facies region of the Siberian Platform.

Jie-Dong, Yang, Sun Wei-Guo, Wang Zong-Zhe, and Wang Yin-Xi. "Sm—Nd isotopic age of Precambrian—Cambrian boundary in China." Geological Magazine 133, no. 1 (January 1996): 53–61. http://dx.doi.org/10.1017/s001675680000724x.

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AbstractBy the new method of Sm—Nd isotopic dating on phosphatic small skeletal fossils and collo-phanite minerals, the Zhongyicun Member of the earliest Cambrian Meishucun Stage at Meishucun in Yunnan, southern China, has been dated at 562.8 ± 7.9 Ma and 562.1 ± 5.7 Ma. Another Sm—Nd age, 570.3 ± 17.1 Ma, has been obtained with samples from the Zhongyicun Member in Yunnan and its stratigraphic equivalents in Sichuan and Xinjiang. These data tend to suggest that the best age estimate of the Precambrian—Cambrian boundary is very likely within the range of 560–570 Ma. As biophosphates and sedimentary phosphates are widely distributed in sequences of the Precambrian—Cambrian transition, the Sm-Nd isotopic method is recommended as an effective approach for precise dating of the initial Cambrian boundary.

Lindsay, J. F., M. D. Brasier, D. Dorjnamjaa, R. Goldring, P. D. Kruse, and R. A. Wood. "Facies and sequence controls on the appearance of the Cambrian biota in southwestern Mongolia: implications for the Precambrian–Cambrian boundary." Geological Magazine 133, no. 4 (July 1996): 417–28. http://dx.doi.org/10.1017/s0016756800007585.

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AbstractNeoproterozoic–Cambrian rocks of the Zavkhan Basin (Govi-Altay, western Mongolia) comprise large-scale alternations of siliciclastic- and carbonate-dominated units (cf. ‘Grand Cycles’). Analysis of such depositional sequences near the base of the Cambrian confirms that the distribution of trace fossils, small shelly fossils and calcimicrobial structures was strongly controlled by ecology and taphonomy, corresponding to specific points in a sea-level cycle. Evolution of the Cambrian biota is thus viewed through aseries of narrow time windows, once only for each depositional cycle. Correlation of the Precambrian–Cambrian boundary level on the basis of the first appearance of thePhycodes pedumassemblage is also fraught with difficulty, since stratigraphic resolution may be limited to a single sea-level cycle(c. 1–5 Ma). It is suggested that, in many cases, basin analysis will need to be undertaken before this boundary can be drawn.

Korobova, Natalia I., Evgeniya E. Karnyushina, Nadezhda S. Shevchuk, Sergei V. Frolov, Elena A. Bakay, and Grigorii G. Akhmanov. "Geology aspects, sedimentation environments and oil-and-gas bearing capacity of Vendian and Cambrian deposits of Lena-Tunguska basin." Georesursy 24, no. 2 (May 16, 2022): 60–74. http://dx.doi.org/10.18599/grs.2022.2.9.

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At present time several dozen hydrocarbon fields are known in the Vendian-Cambrian complex of the Lena-Tunguska basin, which clearly does not exhaust its potential. The significant stratigraphic interval of the complex, its thickness (up to 3000 m), favorable properties laid down in sedimentogenesis, namely the presence of source, reservoir and seal deposits, allow us to hope for the discovery of new oil and gas deposits. Sedimentological studies of the Vendian-Cambrian complex, carried out using a network of key lithological sections and outcrops, made it possible to create a series of schematic maps of sedimentation environments on a scale of 1:5000000 for six time intervals (Nepa, Tira, Danilovo, Tommotian-Early Atdabanian, Botomian-Amgaian and Late Cambrian). The evolution of sedimentation of the Vendian-Cambrian complex is considered, as well as an assessment of its oil and gas properties, which are primarily associated with various sedimentation environments.

GEYER, G. "The Fish River Subgroup in Namibia: stratigraphy, depositional environments and the Proterozoic–Cambrian boundary problem revisited." Geological Magazine 142, no. 5 (September 2005): 465–98. http://dx.doi.org/10.1017/s0016756805000956.

