scholarly journals Mississippian (Osagean) Shallow-Water, Mid-Latitude Siliceous Sponge Spicule and Heterozoan Carbonate Facies

2006 ◽  
pp. 1-23
Author(s):  
Evan K. Franseen
Keyword(s):  
North America ◽  
Shallow Water ◽  
Siliceous Sponge ◽  
Inner Shelf ◽  
Sponge Spicule ◽  
Dissolved Silica ◽  
Subaerial Exposure ◽  
Middle Mississippian ◽  
Facies Associations ◽  
Heterozoan Carbonates

Mixtures of biosiliceous and heterozoan-dominated carbonate deposits are commonly interpreted as recording cold-water polar or deep basinal conditions. However, a growing body of literature is documenting examples from the rock record that show these deposits accumulated in shallow-water middle- to low-latitude environments. The continued recognition of ancient neritic heterozoan carbonate and biosiliceous accumulations is broadening our understanding of the various paleoenvironmental controls on their development. Early-Middle Mississippian time was characterized by the development of biosiliceous and carbonate accumulations in North America. This study focuses on Osagean cherty dolomitic strata in cores from the Schaben field in Kansas, which is located in Ness County on the southwest flank of the Central Kansas uplift (CKU). During the Osagean, Kansas was located at approximately 20° S latitude, within the tropical to subtropical latitudinal belt. Study area strata are characterized by shallow-water inner-shelf carbonates that were deposited on a gently southward-sloping shelf (ramp). Two depositional sequences (DS1 and DS2) are identified in cores and are separated by a sequence boundary (SB1) that evidences subaerial exposure. The primary facies in the two depositional sequences include 1) Mudstone-Wackestone (MW); 2) Sponge Spicule-Rich Wackestone-Packstone (SWP); 3) Echinoderm-Rich Wackestone-Packstone-Grainstone (EWPG); and 4) Dolomitic Siltstones and Shale facies. Other features identified in cores include 1) Silica Cementation and Replacement; 2) Silica Replaced Evaporites; 3) Brecciation and Fracturing; and 4) Calcite Cementation and Replacement. The abundance of echinoderm facies with other diverse fauna, evidence of extensive reworking by burrowing organisms, and only rare occurrence of evaporites suggest subtidal deposition in a normal to slightly restricted marine inner-shelf setting for DS1. After the SB1 subaerial exposure event, marine conditions returned but the depositional environment over the study area changed compared to that for much of DS1 deposition. The volumetric increase of sponge-spicule wackestone and packstone (SWP) with less diverse fauna, abundance of early evaporites (replaced by silica), and evidence for shallowest water to subaerially exposed conditions throughout DS2 suggest deposition in more restricted environments that likely ranged from restricted inner shelf/protected embayment to evaporative lagoon and possibly supratidal flat. One of the more significant characteristics in DS2 is the dominance of siliceous sponge spicule facies and heterozoan carbonates that were deposited in shallow-water and restricted environments. This study and others from numerous periods in the geologic record are indicating that shallow-marine, mid-latitude biosiliceous and heterozoan carbonates may be more common than previously thought. Especially interesting are the examples from Mississippian (Osagean-Meramecian) strata in North America that show similar facies associations with DS2 strata of this study. The predominance of Early-Middle Mississippian heterozoan carbonate and biosiliceous (spiculitic) deposits, and lack of photozoan deposits, in the mid-latitude shallow-shelf setting in Kansas and surrounding areas was likely due to abundant nutrients and dissolved silica derived from basinal and/or terrestrial sources. Based on available evidence, upwelling of basinal waters rich in nutrients and dissolved silica appears to have been a primary control on shelf margin and shelf facies. Upwelling even may have had a primary imprint on shallow-water, inner-shelf areas, especially during transgression(s). Nutrients and dissolved silica from terrestrial sources may have contributed to the facies associations in shallowest water, inner-shelf areas. However, the available evidence suggests that terrestrial sourced nutrients and dissolved silica were not the dominant control. The results of this study have implications from a petroleum reservoir standpoint. The DS2 sponge spicule, heterozoan carbonate, and silica-replaced evaporite facies in this study form reservoirs in Schaben field and another nearby field composed of similar facies. Because regional upwelling is likely to have had at least some control, facies similar to DS2 strata may form important reservoirs in Lower-Middle Mississippian strata that were deposited in shallow-water inner shelf/ramp settings elsewhere in Kansas and North America. Continuing studies of the controls on biosiliceous and heterozoan carbonate deposition and diagenesis in mid-latitude neritic settings will improve our understanding and predictive capabilities.

