The Fish River Subgroup in Namibia: stratigraphy, depositional environments and the Proterozoic–Cambrian boundary problem revisited

2005 ◽  
Vol 142 (5) ◽  
pp. 465-498 ◽  
Author(s):  
G. GEYER
Keyword(s):  
Trace Fossils ◽  
Global Scale ◽  
Depositional Environments ◽  
Trace Fossil ◽  
Braided River ◽  
Shallow Marine ◽  
Sequence Stratigraphic ◽  
Marine Habitats ◽  
Short Period ◽  
Distinct Sequence

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.

Devonian depositional environments in the Darwin Mountains: Marine or non-marine?

1993 ◽  
Vol 5 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Ken J. Woolfe
Keyword(s):  
Fresh Water ◽  
Depositional Environment ◽  
Trace Fossils ◽  
Depositional Environments ◽  
Trace Fossil ◽  
Glacier Area ◽  
Red Beds ◽  
Fossil Assemblage ◽  
Considerable Debate

The depositional environment of the Devonian Taylor Group has been subject to considerable debate for over 30 years. The debate stems largely from a belief that the abundant and diverse trace fossils represent a marine ichnofauna, whereas sedimentary features, including palaeosols, desiccation polygons and red beds, are more typical of a non-marine setting. The debate is reconciled by a reinterpretation of the trace fossil assemblage which shows that the trace fossils comprise a typical fresh water (Scoyenia ichnofacies) assemblage, and their occurrence in the Taylor Group in the Darwin Glacier area is entirely consistent with deposition in a mixed fluvial-lacustrine-subaerial environment.

scholarly journals Sedimentology and Ichnology of Paleozoic Estuarine and Shoreface Reservoirs, Morrow Sandstone, Lower Pennsylvanian of Southwest Kansas, USA

1999 ◽  
pp. 1-35
Author(s):  
Luis A. Buatois ◽  
Gabriela M. Mangano ◽  
Timothy R. Carr
Keyword(s):  
Oil And Gas ◽  
Petroleum Industry ◽  
Integrated Approach ◽  
Trace Fossils ◽  
Depositional Environments ◽  
Trace Fossil ◽  
Reservoir Modeling ◽  
Delta Front ◽  
Valley Fill ◽  
Biogenic Structures

Integration of facies and trace-fossil evidence tests and refines depositional models constructed solely on the basis of physical sedimentology. In recent years, the petroleum industry has increasingly used trace-fossil analysis of cores as an aid in reservoir characterization. In particular, ichnologic data have been instrumental in the recognition of estuarine deposits and their distinction from open-marine facies (e.g., MacEachern and Pemberton, 1994). Previous ichnologic analyses of cores, however, have concentrated on post-Paleozoic reservoirs (e.g., Bockelie, 1991; Pemberton, 1992; Taylor and Gawthorpe, 1993; Howell et al., 1996; Martin and Pollard, 1996; MacEachern and Pemberton, 1997). The present study represents one of the first attempts to apply trace-fossil analysis to cores from Paleozoic reservoirs. The Lower Pennsylvanian Morrow Sandstone contains oil and gas reservoirs in a wide variety of shallow and marginal-marine depositional environments. Delta-front, shoreface, and estuarine valley-fill reservoir sandstones are encased in offshore and estuarine mudstones (Sonnenberg, 1985; Krystinik and Blakeney, 1990; Sonnenberg et al., 1990; Wheeler et al., 1990). An integrated stratigraphic, sedimentologic, and ichnologic study provides a more accurate characterization of reservoir facies and geometry. This study allows distinction between marine-shoreface and estuarine valley-fill sandstones from four cores of the lower Morrow in southwestern Kansas. Core analysis subsequently was integrated with well-log information. Previous studies have emphasized the presence of estuarine valley-fills in the upper Morrow (Wheeler et al., 1990). Our integrated approach extends the estuarine valley interpretation into the lower Morrow. Within the midcontinent, trace fossils are useful in distinguishing different facies in estuarine incised valleys and marine shorefaces. Detailed study of biogenic structures provides high-resolution information to solve problems in facies, stratigraphic, and reservoir modeling. In some cases, they represent the only evidence available to develop a reasonable picture of depositional conditions and to estimate reservoir heterogeneity. The present study provides a detailed analysis of the sedimentary facies, documents the associated trace fossils, and illustrates how trace fossils are used to refine environmental interpretations of the lower Morrow sandstone reservoirs.

