Gabriela Mangano | University of Saskatchewan (original) (raw)

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Papers by Gabriela Mangano

Earth-Science Reviews, 2022

Communications Earth & Environment, 2021

The exceptionally preserved fossils entombed in the deposits of sediment-gravity flows in the Cam... more The exceptionally preserved fossils entombed in the deposits of sediment-gravity flows in the Cambrian Burgess Shale of British Columbia have been fundamental for understanding the origin of major animal groups during the Cambrian explosion. More recently, they have been used to investigate the evolution of community structure; however, this assumes that the fossil assemblage represents an in-life community. Here we test this assumption for the first time based on experimental and field approaches. We use flume experiments to create analog flows and show that transport of the polychaete Alitta virens over tens of kilometers does not induce significantly more damage beyond that already experienced due to normal decay processes. Integration of experimental results with taphonomic assessment of fossils and sedimentological analysis suggests that the organisms of the Burgess Shale in the classic Walcott Quarry locality could have undergone substantial transport and may represent a confl...

Sedimentology, 2021

The Aptian evaporitic transitional sequence (sag phase) of the Brazilian marginal basins records ... more The Aptian evaporitic transitional sequence (sag phase) of the Brazilian marginal basins records the first connection between the Central and South Atlantic oceans in the equatorial area. During this phase, lacustrine carbonate reservoirs and giant salt deposits developed in the southern basins of Santos and Campos, forming world‐class petroleum reservoirs. The sag succession is also well‐preserved in the interior rift basins of north‐eastern Brazil, where upper Aptian strata are represented by a continuous section. This contribution presents an interpretation of the evolution of a third‐order depositional sequence comprising lacustrine limestones, marine siliciclastic facies and evaporite deposits of the intracontinental Araripe Basin. The Lowstand Systems Tract is characterized by fluvial deposits filling accommodation generated during the syn‐rift phase. The overlying deposits comprise marine facies with preservation of dinoflagellates and marine ichnotaxa, evidencing marine depo...

Journal of South American Earth Sciences, 2021

Abstract Although the middle Miocene Oficina Formation of the Orinoco Oil Belt represents most of... more Abstract Although the middle Miocene Oficina Formation of the Orinoco Oil Belt represents most of Venezuela's hydrocarbon resource, a comprehensive and detailed sedimentary facies model for the whole belt has never been put forward. Based on the analysis of cores and well logs, nine sedimentary facies (FA-I), forming five facies assemblages (FA1-5), have been characterized. Both sedimentologic and ichnologic datasets have been integrated in this study. The Oficina Formation records the typical succession of fluvial incision during relative sea-level fall, fluvial deposition during lowstand, transition from fluvial to estuary valleys during the subsequent transgression and deltaic progradation during highstand. FA1 consists of fluvial-braided channel (FB), floodplain (FG2), and swamp (FH1) deposits, as well as paleosols (FG3). This facies assemblage occurs in the lower member, representing the infill of lowstand fluvial valleys. FA2 consists of meandering estuary-channel deposits (FA, FC, FD, FE, and FI). This facies assemblage occurs in the middle member, representing the infill of tide-dominated estuary valleys during the early stages of the Langhian transgression. FA3 consists of tidal-flat and tidal-creek (FC, FD, FE, FF, and FG2), and swamp (FH1 and FH2) deposits, together with paleosols (FG3). This facies assemblage is present in the middle member, revealing backstepping and retrogradation within the estuary system during a continuing transgression. FA4 consists of outer-estuary sandbar (FC, FD, and FG1); swamp (FH2) deposits and paleosols are present at the margins of the estuary (FG3). This facies assemblage occurs in the uppermost part of the middle members, representing a late stage of the Langhian transgression, culminating in a maximum flooding surface. FA5 consists of deltaic distributary channel (FC and FD), floodplain and interdistributary-bay (FG2), and swamp (FH1) deposits. This facies assemblage occurs in the upper member, recording sedimentation in the delta plain of a tide-dominated delta during a highstand. Freshwater conditions in the fluvial system, as well as in the inner portions of the estuary and the delta plain are further supported by the presence of the Scoyenia Ichnofacies, whereas brackish-water segments of the estuary are characterized by the Skolithos and depauperate Cruziana Ichnofacies. The substrate-controlled Teredolites, and Glossifungites Ichnofacies occur in connection to erosional exhumation during ravinement. The absence of fully marine ichnofaunas is consistent with the embayed nature of the Orinoco Oil Belt. The tropical and humid character of the Oficina depositional systems is manifested in the development of widespread wetlands in marginal-marine settings, with formation of swamps and embayed areas, typically displaying evidence of waterlogged paleosols with pervasive root trace fossils. The abundance of crustacean burrows, such as Ophiomorpha and Thalassinoides, is also typical of low-latitude marginal- and shallow-marine settings. Although tidal forces tend to be weaker in lower latitudes because Coriolis effects are stronger there, both the estuary and delta systems are regarded as tide-dominated, most likely reflecting the embayed nature of the shoreline.

