scholarly journals Trace fossils from the Lower and Middle Jurassic marginal marine deposits of the Sorthat Formation, Bornholm, Denmark

2003 ◽  
Vol 50 ◽  
pp. 185-208
Author(s):  
Richard G. Bromley
Keyword(s):  
Middle Jurassic ◽  
Trace Fossils ◽  
Trace Fossil ◽  
South Coast ◽  
Marine Environments ◽  
Salinity Fluctuation ◽  
Fossil Assemblage ◽  
Marine Deposits ◽  
Low Degree ◽  
The Baltic

The Lower to Middle Jurassic Sorthat and Bagå Formations of the Baltic island of Bornholm, Denmark, are a predominantly fluviatile unit. On the south coast of the island at Korsodde, however, an interval within the Sorthat Formation contains a diverse trace fossil assemblage indicating a marine incursion. Study of this interval revealed 15 ichnotaxa, among which one is new: Bornichnus tortuosus nov. igen. et isp. Several of the trace fossils present are generally considered characteristic of the lower shoreface to offshore environments (e.g. Teichichnus and Asterosoma). However, the low degree of bioturbation and ichnodiversity, and sedimentological features, indicate an environment influenced by salinity fluctuation, probably a tidally influenced delta. Five ichnofabrics are defined that describe this setting and which may be indicative of marginal-marine environments that are influenced by salinity fluctuations.

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.

scholarly journals CHONDRITES-CLADICHNUS ICHNOCOENOSIS FROM THE DEEP-SEA DEPOSITS OF PIERFRANCESCO (CRETACEOUS; ITALY): OXYGEN- OR NUTRIENT-LIMITED?

2022 ◽  
Vol 128 (1) ◽  
Author(s):  
ANDREA BAUCON ◽  
GIROLAMO LO RUSSO ◽  
CARLOS NETO DE CARVALHO ◽  
FABRIZIO FELLETTI
Keyword(s):  
Late Cretaceous ◽  
Deep Sea ◽  
Trace Fossils ◽  
Northern Apennines ◽  
Trace Fossil ◽  
Ecological Succession ◽  
Rhythmic Pattern ◽  
Low Oxygen ◽  
Fossil Assemblage

The Italian Northern Apennines are acknowledged as the place where ichnology was born, but there is comparatively little work about their ichnological record. This study bridges this gap by describing two new ichnosites from the locality of Pierfrancesco, which preserve an abundant, low-disparity trace-fossil assemblage within the Late Cretaceous beds of the M. Cassio Flysch. Results show that lithofacies and ichnotaxa are rhythmically organized. The base of each cycle consists of Megagrapton-bearing calciclastic turbidites, which are overlain by marlstone beds with an abundant, low-disparity assemblage of trace fossils. This includes Chondrites intricatus, C. patulus, C. targionii, C. recurvus and Cladichnus fischeri. The cycle top consists of mudstones with no distinct burrows. The rhythmic pattern of Pierfrancesco reflects a deep-sea ecological succession, in which species and behaviour changed as turbidite-related disturbances altered the seafloor. This study opens the question of whether the Chondrites-Cladichnus ichnocoenosis represents low-oxygen or nutrient-poor settings.

The trace fossil Dactyloidites ottoi (Geinitz, 1849) from the Neogene August Town Formation of south-central Jamaica

1993 ◽  
Vol 67 (6) ◽  
pp. 1070-1074 ◽  
Author(s):  
Ron K. Pickerill ◽  
Stephen K. Donovan ◽  
Harold L. Dixon
Keyword(s):  
Detailed Analysis ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Marine Environments ◽  
Biogenic Origin ◽  
South Central ◽  
Rock Record ◽  
Distinctive Morphology ◽  
Detailed Interpretation ◽  
Deposit Feeding

Rosette-shaped problematica are relatively common structures in the Phanerozoic rock record. Historically, they have been accorded a variety of names and documented from various shallow to deep marine environments. Unfortunately, the detailed interpretation of many such structures as biogenic (trace fossils, medusoids, or other body fossils; see, for example, Häntzschel, 1970, 1975) or nonbiogenic (for example, Pickerill and Harris, 1979) in origin still remains to be resolved. However, a detailed analysis of one such structure by Fürsich and Bromley (1985), namely Dactyloidites Hall, 1886, convincingly demonstrated its biogenic origin. The distinctive morphology of Dactyloidites and its synonyms was interpreted by Fürsich and Bromley (1985) to result from successive probings of an essentially stationary deposit-feeding, worm-like organism, possibly possessing a proboscis, to produce a rosetted, vertical spreiten with a centrally located, vertical or subvertical shaft.