scholarly journals Cryostratigraphy, sedimentology, and the late Quaternary evolution of the Zackenberg River delta, northeast Greenland

2017 ◽  
Vol 11 (3) ◽  
pp. 1265-1282 ◽  
Author(s):  
Graham L. Gilbert ◽  
Stefanie Cable ◽  
Christine Thiel ◽  
Hanne H. Christiansen ◽  
Bo Elberling
Keyword(s):  
Late Quaternary ◽  
Sediment Cores ◽  
River Delta ◽  
Optically Stimulated Luminescence ◽  
Delta Plain ◽  
Valley Fill ◽  
Subaerial Exposure ◽  
Facies Associations ◽  
Delta Progradation ◽  
Ice Content

Abstract. The Zackenberg River delta is located in northeast Greenland (74°30′ N, 20°30′ E) at the outlet of the Zackenberg fjord valley. The fjord-valley fill consists of a series of terraced deltaic deposits (ca. 2 km2) formed during relative sea-level (RSL) fall. We investigated the deposits using sedimentological and cryostratigraphic techniques together with optically stimulated luminescence (OSL) dating. We identify four facies associations in sections (4 to 22 m in height) exposed along the modern Zackenberg River and coast. Facies associations relate to (I) overriding glaciers, (II) retreating glaciers and quiescent glaciomarine conditions, (III) delta progradation in a fjord valley, and (IV) fluvial activity and niveo-aeolian processes. Pore, layered, and suspended cryofacies are identified in two 20 m deep ice-bonded sediment cores. The cryofacies distribution, together with low overall ground-ice content, indicates that permafrost is predominately epigenetic in these deposits. Fourteen OSL ages constrain the deposition of the cored deposits to between approximately 13 and 11 ka, immediately following deglaciation. The timing of permafrost aggradation was closely related to delta progradation and began following the subaerial exposure of the delta plain (ca. 11 ka). Our results reveal information concerning the interplay between deglaciation, RSL change, sedimentation, permafrost aggradation, and the timing of these events. These findings have implications for the timing and mode of permafrost aggradation in other fjord valleys in northeast Greenland.

Taxonomic affinities and paleogeography of Stromatomorpha californica Smith, a distinctive Upper Triassic reef-adapted demosponge

2009 ◽  
Vol 83 (5) ◽  
pp. 783-793 ◽  
Author(s):  
B. Senowbari-Daryan ◽  
G. D. Stanley
Keyword(s):  
North America ◽  
Shallow Water ◽  
Type Species ◽  
Upper Triassic ◽  
Northern Calcareous Alps ◽  
Late Triassic ◽  
Separate Species ◽  
Northern Calcareous ◽  
Siliceous Spicules ◽  
Horizontal Layers

Stromatomorpha californica Smith is a massive, calcified, tropical to subtropical organism of the Late Triassic that produced small biostromes and contributed in building some reefs. It comes from the displaced terranes of Cordilleran North America (Eastern Klamath terrane, Alexander terrane, and Wrangellia). This shallow-water organism formed small laminar masses and sometimes patch reefs. It was first referred to the order Spongiomorphidae but was considered to be a coral. Other affinities that have been proposed include hydrozoan, stomatoporoid, sclerosponge, and chambered sponge. Part of the problem was diagenesis that resulted in dissolution of the siliceous spicules and/or replaced them with calcite. Well-preserved dendroclone spicules found during study of newly discovered specimens necessitate an assignment of Stromatomorpha californica to the demosponge order Orchocladina Rauff. Restudy of examples from the Northern Calcareous Alps extends the distribution of this species to the Tethys, where it was an important secondary framework builder in Upper Triassic (Norian-Rhaetian) reef complexes. Revisions of Stromatomorpha californica produce much wider pantropical distribution, mirroring paleogeographic patterns revealed for other tropical Triassic taxa. Review of Liassic material from the Jurassic of Morocco, previously assigned to Stromatomorpha californica Smith var. columnaris Le Maitre, cannot be sustained. Species previously included in Stromatomorpha are: S. stylifera Frech (type species, Rhaetian), S. actinostromoides Boiko (Norian), S. californica Smith (Norian), S. concescui Balters (Ladinian-Carnian), S. pamirica Boiko (Norian), S. rhaetica Kühn (Rhaetian), S. stromatoporoides Frech, and S. tenuiramosa Boiko (Norian). Stromatomorpha rhaetica Kühn described from the Rhaetian of Vorarlberg, Austria shows no major difference from S. californica. An example described as S. oncescui Balters from the Ladinian-Carnian of the Rarau Mountains, Romania, is very similar to S. californica in exhibiting similar spicule types. However, because of the greater distance between individual pillars, horizontal layers, and the older age, S. oncescui is retained as a separate species. The net-like and regular skeleton of Spongiomorpha sanpozanensis Yabe and Sugiyama, from the Upper Triassic of Sambosan (Tosa, Japan), suggests a closer alliance with Stromatomorpha, and this taxon possibly could be the same as S. californica.