scholarly journals Coniacian sandstones from the North Sudetic Synclinorium revisited: palaeoenvironmental and palaeogeographical reconstructions based on trace fossil analysis and associated body fossils

Geologos ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 29-53 ◽  
Author(s):  
Alina Chrząstek ◽  
Monika Wypych
Keyword(s):  
Trace Fossils ◽  
Trace Fossil ◽  
Fair Weather ◽  
Soft Substrate ◽  
Southeastern Part ◽  
Shallow Marine ◽  
The North ◽  
Low Diversity ◽  
Storm Deposits ◽  
Interesting Compound

AbstractThe Coniacian quartz sandstones (Żerkowice Member, Rakowice Wielkie Formation) that crop out at quarries near Czaple-Nowa Wieś Grodziska (North Sudetic Synclinorium) contain a low-diversity assemblage of trace fossils:Gyrochorteisp.,Ophiomorpha nodosaLundgren, 1891,Ophiomorphaisp.,Phycodescf.curvipalmatum(Pollard, 1981), ?Phycodesisp.,Planolitescf.beverleyensis(Billings, 1862),Thalassinoides paradoxicusWoodward, 1830 and ?Thalassinoidesisp. Moreover, interesting compound burrow systems, here referred to asThalassinoides-Phycodescf.palmatusand ?Thalassinoides-Phycodes, were recognised at the Czaple Quarry. Additionally, ?Gyrochorteisp.,Phycodescf.flabellum(Miller and Dyer, 1878) and ?Treptichnusisp. were encountered at correlative levels in the Rakowice Małe Quarry. Some of these ichnotaxa have not been recorded previously from Coniacian sandstones of the Żerkowice Member. Additionally, in slabs of these sandstones, the gastropodNerinea bicinctaBronn, 1836 and the bivalveLima haidingeriZittel, 1866 were found. These interesting finds, in particular the gastropods, were already noted from the study area in the first half of the twentieth century by Scupin (1912–1913). Ethologically, the trace fossil assemblage is represented by domichnia or domichnia/fodinichnia (Ophiomorpha,Thalassinoides), fodinichnia (Phycodes) and pascichnia (Gyrochorte,Planolites). The compound burrow systems (Thalassinoides-Phycodes) are interpreted as dwelling/feeding structures. The possible tracemakers are crustaceans (Ophiomorpha,Thalassinoides) or worm-like animals (annelids and other) (Planolites, ?Phycodes,Gyrochorteand ?Treptichnus). The assemblage of trace fossils is characteristic of theSkolithosichnofacies andCruzianaichnofacies, typical of shallow-marine settings. Ichnological studies, as well as the presence of accompanying fossils (bivalves, gastropods), confirm the palaeoenvironmental reconstruction of the Żerkowice Member sandstones by Leszczyński (2010). That author interpreted the Coniacian sandstones as bar and storm deposits laid down in a shallow epicontinental sea (mainly the foreshore-upper shoreface; up to the middle shoreface) under normal oxygenation and salinity, in soft substrate, above fair-weather wave base. The deposition of the Żerkowice Member sandstones is linked to a regression that started after uplift of the southeastern part of the North Sudetic Synclinorium.

