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Gutiérrez-marco J. C. - One of the best experts on this subject based on the ideXlab platform.

  • Remarkable ichnological sites in the Armorican Quartzite (Lower Ordovician) from the Almadén- Porzuna areas (Central Iberian Zone, Spain)
    'Japanese Society of Applied Entomology & Zoology', 2016
    Co-Authors: Lorenzo Saturnino, Gutiérrez-marco J. C., Sá, Artur A.
    Abstract:

    Trabajo presentado en el 4th International Congress on Ichnology - ICHNIA 2016: Ichnology for the 21st century: (Palaeo) Biological Traces towards Sustainable Development, celebrado en Idanha-a-Nova (Portugal), del 6 al 9 de mayo de 2016Uppermost Armorican Quartzite strata in the synclines of Almadén and Porzuna comprise thick-bedded sandstones with an outstanding ichnofossil record. A locality near Ermita de San Blas (Agudo, Ciudad Real) exposed a large top surface of a quartzite bed yielding numerous Cruziana furcifera and weathered “Catenichnus” isp. in a concave epirelief preservation. The second locality lies 1km southwest of Ermita La Cruz de Mayo, near Porzuna, also in the province of Ciudad Real. The Skolithos and Cruziana ichnofacies alternate in successive thick sandstone beds. The first one stands out by the “pipe-rock” concentrations of Skolithos that vertically grades in large concentrations of wide Daedalus visible in cross-sections. The Cruziana ichnofacies is represented by large exposures showing circling behaviour of cruzianids, preserved as concave epireliefs. These outcrops were erroneously interpreted by locals and cultural officers as archeological rather than paleontological sites. The existence of these large ichnological surfaces may contribute in the future to allow a detailed study on the behaviour of trace markers in the shallow epicratonic South Gondwana shelf.This research is a contribution to the projects CGL2012-39471 of the Spanish MINECO, IGCP-591 (IUGSUNESCO).Peer reviewe

  • Bedding-plane assemblage of ""Catenichnus"" in the Santa Justa Formation (Lower Ordovician, N Portugal)
    'Japanese Society of Applied Entomology & Zoology', 2016
    Co-Authors: Sá, Artur A., Gutiérrez-marco J. C.
    Abstract:

    Trabajo presentado en el 4th International Congress on Ichnology - ICHNIA 2016: Ichnology for the 21st century: (Palaeo) Biological Traces towards Sustainable Development, celebrado en Idanha-a-Nova (Portugal), del 6 al 9 de mayo de 2016The Santa Justa Formation (Armorican Quartzite facies) is named after the Santa Justa hill in the vicinity of Valongo (East of Oporto, N Portugal). This locality is a touristic place and along the path from the St. Sabinus chapel to the St. Justa chapel there is an outcrop of thick beds of quartzite, which corresponds to the upper part of the formation (Sá et al., 2011). A large bedding plane facing the path is crowded by shallow, elongate depressions, not preferentially oriented, which represents large “Catenichnus” (ca. 20 cm long) in epirelief preservation. The best samples show a U-shape burrow with divergent arms and a fairly uniform diameter within each structure up to 10 mm. The presence of a thick-mud lining differentiate the studied specimens from “Catenichnus” contentus McCarthy and ichnospecies of the genera Catenarichnus and Arenicolites. The weathering of the mud lining favoured the removal of the internal U-shaped cylinder, so that many specimens resemble “bath-tube” epireliefs without any internal detail. Occurrences of similar shaped “Catenichnus” have been recently described from the Pochico Formation (Arenigian) of Sierra Morena, Spain (RodríguezTovar et al., 2014). Two new Spanish records with similar characteristics are also here reported from the Armorican Quartzite of the Cabañeros National Park and the Agudo Syncline, in the Province of Ciudad Real.This research is a contribution to the projects CGL2012-39471 of the Spanish MINECO and the 727/2012 of the Spanish National Parks Network.Peer reviewe

  • Ploughing, tunnelling and biting in the Middle Ordovician of northern Portugal
    'Japanese Society of Applied Entomology & Zoology', 2016
    Co-Authors: Sá, Artur A., Gutiérrez-marco J. C., García-bellido Diego
    Abstract:

    Trabajo presentado en el 4th International Congress on Ichnology - ICHNIA 2016: Ichnology for the 21st century: (Palaeo) Biological Traces towards Sustainable Development, celebrado en Idanha-a-Nova (Portugal), del 6 al 9 de mayo de 2016Middle Ordovician shales from the Valongo and Moncorvo formations recorded temporary dysoxic environments, inhabited by opportunistic faunas that also include highly specialized deposit feeders. Resulting ichnofossils include Phycodes noa Mikuláš, a horizontally-ramified burrow complex, so far only known from older beds in the Prague Basin, as well as a large spiral grazing trace close to Rotundusichnium zumayensis Gómez de Llarena, which is widely distributed in Alpine flysch deposits. Phycodes noa from the Valongo Formation occurs as quite large, horizontally flabellate structure with up to 10 diverging passages. Specimens from the Canelas quarry (Arouca) are commonly infilled by pellets (Tomaculum), and are preserved flattened and tectonically expanded. Giant Rotundusichnium-like forms are exclusive from the Canelas quarry and consist of ?concentric to tightly spiral traces with a large elliptical outline (major axis up to 130 cm long), showing endichnial ribbons inclined to the centre of the structure. These are associated with imploded fragmocones of nautiloids preserved under them, and the trace maker harvested the microbial proliferation around them in tight centrifugal coils. The third remarkable trace corresponds to bite marks preserved in large trilobite carapaces. They have a consistent acute V-shaped outline and represent marginal breakage, usually placed in the right pygidial pleural border of asaphids, in diverse margins of calymenaceans or in semi-infaunal molluscs. These triangular bite marks are attributed to large nautiloid predators or scavengers, sometimes attacking freshly-molted giant trilobites.This research is a contribution to the projects CGL2012-39471 of the Spanish MINECO and IGCP-591 (IUGS-UNESCO).Peer reviewe

  • "Outstanding Paleozoic ichnofossils from Cabañeros National Park (Central Spain) and large casting processes for the preservation of Geological Heritage"
    'Japanese Society of Applied Entomology & Zoology', 2016
    Co-Authors: Gutiérrez-marco J. C., Sá, Artur A., Baeza E.
    Abstract:

    Trabajo presentado en el 4th International Congress on Ichnology - ICHNIA 2016: Ichnology for the 21st century: (Palaeo) Biological Traces towards Sustainable Development, celebrado en Idanha-a-Nova (Portugal), del 6 al 9 de mayo de 2016Outstanding trace fossils preserved in Cambrian and Ordovician sandstones constitute part of the geological heritage of Cabañeros National Park (CastillaLa Mancha Region, Central Spain) which has thousands of visitors each year. The lower Cambrian record is represented by the ichnogenus Astropolichnus, occurring as convex hyporeliefs, even preserving the central cylinder, or as concave epireliefs on rippled surfaces of the Azorejo Formation (GutiérrezMarco et al., 2015). Overlaying the Toledanian angular unconformity, the lower Floian “Intermediate Beds” bear unique large burrows, measuring up to 1160 cm long and 20 cm wide, preserved as full-reliefs at the top of several quartzite beds and sometimes forming prominent loops. Further up in the section, the Armorican Quartzite yield abundant traces of the Cruziana and Skolithos ichnofacies. Among them stands out a large bedding plane covered by “rusophyciform”-like Cruziana hyporeliefs, which may reflect a massmating event by their producers. Finally, the same beds yielded a very large burrow (45 cm wide) of a still unknown trace (Gutiérrez-Marco et al., 2010). In order to preserve and study these astonishing bedding planes, we made two large casts measuring up to 13.4 m2 . The concentration of a very wide Cruziana required the use of thixotropic agents on the moulding silicone and on the polyester shells prepared on-site. The resulting casts were made of epoxy resins, strengthened with woven and non-woven fibreglass fabrics and epoxy rebars, and coloured with mineral pigments (Baeza et al., 2013). The replica of Cruziana is the second largest single-piece cast in the world in the field of invertebrate paleoIchnology, and is housed in the main Interpretation Centre in Cabañeros National Park as a permanent exhibition.This research is a contribution to the projects CGL2012-39471 of the Spanish MINECO and 727/2012 of the Spanish National Parks Network.Peer reviewe

Sá, Artur A. - One of the best experts on this subject based on the ideXlab platform.