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The Fish River Subgroup of the Nama Group, southern Namibia, is restudied in terms of lithostratigraphy and depositional environment. The study is based on partly fine-scaled sections, particularly of the Nababis and Gross Aub Formation. The results are generally in accordance with earlier studies. However, braided river deposits appear to be less widely distributed in the studied area, and a considerable part of the formations of the middle and upper subgroup apparently were deposited under shallowest marine conditions including upper shore-face. Evidence comes partly from sedimentary features and facies distribution, and partly from trace fossils, particularly Skolithos and the characteristic Trichophycus pedum. Environmental conditions represented by layers with T. pedum suggest that the producer favoured shallow marine habitats and transgressive regimes. The successions represent two deepening-upward sequences, both starting as fluvial (braided river) systems and ending as shallow marine tidally dominated environments. The first sequence includes the traditional Stockdale, Breckhorn and lower Nababis formations (Zamnarib Member). The second sequence includes the upper Nababis (Haribes Member) and Gross Aub formations. As a result, the Nababis and Gross Aub formations require emendation: a new formation including the Haribes and Rosenhof and possibly also the Deurstamp members. In addition, four distinct sequence stratigraphic units are deter-minable for the Fish River Subgroup in the southern part of the basin. The Proterozoic–Cambrian transition in southern Namibia is most probably located as low as the middle Schwarzrand Subgroup. The environmentally controlled occurrence of Trichophycus pedum undermines the local stratigraphic significance of this trace fossil which is eponymous with the lowest Cambrian and Phanerozoic trace fossil assemblage on a global scale. However, occurrences of such trace fossils have to be regarded as positive evidence for Phanerozoic age regardless of co-occurring body fossils. Other suggestions strongly dispute the concept of the formal Proterozoic–Cambrian and Precambrian–Phanerozoic boundary. Carbon isotope excursions and radiometric datings for the Nama Group do not help to calibrate precisely the temporal extent of the Fish River Subgroup. Fossil content, sequence stratigraphy and inferred depositional developments suggest that this subgroup represents only a short period of late orogenic molasse sedimentation during the early sub-trilobitic Early Cambrian.

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Дисертації з теми "Geology, Stratigraphic Cambrian":

Dilliard, Kelly Ann. "Sequence stratigraphy and chemostratigraphy of the Lower Cambrian Sekwi Formation, Northwest Territories, Canada." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Dissertations/Spring2006/K%5FDilliard%5F042406.pdf.

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Baghiyan-Yazd, Mohammad Hassan. "Palaeoichnology of the terminal Proterozoic-Early Cambrian transition in central Australia : interregional correlation and palaeoecology." Title page, table of contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phb1445.pdf.

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Osleger, David Allen. "Cyclostratigraphy of Late Cambrian cyclic carbonates : an interbasinal field and modelling study, U.S.A. /." Diss., This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03262008-175224/.

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Malhame, Pierre. "Quartz arenites of the uppermost Cambrian-lowermost Ordovician Kamouraska Formation, Québec, Canada : gravity flow deposits of eolian sand in the deep sea." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101868.

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The uppermost Cambrian-Lower Ordovician Kamouraska Formation in the external Humber Zone of the Quebec Appalachians consists of dominant thick massive to graded quartz arenite beds, subordinate pebble conglomerate and intercalated thin shale and siltstone beds. It was deposited by hyperconcentrated to concentrated density flows in a meandering submarine canyon on the continental slope bordering the Iapetus Ocean. Turbidity currents deposited beds with turbidite structure divisions. The sandstones consist of well sorted, well rounded quartz sand with frosted grains. Scanning electron microscopy reveals the presence of textures supporting eolian transport before redeposition in the deep sea. The Kamouraska quartz arenites are considered an ancient equivalent of Pleistocene eolian-sand turbidites on an abyssal plain off West Africa consisting of Sahara sand. Sand provenance is attributed to eolian equivalents of the Cairnside Formation of the Potsdam Group. The quartz arenites of the Kamouraska Formation provide a variant to tectonic sandstone provenance proposed in the scheme of Dickinson and Suczek (1979).

Sundberg, Frederick Allen. "Morphological diversification of the ptychopariid trilobites in the Marjumiid biomere (Middle to Upper Cambrian)." Diss., This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-07102007-142511/.

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Eagan, Keith E. "Paleoenvironmental and Stratigraphic Interpretation of the Middle Cambrian Ute Formation, Northern Utah." DigitalCommons@USU, 1996. https://digitalcommons.usu.edu/etd/6791.