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.

The evolutionary significance of a Lower Cambrian trace-fossil assemblage from the Meguma terrane, Nova Scotia

2011 ◽  
Vol 48 (1) ◽  
pp. 71-85 ◽  
Author(s):  
Murray K. Gingras ◽  
John W.F. Waldron ◽  
Chris E. White ◽  
Sandra M. Barr
Keyword(s):  
Nova Scotia ◽  
Lower Cambrian ◽  
Trace Fossils ◽  
Trace Fossil ◽  
Evolutionary Significance ◽  
Fossil Assemblage ◽  
Approximate Order ◽  
Meguma Terrane ◽  
Wrinkle Structures ◽  
Fossil Preservation

We report a diverse assemblage of trace fossils from the Lower(?) Cambrian High Head member of the Church Point Formation near Yarmouth, Nova Scotia. Based on the presence of sharp-based beds, load casts, and flute casts, along with other sedimentological criteria, the strata are interpreted to have a turbidite origin. Other characteristics, including wrinkle structures and high fidelity of trace-fossil preservation, suggest that the inter-episode biotope was influenced by the presence of biomats. The trace-fossil assemblage includes (in approximate order of abundance) Planolites , Helminthopsis , Oldhamia , Chondrites , Gordia , Cladichnus , Psammichnites gigas , Treptichnus , Phycodes , Lorenzinia , Palaeophycus , and Teichichnus . Trace fossils are increasingly abundant upwards in the section, but they are ultimately mitigated by an increase in (inferred) sedimentation rates. The trace-fossil assemblage, which bears many similarities to other Lower Cambrian locales (e.g., Puncoviscana Formation of northwest Argentina, Chapel Island Formation of southeastern Newfoundland), and the distribution of ichnofossils strongly support an earliest Cambrian age for the studied strata. More importantly, evolutionary trends can be interpreted from the trace-fossil assemblage, namely (1) an increase in size and diversity of animals in deep water; (2) an expansion of motile strategies used to coexist with biomats; and, (3) increasingly complex mining strategies below the sediment-biomat interface.

scholarly journals Paleoecologic and Biostratigraphic Significance of Trace Fossils From Shallow- to Marginal-Marine Environments From the Middle Cambrian (Stage 5) of Jordan

2012 ◽  
Vol 86 (6) ◽  
pp. 931-955 ◽  
Author(s):  
Richard Hofmann ◽  
M. Gabriela Mángano ◽  
Olaf Elicki ◽  
Rafie Shinaq
Keyword(s):  
Trace Fossils ◽  
Trace Fossil ◽  
Type Locality ◽  
Early Cambrian ◽  
Marine Environments ◽  
Middle Cambrian ◽  
Fossil Assemblages ◽  
Maximum Flooding Surface