  • Remarkable ichnological sites in the Armorican Quartzite (Lower Ordovician) from the Almadén- Porzuna areas (Central Iberian Zone, Spain)
    'Japanese Society of Applied Entomology & Zoology', 2016
    Co-Authors: Lorenzo Saturnino, Gutiérrez-marco J. C., Sá, Artur A.
    Abstract:

    Trabajo presentado en el 4th International Congress on Ichnology - ICHNIA 2016: Ichnology for the 21st century: (Palaeo) Biological Traces towards Sustainable Development, celebrado en Idanha-a-Nova (Portugal), del 6 al 9 de mayo de 2016Uppermost Armorican Quartzite strata in the synclines of Almadén and Porzuna comprise thick-bedded sandstones with an outstanding ichnofossil record. A locality near Ermita de San Blas (Agudo, Ciudad Real) exposed a large top surface of a quartzite bed yielding numerous Cruziana furcifera and weathered “Catenichnus” isp. in a concave epirelief preservation. The second locality lies 1km southwest of Ermita La Cruz de Mayo, near Porzuna, also in the province of Ciudad Real. The Skolithos and Cruziana ichnofacies alternate in successive thick sandstone beds. The first one stands out by the “pipe-rock” concentrations of Skolithos that vertically grades in large concentrations of wide Daedalus visible in cross-sections. The Cruziana ichnofacies is represented by large exposures showing circling behaviour of cruzianids, preserved as concave epireliefs. These outcrops were erroneously interpreted by locals and cultural officers as archeological rather than paleontological sites. The existence of these large ichnological surfaces may contribute in the future to allow a detailed study on the behaviour of trace markers in the shallow epicratonic South Gondwana shelf.This research is a contribution to the projects CGL2012-39471 of the Spanish MINECO, IGCP-591 (IUGSUNESCO).Peer reviewe

  • Bedding-plane assemblage of ""Catenichnus"" in the Santa Justa Formation (Lower Ordovician, N Portugal)
    'Japanese Society of Applied Entomology & Zoology', 2016
    Co-Authors: Sá, Artur A., Gutiérrez-marco J. C.
    Abstract:

    Trabajo presentado en el 4th International Congress on Ichnology - ICHNIA 2016: Ichnology for the 21st century: (Palaeo) Biological Traces towards Sustainable Development, celebrado en Idanha-a-Nova (Portugal), del 6 al 9 de mayo de 2016The Santa Justa Formation (Armorican Quartzite facies) is named after the Santa Justa hill in the vicinity of Valongo (East of Oporto, N Portugal). This locality is a touristic place and along the path from the St. Sabinus chapel to the St. Justa chapel there is an outcrop of thick beds of quartzite, which corresponds to the upper part of the formation (Sá et al., 2011). A large bedding plane facing the path is crowded by shallow, elongate depressions, not preferentially oriented, which represents large “Catenichnus” (ca. 20 cm long) in epirelief preservation. The best samples show a U-shape burrow with divergent arms and a fairly uniform diameter within each structure up to 10 mm. The presence of a thick-mud lining differentiate the studied specimens from “Catenichnus” contentus McCarthy and ichnospecies of the genera Catenarichnus and Arenicolites. The weathering of the mud lining favoured the removal of the internal U-shaped cylinder, so that many specimens resemble “bath-tube” epireliefs without any internal detail. Occurrences of similar shaped “Catenichnus” have been recently described from the Pochico Formation (Arenigian) of Sierra Morena, Spain (RodríguezTovar et al., 2014). Two new Spanish records with similar characteristics are also here reported from the Armorican Quartzite of the Cabañeros National Park and the Agudo Syncline, in the Province of Ciudad Real.This research is a contribution to the projects CGL2012-39471 of the Spanish MINECO and the 727/2012 of the Spanish National Parks Network.Peer reviewe

  • Ploughing, tunnelling and biting in the Middle Ordovician of northern Portugal
    'Japanese Society of Applied Entomology & Zoology', 2016
    Co-Authors: Sá, Artur A., Gutiérrez-marco J. C., García-bellido Diego
    Abstract:

    Trabajo presentado en el 4th International Congress on Ichnology - ICHNIA 2016: Ichnology for the 21st century: (Palaeo) Biological Traces towards Sustainable Development, celebrado en Idanha-a-Nova (Portugal), del 6 al 9 de mayo de 2016Middle Ordovician shales from the Valongo and Moncorvo formations recorded temporary dysoxic environments, inhabited by opportunistic faunas that also include highly specialized deposit feeders. Resulting ichnofossils include Phycodes noa Mikuláš, a horizontally-ramified burrow complex, so far only known from older beds in the Prague Basin, as well as a large spiral grazing trace close to Rotundusichnium zumayensis Gómez de Llarena, which is widely distributed in Alpine flysch deposits. Phycodes noa from the Valongo Formation occurs as quite large, horizontally flabellate structure with up to 10 diverging passages. Specimens from the Canelas quarry (Arouca) are commonly infilled by pellets (Tomaculum), and are preserved flattened and tectonically expanded. Giant Rotundusichnium-like forms are exclusive from the Canelas quarry and consist of ?concentric to tightly spiral traces with a large elliptical outline (major axis up to 130 cm long), showing endichnial ribbons inclined to the centre of the structure. These are associated with imploded fragmocones of nautiloids preserved under them, and the trace maker harvested the microbial proliferation around them in tight centrifugal coils. The third remarkable trace corresponds to bite marks preserved in large trilobite carapaces. They have a consistent acute V-shaped outline and represent marginal breakage, usually placed in the right pygidial pleural border of asaphids, in diverse margins of calymenaceans or in semi-infaunal molluscs. These triangular bite marks are attributed to large nautiloid predators or scavengers, sometimes attacking freshly-molted giant trilobites.This research is a contribution to the projects CGL2012-39471 of the Spanish MINECO and IGCP-591 (IUGS-UNESCO).Peer reviewe

  • "Outstanding Paleozoic ichnofossils from Cabañeros National Park (Central Spain) and large casting processes for the preservation of Geological Heritage"
    'Japanese Society of Applied Entomology & Zoology', 2016
    Co-Authors: Gutiérrez-marco J. C., Sá, Artur A., Baeza E.
    Abstract:

    Trabajo presentado en el 4th International Congress on Ichnology - ICHNIA 2016: Ichnology for the 21st century: (Palaeo) Biological Traces towards Sustainable Development, celebrado en Idanha-a-Nova (Portugal), del 6 al 9 de mayo de 2016Outstanding trace fossils preserved in Cambrian and Ordovician sandstones constitute part of the geological heritage of Cabañeros National Park (CastillaLa Mancha Region, Central Spain) which has thousands of visitors each year. The lower Cambrian record is represented by the ichnogenus Astropolichnus, occurring as convex hyporeliefs, even preserving the central cylinder, or as concave epireliefs on rippled surfaces of the Azorejo Formation (GutiérrezMarco et al., 2015). Overlaying the Toledanian angular unconformity, the lower Floian “Intermediate Beds” bear unique large burrows, measuring up to 1160 cm long and 20 cm wide, preserved as full-reliefs at the top of several quartzite beds and sometimes forming prominent loops. Further up in the section, the Armorican Quartzite yield abundant traces of the Cruziana and Skolithos ichnofacies. Among them stands out a large bedding plane covered by “rusophyciform”-like Cruziana hyporeliefs, which may reflect a massmating event by their producers. Finally, the same beds yielded a very large burrow (45 cm wide) of a still unknown trace (Gutiérrez-Marco et al., 2010). In order to preserve and study these astonishing bedding planes, we made two large casts measuring up to 13.4 m2 . The concentration of a very wide Cruziana required the use of thixotropic agents on the moulding silicone and on the polyester shells prepared on-site. The resulting casts were made of epoxy resins, strengthened with woven and non-woven fibreglass fabrics and epoxy rebars, and coloured with mineral pigments (Baeza et al., 2013). The replica of Cruziana is the second largest single-piece cast in the world in the field of invertebrate paleoIchnology, and is housed in the main Interpretation Centre in Cabañeros National Park as a permanent exhibition.This research is a contribution to the projects CGL2012-39471 of the Spanish MINECO and 727/2012 of the Spanish National Parks Network.Peer reviewe

Murray K Gingras - One of the best experts on this subject based on the ideXlab platform.

