To see the other types of publications on this topic, follow the link: Paleozoic.
Journal articles on the topic 'Paleozoic'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Paleozoic.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Heredia, N., J. García-Sansegundo, G. Gallastegui, P. Farias, R. Giacosa, J. L. Alonso, P. Busquets, et al. "Evolución Geodinámica de los Andes argentino-chilenos y la Península Antártica durante el Neoproterozoico tardío y el Paleozoico Late Neoproterozoic-Paleozoic geodynamic evolution of the Argentine-Chilean Andes and the Antarctic Peninsula." Trabajos de Geología 36, no. 36 (September 12, 2018): 237. http://dx.doi.org/10.17811/tdg.36.2016.237-278.
Full textAbstract:
Resumen: Durante el Neoproterozoico tardío y el Paleozoico, el actual segmento argentino-chileno de la Cordillera de los Andes y desde finales del Paleozoico la Península Antártica, formaron parte del margen suroccidental de Gondwana. Durante este periodo de tiempo, a dicho margen se fue acrecionando un conjunto de fragmentos continentales de tamaño y aloctonía variable, dando lugar en el Paleozoico a seis orogenias de diferente extensión temporal y espacial: Pampeana (Ediacárico-Cámbrico temprano), Famatiniana (Ordovícico Medio-Silúrico), Chánica (Devónico Medio-Carbonífero temprano), Oclóyica (Ordovícico Medio-Devónico), Gondwánica (Devónico Medio-Pérmico medio) y Tabarin (Pérmico tardío-Triásico). Todas estas orogenias son colisionales, salvo la Tabarin y la Gondwánica al sur de los 38º S.Palabras clave: Evolución geodinámica, Paleozoico, Andes argentino-chilenos, Península Antártica, Orógeno Oclóyico, Orógeno Famatiniano, Orógeno Chánico, Orógeno Gondwánico, Orógeno Tabarin.Abstract: During the late Neoproterozoic and Paleozoic times, the Argentine-Chilean Andes, -and since the late Paleozoic the Antarctic Peninsula,- formed part of the southwestern margin of Gondwana. During this period of time, several continental fragments of variable extensión and allochtonie were successively accreted to that margin, resulted in six Paleozoic orogenies of different temporal and spatial extension: Pampean (Ediacaran-early Cambrian), Famatinian (Middle Ordovician-Silurian), Chanic (Middle Devonian-early Carboniferous), Ocloyic (Middle Ordovician-Devonian), Gondwanan (Middle Devonian-middle Permian) and Tabarin (late Permian-Triassic). All these orogenies had a collisional character, with the exception of the Tabarin and the Gondwanan south of 38º S.Keywords: Geodynamic evolution, Paleozoic, Argentine-Chilean Andes, Antarctic Peninsula, Ocloyic orogen, Famatinian orogen, Chanic orogen, Gondwanan orogen, Tabarin orogen.
2
Ross, Charles A., and June R. P. Ross. "Paleozoic foraminifera." Biosystems 25, no. 1-2 (January 1991): 39–51. http://dx.doi.org/10.1016/0303-2647(91)90011-9.
Full text
3
Foote, Mike. "Morphological Diversity In The Evolutionary Radiation Of Paleozoic and Post-Paleozoic Crinoids." Paleobiology 25, S2 (1999): 1–115. http://dx.doi.org/10.1017/s0094837300020236.
Full textAbstract:
The Paleozoic and post-Paleozoic radiations of crinoids present an opportunity to explore genomic and ecological explanations for patterns of morphologic diversification. Analysis of discrete-character data that cover the principal features of the crinoid skeleton shows that both Paleozoic and post-Paleozoic increases in morphological disparity were abrupt; this is consistent with rapid exploitation of open ecological opportunities in both cases. For the post-Paleozoic, this result is sensitive to some aspects of data analysis and sampling, so it cannot be regarded as unequivocal. The deceleration in morphological diversification within each radiation is consistent with an observed decline in rates of taxonomic origination as well as with the attainment of functional or structural limits. Despite these similarities in the two radiations, Paleozoic crinoids exploited a wider range of morphological designs than did their post-Paleozoic successors. Post-Paleozoic crinoids exploited a wide range of ecological strategies despite being stereotyped in many aspects of form. This difference between the radiations is consistent with an increase in the rigidity of genetic and developmental systems. The range of post-Paleozoic designs is not in essence a subset of the Paleozoic spectrum. The two radiations resulted in morphological distributions that are largely nonoverlapping, perhaps reflecting a different range of ecological strategies.