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The Middle Cambrian Ute Formation includes some 200 m of cyclically alternating carbonates and mud rocks. These are arranged in eight to nine, meter-scale, shallowing-upwards packages, representing deposition under predominantly subtidal conditions. The packages consist of vertical sequences of shale, silty limestone, oncolitic packstone, and oolitic grainstone that exhibit little variance in this general pattern. Small-scale unconformities separate the packages. The inferred depositional environment consists of an intrashelf basin that has a peritidal platform near its margins. The craton, which supplied most of the terrigenous sediment, was situated to the south (Cambrian orientation), and located near the equator. One cycle includes a stromatolite biostrome that is distributed across more than 1500 km2 in northern Utah and southern Idaho. Stromatolites range from mound-like to club-shaped to columnar and reach up to 2 min vertical dimension, and 0.15 min diameter. These large columnar structures were apparently established just basinward of an oolitic shoal. These ancient stromatolites, which are in many ways similar to those stromatolites recently reported from the Bahamas, contain many clues that suggest that they grew in normal marine conditions. These findings require a rethinking of the commonly held belief that Phanerozoic columnar stromatolites are indicators of restricted, hypersaline conditions. Analysis of several orders of laminae in Ute Formation stromatolites indicates periodicity in accumulation from which yearly accumulation rates may be inferred. Values obtained for growth rate range from 4.39-4.88 cm/yr. Such rates of accumulation are in accord with those documented for ancient stromatolites from the Bitter Springs Formation. Thus, even considering the occurrence of hiatal surfaces within the stromatolites, the duration of the columnar-stromatolite horizon probably encompasses 10-2 - 10-3 yr. The biostrome's position in the sequence of cycles and the changes in stromatolite morphology across depositional dip suggest that the biostrome may be essentially isochronous across its outcrop area and, thus, may be viewed as a bioevent horizon. The stromatolites also contribute to a better understanding of the paleogeography of the study area during the Middle Cambrian by providing information on relative energy levels and flow directions. (212 pages)

Singh, Updesh. "Late Precambrian and Cambrian carbonates of the Adelaidean in the Flinders Ranges, South Australia : a petrographic, electron microprobe and stable isotope study /." Title page, abstract and contents only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phs1792.pdf.

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Tremblay, James Vincent. "Trilobites and strata of the Lower and Middle Cambrian Peyto, Mount Whyte and Naiset Formations, Alberta and British Columbia /." *McMaster only, 1996.

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Simpson, Edward L. "Sedimentology and tectonic implications of the Late Proterozoic to Early Cambrian Chilhowee Group in southern and central Virginia." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/53660.

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Few detailed facies analyses of rift to passive-margin transitions have been undertaken in exhumed orogenic belts. In the central Appalachians, the Chilhowee Group records such an evolution. The Unicoi and basal Hampton Formations record the transition from rifting to opening of the Iapetus Ocean. The majority of the Hampton Formation and the overlying Erwin Formation represent an overall regressive sequence punctuated by five progradational packages that accumulated along a passive margin. The rift to passive·margin phases of sedimentation in the central Appalachians reflect a continuum from fault·influenced to thermotectonic subsidence. Alluvial sediments and intercalated basalts of the lower Unicoi Formation developed in a rift setting. Paleontological data indicate that rifting continued into lower Cambrian time. The upper Unicoi Formation represents the incipient phase of passive-margin sedimentation related to a first-order, sea level rise. Differences in degree of crustal attenuation controlled the distribution of sedimentary environments during transgression. On the most attenuated crust to the east, initial transgressive facies consist of tidal sandwave and sandridge deposits intercalated with proximal and medial braid-pIain deposits. As transgression progressed cratonwards onto less attenuated crust, tidal sedimentation was supplanted by tide- and wave-influenced sedimentation characterized by sandwave complexes, tidal inlets and longshore bedforms. Drowning at the top of the Unicoi Formation is indicated by outer-shelf black mudstones. Deepening may have been enhanced by continued movement along listric faults throughout the incipient phase of passive-margin development. Examination of outcrops of the Hampton and Erwin Formations on different thrust sheets has permitted an across-strike reconstruction of the Early Cambrian Chilhowee shelf in space and time. Progradational packages developed under storm- and fair·weather wave conditions. Coarsening· and thickening-upward sequences on westerly thrust sheets were generated during progradation of shoreface, inner-shelf and outer-shelf environments. Outer-shelf facies predominate on easterly thrust sheets. Intertidal-flat deposits on the most westerly thrust sheet erosively overlie progradational shoreface sediments and developed during transgression in an embayment in which the tidal wave was amplified. More distal transgressive deposits consist of fining- and thinning·upward sequences with glauconitic horizons, and condensed sections in mudstones.
Ph. D.