  • PYCHNO: A CORE-IMAGE QUANTITATIVE Ichnology LOGGING SOFTWARE
    PALAIOS, 2016
    Co-Authors: Eric R. Timmer, Murray K Gingras, John-paul Zonneveld
    Abstract:

    Collecting and analyzing semi-quantitative ichnological parameters such as size-diversity index and bioturbation intensity, can increase the resolution of paleoenvironmental analyses. Specialized software, PyCHNO, was designed to ease, improve, and standardize current ichnological data collection techniques. With PyCHNO, ichnological data derived from burrow diameter measurements, trace fossil identification (ichnogenus level), and bioturbation index are collected at a user-defined scale, and size-diversity index is calculated from these measurements. Data collected in PyCHNO, including size-diversity index, maximum burrow diameter, trace fossil diversity, trace fossil taxon abundance, and bioturbation index is easily exported as text files or plotted as PDF logs.

  • the glossifungites ichnofacies and sequence stratigraphic analysis a case study from middle to upper eocene successions in fayum egypt
    Ichnos-an International Journal for Plant and Animal Traces, 2016
    Co-Authors: Zaki A Abdelfattah, George S Pemberton, Murray K Gingras, Michael W Caldwell, James A Maceachern
    Abstract:

    ABSTRACTThe Glossifungites Ichnofacies was erected by Dolf Seilacher (the father of modern Ichnology) in the mid-nineteen sixties to encompass burrows excavated into firm or compacted substrates. Correspondingly, this firmground ichnofacies has been used extensively in the identification of omission surfaces and the identification and interpretation of sequence stratigraphic discontinuities. A case study from Eocene strata in the Fayum depression of Egypt presents an opportunity to showcase a genetic approach for classifying occurrences of the Glossifungites Ichnofacies. More than twenty-five Glossifungites Ichnofacies–demarcated surfaces are documented and examined in this study. Based on the origin and character of these discontinuities, the examined surfaces are grouped into two main types: those of autogenic origin and those of allogenic derivation. The allogenically generated expressions of the Glossifungites Ichnofacies are associated with key-stratigraphic discontinuities of sequence stratigraphic ...

  • oregon sea stack ecological diversity of a modern trypanites ichnofacies
    Ichnos-an International Journal for Plant and Animal Traces, 2016
    Co-Authors: Carolyn M Furlong, Murray K Gingras, Sarah K Schultz, John-paul Zonneveld
    Abstract:

    AbstractThe paleoecology of rocky substrates in the rock record is commonly interpreted based on Ichnology and is frequently associated with a bioeroding community (the Trypanites Ichnofacies) with low ichnological diversity. However, analyses of a modern, siliciclastic, intertidal hardground community at Lion Rock, located at Arcadia Beach State Park, Oregon, reveals a diverse community of boring, encrusting, and squatting/clinging organisms. Through observations and descriptions of organism distribution and abundance, more than 40 species of plants and animals are reported to reside within three littoral zones (upper, middle, and lower littoral zone) on the sea stack. A newly established erosional lower littoral zone is a subdivision of the lower littoral zone, where shifting foreshore sand influences colonization and biotic diversity. Borings are produced by four bivalves, Adula californiensis, Hiatella arctica, Penitella penita, and Zirfaea pilsbryi, and are identified as Gastrochaenolites traces. It ...