4
Isaev, Valery I., Margarita F. Galieva, Galina Lobova, Stanislav G. Kuzmenkov, Vitaly I. Starostenko, and Alexander N. Fomin. "Original Article Paleozoic and Mesozoic hydrocarbon foci of generation and assessment of their role in formation oil deposits of the Pre-Jurassic complex of Western Siberia." Georesursy 24, no. 2 (September 30, 2022): 17–48. http://dx.doi.org/10.18599/grs.2022.3.3.
Full textAbstract:
The following problem is solved by the present research: the probable sources of Paleozoic hydrocarbon deposits are determined on the basis of modeling the hydrocarbon foci of generation Paleozoic-Mesozoic oil source formations (for example, the southeast of Western Siberia, Tomsk Region). The research area is the lands Ostanino field group: the Selveikin area of deep drilling, the Ostaninskoye and Gerasimovskoye oil and gas condensate fields. Pre-Jurassic strata with oil source potential, including the Paleozoic Larinskaya (S1lr), Mirnaya (D13mr), Chuzikskaya (D2cz), Chaginskaya (D3cg) and Kehoregskaya (C1kh) formations, as well as Jurassic Bazhenovskaya (J3bg) and Tyumenskaya (J1-2tm ) formations, and, accordingly, the reservoirs of the weathering crust and bed-rock Paleozoic reservoirs are the objects of study. The subject of analysis was selected in accordance with the concept of the geothermal regime of the subsoil, as a leading factor in the implementation of the generation potential of the parent sediments. The research methods are digital paleotemperature modeling and historical-geological analysis. The results and conclusions concerning the fundamental problems of “Paleozoic oil” are obtained. 1. Source of the Paleozoic oil deposits can be both the Domanic type rocks of the Paleozoic formations and the Jurassic oil source formations. Thus, both upward vertical interstratal HC migration and downward HC migration can take place. Therefore, the two concepts of “main source” are compatible and should not be considered, as often, orthodoxly alternative. 2. The domanicoid rocks of the Paleozoic formations are most likely the source for Paleozoic gas and gas condensate deposits. 3. Paleozoic formations the roof of the bed-rock Paleozoic (on the Ostankinskaya group of fields – C1kh and D3cg) can be only the source of the «Paleozoic oil» and gas deposits in the Pre-Jurassic oil and gas complex. 4. Bazhenov formation – J3bg may be the “Jurassic” source of oil deposits in the Pre-Jurassic oil and gas complex. The results were obtained and conclusions were drawn concerning the applied (search) aspects of the problem: 1. Results additionally substantiate the author’s search criterion for the oil and gas content of the Paleozoic – these are anomalous geophysical and petrophysical characteristics of the Jurassic section. 2. The absence of hydrocarbon deposits in the Jurassic section is most likely a negative sign of the Paleozoic oil and gas content. 4. The low density of the modern heat flow (less than 40 mW/m2) is most likely a negative sign of oil deposits in the Paleozoic. 3. High paleotemperatures in terms of VR (more than 175oC) are most likely a negative sign of oil and gas deposits in the Paleozoic. 4. Reasons have been obtained to state that oil deposits in the Paleozoic cannot be richer than oil deposits in the Jurassic.
5
Aitchison, Jonathan C., Noritoshi Suzuki, Martial Caridroit, Taniel Danelian, and Paula Noble. "Paleozoic radiolarian biostratigraphy." Geodiversitas 39, no. 3 (September 2017): 503–31. http://dx.doi.org/10.5252/g2017n3a5.
Full text
6
Harper, David A. T., and Michael R. Sandy. "Paleozoic Brachiopod Biogeography." Paleontological Society Papers 7 (November 2001): 207–22. http://dx.doi.org/10.1017/s1089332600000978.
