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Pioneer colonization, evidenced by Rhizocorallium in the Middle Triassic of Poland

Stachacz Michał

Annales Societatis Geologorum Poloniae

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2023

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Vol. 93, No. 4

363--379

EN

A large collection of the trace fossil Rhizocorallium from the Middle Triassic of the Polish part of the Germanic Basin (Peri-Tethys) is analysed and their ichnotaxonomical classification presented. Special attention is given to the deep form of Rhizocorallium with a vertical retrusive spreite, filled with faecal pellets, with detailed documentation of this structure, based on isolated specimens and serial sections. This analysis also reveals ∩-shaped and deep, protrusive structures. A former interpretation of Rhizocorallium as a rapidly formed fugichnion is not followed here; instead, an interpretation of the trace fossil as a complex fodinichnion is proposed. Scavengers and their relation to crinoid meadows, as well as predators, are indicated as potential tracemakers of some Rhizocorallium. Although Rhizocorallium is common throughout the Middle Triassic, unusual forms and the domination of substrates by Rhizocorallium in general mostly occur in the transgressive system of the lowermost Muschelkalk, and in regressive, marginal facies of the lower Keuper. Such a distribution of unusual forms of Rhizocorallium is interpreted as representing opportunistic, pioneer burrow assemblages that developed during the long-term benthic recovery after the P-T crisis, or in unfavourable conditions generally. Moreover, dynamic conditions with mixed clastic-carbonate sedimentation and rapidly varying salinity promoted smooth transitions from Rhizocorallium to Diplocraterion. Similar successions of dominant trace-fossil assemblages, of comparable sizes, occur in many sections around the world and demonstrate the record of slow recovery that continued through the Middle Triassic. The illustrated record of evolution of the Middle Triassic Rhizocorallium assemblages in Poland documents the last two stages of benthos recovery after the P-T boundary. A similar situation is observed around the world and, in many cases, great abundance of Rhizocorallium seems to be an indication of pioneer burrowing in dynamic, unfavourable environments.

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Large cruzianid trace fossils in the Ordovician of the peri-Baltic area : the case of the Bukówka Formation (Holy Cross Mountains, Poland)

Stachacz M., Łaska W., Uchman A.

Geological Quarterly

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2018

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Vol. 62, No. 2

400--414

EN

The Middle Ordovician Bukówka Formation, composed of fine-grained quartz sandstones with siltstone intercalations, belongs to the Kielce Region of the Holy Cross Mountains (peri-Baltic palaeogeographic position). It contains trace fossils of low diversity and poor preservation. Particularly noteworthy are the large Cruziana and Rusophycus, that are typical of peri-Gondwanan areas. They consist of casts of bilobate furrows showing diverse preservation. Other trace fossils include mostly horizontal pascichnia, cubichnia, and fodinichnia, but also vertical domichnia. The trace fossil assemblage is typical of the archetypal Cruziana and partly of the Skolithos ichnofacies. Some beds contain abundant orthid brachiopods. The trace fossils and sedimentary structures (horizontal, low-angle and wave ripple cross-laminations, hummocky cross-stratification) suggest deposition on the middle and lower shoreface with storm influence. The poor preservation and low diversity of the trace fossils are related to the homogeneous lithology, low accumulation rate, shallow burial of organic matter and strong bioturbation. Therefore, animals burrowed strongly but mostly in shallow tiers. Thus, the preservation potential of their traces was much lower than in many peri-Gondwanan sections but still higher than in Baltica sedimentary rocks. This explains the provincial differences in ichnofauna during the Ordovician, which at least partly were influenced by the preservation potential.

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Context-dependent consequences of Marenzelleria spp. (Spionidae: Polychaeta) invasion for nutrient cycling in the Northern Baltic Sea

Maximov A., Bonsdorff E., Eremina T., Kauppi L., Norkko A., Norkko J.