Early Cambrian and Older Trace Fossils from the Southern Cordillera of Canada

1972 ◽  
Vol 9 (1) ◽  
pp. 1-17 ◽  
Author(s):  
F. G. Young
Keyword(s):  
British Columbia ◽  
Marine Environment ◽  
Carbonate Rocks ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Older Age ◽  
Early Cambrian ◽  
Shallow Marine ◽  
Sedimentary Environments ◽  
Organic Life

Metazoan trace fossils of Early Cambrian and older age have been found in parts of the Gog, Cariboo, and Miette Groups of eastern British Columbia and western Alberta. Most of them occur in beds immediately below the zones containing the earliest Cambrian trilobites and archaeocyathids. These beds represent a variety of sedimentary environments, including the beach and littoral (Skolithos – facies), and shallow marine (Cruziana – facies) environments in the upper McNaughton Formation of the Gog Group: and a moderately deep marine environment in the Midas Formation of the Cariboo Group. Below these zones evidence of organic life is mainly restricted to stromatolites in carbonate rocks, and simple feeding-burrows in argillaceous silt-stones. A rare, but important trace fossil in this zone is a doubly furrowed trail, which is herein named Didymaulichnus miettensis (gen. et sp. nov.). This fossil indicates that metazoans existed before the Cambrian Period by a span of time represented by the net deposition of up to 2000 m of detrital sediments.

Introduction to Trace Fossils and Dedication to Robert W. Frey

1992 ◽  
Vol 5 ◽  
pp. 1-14 ◽  
Author(s):  
Christopher G. Maples ◽  
Ronald R. West
Keyword(s):  
Trace Fossils ◽  
Trace Fossil ◽  
Body Parts ◽  
Sequence Stratigraphic ◽  
Short Course ◽  
Short Courses ◽  
Different Parts

Over the years, we've participated in several different workshops and short courses on trace fossils. So why this one? Our intention in bringing together these papers for the Trace Fossil Short Course is to give an overview of how trace fossils can be used in paleontology. Historically, trace fossil research has centered on paleoenvironmental and depositional reconstructions—areas where trace fossils have much to tell. Indeed, the use of trace fossils by sedimentologists has flourished and is experiencing another burst of activity through the use of ichnofabrics in sequence stratigraphic studies. But trace fossils have paleontological stories to tell as well. Their use in uncovering the first occurrences of life in different parts of the stratigraphic column is well documented (e.g., the classic example of trace fossils occurring before body fossils in Precambrian/Cambrian transitional strata) as is their use in detailing different morphological details of unpreserved taxa or body parts.

scholarly journals Sedimentary facies and environments of the sedimentary fill of Southern Bida Basin, Nigeria

2021 ◽  
Vol 19 (1) ◽  
pp. 53-74
Author(s):  
George Uchebike Ozulu ◽  
Anthony Uwaoma Okoro ◽  
Evangeline Njideka Onuigbo
Keyword(s):  
Sedimentary Facies ◽  
Depositional Environments ◽  
Alluvial Fan ◽  
Coarse Grained ◽  
Carbonaceous Shale ◽  
Intertidal Flat ◽  
Braided River ◽  
River Channels ◽  
Shallow Marine ◽  
Lithofacies Association