  • tidal Ichnology of shallow water clastic settings
    2012
    Co-Authors: Murray K Gingras, James A Maceachern
    Abstract:

    This chapter explores using ichnological data as an indicator of tidal influence on sedimentation. Presently, the most commonly used method for establishing tidal influence with trace-fossil datasets is the presence of a brackish-water suite of trace fossils. Brackish-water trace-fossil suites generally comprise low-diversity, comparably diminutive trace fossils including forms such as Cylindrichnus, Planolites, Thalassinoides, Teichichnus, Arenicolites, Skolithos and cryptobioturbation. A problem with this method is that tidal currents and brackish-water do not always accompany one another. We attempt to build on previous brackish-water studies by examining the influence of tides on trace-fossil assemblages by considering 5 major impacts of tidal sedimentation. (1) The impact of rhythmic changes in current velocity on (passive) burrow infill, which can generate rhythmically infilled, large-diameter trace fossils (e.g. Thalassinoides and Psilonichnus) that correspond to tubular tidalites. (2) The influence of longer periodicity tidal rhythms on bed colonization, which produce regular waxing and waning of bioturbation intensity at the bed and/or bed-set scale. (3) The effect of tidal currents on burrow distributions, which produces a characteristic bioturbation-increasing-landwards trend into the middle part of bays and estuaries. (4) The impact of differing sedimentation rates between subtidal and intertidal settings, which contributes to a characteristic bioturbation-increasing-upwards profile on tidal bars. (5) And, the influence of variable resource distribution due to variable current energy, which results in a preponderance of interface deposit-feeding structures, stellate feeding traces and the presence of systematic deposit feeding trace fossils. Notably, the potential of using trace fossils to identify tidal influence on sedimentation and faunal colonization is at its inception. Substantial data is still needed to refine the ichnological model proposed herein.

  • process Ichnology and the elucidation of physico chemical stress
    Sedimentary Geology, 2011
    Co-Authors: Murray K Gingras, James A Maceachern, Shahin E Dashtgard
    Abstract:

    Abstract This paper sets out a philosophical approach to ichnological (trace fossil) analysis, which focuses on the interpretation of trace fossils as sedimentary structures rather than as paleontological entities per se . Using wide-ranging datasets and a large number of observations and interpretations, a “Process Ichnology” framework is proposed. This interpretive framework provides an improved means of estimating the presence and magnitude of various physical and chemical (i.e., physico-chemical) depositional stresses (e.g., water turbidity, sedimentation rates, substrate consistency, salinity, and oxygenation) in ancient sedimentary environments. Ichnological datasets that are considered include: 1) trace-fossil distributions; 2) ethological diversity and the range of diversity; 3) the significance of burrow linings; 4) trace-fossil size; and, 5) post-depositional compaction of trace fossils. From these data, higher-resolution estimates can be made for the determination of sedimentation rates, temporal variation in sedimentation rate, sediment consistency, and aspects of the bottom- and interstitial-water chemistries. Additionally, the character of depositional bypassing of sediment grains can be determined. The methodologies and interpretations herein are intended for use by non-ichnologists in a manner akin to the interpretation of physical sedimentary structures. However, the outlined framework is complementary to other methods of ichnological analysis, such as ichnofacies- or ichnofabric-analysis, and can be applied as such. Indeed, this method is a derivative of these and other earlier techniques, and should be employed where a systematic approach to obtaining high-resolution sedimentological interpretations is a required aspect of the study.

James A Maceachern - One of the best experts on this subject based on the ideXlab platform.

  • the glossifungites ichnofacies and sequence stratigraphic analysis a case study from middle to upper eocene successions in fayum egypt
    Ichnos-an International Journal for Plant and Animal Traces, 2016
    Co-Authors: Zaki A Abdelfattah, George S Pemberton, Murray K Gingras, Michael W Caldwell, James A Maceachern
    Abstract:

    ABSTRACTThe Glossifungites Ichnofacies was erected by Dolf Seilacher (the father of modern Ichnology) in the mid-nineteen sixties to encompass burrows excavated into firm or compacted substrates. Correspondingly, this firmground ichnofacies has been used extensively in the identification of omission surfaces and the identification and interpretation of sequence stratigraphic discontinuities. A case study from Eocene strata in the Fayum depression of Egypt presents an opportunity to showcase a genetic approach for classifying occurrences of the Glossifungites Ichnofacies. More than twenty-five Glossifungites Ichnofacies–demarcated surfaces are documented and examined in this study. Based on the origin and character of these discontinuities, the examined surfaces are grouped into two main types: those of autogenic origin and those of allogenic derivation. The allogenically generated expressions of the Glossifungites Ichnofacies are associated with key-stratigraphic discontinuities of sequence stratigraphic ...