Oceanologia

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2015

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No. 57 (4)

342--348

EN

Within the framework of the possibility of using the Mediterranean pen shell Pinna nobilis in restoration and conservation plans of benthic habitats, an in situ experiment was conducted using empty P. nobilis shells. The latter were transplanted in a bare soft-bottomed area and their associated fauna were followed along 120 days and compared at different temporal points and with the assemblages living in the surrounding soft-sediment area. Compared to soft-sediment communities, an evidently increasing succession of species richness, abundance, and diversity descriptors (Shannon-Wiener H′ and Pielou's evenness J′) was observed with the community inhabiting empty Pinna shells. Among the forty-five (45) species found in association with the transplanted empty shells, seventeen (17) were found constantly in the three temporal points; the other twenty-eight (28) species appeared in the samples collected in the second and/or third sampling time. While motile and sessile species associated to Pinna shells showed an increasing pattern of appearance and abundance along the experiment time, those of soft sediment remained almost constant. The comparison between Pinna shells and soft-sediment associated communities showed that the species richness was slightly different between the two different sample types (49 for soft sediment versus 45 for empty Pinna shells); however the total abundance was found more important with empty Pinna shells. The results obtained herein argue in favor of the important engineering effect of P. nobilis in soft benthic habitats and therefore for the necessity of its conservation.

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Cylindrichnus concentricus Toots in Howard, 1966 (trace fossil) in its type locality, Upper Cretaceous, Wyoming

Ekdale A. A., Harding S. C.

Annales Societatis Geologorum Poloniae

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2015

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Vol. 85, No. 3

427--432

EN

Cylindrichnus concentricus is a wide spread trace fossil in shallow marine sedimentary rocks of Mesozoic and Cenozoic age. This paper clarifies the ichnotaxonomy of C. concentricus by of fering an emended diagnosis of the ichnogenus and a new diagnosis of the ichnospecies. The broad, bow-shaped architecture of C. concentricus with two openings at the sediment surface suggests that the trace maker was either a filter-feeding animal that captured suspended food particles from the water column or else a surface deposit feeder that employed tentacles or an eversible pharynx to collect nutritious sediment from the surface around one or both of the burrow openings. Although C. concentricus has been reported in a variety of different sedimentary environments around the world, in its type locality in the Cretaceous of Wyoming the trace fossilis found in low-diversity or monoichnospecific beds that exhibit hummocky cross stratification. This occurrence suggests the burrower’s tolerance (or perhaps preference) for an episodic high-energy hydrodynamic environmentre lated to major storms.

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The trace fossil Lepidenteron lewesiensis (Mantell, 1822) from the Upper Cretaceous of southern Poland

Jurkowska A., Uchman A.

Acta Geologica Polonica

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2013

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Vol. 63, no. 4

611--623

EN

Lepidenteron lewesiensis (Mantell, 1822) is an unbranched trace fossil lined with small fish scales and bones, without a constructed wall. It is characteristic of the Upper Cretaceous epicontinental, mostly marly sediments in Europe. In the Miechów Segment of the Szczecin-Miechów Synclinorium in southern Poland, it occurs in the Upper Campanian–Lower Maastrichtian deeper shelf sediments, which were deposited below wave base and are characterized by total bioturbation and a trace fossil assemblage comprising Planolites, Palaeophycus, Thalassinoides, Trichichnus, Phycosiphon, Zoophycos and Helicodromites that is typical of the transition from the distal Cruziana to the Zoophycos ichnofacies. L. lewesiensis was produced by a burrowing predator or scavenger of fishes. The tracemaker candidates could be eunicid polychaetes or anguillid fishes.

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Palaeoenvironmental significance of iron carbonate concretions from the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland

Witkowska M.