Full textAbstract:
Over two hundred years ago the Swedish scientist Carl Linnæus (1781), in an analysis of the biogeographic patterns of living organisms, suggested that all species originated in Paradise. Although there has been considerable progress in the understanding of biogeographical patterns during the intervening two centuries, modern debate has focused on the general applicability of the concept of faunal realms together with the relevance of dispersal, panbiogeographic, and vicariance models (Nelson and Platnick, 1981). To date, studies of Paleozoic brachiopod biogeography have no strong theoretical base; rather the various numerical techniques available, including both cladistic and phenetic methodologies, have helped organize the growing amount of distributional data into recognizable and useful structures.
7
Jurdy, Donna M., Michael Stefanick, and Christopher R. Scotese. "Paleozoic plate dynamics." Journal of Geophysical Research: Solid Earth 100, B9 (September 10, 1995): 17965–75. http://dx.doi.org/10.1029/95jb01477.
Full text
8
Parrish, R. R., and I. Reichenbach. "Age of xenocrystic zircon from diatremes of western Canada." Canadian Journal of Earth Sciences 28, no. 8 (August 1, 1991): 1232–38. http://dx.doi.org/10.1139/e91-110.
Full textAbstract:
Numerous diatremes of middle and late Paleozoic age intrude miogeoclinal middle and lower Paleozoic strata in the Canadian Cordillera. In addition to abundant crustal xenoliths and conspicuous mantle-derived mineral xenocrysts, rare zircon grains are present. U–Pb dating of single zircon crystals from many of these diatremes has failed to identify the presence of cogenetic (magmatic) zircons. All dated zircon grains are interpreted as xenocrysts derived from the crust. Their morphologies range from euhedral to very rounded, and their ages range from early Paleozoic to Archean. Most ages fall between 1.8 and 2.1 Ga, with subordinate age groupings in the late Archean (ca. 2.6 Ga), Middle Proterozoic (1.0–1.1 Ga), and early Paleozoic (ca. 470 Ma, 530 Ma). The Proterozoic and Archean zircons could have been derived from either the crystalline basement or its overlying sedimentary cover of Late Proterozoic to early Paleozoic age. Paleozoic zircons were probably derived from either intrusions within the basement or sills that intrude the early Paleozoic sedimentary cover, and they signify magmatic activity possibly related to rifting of the continental margin.
9
Foote, Mike. "Origination and extinction components of taxonomic diversity: Paleozoic and post-Paleozoic dynamics." Paleobiology 26, no. 4 (2000): 578–605. http://dx.doi.org/10.1666/0094-8373(2000)026<0578:oaecot>2.0.co;2.
Full textAbstract:
Changes in genus diversity within higher taxa of marine animals on the temporal scale of a few million years are more strongly correlated with changes in extinction rate than with changes in origination rate during the Paleozoic. After the Paleozoic the relative roles of origination and extinction in diversity dynamics are reversed. Metazoa as well as individual higher taxa shift from one mode of diversity dynamics to the other. The magnitude of taxonomic rates, the relative variance of origination and extinction rates, and the presence or absence of a long-term secular increase in diversity all fail to account for the shift in importance of origination and extinction in diversity changes. Origination and extinction rates both tend to be diversity-dependent, but different modes of diversity-dependence may contribute to the change in diversity dynamics from the Paleozoic to the post-Paleozoic. During the Paleozoic, there is a weak tendency for extinction rates to be more diversity-dependent than origination rates, whereas after the Paleozoic the two rates are about equally diversity-dependent on average.
10
Blake, Daniel B., and Thomas E. Guensburg. "Two new multiarmed Paleozoic (Mississippian) asteroids (Echinodermata) and some paleobiologic implications." Journal of Paleontology 63, no. 3 (May 1989): 331–40. http://dx.doi.org/10.1017/s0022336000019491.
Full textAbstract:
Lacertasterias elegans and Schondorfia fungosa are new genera and species of multiarmed asteroids described from the Kinderhookian? (Mississippian) Gilmore City Formation of Iowa and the Chesterian (Mississippian) Haney Formation of Illinois, respectively. Based on ambulacral construction, the former belongs to the Paleozoic asteroid stem group whereas the latter is distinct from but closer to post-Paleozoic asteroids.The multiarmed condition is atypical today; nevertheless, multiarmed species are morphologically varied and taxonomically widely distributed. The condition is considered problematic; it is uncertain whether or not multiarmed organization is adaptively neutral. Although only convergent with rather than ancestral to post-Paleozoic multiarmed asteroids, both new genera share important similarities with modern multiarmed predators, implying a predatory life mode for the fossils. The similarity between phylogenetically disparate Paleozoic and post-Paleozoic asteroids implies the multiarmed condition is beneficial, and benefits endured in spite of the major biotic changes that occurred around the end of the Paleozoic.