Palaeogeography, Palaeoclimatology, Palaeoecology, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Earth-Science Reviews, 2019

The fluvio-tidal transition zone (FTZ) is sedimentologically and ichnologically complex, encompas... more The fluvio-tidal transition zone (FTZ) is sedimentologically and ichnologically complex, encompassing variable sedimentary facies. Published research on the FTZ implies a wide range of physical and chemical conditions as well as resultant sedimentary structures. Variable definitions and terms have been applied to this transition zone for decades. This paper aims to refine the existing models of fluviotidal sedimentation, provide an inventory of sedimentological and ichnological characteristics collected from modern and ancient datasets, and produce useful criteria to facilitate its paleogeographic recognition. The usage of the descriptive term "fluvio-tidal transition zone" (abbreviated FTZ) is recommended. The zone is defined by the effective tidal limit at its upper end and the salinity limit at its lower end. The length and position of the FTZ can change with time depending on the fluvial flux and tidal force. However, the averaged position of the FTZ should be determined for the rock record based on a number of physical and biogenic sedimentary structures. Lithologically, the FTZ is represented by medium-grained sandstone to pebble conglomerate in smaller systems, and very fine-to fine-grained sandstone in middle-to large-scale depositional systems. The typical sedimentary structures constitute: unidirectional and bidirectional trough cross-stratification and ripple cross-lamination, abundant carbonaceous debris, coal beds, mudstone and peat rip-up clasts, massive bedding, tidal bundles and rhythmites, inclined heterolithic stratification (IHS), soft-sediment deformation, herringbone bedding, sigmoidal cross-bedding, and reactivation surfaces. Ichnologically, the FTZ is subdivided into the lower or tidal-fluvial part characterized by the Skolithos and depauperate Cruziana ichnofacies passing upstream into the upper or fluvio-tidal part, represented by the Scoyenia and Mermia ichnofacies.

Ichnos, 2018

The lower Paleozoic marine siliciclastic succession of the Central Andean Basin, northwestern Arg... more The lower Paleozoic marine siliciclastic succession of the Central Andean Basin, northwestern Argentina, provides a valuable record of the onset of the Great Ordovician Biodiversification Event in western Gondwana. A new ichnospecies of rosette trace fossil, Gyrophyllites cristinae, is documented from lower and upper Tremadocian (Tr1 and Tr2) deposits of this basin. It is characterized by five to six non-overlapping petaloid lobes and can be easily differentiated from the other four formally defined ichnospecies. Gyrophyllites cristinae occurs at the top of hummocky cross-stratified sandstone regularly interbedded with mudstone. These deposits are interpreted as reflecting the alternation of high-energy storm events and lowenergy fair-weather conditions immediately below the fair-weather wave base, representing deposition in offshore transition environments. Gyrophyllites has been traditionally interpreted as the product of worms of uncertain taxonomic affinity that mined the sediment in search for food (fodinichnia). The occurrence of Gyrophyllites cristinae in these Ordovician deposits records post-storm colonization. Storms may have increased oxygenation and supplied fresh organic detritus that were exploited by worm-like, surface detritus-or shallow deposit-feeders exploring the uppermost silt-rich fine-grained sediments.

Palaeogeography, Palaeoclimatology, Palaeoecology, 2017

Venezuela has the largest hydrocarbon reserves in the world and most of these are within the Orin... more Venezuela has the largest hydrocarbon reserves in the world and most of these are within the Orinoco Oil Belt. The Oficina Formation of the Orinoco Oil Belt and the Oritupano Field comprises a wide range of environments formed under variable salinity conditions. These include freshwater fluvial and fluvio-tidal transition zones, brackish-water estuarine and deltaplain segments, alternating brackish-water and near-normal marine delta-front and prodelta settings, and normal-marine wave-dominated shoreface and offshore-shelf environments. The Oficina Formation thus provides an ideal opportunity to evaluate trace-fossil distribution and ichnofacies gradients along a depositional profile and to calibrate salinity-related trace-fossil models. The Oficina Formation contains four softground ichnofacies (Scoyenia, depauperate Cruziana, Skolithos, and archetypal Cruziana) and two substrate-controlled ichnofacies (Teredolites and Glossifungites). Fluvial deposits in freshwater portions of tide-influenced, estuarine channels and distributary channels of tide-dominated deltas are locally intensely