Maguire, Henry C. "Application Of Geophysical And Geochronological Methods To Sedimentologic And Stratigraphic Problems In The Lower Cambrian Monkton Formation: Northwestern Vermont." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/938.

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The Monkton Formation of the western shelf stratigraphic sequence in Vermont (VT) is identified as a Lower Cambrian regressive sandstone unit containing parasequences recording tidal flat progradation. Previous workers identified cycles believed to represent parasequences in a portion of a 1034' deep geothermal well drilled at Champlain College in Burlington, Vermont. For this study, both outcrop and well geophysical surveys were completed to better identify gamma emission curves and relative values for parasequences and select lithologies that are indicators of bathymetry and sea level. After using physical stratigraphic techniques to assemble a composite stratigraphic section for the Monkton Formation, analysis of the gamma emission curve and relative gamma values resulted in the identification and characterization of parasequences and select lithologies within the Monkton. Interpretation of bathymetry-sensitive lithologies along with parasequence architecture and thickness trends reveals three distinctive intervals over the thickness of the Monkton. It is recognized that the succession of these intervals represents an overall decreasing rate in accommodation space generation through Monkton deposition. Previous workers have suggested that biostratigraphic relationships of the Monkton Formation to the Potsdam Group in New York (NY) suggest that that they would be at least partially correlative. To further refine age relationships and constrain and compare the provenance of the Vermont stratigraphy locally and regionally, zircon samples were collected from the Monkton and the overlying Danby Formations and radiometric age determinations were completed by laser ablation–inductively coupled plasma mass spectrometry (LA-ICPMS) at University of Arizona Laserchron Center. Zircon age probability distribution curves show two dominate age peaks between 1.05-1.09 Ga and 1.15-1.18 Ga for the Monkton and Danby suggesting either a continuity of provenance through the Cambrian or the cycling of the Monkton's sand. The 1.05-1.09 Ga age range corresponds to rocks generated during the Ottawan Orogeny while the 1.15-1.18 Ga range is associated with the Shawinigan Orogeny and anorthosite-mangerite-charnockite-granite (AMCG) plutonism. Dominant age peaks in the Vermont samples between 1.15-1.18 Ga are similar to the 1.16 Ga age peak reported by other workers from the Altona and Ausable Formations of the Potsdam Group of New York. The shared dominant age peak and close proximity of the Vermont and New York stratigraphy may suggest a primarily shared provenance.

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Книги з теми "Geology, Stratigraphic Cambrian":

Secord, James A. Controversy in Victorian geology: The Cambrian-Silurian dispute. Princeton, N.J: Princeton University Press, 1986.

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Jankauskas, Tadas. Cambrian stratigraphy of Lithuania. Vilnius: Geologijos institutas, 2002.

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W, Cowie J., and Brasier M. D, eds. The Precambrian-Cambrian boundary. Oxford: Clarendon Press, 1989.

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Secord, James A. Controversy in Victorian geology: The Cambria-Silurian dispute. Oxford: Princeton University Press, 1990.

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Ineson, Jon R. Cambrian shelf stratigraphy of North Greenland. Copenhagen, Denmark: Geological Survey of Denmark and Greenland, Ministry of Environment and Energy, 1997.

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1879-1960, Knight Cyril W., and Canada Mines Branch, eds. The Pre-Cambrian geology of southeastern Ontario. Toronto: L.K. Cameron, 1997.

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Aceñolaza, Guillermo Federico, and Silvio Peralta. Cambrian from the southern edge. San Miguel de Tucumán, Républica Argentina: Consejo Nacional de Investigaciones Cientif́icas y Técnicas, Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, 2000.

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Mokrik, Robert. The palaeohydrogeology of the Baltic Basin: Vendian & Cambrian. Tartu: Institute of Geology, Lithuania, 1997.

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I︠U︡, Zhuravlev A., and Riding Robert, eds. The ecology of the Cambrian radiation. New York: Columbia University Press, 2001.

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1879-1960, Knight Cyril W., ed. Revision of pre-Cambrian classification in Ontario. [Canada?: s.n., 1997.