Acta Geologica Polonica

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2012

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Vol. 62, no. 3

307-324

EN

Iron carbonate concretion horizons are characteristic features of the Bathonian (Middle Jurassic) claystone-mudstone succession at Gnaszyn. They occur in single horizons, which generally represent the same genetic type. The siderite concretions are the main type of iron carbonate concretions at Gnaszyn; a second type is represented by phosphate-siderite concretions. On the basis of the fieldwork, and their petrographical and mineralogical characteristics, the genesis of the concretions and their palaeoenvironmental significance is discussed. The results of this study (based on the localization, mode of occurrence, mineralogy of iron carbonate concretions and also the textural relationship between the concretions and host sediment layers) suggest an early diagenetic origin of the concretions. The preferential occurrence of the concretion horizons in single layers in the ambient sediments was associated with particular conditions of their deposition and early diagenesis, favored by a slower sedimentation rate and more intense bioturbation, and related primarily to the greater availability of reactive iron ions. From the viewpoint of physicochemical conditions the horizons with iron carbonate concretions in the study area reflect the redox boundary between oxic/bioturbated and anoxic/non-bioturbated zones. The conditions favoring the formation of such horizons was possibly due to longer periods of diminished sedimentation rate when the redox boundary remained in the same position within the sediment.

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Coniacian-?Santonian paralic sedimentation in the Rakowice Małe area of the North Sudetic Basin, SW Poland: sedimentary facies, ichnological record and palaeogeographical reconstruction of an evolving marine embayment

Leszczyński S.

Annales Societatis Geologorum Poloniae

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2010

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Vol. 80, No 1

1-24

EN

The Coniacian-?Santonian siliciclastic succession outcropped in a sandstone quarry at Rakowice Małe (Żerkowice Member of the Rakowice Wielkie Formation, and the Czerna Formation including the Nowogrodziec Member; North Sudetic Basin, SW Poland) provides an interesting example of paralic deposits. Lithofacies and ichnofossil examination indicate coastal, lacustrine, paludal and lagoonal sedimentation. Valuable new data are supplied by trace fossils, a feature not considered yet in the literature on the Upper Cretaceous of the North Sudetic Basin. Trace fossils are overall abundant in the upper part of the Nowogrodziec Member and overlying part of the Czerna Formation. The following ichnogenera: Thalassinoides, Ophiomorpha, Asterosoma, Palaeophycus, Planolites, Skolithos, Teredolites, Chondrites, Cylindrichnus, Arenicolites, Rosselia, Teichichnus, Phycodes, Phycosiphon, and Schaubcylindrichnus are represented. The trace fossils represent the Skolithos, Teredolites and Cruziana ichnofacies. The Cruziana Ichnofacies is typified by the richest trace fossil assemblage characteristic of its archetypal, proximal and stressed expressions. An upper shoreface to foreshore origin of these sediments is documented using lithofacies and the ichnofossils Ophiomorpha and Thalassinoides in the exposed part of the Żerkowice Member. Dominance of kaolinite, lack of burrows and upward passage into paludal deposits is interpreted to indicate a lacustrine origin of variegated clayey mudstone at the base of the Nowogrodziec Member. The changes of depositional environments are interpreted as resulting from separation of the area from the open sea by a sand barrier formed due to the termination of the forced regression. Siltstones containing plant roots and fragments of drifted wood showing the trace fossil Teredolites clavatus, together with coal-seams containing Thalassinoides isp., are assigned to indicate a coastal plain, paludal deposition of the overlying part of the Nowogrodziec Member and incursion of marine waters. The fining upward sequence constituting the top part of the Nowogrodziec Member and showing almost archetypal Cruziana Ichnofacies substituted by its expression indicative of highly stressed, brackish conditions are shown to indicate extensive drowning of the area and lagoonal sedimentation. Termination of the drowning, embodied in a maximum flooding surface, is indicated in a bed of coaly mudstone at the top of the Nowogrodziec Member. Sedimentation on a periodically prograded brackish bay shoreface is inferred from lithofacies, ichnofossils and body fossils for the deposits overlying the Nowogrodziec Member and topping the examined succession. The trace fossils indicate Cruziana Ichnofacies and Skolithos Ichnofacies in the expression of slightly stressed environ- ments. The whole examined part of the Czerna Formation is interpreted as a fifth-order transgressive-regressive cycle.

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Deep-sea ichnology : observations in modern sediments to interpret fossil counterparts

Wetzel A.