Six lithofacies were identified in the Lokoja Formation, Southern Bida Basin: fanglomerate/ conglomerate lithofacies (Gmc), fine to coarse-grained ferruginized weakly cross-bedded, pebbly sandstone lithofacies (Scx), fine to coarsegrained sandstone lithofacies (Sfc), silty claystone lithofacies (Csm), siltstone lithofacies (Slt) and lateritic ironstone lithofacies (Ilt). These were grouped into three lithofacies associations viz: alluvial fan, braided river channel, floodplain lithofacies association. Nine lithofacies were identified in the Ahoko Formation. These are: black-dark grey carbonaceous shale lithofacies (Shc), bioturbated ripple-laminated siltstone lithofacies (Sbr), poorly cross-laminated claystone lithofacies (Cxl), concretionary/nodular ironstone lithofacies (Icn), medium to coarse-grained sandstone lithofacies (Smc) fine grained, well-sorted, friable bioturbated herringbone cross-bedded sandstone lithofacies (Sxf), massive brownish claystone lithofacies (Clm), massive claystone with lateritic ironstone lithofacies (Cli) and lateritic ironstones lithofacies (Ilt). These have been grouped into three lithofacies associations viz: shallow marine lithofaciesassociation, tidal-intertidal flat lithofacies association and floodplain lithofacies association. Similarly, three lithofacies were identified in the Agbaja Formation and have been grouped into two lithofacies association. These are: fine to medium-grained sandstone ironstone interbedded lithofacies (Sti), oolitic–pisolitic ironstone lithofacies (Iop) and concretionary ironstone lithofacies (Icr). The lithofacies associations are: tidal-intertidal flat lithofacies association and shallow marine lithofacies association. Result of lithofacies analysis helped in interpreting the depositional environments. The Lokoja Formation is a product of a fluvial dominated alluvial system from debris/gravity flow in alluvial fan. This developed further into braided river channels and later meandering river during the closing stages. Sediments of the Ahoko Formation were deposited in tidal/intertidal flats and shallow marine environments while sediments of the Agbaja Formation were produced by a shallow marine system with a high tidal influence.  

Trace fossil assemblages reflecting stressed environments in the Middle Jurassic Carmel Seaway of central Utah

1999 ◽  
Vol 73 (4) ◽  
pp. 711-720 ◽  
Author(s):  
J. M. De Gibert ◽  
A. A. Ekdale
Keyword(s):  
Benthic Community ◽  
Middle Jurassic ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Pore Waters ◽  
Shallow Marine ◽  
Marine Carbonate ◽  
Marine Carbonates ◽  
Low Diversity ◽  
Fossil Assemblages

The shallow-marine Carmel Formation (Middle Jurassic) in central Utah hosts low-diversity trace fossil assemblages, including Arenicolites, Chondrites, Gyrochorte, Lockeia, Planolites, Protovirgularia, Rosselia, Scalarituba, Skolithos, Taenidium, and Teichichnus. Non specialized ichnotaxa with a remarkably small burrow size dominate the assemblages. The amount of bioturbation is lower than expected in comparison with modern shallow-marine carbonate environments. These ichnological features also are significantly different from those of other Jurassic shallow-marine carbonates. The trace fossils represent an environmentally stressed benthic community in a marginal marine, restricted setting, with salinities above normal marine and with depletion of oxygen in pore waters.

scholarly journals Trace fossils and fluvial-lacustrine ichnofacies of the Eocene Uinta and Duchesne River Formations, northern Uinta Basin, Utah

2018 ◽  
Vol 5 ◽  
pp. 209-226
Author(s):  
Takashi Sato ◽  
Marjorie Chan ◽  
Allan Ekdale
Keyword(s):  
Large Scale ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Small Scale ◽  
Uinta Basin ◽  
Sequence Stratigraphic ◽  
Environmental Controls ◽  
Fossil Assemblages ◽  
Continental Basin ◽  
Lacustrine Facies

Trace fossil assemblages in a fluvial-lacustrine sequence stratigraphic context hold significant poten-tial for expanding our understanding of environmental controls and continental basin-fill history. The succession of the Eocene Uinta Formation and four members of the Duchesne River Formation is ex¬tremely well-exposed in the Uinta Basin of northeastern Utah, revealing a robust stratigraphic framework to document broad-scale fluvial-lacustrine facies architectures and associated trace fossil assemblages. Greenish- and gray-colored mudstone beds with interbedded tabular sandstone representing lacustrine environments contain the trace fossils Arenicolites and Gordia (= Haplotichnus). In contrast, red mudstone beds with interbedded channelized sandstone representing upstream fluvial and alluvial environments contain a variety of insect trace fossils, including Scoyenia, Ancorichnus, and nest structures. Transitional, interfingering lithologies of wetland or shallow, short-lived lacustrine environments on the alluvial plain contain the trace fossil Steinichnus. Although there are many small-scale (bed-scale) physical sedimen¬tary structures and trace fossils from continental subenvironments, this study focuses on the large-scale (member-scale) change in trace fossil assemblages, with results indicating that the ichnofacies corroborate continental sequence stratigraphic interpretations in a fluvial-lacustrine setting.