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Частини книг з теми "Geology, Stratigraphic Cambrian":

Huntoon, Peter W. "Cambrian stratigraphic nomenclature,Grand Canyon, Arizona: Mappers nightmare." In Geology of Grand Canyon, Northern Arizona (with Colorado River Guides): Lee Ferry to Pierce Ferry, Arizona, 128–30. Washington, D. C.: American Geophysical Union, 1989. http://dx.doi.org/10.1029/ft115p0128.

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Dorjnamjaa, D., B. Enkhbaatar, and G. Altanshagai. "Precambrian and Cambrian Regional Stratigraphy of Mongolia." In Springer Geology, 391–95. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-04364-7_76.

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Zellouf, Khemissi, and Hamid Aït Salem. "Sequence Stratigraphy of the Cambrian and Ordovician Series in the Illizi Basin (Algeria)." In Springer Geology, 815–20. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-04364-7_153.

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Sukhov, Sergey. "Sedimentological Causes of Some Problems in the Cambrian Stratigraphy of the Siberian Platform." In Springer Geology, 453–56. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-04364-7_87.

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Azmy, Karem, Gabriella Bagnoli, Svend Stouge, and Uwe Brand. "High-Resolution Carbon-Isotope Stratigraphy of the Cambrian–Ordovician GSSP: An Enhanced International Correlation Tool." In Springer Geology, 233–37. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-04364-7_47.

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Cook, Harry E. "Geology of the Basin and Range Province, western United States: An overview." In Cambrian and Early Ordovician Stratigraphy and Paleontology of the Basin and Range Province, Western United States: Las Vegas, Nevada to Salt Lake City, Utah, July 1–7, 1989, 6–13. Washington, D. C.: American Geophysical Union, 1989. http://dx.doi.org/10.1029/ft125p0006.

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Desrochers, André, Patricia Brennan-Alpert, Denis Lavoie, and Guoxiang Chi. "Regional Stratigraphic, Depositional, and Diagenetic Patterns of the Interior of St. Lawrence PlatformThe Lower Ordovician Romaine Formation, Western Anticosti Basin, Quebec." In Great American Carbonate BankThe Geology and Economic Resources of the Cambrian—Ordovician Sauk Megasequence of Laurentia. American Association of Petroleum Geologists, 2012. http://dx.doi.org/10.1306/13331505m983504.

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Skehan, James W., Michael J. Webster, and Daniel F. Logue. "Cambrian stratigraphy and structural geology of southern Narragansett Bay, Rhode Island." In Centennial Field Guide Volume 5: Northeastern Section of the Geological Society of America, 195–200. Geological Society of America, 1987. http://dx.doi.org/10.1130/0-8137-5405-4.195.

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Rowland, Stephen M. "Geology of Frenchman Mountain and Rainbow Gardens, southern Nevada, USA." In Field Excursions from Las Vegas, Nevada: Guides to the 2022 GSA Cordilleran and Rocky Mountain Joint Section Meeting, 23–43. Geological Society of America, 2022. http://dx.doi.org/10.1130/2022.0063(02).

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ABSTRACT This field guide synthesizes more than a half century of research by many geologists and paleontologists on Frenchman Mountain and Rainbow Gardens, southern Nevada, USA. The field-trip consists of seven stops to be visited in one day. The guide was written not only for field-trip participants on the occasion of the 2022 Cordilleran/Rocky Mountain Geological Society of America Joint Section Meeting in Las Vegas, but also with future users in mind. The Frenchman Mountain/Rainbow Gardens block of crust exposes an extraordinary sample of Earth history. The geologic features include (1) Proterozoic crystalline rocks, (2) the Great Unconformity, (2) a Paleozoic interval that is essentially a tilted section of the western Grand Canyon, (3) a Mesozoic interval that preserves strata that were eroded off the southern Colorado Plateau during the Miocene “Great Denudation” episode, and (4) a Cenozoic section that records a wealth of paleoclimatic, paleontological, and tectonic data. Among the many stories that are recorded in the rocks of the Frenchman Mountain/Rainbow Gardens block, I have chosen three to emphasize in this field guide: (1) the history recorded in the Proterozoic Vishnu Basement Complex and the Great Unconformity; (2) the stratigraphy, sedimentology, paleontology, and geochronology of the Cambrian Tonto Group [with a focus on (a) trilobite biostratigraphy in the Bright Angel Formation, (b) the significance of the abundance of glauconite in the Tonto Group, and (c) the Frenchman Mountain Dolostone]; and (3) the tectonic story recorded in the Thumb Member of the Horse Spring Formation. The basement rocks record events and processes associated with the assembly of supercontinents Nuna and Rodinia. The Great Unconformity records the breakup of Rodinia and the associated denudation interval that played a role in triggering the Cambrian explosion. The Tonto Group, which was recently expanded to include the Frenchman Mountain Dolostone, records the Sauk Transgression. And the Thumb Member of the Horse Spring Formation contains rock avalanche deposits that have played a key role in sorting out the tectonic history of the southern Nevada region and the translational history of the Frenchman Mountain/Rainbow Gardens block.