Acta Geologica Polonica

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2010

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Vol. 60, no. 1

125-138

EN

Extensive areas of the abyss represent a dynamic environment experiencing seasonally strongly fluctuating organic-matter deposition that in turn affects the oxygen content of the pore water. At high organic-matter deposition, oxygenation of the pore water decreases and forces organisms respiring this water to move upward. Thus, times of benthic food richness on the seafloor affect the behaviour of endobenthic organisms; aside from deep-deposit feeding, temporary surface feeding (including unselective bulldozing) represents an additional nutritional strategy. This has been shown for the producers of Nereites and Scolicia as well as Thalassinoides and Zoophycos, the latter two have an open tube. Each of these activities leads to intense sediment mixing and prevents or disturbs the formation of near-surface burrows including graphoglyptids. The distribution of organic matter in the sediments is reflected by the orientation and geometry of Phycosiphon. Quantity and quality of food appear to be related to abundance and size of Scolicia. Food selectivity, the ability of selective feeding and organism mobility all appear to be important factors in benthic ecology, however, they are as yet little known. To use the full potential of uniformitarian studies relying on cores taken in soft sediments, they should be based on X-ray radiographs, contain information about the timing of burrow production and focus on ichnotaxonomically determinable burrows.

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Lacustrine trace fossils and environmental conditions in the Early Miocene Ermenek Basin, southern Turkey

Uchman A., Nemec W., Ilgar A., Messina C.

Annales Societatis Geologorum Poloniae

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2007

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Vol. 77, No 2

123-139

EN

The Early Miocene lacustrine succession of the Ermenek Basin, an intramontane graben in southern Anatolia, consists of hemipelagic, variably calcareous mudstones and pelagic marlstones densely interspersed with tempestite sandstone sheets, subordinate turbidite sandstone sheets and sporadic layers of evaporitic limestone. The marly lake was hydrologically closed and mainly no deeper than 10 m, with the mean fairweather wave base at 1.5 m and storm wave base around 5 m. The deposits abound in trace fossils, including Vagorichnus cf. anyao (its second recognized occurrence), endichnial ferruginous ribbons, large tubular structures, oblique cylinders, small discontinuous ridges, undulating ridges, planar wall structures and a range of other bioturbational features. The tempestites and turbidites show both pre-and post-event trace fossils, with recognizable mixed and transitional layers similar as reported from marine tempestites and turbidites. The trace fossils constitute an impoverished Mermia ichnofacies indicating a considerable environmental stress. The lake salinity fluctuated, and the stress factor is attributed to the extreme environmental conditions (increased salinity and unusual water chemistry) caused by episodes of brackishness due to decreases in rainfall and increases in evaporation. Freshwater conditions are indicated by benthic ostracods and mollusc shells in offshore mudstones and by gastropod shells in coastal coal deposits, whereas marly layers contain only the ostracod species Miocyprideis glabra asulcata, implying mesohaline to polyhaline conditions.

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Impact of invasive benthic crustaceans on the resuspension of bottom sediments : an experimental study

Zaiko A., Olenin S.

Oceanological and Hydrobiological Studies

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2004

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Vol. 33, No. 3

99--110

EN

The resuspension process caused by the burrowing activity of three Ponto-Caspian amphipod species (Pontogammarus robustoides, P. crassus and Chaetogammarus ischus) introduced to the Curonian Lagoon, Baltic Sea, was studied in a laboratory. The experimental set-up included aquaria with three types of bottom sediments: 1) sand; 2) sand with pebbles; 3) sand with stones up to 30 cm in diameter. The experimental aquaria contained amphipods in numbers that mimicked their density in situ, while control aquaria contained no animals. Water was sampled from three different layers (1, 5, and 9 cm above the sediment surface) from experimental and control aquaria and analyzed with a spectrophotometer at a wavelength of 660 nm in order to estimate the density of suspended material. The burrowing activity of the amphipods in all sediment types increased the amount of suspended material throughout the studied water layer (10 cm). The most visible effect was detected above the sandy bottom with large stones, the least – above the sandypebble bottom. The conclusion was drawn that the invasive burrowing amphipods can increase the resuspension of bottom sediments in invaded ecosystems.