11
Ezaki, Yoichi. "Paleozoic Scleractinia: progenitors or extinct experiments?" Paleobiology 24, no. 2 (1998): 227–34. http://dx.doi.org/10.1666/0094-8373(1998)024[0227:pspoee]2.3.co;2.
Full textAbstract:
Abstract The Scleractinia, which are one of the most important builders of modern reefs, have been considered to have first appeared in the Middle Triassic. Recently, Paleozoic scleractiniamorphs have been reported from both the Ordovician and the Permian, suggesting that the scleractinian-like body plan was already established in the Paleozoic. Those Paleozoic scleractiniamorphs are considered either unsuccessful skeletonized offshoots (extinct experiments) or Paleozoic progenitors of the post-Paleozoic Scleractinia. Permian scleractiniamorphs are characterized by “ancestral” features and have no specific morphologies that deny scleractinian affinities. Molecular phylogenetics also indicate that extant scleractinians are monophyletic and originated long before their Triassic appearance. A Paleozoic origin for the Scleractinia is supported by morphological and molecular phylogenetic data. On the other hand, there is no positive evidence to show that different groups of scleractinians had separate soft-bodied precursors. The Paleozoic scleractinians evolved within the framework of their basic body plan, and a direct derivation of the Scleractinia from the Rugosa is not probable. The Anthozoa are characterized by a bilaterally symmetrical body plan, which is traditionally considered to have been derived from other radially symmetrical Cnidaria. The problem of the origin of scleractinian body plan may provide a key for deciphering the early anthozoan radiation within the Bilateria. Other examples of Paleozoic Scleractinia and scleractiniamorphs will be found, probably in shallow-water reefal facies or deeper-water communities, bridging the stratigraphic gaps in occurrence and elucidating the origin of the Scleractinia and their body plan.
12
Wu, Xiaoqi, Jianhui Zhu, Chunhua Ni, Kuang Li, Yanqing Wang, Ye Hu, Jianhong Lv, Yingli Wu, and Qi Qiu. "Genetic types and sources of Lower Paleozoic natural gas in the Daniudi gas field, Ordos Basin, China." Energy Exploration & Exploitation 35, no. 2 (January 9, 2017): 218–36. http://dx.doi.org/10.1177/0144598716687932.
Full textAbstract:
The molecular composition, stable carbon and hydrogen isotopes, and light hydrocarbons of the Lower Paleozoic natural gas in the Daniudi gas field in the Ordos Basin were investigated to study the geochemical characteristics. The Lower Paleozoic gas in the Daniudi gas field displays methane contents of 87.41–93.34%, dryness coefficients (C1/C1–5) ranging from 0.886 to 0.978, δ13C1 and δ13C2 values ranging from −40.3 to −36.4‰, with an average of −38.3‰, and from −33.6 to −24.2‰, with an average of −28.4‰, respectively, and δD1 values ranging from −197 to −160‰. The alkane gas generally displays positive carbon and hydrogen isotopic series, and the C7 and C5–7 light hydrocarbons of the Lower Paleozoic gas are dominated by methylcyclohexane and iso-alkanes, respectively. The Lower Paleozoic gas in the Daniudi gas field is mixed from coal-derived and oil-associated gases, similar to that observed in the Jingbian gas field. The oil-associated gas in the Lower Paleozoic gas is secondary oil cracking gas and displays a lower cracking extent than that in the Jingbian gas field. The coal-derived gas in the Lower Paleozoic gas in the Daniudi gas field migrated from the Upper Paleozoic gas through the window area where the iron–aluminum mudstone caprocks in the Upper Carboniferous Benxi Formation were missing. The oil-associated gas in the Lower Paleozoic gas in the Daniudi gas field was probably derived from presalt source rocks in the Lower Ordovician Majiagou Formation rather than the limestone in the Upper Carboniferous Taiyuan Formation. It seems unlikely that the marlstone in the Upper Ordovician Beiguoshan Formation and shale in the Middle Ordovician Pingliang Formation on the western and southwestern margins of the Ordos Basin contributed to the oil-associated gas in the Lower Paleozoic gas in the Daniudi gas field.