  • tidal Ichnology of shallow water clastic settings
    2012
    Co-Authors: Murray K Gingras, James A Maceachern
    Abstract:

    This chapter explores using ichnological data as an indicator of tidal influence on sedimentation. Presently, the most commonly used method for establishing tidal influence with trace-fossil datasets is the presence of a brackish-water suite of trace fossils. Brackish-water trace-fossil suites generally comprise low-diversity, comparably diminutive trace fossils including forms such as Cylindrichnus, Planolites, Thalassinoides, Teichichnus, Arenicolites, Skolithos and cryptobioturbation. A problem with this method is that tidal currents and brackish-water do not always accompany one another. We attempt to build on previous brackish-water studies by examining the influence of tides on trace-fossil assemblages by considering 5 major impacts of tidal sedimentation. (1) The impact of rhythmic changes in current velocity on (passive) burrow infill, which can generate rhythmically infilled, large-diameter trace fossils (e.g. Thalassinoides and Psilonichnus) that correspond to tubular tidalites. (2) The influence of longer periodicity tidal rhythms on bed colonization, which produce regular waxing and waning of bioturbation intensity at the bed and/or bed-set scale. (3) The effect of tidal currents on burrow distributions, which produces a characteristic bioturbation-increasing-landwards trend into the middle part of bays and estuaries. (4) The impact of differing sedimentation rates between subtidal and intertidal settings, which contributes to a characteristic bioturbation-increasing-upwards profile on tidal bars. (5) And, the influence of variable resource distribution due to variable current energy, which results in a preponderance of interface deposit-feeding structures, stellate feeding traces and the presence of systematic deposit feeding trace fossils. Notably, the potential of using trace fossils to identify tidal influence on sedimentation and faunal colonization is at its inception. Substantial data is still needed to refine the ichnological model proposed herein.

  • process Ichnology and the elucidation of physico chemical stress
    Sedimentary Geology, 2011
    Co-Authors: Murray K Gingras, James A Maceachern, Shahin E Dashtgard
    Abstract:

    Abstract This paper sets out a philosophical approach to ichnological (trace fossil) analysis, which focuses on the interpretation of trace fossils as sedimentary structures rather than as paleontological entities per se . Using wide-ranging datasets and a large number of observations and interpretations, a “Process Ichnology” framework is proposed. This interpretive framework provides an improved means of estimating the presence and magnitude of various physical and chemical (i.e., physico-chemical) depositional stresses (e.g., water turbidity, sedimentation rates, substrate consistency, salinity, and oxygenation) in ancient sedimentary environments. Ichnological datasets that are considered include: 1) trace-fossil distributions; 2) ethological diversity and the range of diversity; 3) the significance of burrow linings; 4) trace-fossil size; and, 5) post-depositional compaction of trace fossils. From these data, higher-resolution estimates can be made for the determination of sedimentation rates, temporal variation in sedimentation rate, sediment consistency, and aspects of the bottom- and interstitial-water chemistries. Additionally, the character of depositional bypassing of sediment grains can be determined. The methodologies and interpretations herein are intended for use by non-ichnologists in a manner akin to the interpretation of physical sedimentary structures. However, the outlined framework is complementary to other methods of ichnological analysis, such as ichnofacies- or ichnofabric-analysis, and can be applied as such. Indeed, this method is a derivative of these and other earlier techniques, and should be employed where a systematic approach to obtaining high-resolution sedimentological interpretations is a required aspect of the study.

  • Uses of Trace Fossils in Genetic Stratigraphy
    Trace Fossils, 2007
    Co-Authors: James A Maceachern, Murray K Gingras, S. George Pemberton, Kerrie L. Bann, Lynn T. Dafoe
    Abstract:

    SUMMARY: Trace fossils represent both sedimentological and paleontological entities and as such, constitute a unique blending of potential environmental indicators in the rock record. Trace fossils and trace fossil suites can be employed effectively to aid in the recognition and genetic interpretation of various discontinuity types. Ichnology may be employed to resolve surfaces of stratigraphic significance in two main ways: (1) through the identification of discontinuities using omission suites, comprising substrate-controlled ichnofacies (i.e., firmground Glossifungites Ichnofacies, hardground Trypanites Ichnofacies, and woodground Teredolites Ichnofacies) or palimpsest softground suites; and (2) through careful analysis of vertical softground ichnologic successions (analogous to facies successions). Integrating data derived from omission suites with paleoecological data from vertically and laterally juxtaposed softground ichnological suites greatly enhances the recognition and interpretation of potentially significant stratigraphic surfaces.