Siliceous sponge expansion and phosphogenesis in a shallow water environment in the Malyi Karatau Range (Kazakhstan) during the Precambrian-Cambrian transition

2020 ◽  
Vol 347 ◽  
pp. 105830
Author(s):  
Michael Tatzel ◽  
Maria Stuff ◽  
Gerhard Franz ◽  
Dorothee Hippler ◽  
Uwe Wiechert ◽  
...  
Keyword(s):  
Shallow Water ◽  
Water Environment ◽  
Siliceous Sponge ◽  
Shallow Water Environment

Occurrence of the siliceous sponge spicule Konyrium (Hexactinellida) in the upper Cambrian of the Mackenzie Mountains, northwestern Canada

2002 ◽  
Vol 76 (3) ◽  
pp. 565-569 ◽  
Author(s):  
Brian R. Pratt
Keyword(s):  
Fossil Record ◽  
Southern China ◽  
South Australia ◽  
Early Cambrian ◽  
Siliceous Sponge ◽  
Sponge Spicule ◽  
Animal Phyla ◽  
Sponge Diversity ◽  
Siliceous Sponges ◽  
Late Neoproterozoic

The fossil record of siliceous sponges—Hexactinellida and demosponge “Lithistida”—hinges upon both body fossils plus isolated spicules mostly recovered from limestones by acid digestion. The earliest record of siliceous sponge spicules extends back to the late Neoproterozoic of Hubei, southern China (Steiner et al., 1993) and Mongolia (Brasier et al., 1997), and body fossils attributed to the hexactinellids have been described from the Ediacaran of South Australia (Gehling and Rigby, 1996); thus they are the oldest-known definite representatives of extant animal phyla. The Early Cambrian saw a remarkable diversification in spicule morphology, with the appearance of an essentially “modern” array of forms (Zhang and Pratt, 1994). While a diversity decline may have occurred with the late Early Cambrian extinction(s), the subsequent Paleozoic and Mesozoic fossil record of spicules shows a relatively consistent range of morphologies (e.g., Mostler, 1986; Bengtson et al., 1990; Webby and Trotter, 1993; Kozur et al., 1996; Zhang and Pratt, 2000). However, because spicule form is not restricted to individual taxa and many sponge species secrete a variety of spicule shapes, it is difficult to gauge true siliceous sponge diversity and to explore their biostratigraphic utility using only isolated spicules.

Palynology of the Ordovician Kanosh Shale at Fossil Mountain, Utah

2015 ◽  
Vol 89 (3) ◽  
pp. 424-447 ◽  
Author(s):  
Marco Vecoli ◽  
John H. Beck ◽  
Paul K. Strother
Keyword(s):  
North America ◽  
Shallow Water ◽  
New Taxa ◽  
Middle Ordovician ◽  
Incomplete Knowledge ◽  
Late Cambrian ◽  
Freshwater Influence ◽  
Depositional Setting ◽  
Biological Differences

AbstractPalynomorph assemblages recovered from the Kanosh Shale at Fossil Mountain, Utah, are dominated by operculate acritarchs and cryptospores with minor smaller acritarchs. The present findings add new data to the largely incomplete knowledge of Ordovician acritarch assemblages from Laurentia, up to now known only from very few localities in North America. These populations contain some species in common with acritarchs from the Canning and Georgina basins in Australia and with assemblages from China; they indicate a Middle Ordovician (Dapingian-Darriwilian) age. The assemblage is lacking many typical marine acritarchs of this age, which, in combination with some cryptospores, is probably reflecting the likelihood of freshwater influence in the Kanosh Basin. This observation is congruent with previous interpretations of the depositional setting of the Kanosh Shale as a shallow water lagoon that supported the deposition of carbonate hardgrounds.Four new taxa are described: Busphaeridium vermiculatum n. gen., n. sp.; Digitoglomus minutum n. gen., n. sp.; Turpisphaera heteromorpha n. gen., n. sp.; and Vermimarginata barbata n. gen., n. sp. In addition, the abundance of operculate forms has enabled the revision and a new emendation of the genus Dicommopalla and clarification of the “opalla” complex. We also propose new and revised suprageneric taxa that emphasize inferred biological differences among acritarch genera. The Sphaeromorphitae subgroup is emended to include forms lacking sculptural elements. Two new informal subgroups are proposed: the Superornamenti and the Operculate Acritarchs. Cryptospores are abundant throughout the sections studied and they appear to be more closely related to the late Cambrian Agamachates Taylor and Strother than to Darriwilian and younger Ordovician cryptospores from Gondwana.