Estonian Journal of Earth Sciences

GSA Bulletin

The Ediacaran-Cambrian transition interval is described for the west part of the Gondwana Superco... more The Ediacaran-Cambrian transition interval is described for the west part of the Gondwana Supercontinent. This key interval in Earth’s history is recorded in the upper and lower part of the Tagatiya Guazú and Cerro Curuzu formations, Itapucumi Group, Paraguay, encompassing a sedimentary succession deposited in a tidally influenced mixed carbonate-siliciclastic ramp. The remarkable presence of cosmopolitan Ediacaran shelly fossils and treptichnids, which are recorded in carbonate and siliciclastic deposits, respectively, suggests their differential preservation according to lithology. Their distribution is conditioned by substrate changes that are related to cyclic sedimentation. The associated positive steady trend of the δ13C values in the carbonate facies indicates that the Tagatiya Guazú succession is correlated to the late Ediacaran positive carbon isotope plateau. Sensitive high-resolution ion microprobe U-Pb ages of volcanic zircons from an ash bed ∼30 m above the fossil-beari...

Palaeogeography, Palaeoclimatology, Palaeoecology, 2021

Abstract Luancaia igen. nov. and its two new ichnospecies, L. candasensis and L. elongata, from t... more Abstract Luancaia igen. nov. and its two new ichnospecies, L. candasensis and L. elongata, from the Middle Devonian Naranco Formation of Asturias, northern Spain, record infaunal molting. The new ichnogenus has an elongate to oblong outline, and displays a distinctly trilobate appearance that includes an axial longitudinal lobe characterized by a distinctive ridge flanked by lateral lobes at each side. Well-defined transverse ridges convey a metameric-like appearance consisting of up to nine distinct segments. The anterior-most part is more variable, but consistently features a pair of oval strongly convex, or a subtriangular fan-like ridge in well-preserved specimens. Luancaia is similar to Rusophycus in its general segmented appearance, suggesting a euarthropod producer, but differs in the presence of a distinctive axial ridge and in the absence of scratch imprints. Luancaia closely resembles the dorsal side of the enigmatic Carboniferous oniscid-like euarthropod Camptophyllia. We propose that Luancaia records supine (i.e. upside-down) infaunal molting of a euarthropod with a dorsal exoskeletal morphology similar to Camptophyllia, in which exuviation was facilitated by dorsal anchoring on a firm muddy substrate. The Naranco Formation records sedimentation in a shallow- and marginal-marine setting that at times was affected by fluvial discharge most likely during storm floods. In particular, Luancaia is preserved in storm-flood beds that accumulated in relative proximity to a river mouth. These latter deposits consist of sparsely bioturbated sandstone and mudstone that reflect deposition under stressful conditions, such as salinity stress, erosion and by pass high sedimentation rate, and turbidity. By burrowing into the sediment, the producer avoided the stressed physical conditions of the sediment surface. Marginal-marine settings, where competition and predation pressures were significantly lower than in adjacent fully marine environments, may have served as safe molting sites during the mid-Paleozoic marine radiation.

Ichnos, 2019

Abstract The ichnospecies Nummipera eocenica occurs in thick-bedded, tabular bioclastic massive s... more Abstract The ichnospecies Nummipera eocenica occurs in thick-bedded, tabular bioclastic massive sandstone of the upper Eocene San Jacinto Formation in the San Jacinto Fold Belt Basin, Colombia. Nummipera eocenica is a vertical to oblique burrow locally displaying a conical shape. The lining structure of the specimens studied consists of uniformly distributed lepidocyclinids and operculinids, with tests typically dipping towards the burrow wall, and well-compacted lining. The burrow infill is identical to the host rock, a bioclastic sandstone with abundant bivalve fragments. The diagnosis of Nummipera is emended to include as components of burrow lining all representatives of the Subclass Rotaliana characterized by being lenticular to discoidal in shape. In the San Jacinto Formation, Nummipera eocenica is present in the transition between deltaic mouth-bar and carbonate platform deposits.

Ichnos, 2001

The Paleocene to Middle Eocene Tarcau Sandstone at Buzau Valley, eastern Carpathians, Romania, re... more The Paleocene to Middle Eocene Tarcau Sandstone at Buzau Valley, eastern Carpathians, Romania, records sedimentation in a turbidite system. These strata contain a diverse and abundant pre‐and postdepositional ichnofauna consisting of 35 ichnogenera and 54 ...