13
Shear, William A., and Jarmila Kukalová-Peck. "The ecology of Paleozoic terrestrial arthropods: the fossil evidence." Canadian Journal of Zoology 68, no. 9 (September 1, 1990): 1807–34. http://dx.doi.org/10.1139/z90-262.
Full textAbstract:
The available fossil evidence for the ecology of terrestrial arthropods in the Paleozoic is reviewed and reinterpreted. Some original data are provided, derived mainly from the detailed morphology of mouthparts, genitalia, cuticular vestiture, and body form. Paleozoic chelicerates were more diverse than their modern descendants and were probably dominant ground-level and arboreal predators. Web-building spiders and highly diversified mites appear to have been absent. Paleozoic myriapods include possibly the earliest land animals, and as abundant detritivores, provided a major conduit for primary productivity into higher trophic levels. Paleozoic insects present many difficulties of interpretation, but appear to have been extraordinarily diverse and may have played quite different ecological roles from today's insects, viewed as a whole. It is postulated that herbivory, defined as predation on living plants, may have been rare in early Paleozoic terrestrial ecosystems, and that most primary productivity was funneled through detritivores and decomposers. In the late Paleozoic, the evidence for herbivory by insects, except for feeding on fructifications, is rare. Insects seem to have played a major part as a selective force on plant fructifications.
14
Nützel, A., D. H. Erwin, and R. H. Mapes. "Identity and phylogeny of the late Paleozoic Subulitoidea (Gastropoda)." Journal of Paleontology 74, no. 4 (July 2000): 575–98. http://dx.doi.org/10.1017/s0022336000032728.
Full textAbstract:
The Subulitoidea have long been an enigmatic group of Paleozoic gastropods and share many characters of post-Paleozoic clades. Newly described protoconchs from several late Paleozoic subulitoid species have been employed in a phylogenetic analysis of the group. Late Paleozoic representatives, the Soleniscidae, are caenogastropods with an unornamented orthostrophic larval shell. The Meekospiridae have a smooth blunt protoconch of about two whorls. In contrast to previous interpretations, this protoconch is not heterostrophic or heterostrophy is not obvious. Therefore, a placement of the Meekospiridae with the genus Girtyspira in the Opisthobranchia is to be treated with caution. The new lanthinopsis-like genus Imogloba has a gobular subulitid-like teleoconch but its protoconch consists of a smooth first whorl which is loosely coiled and a larval shell with a characteristic non collabral ornament. Therefore, a close relationship between Soleniscidae and Imogloba is unlikely and the new family Imoglobidae is proposed. We found no clearly heterostrophic groups within the late Paleozoic subulitoid gastropods. The phylogenetic analysis of all subulitoid genera with known protoconchs provides little support for the monophyly of the Subulitoidea, particularly for a close relation between the Meekospiridae and the Soleniscidae. However, the Soleniscidae and Meekospiridae are probably monophyletic groups. Most genera are restricted to the Paleozoic, although several Mesozoic genera may hold descendants of Paleozoic Subulitoidea. Finally, a hypothesized link between Subulitoidea and Neogastropoda based on the presence of an anterior notch in both groups is unlikely.
15
Amiribesheli, Said, Joshua Thorp, and Julia Davies. "The Paleozoic prospectivity of the Browse Basin, Australia." APPEA Journal 60, no. 2 (2020): 685. http://dx.doi.org/10.1071/aj19059.