Hardgrounds in the Lower Leintwardine Beds (Silurian) of the Welsh Borderland

1980 ◽  
Vol 117 (4) ◽  
pp. 311-326 ◽  
Author(s):  
Lesley Cherns
Keyword(s):  
Shallow Water ◽  
Aerial Exposure ◽  
Subsequent Removal ◽  
Faunal Assemblage ◽  
Inner Shelf ◽  
Water Conditions ◽  
History Of

SummaryThe base of the Lower Leintwardine Beds (Silurian-Ludlow Series) in the shelf sequences of the Welsh Borderland is marked by a widespread development of shelly conglomeratic limestone beds. Borings into some intraclasts indicate that they were hardgrounds. The early lithification, sometimes in situ, of both sand-grade and mud-grade carbonates is demonstrated by the conglomerates. Some compound intraclasts (‘hiatus concretions’) indicate a complex history of deposition, scouring and lithification. Boring of clasts which have not been further eroded is inferred to have taken place locally. The borings are of the narrow, single entrance form referable to Trypanites. The distribution of the conglomerates relates closely to Leintwardinian palaeogeography. Repeated hardground formation in sequences of inner shelf areas reflects episodic deposition alternating with periods of omission and erosion. There is evidence throughout the shelf of a break in sedimentation with hardground formation at the end of Bringewoodian times. The nature of the conglomerates suggests that they formed in shallow water conditions; there is no lithological indication of sub-aerial exposure. The absence of the Aymestry Limestone in the SE shelf is more probably due to its non-deposition or lateral lithological change to muddier beds with a different faunal assemblage than to its subsequent removal by erosion.

A new Gorstian radiolarian fauna from the upper Silurian of the Cape Phillips Formation, Cornwallis and Bathurst islands, Canadian Arctic

2015 ◽  
Vol 52 (10) ◽  
pp. 863-879 ◽  
Author(s):  
Martin Tetard ◽  
Paula J. Noble ◽  
Taniel Danelian ◽  
Claude Monnet ◽  
Alfred C. Lenz
Keyword(s):  
Canadian Arctic ◽  
Alpha Diversity ◽  
Siliceous Sponge ◽  
Sponge Spicule ◽  
Cape Phillips Formation ◽  
Cortical Shell ◽  
Stratigraphic Ranges ◽  
Shelf Margin ◽  
Cornwallis Island

This study provides a taxonomic treatment and comparison of lower Gorstian (Silurian) radiolarians recovered from two sections of the Cape Phillips Formation in the Canadian Arctic that accumulated in two different paleoenvironmental settings. Twilight Creek is more basinal, located ∼100 km from the paleo-shelf margin, whereas Snowblind Creek is located within 1 km of the paleo-shelf break, on Cornwallis Island. The fauna, like other material from the Cape Phillips Formation, is extremely well preserved and was recovered from four samples at two localities, all from the Lobograptus progenitor graptolite Zone, an interval that has few published studies regarding radiolarians. A total of 28 species are recognized, of which two are new and described herein (Fusalfanus bilateralis n. sp. and Pseudospongoprunum parvispina n. sp.), belonging to the Haplotaeniatidae, Inaniguttidae, “Sponguridae”, Ceratoikiscidae, Entactiniidae, Palaeoscenidiidae, and Secuicollactidae. Based on these new data, the stratigraphic ranges of some taxa are extended. The species concepts of several closely related inaniguttid species are re-evaluated. As a result, Inanihella tarangulica Nazarov and Ormiston, 1984 is transferred to the genus Fusalfanus Furutani, 1990 based on cortical shell structure, and Inanihella duroacus, Inanihella legiuncula, and Inanihella perarmata are synonymized under Fusalfanus tarangulica sensu lato. Aciferopylorum admirandum is transferred to Fusalfanus and considered a junior synonym of Fusalfanus osobudaniensis. The comparative analysis of taxonomic richness and composition reveals that the more distal sample from Bathurst Island exhibits a slight, but statistically significant, higher alpha diversity at the species rank than the more proximal basin/platform samples from Snowblind Creek. Biodiversity indices at the genus rank produced mixed results, indicating that differences between sites are at best slight. There is also a strong taxonomic separation between the fine and coarse size radiolarian fractions recovered during the sieving of each sample. The siliceous sponge spicule assemblages from these faunas show an inverse diversity relationship to the radiolarians in that Snowblind Creek contains greater alpha diversity than Twilight Creek. This study provides the first documentation of facies-controls in Silurian radiolarian diversity and is useful in evaluating the role of taxa used in biostratigraphy.