Martens, Uwe C., and Roberto S. Molina Garza. "Mexico: Basement framework and pre-Cretaceous stratigraphy." In Southern and Central Mexico: Basement Framework, Tectonic Evolution, and Provenance of Mesozoic–Cenozoic Basins, 1–27. Geological Society of America, 2021. http://dx.doi.org/10.1130/2021.2546(01).

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ABSTRACT Provenance determinations of sediment deposited in circum–Gulf of Mexico basins rely on understanding the geologic elements present in the basement provinces located from northeast Mexico to Honduras. Relevant geologic features of these provinces are herein summarized in text and pictorial form, and they include the Huizachal-Peregrina uplift, western Gulf of Mexico, Huayacocotla, Zapoteco, Mixteca, Xolapa, Juchatengo, Cuicateco, Mixtequita, south-central Chiapas, southeast Chiapas, western Guatemala, central Guatemala, Maya Mountains, and the Chortis block. We recognized basement elements of local character that serve as fingerprints for specific source areas. However, many elements are ubiquitous, such as 1.4–0.9 Ga, high-grade metamorphic rocks that occur both as broad exposures and as inliers in otherwise reworked crust. Xenocrystic and detrital zircon of Mesoproterozoic age is very common and hence not diagnostic of provenance. Neoproterozoic rocks are very scarce in Mexican basement provinces. However, Ediacaran–Cambrian detrital zircon grains are found in Mexican Paleozoic strata; these were possibly derived from distant sources in Gondwana and Pangea. Ordovician–Silurian magmatism is present in approximately half the provinces; magmatic detrital zircon of such age is somewhat informative in terms of provenance. More useful populations are detrital zircon grains with Ordovician–Silurian metamorphic overgrowth, which seem to be mainly sourced from the Mixteca region or the southern Chiapas Massif. Devonian basement has only been discovered in the Maya Mountains of Belize, and detrital zircon of such age seems to be characteristic of that source. A similar case can be made about Carboniferous zircon and the Acatlán Complex, Middle Pennsylvanian zircon and Juchatengo plutons, and Late Triassic zircon and the basement exposed in central Guatemala. In all these cases, the age and geographic extent of the zircon source are restricted and serve as a distinct fingerprint. Plutons of Permian–Early Triassic age are widespread, and detrital zircon grains from them are rather nonspecific indicators of source area. Future dating of detrital white mica using 40Ar-39Ar could help in recognizing Carboniferous–Triassic schist from more restricted schist occurrences such as west Cuicateco (Early Cretaceous) and central Guatemala (Late Cretaceous).

Тези доповідей конференцій з теми "Geology, Stratigraphic Cambrian":

Hughes, G. M., and A. Al Lawati. "An updated Stratigraphic Framework for the Haima Supergroup of North Oman." In Seventh Arabian Plate Geology Workshop: Pre-Cambrian to Paleozoic Petroleum Systems in the Arabian Plate. Netherlands: EAGE Publications BV, 2018. http://dx.doi.org/10.3997/2214-4609.201900227.

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Al-Bloushi, A., S. K. Tanoli, R. Husain, M. Al-Wadi, A. Horbury, and P. Clews. "Pre-Khuff subsurface stratigraphy in Kuwait." In Seventh Arabian Plate Geology Workshop: Pre-Cambrian to Paleozoic Petroleum Systems in the Arabian Plate. Netherlands: EAGE Publications BV, 2018. http://dx.doi.org/10.3997/2214-4609.201900215.