scholarly journals Trace fossils and fluvial-lacustrine Ichnofacies of the Eocene Uinta and Duchesne River Formations, northern Uinta Basin, Utah

2018 ◽  
Vol 5 ◽  
pp. 209-226
Author(s):  
Takashi Sato ◽  
Marjorie A. Chan ◽  
Allan A. Ekdale
Keyword(s):  
Large Scale ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Small Scale ◽  
Uinta Basin ◽  
Sequence Stratigraphic ◽  
Environmental Controls ◽  
Fossil Assemblages ◽  
Continental Basin ◽  
Lacustrine Facies

Trace fossil assemblages in a fluvial-lacustrine sequence stratigraphic context hold significant poten-tial for expanding our understanding of environmental controls and continental basin-fill history. The succession of the Eocene Uinta Formation and four members of the Duchesne River Formation is ex¬tremely well-exposed in the Uinta Basin of northeastern Utah, revealing a robust stratigraphic framework to document broad-scale fluvial-lacustrine facies architectures and associated trace fossil assemblages. Greenish- and gray-colored mudstone beds with interbedded tabular sandstone representing lacustrine environments contain the trace fossils Arenicolites and Gordia (= Haplotichnus). In contrast, red mudstone beds with interbedded channelized sandstone representing upstream fluvial and alluvial environments contain a variety of insect trace fossils, including Scoyenia, Ancorichnus, and nest structures. Transitional, interfingering lithologies of wetland or shallow, short-lived lacustrine environments on the alluvial plain contain the trace fossil Steinichnus. Although there are many small-scale (bed-scale) physical sedimen¬tary structures and trace fossils from continental subenvironments, this study focuses on the large-scale (member-scale) change in trace fossil assemblages, with results indicating that the ichnofacies corroborate continental sequence stratigraphic interpretations in a fluvial-lacustrine setting.

scholarly journals Pleistocene golden mole and sand-swimming trace fossils from the Cape coast of South Africa

2021 ◽  
pp. 1-18
Author(s):  
Martin G. Lockley ◽  
Charles W. Helm ◽  
Hayley C. Cawthra ◽  
Jan C. De Vynck ◽  
Michael R. Perrin
Keyword(s):  
South Africa ◽  
Trace Fossils ◽  
Trace Fossil ◽  
South Coast ◽  
Environmental Reconstruction ◽  
Cape Coast ◽  
Southeast Coast ◽  
Show Evidence ◽  
Golden Mole ◽  
Body Fossil

Abstract More than 250 Pleistocene vertebrate trace fossil sites have been identified on the Cape south coast of South Africa in aeolianites and cemented foreshore deposits. These discoveries, representing the epifaunal tracks of animals that moved over these sand substrates, complement traditional body fossil studies, and contribute to palaeo-environmental reconstruction. Not described in detail until now, but also important faunal components, are the infaunal traces of animals that moved within these sandy substrates. Six golden mole burrow trace sites (Family Chrysochloridae) have been identified on the Cape south coast. In addition, three sites, including one on the Cape southeast coast, have been identified that show evidence of sand-swimming, probably by a golden mole with a means of locomotion similar to that of the extant Eremitalpa genus. Such traces have not been described in detail in the global ichnology record, and merit the erection of a new ichnogenus Natatorichnus, with two ichnospecies, N. subarenosa ichnosp. nov and N. sulcatus ichnosp. nov. Care is required in the identification of such traces, and the orientation of the trace fossil surface needs to be determined, to avoid confusion with hatchling turtle tracks. Substantial regional Pleistocene dune environments are inferred from these sand-swimming traces.

Sign in / Sign up

Export Citation Format

Share Document