Bulletin of Canadian Petroleum Geology, 2016

The Upper Devonian–Lower Mississippian Bakken Formation in the subsurface of the Williston Basin ... more The Upper Devonian–Lower Mississippian Bakken Formation in the subsurface of the Williston Basin in northeastern Montana, North Dakota, southwestern Manitoba and southern Saskatchewan typically includes three members: the lower and upper organic-rich black shale, and the middle calcareous/dolomitic sandstone and siltstone, which makes a “perfect” petroleum system including source rock, reservoir, and seal all within the same formation. In eastern Saskatchewan, the Bakken Formation is divided into eight facies, and one of which (Facies 2) is subdivided into two subfacies: Facies 1 (planar cross-stratified fine-grained sandstone); Facies 2A (wavy- to flaser-bedded very fine-grained sandstone); Facies 2B (thinly parallel-laminated very fine-grained sandstone and siltstone); Facies 3 (parallel-laminated very fine-grained sandstone and muddy siltstone); Facies 4 (sandy siltstone); Facies 5 (highly bioturbated interbedded very fine-grained sandstone and siltstone); Facies 6 (interbedded highly bioturbated sandy siltstone and micro-hummocky cross-stratified very fine-grained sandstone); Facies 7 (highly bioturbated siltstone); and Facies 8 (black shale). Our integrated sedimentologic and ichnologic study suggests that deposition of the Bakken occurred in two different paleoenvironmental settings: open marine (Facies 4 to 8) and brackish-water marginal marine (Facies 1 to 3). The open-marine facies association is characterized by the distal Cruziana Ichnofacies, whereas the brackish-water marginal-marine facies association is characterized by the depauperate Cruziana Ichnofacies. Isochore maps show that both open-marine and marginal-marine deposits are widely distributed in the study area and suggest the existence of a N-S trending paleo-shoreline. The Bakken strata in the study area represent two different transgressive systems tracts separated by a coplanar surface or amalgamated sequence boundary and transgressive surface. This surface has been identified in previous studies west-southwest of the study area, therefore assisting in high-resolution correlation of Bakken strata. The unusual stratigraphic architecture of the Bakken Formation in this area resulted from its proximal emplacement which favored intense erosion and cannibalization of previously accumulated deposits.

Palaeogeography, Palaeoclimatology, Palaeoecology, 2012

ABSTRACT The new ichnosubspecies Rhizocorallium jenense spinosus from the Late Sinemurian (Early ... more ABSTRACT The new ichnosubspecies Rhizocorallium jenense spinosus from the Late Sinemurian (Early Jurassic) of Asturias (northern Spain) is described. This ichnotaxon occurs in three outcrops (El Puntal, Punta Rodiles and Punta La Llastra), near the Villaviciosa estuary, belonging to the Buerres Member of the Rodiles Formation. Rhizocorallium jenense spinosus is similar in shape and size to the ichnospecies Rhizocorallium jenense (herein ichnosubspecies R. jenense jenense) in comprising short and more or less straight U-shaped spreite burrows, commonly obliquely oriented with respect to the bedding plane, but is characterized by the presence of spine-shaped protuberances on the outer margin of the arm. Number of observed spine-shaped protuberances per specimen is variable, being commonly 2–4. Protuberances form obtuse, equilateral or acute triangles. The apical end of the spine-shaped protuberance varies from pointed to rounded. The specimens were emplaced in soft or slightly stiffer substrates to firmgrounds. Recurrent distribution of the spine-shaped protuberances reveals a well programmed behavioural pattern of the tracemaker, previously unknown in Rhizocorallium. Several strategies are envisaged: (a) a cache strategy, implying that the tracemaker collected organic matter during favourable times and subsequently stored material in the spine-shaped protuberances for resource-poorer times, (b) a farming strategy, the spine-shaped protuberances being used for concentration of micro-organisms (bacteria, fungi), and (c) a brooding strategy of the tracemaker, revealing a relationship between brood care and oxygen provision, with the location of the spine-shaped protuberances on the external margin of the arms related to a better water circulation.