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Yassin, M., M. Mahgoub, M. Hariri, M. Makkawi, and O. Abdullatif. "The Lithofacies, Porosity and Geomechanical Stratigraphy of Qusaiba Shale, Outcrop Analog Study from Central Saudi Arabia." In Seventh Arabian Plate Geology Workshop: Pre-Cambrian to Paleozoic Petroleum Systems in the Arabian Plate. Netherlands: EAGE Publications BV, 2018. http://dx.doi.org/10.3997/2214-4609.201900219.

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Al Rawahi, H., I. Gomez-Perez, K. Bergmann, M. Cantine, and C. Fonseca-Rivera. "Sedimentology and Isotopes Stratigraphy of the Fara Formation in North Oman Outcrops and its Relation to the South Oman Subsurface." In Seventh Arabian Plate Geology Workshop: Pre-Cambrian to Paleozoic Petroleum Systems in the Arabian Plate. Netherlands: EAGE Publications BV, 2018. http://dx.doi.org/10.3997/2214-4609.201900213.

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Farrell, Thomas, Hannah Cothren, Laura J. Crossey, Carol Dehler, John R. Foster, James W. Hagadorn, Karl E. Karlstrom, Fred A. Sundberg, Mark D. Schmitz, and Mark Webster. "NUMERICAL CALIBRATION OF WESTERN LAURENTIAN CAMBRIAN STRATIGRAPHIC SUCCESSIONS INTO THE GLOBAL GEOLOGIC TIME SCALE." In GSA Connects 2021 in Portland, Oregon. Geological Society of America, 2021. http://dx.doi.org/10.1130/abs/2021am-368486.

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Orndorff, Randall, and Mercer Parker. "CAMBRIAN-ORDOVICIAN STRATIGRAPHY OF THE SOUTHERN CHAMPLAIN VALLEY, NEW YORK AND VERMONT: RECONCILING GEOLOGIC MAPPING OF FORMATIONS." In Northeastern Section - 57th Annual Meeting - 2022. Geological Society of America, 2022. http://dx.doi.org/10.1130/abs/2022ne-373885.

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Звіти організацій з теми "Geology, Stratigraphic Cambrian":

Cecile, M. P., B. S. Norford, G. S. Nowlan, and T. T. Uyeno. Lower Paleozoic stratigraphy and geology, Richardson Mountains, Yukon (with stratigraphic and paleontological appendices). Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329454.

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The Richardson Trough was a rift basin on the southern margin of an ancestral Iapetus Ocean. It was part of a complex paleogeography that included at least two major rift basins on western Franklinian and northern Cordilleran continental shelves. This paleogeography included the Ogilvie Arch, Porcupine Platform, Blackstone 'supra-basin', Babbage Basin, Husky Lakes Arch, Richardson Trough, Mackenzie Arch, Lac des Bois Platform, and the White Mountains and Campbell uplifts. The Richardson Trough was the failed arm of a triple rift system that formed when an early Paleozoic Iapetus Ocean developed north of the trough. The Richardson Trough displays a classic 'steer's head' profile with two rift fill cycles. The first features late early to middle late Cambrian rifting and late late Cambrian to late Early Ordovician post-rift subsidence; the second, late Early Ordovician to early Silurian rifting and late early Silurian to early Middle Devonian post-rift subsidence. Lower Paleozoic strata exposed in the Richardson Trough range in age from middle Cambrian to early Middle Devonian and are similar to strata in their sister rift, the Misty Creek Embayment. Before this study, the stratigraphic units defined for the Richardson Trough were the Slats Creek Formation and the Road River Formation. Here, the Slats Creek Formation and a new Road River Group are recognized. In order, this group consists of the middle and/or late Cambrian to Early Ordovician Cronin Formation; the early Early Ordovician to latest early Silurian Mount Hare Formation; the early Silurian to late Silurian Tetlit Formation; and the late Silurian to early Middle Devonian Vittrekwa Formation. These Road River Group strata are unconformably overlain by the late Middle to Late Devonian Canol Formation (outcrop) and by the Early Devonian Tatsieta Formation (subsurface).

Fallas, K. M., and R. B. MacNaughton. Bedrock mapping and stratigraphic studies in the Mackenzie Mountains, Franklin Mountains, Colville Hills, and adjacent areas of the Northwest Territories, Geo-mapping for Energy and Minerals program 2009-2019. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/326093.