Full textAbstract:
Most of the discovered hydrocarbons in the Browse Basin occurred within the Mesozoic intervals, while deeper Paleozoic sequences have been seldom explored. Lack of Paleozoic exploration in the Browse Basin has been attributed to the lack of well penetrations, poor understanding of the petroleum systems and paucity of seismic data. The onshore Canning Basin with several commercial fields and discoveries is the most appropriate analogue for understanding the Paleozoic sequences in the region. With the integration of geophysical data (i.e. gravity, magnetic and seismic), well data and geology, the Paleozoic prospectivity of the Browse Basin can be further enlightened. Modern long offset (8 m) Vampire 2D seismic data were acquired by Searcher to address some of the complex challenges in the Browse Basin. Reservoir quality of the Brewster Formation, volcanic discrimination within the Plover Formation and identification of deeper Triassic and Paleozoic plays are some examples of these challenges in the Browse Basin. Recently Searcher reprocessed this regionally important Vampire 2D seismic dataset that ties to 60 wells. The broadband pre-stack depth migration reprocessed data were inverted to extract three petro-elastic properties of acoustic impedance, Vp/Vs and density by three-term amplitude versus offset inversion algorithm to improve imaging of deeper plays and delineate reservoir properties. This paper discusses how several potential Paleozoic reservoir-seal pairs can be identified in the Browse Basin by utilising the integration of Vampire 2D seismic data, quantitative interpretation products, regional geology and knowledge of the Canning Basin’s fields and discoveries. Previously there was little exploration of Paleozoic plays because they could not be imaged on seismic data. The potential Paleozoic reservoirs identified in this study include Permo-Carboniferous subcrop, Carboniferous-Devonian anticline and Carboniferous-Devonian rollover plays.
16
Sexton, John L., and Paul B. Jones. "Mini-sosie high-resolution reflection survey of the Cottonwood Grove fault in northwestern Tennessee." Bulletin of the Seismological Society of America 78, no. 2 (April 1, 1988): 838–54. http://dx.doi.org/10.1785/bssa0780020838.
Full textAbstract:
Abstract The Cottonwood Grove fault is located within a portion of the New Madrid seismic zone in northwestern Tennessee. Focal mechanism studies indicate that this area is a seismic transition zone. To the southwest is a southwest-northeast seismic trend in which movements along deeper seated faults is predominantly right-lateral strike-slip. To the north is a southeast-northwest seismic trend in which reverse and normal faulting predominate. The Cottonwood Grove fault is buried beneath the poorly consolidated sediments of the Mississippi embayment. The fault, as identified by an earlier Vibroseis ®* survey is a northeast-southwest trending, eastward-dipping reverse fault with approximately 75 m (245 ft) of displacement on the Paleozoc-Cretaceous boundary. A Mini-Sosie™† high-resolution seismic reflection survey was conducted through the village of Cottonwood Grove along the previously surveyed Vibroseis line to improve estimates of the age, geometry, and displacements of the Cottonwood Grove fault. Results of the Mini-Sosie survey reveal that displacements across the major fault are relatively consistent within Cretaceous, Paleocene, and middle Eocene sedimentary rocks. In upper Eocene and younger rocks, however, there is no evidence for faulting. Our interpretation includes a previously undetected secondary fault at the boundary between upper Cretaceous and Paleocene rocks. Also included in our interpretation of the subsurface profile through Cottonwood Grove is an Eocene age channel feature located 2 km east of the Cottonwood Grove fault. In addition, the Paleozoic-Cretaceous boundary is interpreted to be an erosional surface with no intrusives included in the Paleozoic rocks. Synthetic seismogram modeling, detailed gravity survey data, and theoretical gravity calculations support this interpretation, and indicate that shallow intrusive bodies within Paleozoic rocks are not needed to explain the observed data. Seismic reflections which would be expected if the intrusives were present are not observed, and the observed Bouguer gravity anomaly can be explained by use of irregularities on the erosional Paleozoic bedrock surface along with sedimentary features within the post-Paleozoic sediments. These data suggest that Cottonwood Grove fault formed during middle Eocene time and that since that time, any major movement on deeper faults has been predominantly strike-slip with little or no vertical reactivation. This interpretation is consistent with the prevailing hypotheses relating current seismicity of the New Madrid seismic zone to the contemporary regional compressive stress field acting on zones of weakness associated with the Precambrian Reelfoot Rift Complex. ®* Registered trademark of Conoco, Inc. ™† Registered trademark of Société Nationale Elf Aquitane (Production).
17
Fischer, Alfred G., and Douglas H. Erwin. "The Great Paleozoic Crisis." PALAIOS 8, no. 5 (October 1993): 507. http://dx.doi.org/10.2307/3515024.