Earth-Science Reviews, 2022

Communications Earth & Environment, 2021

Sedimentology, 2021

Journal of South American Earth Sciences, 2021

Palaeogeography, Palaeoclimatology, Palaeoecology, 2020

Earth-Science Reviews, 2019

Ichnos, 2018

Palaeogeography, Palaeoclimatology, Palaeoecology, 2017

Estonian Journal of Earth Sciences

GSA Bulletin

Palaeogeography, Palaeoclimatology, Palaeoecology, 2021

Ichnos, 2019

Ichnos, 2001

Bulletin of Canadian Petroleum Geology, 2016

Palaeogeography, Palaeoclimatology, Palaeoecology, 2012

Monografias da Sociedade Brasileira de Paleontologia, volume 2, Dec 2012

PREFACE Ichnology, the study of traces, is a fast growing field that feeds from different and ... more PREFACE

Ichnology, the study of traces, is a fast growing field that feeds from different and diverse disciplines such as sedimentology, stratigraphy, biology and paleontology. The special publication “Ichnology of Latin America - Selected Papers" arose after the Latin American Symposium on Ichnology 2010 (SLIC 2010) that was held from October 30th to November 7th, 2010, in Sao Leopoldo, south of Brazil. About eighty participants attended the conference, representing 21 institutions from South America, 1 from Central America, 3 from North America, 3 from Europe, and 1 from Asia. The ichnologic community of Latin America is not only one of the largest, but also one of the most active. In that sense, it was worthy to produce this special volume as a synthesis of the current knowledge of ichnology in Latin America.
Two papers address the importance of the trace fossils in the terminal Proterozoic-early Phanerozoic successions of South America. Netto (p. 14-25) synthesizes the knowledge of biogenic structures, body fossils and microbially induced sedimentary structures of the terminal Proterozoic basins of southern Brazil, and discusses the possible relationship between these beds and those from the Avalonian terrane. Buatois & Mángano (p. 27-36) review the ichnology of the Ediacaran-Cambrian Puncoviscana Formation of the North of Argentina from a paleoecologic and macroevolutionary perspective, emphasizing the importance of the feeding strategies related to microbial matgrounds recorded in this succession, as well as the appearance of new body plans and sophisticated feeding strategies.
The other contributions explore part of the Phanerozoic ichnologic record in Latin America. Netto et al. (p. 37-68) make a synthetic review of the ichnology of the Paraná Basin in southern Brazil, with emphasis in the invertebrate record. Alonzo-Muruaga et al. (p. 69-81) present the state-of-art of the ichnology of the Upper Paleozoic deposits of Paganzo and Callingasta-Uspallata basins, in the northwestern Argentina. Carmona et al. (p. 83-97) characterize the most representative trace fossils from the Neogene marine deposits of Patagonia (southeastern Argentina), providing an analysis of this ichnofauna considering local paleoceanographic conditions and exploring its relation with the establishment of the Modern Evolutionary Fauna. VillegasMartín & Rojas-Consuegra (p. 99-106) synthesize the knowledge of the Cuban ichnology through the analysis of the existing literature and the material available in collections. These authors also discuss the future perspectives of this discipline in Cuba. Finally, Souto (p. 107-115) overviews the records of vertebrate’s coprolites found in different units of Latin America, providing a general evaluation of morphologic aspects necessary to describe these structures, and introducing the new methods to study them.
Some case studies are also presented herein, reflecting the emergent ichnological research in Latin America. Invertebrate and vertebrate bioturbaton as well as bioerosion are the main addressed themes. Souza et al. (p. 119-128) present an initial approach to the ichnology of the Lower Devonian Maecuru Formation (Amazonas Basin, northern Brazil). Dentzien-Dias et al. (p. 129-139) describe vertebrate trace fossils from the Upper Jurassic Guará Formation (south of Brazil) and the Batoví Member of the Tacuarembó Formation (north of Uruguay), which contain numerous dinosaur tracks, dominated by theropod and sauropod tracks and different vertebrate burrows. Frank et al. (p. 141-157) synthesize the present knowledge of large tunnels assigned to Cenozoic vertebrates in the southern states of Brazil, and try to identify the possible tracemakers among the South American Megafauna representatives.
In the field of bioerosion, Richiano et al. (p. 159-177) focus on the bioerosion structures in Quaternary marine mollusks from the Atlantic Argentine coast (from Rio de la Plata to the south of Santa Cruz province) while Lopes (p. 179-194) describes the bioerosion and bioincrustation in Quaternary body fossils from the Coastal Plain of Rio Grande do Sul State (CPRS), in southern Brazil.
There is much more of the ichnology of Latin America than what is presented in this book. Several high quality papers have been published in indexed journals in the last 30 years, and innumerous papers were published in local journals since the 1950s. An important part of this knowledge is missing in this book, but future editions of the Latin American Symposium on Ichnology will help to fill this gap. To all contributors that helped to construct this compendium, our sincere gratitude. Our special thanks to Jordi M. de Gibert, who was a great enthusiast of the ichnologic research developed in Latin America and who contributed to make this book a reality until his passing, last September.

Renata G. Netto
Noelia B. Carmona
Francisco M.W. Tognoli