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The Geo-mapping for Energy and Minerals (GEM) program provided an opportunity to update bedrock geological maps for nearly 92 000 km2 of the northwestern portion of the mainland area of the Northwest Territories. Twenty-four new maps (at the scale of 1:100 000 or 1:250 000) cover a region from the Colville Hills southwestward into the Mackenzie Mountains, including areas of significant mineral and energy resource potential. New mapping was informed by archived Geological Survey of Canada data, notably from Operation Norman (1968-1970), as well as by public-domain industry data. Maps incorporate numerous stratigraphic revisions that postdate Operation Norman, including GEM program innovations affecting Neoproterozoic (specifically Tonian and Ediacaran), Cambrian, and Ordovician units. In this paper, the mapping effort and stratigraphic revisions are documented, a preliminary treatment of structural geology is provided, and related subsurface studies are summarized. Following GEM, GIS-enabled bedrock maps will be available for a swath of territory stretching from the edge of the Selwyn Basin, near the Yukon border, to the Brock Inlier in the northeastern portion of the mainland area of the Northwest Territories.

Tweet, Justin, Holley Flora, Summer Weeks, Eathan McIntyre, and Vincent Santucci. Grand Canyon-Parashant National Monument: Paleontological resource inventory (public version). National Park Service, December 2021. http://dx.doi.org/10.36967/nrr-2289972.

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Grand Canyon-Parashant National Monument (PARA) in northwestern Arizona has significant paleontological resources, which are recognized in the establishing presidential proclamation. Because of the challenges of working in this remote area, there has been little documentation of these resources over the years. PARA also has an unusual management situation which complicates resource management. The majority of PARA is administered by the Bureau of Land Management (BLM; this land is described here as PARA-BLM), while about 20% of the monument is administered by the National Park Service (NPS; this land is described here as PARA-NPS) in conjunction with Lake Mead National Recreation Area (LAKE). Parcels of state and private land are scattered throughout the monument. Reports of fossils within what is now PARA go back to at least 1914. Geologic and paleontologic reports have been sporadic over the past century. Much of what was known of the paleontology before the 2020 field inventory was documented by geologists focused on nearby Grand Canyon National Park (GRCA) and LAKE, or by students working on graduate projects; in either case, paleontology was a secondary topic of interest. The historical record of fossil discoveries in PARA is dominated by Edwin McKee, who reported fossils from localities in PARA-NPS and PARA-BLM as part of larger regional projects published from the 1930s to the 1980s. The U.S. Geological Survey (USGS) has mapped the geology of PARA in a series of publications since the early 1980s. Unpublished reports by researchers from regional institutions have documented paleontological resources in Quaternary caves and rock shelters. From September to December 2020, a field inventory was conducted to better understand the scope and distribution of paleontological resources at PARA. Thirty-eight localities distributed across the monument and throughout its numerous geologic units were documented extensively, including more than 420 GPS points and 1,300 photos, and a small number of fossil specimens were collected and catalogued under 38 numbers. In addition, interviews were conducted with staff to document the status of paleontology at PARA, and potential directions for future management, research, protection, and interpretation. In geologic terms, PARA is located on the boundary of the Colorado Plateau and the Basin and Range provinces. Before the uplift of the Colorado Plateau near the end of the Cretaceous 66 million years ago, this area was much lower in elevation and subject to flooding by shallow continental seas. This led to prolonged episodes of marine deposition as well as complex stratigraphic intervals of alternating terrestrial and marine strata. Most of the rock formations that are exposed in the monument belong to the Paleozoic part of the Grand Canyon section, deposited between approximately 510 and 270 million years ago in mostly shallow marine settings. These rocks have abundant fossils of marine invertebrates such as sponges, corals, bryozoans, brachiopods, bivalves, gastropods, crinoids, and echinoids. The Cambrian–Devonian portion of the Grand Canyon Paleozoic section is represented in only a few areas of PARA. The bulk of the Paleozoic rocks at PARA are Mississippian to Permian in age, approximately 360 to 270 million years old, and belong to the Redwall Limestone through the Kaibab Formation. While the Grand Canyon section has only small remnants of younger Mesozoic rocks, several Mesozoic formations are exposed within PARA, mostly ranging in age from the Early Triassic to the Early Jurassic (approximately 252 to 175 million years ago), as well as some middle Cretaceous rocks deposited approximately 100 million years ago. Mesozoic fossils in PARA include marine fossils in the Moenkopi Formation and petrified wood and invertebrate trace fossils in the Chinle Formation and undivided Moenave and Kayenta Formations.