Full text
18
Crowley, Thomas J., and Steven K. Baum. "Modeling late Paleozoic glaciation." Geology 20, no. 6 (1992): 507. http://dx.doi.org/10.1130/0091-7613(1992)020<0507:mlpg>2.3.co;2.
Full text
19
Noble, Paula, and Jonathan Aitchison. "Early Paleozoic radiolarian biozonation." Geology 28, no. 4 (April 2000): 367–70. http://dx.doi.org/10.1130/0091-7613(2000)028<0367:eprb>2.3.co;2.
Full text
20
Noble, Paula, and Jonathan Aitchison. "Early Paleozoic radiolarian biozonation." Geology 28, no. 4 (2000): 367. http://dx.doi.org/10.1130/0091-7613(2000)28<367:eprb>2.0.co;2.
Full text
21
Ariunchimeg, Ya. "Paleozoic bryozoans of Mongolia." Paleontological Journal 50, no. 12 (December 2016): 1348–62. http://dx.doi.org/10.1134/s0031030116120030.
Full text
22
Boucot, A. J. "Paleozoic paleogeography and biogeography." Spanish Journal of Palaeontology 8, no. 3 (August 11, 2022): 15. http://dx.doi.org/10.7203/sjp.24652.
Full text
23
LANDMAN, NEIL H., KAZUSHIGE TANABE, ROYAL H. MAPES, SUSAN M. KLOFAK, and JANE WHITEHILL. "Pseudosutures in Paleozoic ammonoids." Lethaia 26, no. 1 (March 1993): 99–100. http://dx.doi.org/10.1111/j.1502-3931.1993.tb01516.x.
Full text
24
Campbell, K. S. W., and R. E. Barwick. "Paleozoic lungfishes?a review." Journal of Morphology 190, S1 (1986): 93–131. http://dx.doi.org/10.1002/jmor.1051900409.
Full text
25
Foote, Mike. "Morphological diversity in the evolutionary radiation of Paleozoic and post-Paleozoic crinoids." Paleobiology 25, sp1 (March 1999): 1–116. http://dx.doi.org/10.1666/0094-8373(1999)25[1:mditer]2.0.co;2.
Full text
26
Smith, Moira T., and George E. Gehrels. "Detrital zircon geochronology of Upper Proterozoic to lower Paleozoic continental margin strata of the Kootenay Arc: implications for the early Paleozoic tectonic development of the eastern Canadian Cordillera." Canadian Journal of Earth Sciences 28, no. 8 (August 1, 1991): 1271–84. http://dx.doi.org/10.1139/e91-113.
Full textAbstract:
The Kootenay Arc in northeastern Washington and southeastern British Columbia contains the transition between autochthonous Upper Proterozoic to lower Paleozoic miogeoclinal strata and outboard Paleozoic to Mesozoic eugeoclinal terranes of uncertain paleogeographic affinity. To better understand the nature of this transition, U–Pb detrital zircon geochronologic studies were carried out on Upper Proterozic and lower Paleozoic sedimentary units in the Kootenay Arc, including miogeoclinal strata of the Horsethief Creek and Hamill groups and eugeoclinal strata of the Broadview and Ajax formations (Lardeau Group) and Daisy Formation (Covada Group). The results indicate that all units sampled are derived from source terranes of ~1.7 to 2.7 Ga, with notable populations of 1.76–1.85, 1.9–2.1, and 2.5–2.7 Ga zircons. These results are consistent with derivation of both the miogeoclinal and lower Paleozoic eugeoclinal units from adjacent portions of the southern Alberta craton. This extends the western limit of supracrustal rocks of known North American affinity, formed approximately in situ in the southern Canadian Cordillera, to outboard of the lower Paleozoic eugeoclinal strata in the Kootenay Arc.
27
Holterhoff, Peter F. "Paleocommunity and evolutionary ecology of Paleozoic crinoids." Paleontological Society Papers 3 (October 1997): 69–106. http://dx.doi.org/10.1017/s1089332600000218.