The Hanneh Member (Cambrian Stage 5) of the Burj Formation and the Umm Ishrin Formation of Jordan represent a transgressive-regressive succession that contains twenty-eight ichnotaxa, including vertical burrows (Arenicolitesisp.,Diplocraterionisp.,Gyrolithes polonicus,Rosseliaisp.,Skolithos linearis, escape trace fossils), horizontal simple burrows and trails (Archaeonassa fossulata,Gordia marina,Helminthoidichnites tenuis,Palaeophycus tubularis,Planolites beverleyensis,P. montanus), plug-shaped burrows (Bergaueria sucta), horizontal branched burrows (Asterosomaisp.,Phycodesisp.,Treptichnuscf.T. pedum), bilobate structures (various ichnospecies ofCruzianaandRusophycus), and trackways and scratch marks (Diplichnitesisp.,Dimorphichnuscf.D. obliquus,Monomorphichnusisp.). Eleven trace-fossil assemblages are identified. TheArenicolitesisp. andDiplocraterionisp. assemblages occur in transgressive tidal dunes and bars whereas theRosseliaisp. assemblage characterizes areas between tidal dunes. TheCruziana salomonisassemblage reflects a wide variety of environmental settings including channels within tidal-bar complexes, bottomsets of tidal dunes, and interdune areas. TheGordia marinaassemblage is present between dune patches. TheGyrolithes polonicusassemblage penetrates into firmground mudstone below the maximum flooding surface. TheBergaueria sucta,Archaeonassa fossulata,Rusophycus aegypticusandCruziana problematicaassemblages occur in different subenvironments of the progradational delta.Cruziana salomonisandRusophycus burjensis, originally considered indicative of an early Cambrian age, are actually middle Cambrian in their type locality. Occurrences ofCruziana jordanicaandRusophycus aegypticusprovide evidence that these ichnospecies are of the same age in Jordan and may co-exist in terms of stratigraphic distribution withC. salomonisandR. burjensis.

scholarly journals Asteriacites and other trace fossils from the Po Formation (Visean–Serpukhovian), Ganmachidam Hill, Spiti Valley (Himalaya) and its paleoenvironmental significance

2017 ◽  
Vol 68 (5) ◽  
pp. 464-478 ◽  
Author(s):  
Birendra P. Singh ◽  
Om N. Bhargava ◽  
Radek Mikuláš ◽  
Subhay K. Prasad ◽  
Garry Singla ◽  
...  
Keyword(s):  
Trace Fossils ◽  
Trace Fossil ◽  
Fossil Assemblage ◽  
Sedimentary Structures ◽  
The Village ◽  
The Himalaya ◽  
Open Shelf

Abstract An assemblage of trace fossils comprising Asteriacites stelliformis, A. quinquefolius, Biformites insolitus, Helminthoidichnites? isp., Lingulichnus isp., Lockeia siliquaria, Palaeophycus tubularis, Planolites isp., Protovirgularia isp. A, Protovirgularia isp. B, Protovirgularia isp. C, Psammichnites isp., Rusophycus isp., and Treptichnus isp. from the Po Formation (Visean-Serpukhovian) exposed along the base of Ganmachidam Hill near the village of Chichong, Spiti Valley in the Himalaya, is described. Storm beds (tempestites) are highly bioturbated. Sedimentary structures such as hummocky cross-stratification (HCS), low-angle planar and trough cross beds, and shallow, slightly asymmetrical gutter casts are observed. The overall trace fossil assemblage indicates the presence of upper shoreface to lower shoreface Cruziana ichnofacies of an open shelf.

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 Glauconitic deposits at Julegård on the south coast of Bornholm, Denmark dated to the Cambrian

2011 ◽  
Vol 59 ◽  
pp. 1-12
Author(s):  
Lars B. Clemmensen ◽  
Richard G. Bromley ◽  
Paul Martin Holm
Keyword(s):  
Lower Cambrian ◽  
Trace Fossils ◽  
Upper Triassic ◽  
South Coast ◽  
The South ◽  
Shallow Marine ◽  
Marine Deposits

Bioturbated, glauconitic siltstones and sandstones are overlain by presumed Upper Triassic deposits at coastal exposures at Julegård on the south coast of Bornholm. These glauconitic deposits have not previously been dated. A 40Ar-39Ar dating of the glaucony gives an age of 493 ± 2 Ma suggesting the deposits belong to the Lower Cambrian Norretorp Member of the Læså Formation. The shallow marine deposits are strongly bioturbated, but only a single ichnoassociation is represented. The ichnogenus is referable to either Trichophycus Miller and Dyer, 1878 or Teichichnus Seilacher, 1955. Rare examples of Rusophycus Hall, 1852, probably trilobite trace fossils, are also represented.

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