Environmental history since 11,000 14c yr b.p. of the northeastern Pampas, Argentina, from alluvial sequences of the Luján River

2004 ◽  
Vol 62 (2) ◽  
pp. 146-161 ◽  
Author(s):  
Aldo R. Prieto ◽  
Adriana M. Blasi ◽  
Claudio G. De Francesco ◽  
Celina Fernández
Keyword(s):  
Shallow Water ◽  
Environmental History ◽  
Environmental Changes ◽  
Water Bodies ◽  
Pollen Record ◽  
Groundwater Levels ◽  
European Settlement ◽  
Subaerial Exposure ◽  
Dry Conditions ◽  
Detailed Record

Sedimentological, malacological, and pollen analyses from 14C-dated alluvial sections from the Luján River provide a detailed record of environmental changes during the Holocene in the northeastern Pampas of Argentina. From 11,200 to 9000 14C yr B.P., both sedimentary and biological components suggest that the depositional environment was eutrophic, alkaline, and freshwater to brackish shallow water bodies without significant water circulation. During this time, bioclastic sedimentation was dominant and the shallow water bodies reached maximum development as the climate became more humid, suggesting an increase in precipitation. Short-term fluctuations in climate during the last stage of this interval may have been sufficient to initiate changes in the water bodies, as reduction of the volume alternated with periods of flooding. The beginning of the evolution of shallow swamps in the wide floodplain or huge wetlands was contemporaneous with a sea level lower than the present one. From 9000 and 7000 14C yr B.P., mesotrophic, alkaline, brackish, probably anoxic swamps existed. Between 7000 and 3000 14C yr B.P., anoxic calcareous swamps were formed, with subaerial exposure and development of the Puesto Berrondo Soil (3500–2900 14C yr B.P.). A trend to a reduction of water bodies is recorded from 9000 to ca. 3000 14C yr B.P., with a significant reduction after ca. 7000 14C yr B.P. A shift to subhumid–dry climate after 7000 14C yr B.P. appears to be the main cause. During this time, an additional external forcing toward higher groundwater levels was caused by Holocene marine transgression causing changes in the water bodies levels. The climate became drier during the late Holocene (ca. 3000 yr B.P.), when clastic sedimentation increased, under subhumid–dry conditions. Flood events increased in frequency during this time. From ca. A.D. 1790 to present, the pollen record reflects widespread disturbance of the vegetation during the European settlement.

Paleogene Verrucidae (Cirripedia: Verrucomorpha) of North America, with descriptions of three new species

Zootaxa ◽  
2019 ◽  
Vol 4712 (1) ◽  
pp. 34-50
Author(s):  
RAY T. PERREAULT ◽  
JOHN S. BUCKERIDGE
Keyword(s):  
North Carolina ◽  
New Species ◽  
North America ◽  
Shallow Water ◽  
Transition Zone ◽  
Middle Eocene ◽  
Washington State ◽  
Upper Eocene ◽  
Two New Species ◽  
Three New Species

In North America, Paleogene Verrucidae are rarely encountered. Only a single named species has been previously discussed by Zullo & Baum (1979), who provisionally assigned a Palaeocene form from North Carolina to Verruca rocana Steinmann, 1921. Eocene deposits in Washington State (USA) have now yielded two new species from intertidal to shallow water environments: Verruca gailgoedertae sp. nov. from the middle Eocene Crescent/McIntosh transition zone, and Verruca sorrellae sp. nov. from the upper Eocene to lowest Oligocene Gries Ranch and basal Lincoln Creek formations. Both species are characterized by punctate shell plates, and are placed in the lineage of Verruca stroemia (O.F. Müller, 1776). In Alabama, marls from the upper Yazoo Formation (Pachuta and Shubuta Members) have yielded Verruca alabamensis sp. nov., an uncommon deeper water form associated with abundant brachiopods and phosphate deposition. This last species shows no development of punctae and is not related to the lineage that leads directly to Verruca stroemia. 

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