  • edward hitchcock and roland bird two early titans of vertebrate Ichnology in north america
    Trace Fossils#R##N#Concepts Problems Prospects, 2007
    Co-Authors: George S Pemberton, Murray K Gingras, James A Maceachern
    Abstract:

    SUMMARY: Vertebrate Ichnology in North America has a long and distinguished history, starting with the remarkable discoveries by Edward Hitchcock of dinosaur footprints and trackways from the Connecticut River Valley. Hitchcock assembled a unique collection that is currently housed in the Pratt Museum, Amherst College, and his work essentially constituted the beginnings of Ichnology as a viable sub-discipline of paleontology. Although his original interpretation that these Late Triassic repichnia were bird tracks was incorrect, he indirectly linked birds and dinosaurs. In the southwest, the gifted American Museum of Natural History collector Roland T. Bird discovered the first sauropod tracks from Cretaceous strata near Glen Rose, Texas. These tracks gave paleontologists a means of assessing the behavior of sauropods, compared to the inaccuracies of preconceived popular conception, and fledgling skeletal reconstructions. The observations of trackways, recording the activity of the organisms while they were alive, ultimately led to the recognition that sauropods actually walked on land and could support their weight rather than requiring water to buoy them, possessed an upright posture with limbs directly beneath them, held their tails above the ground rather than dragging them, and that some forms had adopted herd behavior.

Sanjib K Biswas - One of the best experts on this subject based on the ideXlab platform.

  • postrift deltaic sedimentation in western kachchh basin insights from Ichnology and sedimentology
    Palaeogeography Palaeoclimatology Palaeoecology, 2018
    Co-Authors: Bhawanisingh G Desai, Sanjib K Biswas
    Abstract:

    Abstract The postrift stage in the pericratonic Kachchh Rift Basin of western India is represented by a thick sequence of a diachronous megadelta system. The deposition of this deltaic sequence was initiated during the mid-Kimmeridgian and ended in the Albian. The sedimentation was interrupted by two transgressive events demarcating three subcycles within the megadelta system. The present study addresses the older mid-Kimmeridgian to Tithonian “Jhuran Delta”. An attempt is made here to delineate the nature of the Jhuran Delta using the ichnological and sedimentological parameters. The Jhuran Delta, which consists of 14 lithofacies, is grouped into seven lithofacies associations corresponding to the prodelta, subaqueous gravity flow, delta front, distributary channel, distributary mouth bar, and shoreface depositional environments along with a transgressive unit overlapping the lower delta of the megadelta system. Three distinct stages of deltaic evolution are delineated along with the fourth stage of transgression and delta destruction. The prodelta environment of Stage I is characterized by moderate ichnodiversity represented by nine recurring ichnotaxa, suggesting alternating brackish and fully saline water conditions, which indicate river-dominated deltaic sedimentation. Stage II shows a marked increase in the influence of river (fresh water) water, as indicated by a submarine mass failure that includes debris flow, chaotic and contorted structures, sediment gravity-failure and water-escape structures and suggesting a higher rate of sedimentation. Ichnologically, this phase indicates low ichnodiversity with sporadic occurrences of Ophiomorpha and Palaeophycus. Stage III indicates the mixed dominance of river and wave processes. Sediments deposited in the delta front environment show moderate ichnodiversity with nine ichnotaxa. The distributary mouth bar environment comprises 6 recurring ichnotaxa including the ichnoassemblages of both river and marine wave environments. Integrated ichnological data suggest deposition in a mixed environment. The Jhuran Delta stage ended with a marine transgressive event and reworking of the deltaic sands, which were overlain by a thick shoreface deposit. Thus, the Upper Jurassic Jhuran Delta represents a river-dominated, wave-influenced delta.

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