Full textAbstract:
Crinoids were a common component of Paleozoic benthic paleocommunities, yet they have been under-utilized in paleoecological analyses. Recent efforts to incorporate disarticulated ossicles into these analyses have greatly increased the robustness of paleoecological patterns noted for the Crinoidea. Analyses of crinoid functional morphology, particularly filtration dynamics, have provided testable hypotheses concerning the distribution of crinoids among benthic environments. These models predict that crinoids with dense-mesh filtration fans should be most common in high energy, shoreward paleoenvironments, whereas open-fan crinoids should be most common in low-energy, offshore paleoenvironments. Review of the Paleozoic fossil record appears to support these general predictions—from the Late Ordovician to the end of the Paleozoic, dense-fan crinoids are most abundant in nearshore paleoenvironments, whereas open-fan crinoids are most abundant offshore.The partitioning of crinoid diversity through the Paleozoic shifted through time. Beta diversity was highest in the Ordovician, implying that the early diversification of crinoids was focused on partitioning the benthic landscape among taxa. Beta diversity was quite low by the late Paleozoic, however, local and within-habitat alpha diversity was much greater than during the Ordovician. This resulted in generally higher levels of eurytopy in the late Paleozoic compared to the Ordovician. Patterns of faunal disassembly associated with regional extinctions in North America during the Ordovician and Permian underscore the differences in the paleoecology of these crinoid faunas.
28
Zinchuk, N. N. "ABOUT LITHOMINERALOGICAL COMPOSITION OF ANCIENT SEDIMENTARY DIAMONDIFEROUS ROCKS." Proceedings of higher educational establishments. Geology and Exploration, no. 3 (June 25, 2018): 15–23. http://dx.doi.org/10.32454/0016-7762-2018-3-15-23.
Full textAbstract:
Litho-mineralogical and structural-formation generation features of Upper Devonian-Carboniferous crusts of weathering on terrigenous-carbonate rocks, kimberlites and deposits enriched by products of their redeposition, have been studied, that allowed restoring of the specific features of upper Paleozoic productive horizons generation of the main diamondiferous regions of the Siberian platform, and then, the areas, favorable for generation and preservation of kimberlite (including diamondiferous) material dispersion haloes, have been distinguished within them. Analysis of Upper Paleozoic deposits facies, as well as specific features of their location, has allowed to establish that denudation of the rocks of the region was insignificant since the moment of their crust formation and up to completion of upper Paleozoic sedimentation, and occurred only along the stream flows. The omnipresent availability of crusts of weathering on terrigenous-carbonate rocks of lower Paleozoic, preserved from washout by upper Paleozoic deposits, points on it. These formations are usually elongated in the form of narrow streams and represent fragments of most initial erosion of the crusts of weathering in post-Carboniferous time. That is why, at such minimal shear, practically all kimberlite minerals, occurring in Upper Paleozoic deposits, are redeposited from more ancient pre-Lapchanian formations. The necessity of differentiated approach to studying formation conditions of various facies of diamondiferous upper Paleozoic deposits of continental and coastal genesis has been substantiated, and firstly — studying of their specific features. The complex research is required, with application of structural-tectonic, lithological-facial and formation-cyclic analyses, which would allow allocating specific areas favorable for generation of ancient placers of diamonds or discovering kimberlite pipes.
29
Aqrawi, Adnan A. M. "Paleozoic Stratigraphy and Petroleum Systems of the Western and Southwestern Deserts of Iraq." GeoArabia 3, no. 2 (April 1, 1998): 229–48. http://dx.doi.org/10.2113/geoarabia0302229.
Full textAbstract:
ABSTRACT A stratigraphic scheme for the Paleozoic of the Southwestern Desert of Iraq is proposed based upon the review of recently published data from several deep wells in the western part of the country and from outcrops in other regions in Iraq. The main formations are described in terms of facies distribution, probable age, regional thickness, and correlations with the well-reported Paleozoic successions of the adjacent countries (e.g. Jordan and Saudi Arabia), as well as with the Thrust Zone of North Iraq. The Paleozoic depositional and tectonic evolution of the Western and Southwestern Deserts of Iraq, particularly during Cambrian, Ordovician and Silurian, shows marked similarity to those of eastern Jordan and northern Saudi Arabia. However, local lithological variations, which are due to Late Paleozoic Hercynian tectonics, characterize the Upper Paleozoic sequences. The Lower Silurian marine “hot” shale, 65 meters thick in the Akkas-1 well in the Western Desert, is believed to be the main Paleozoic source rock in the Western and Southwestern Deserts. Additional potential source rocks in this region could be the black shales of the Ordovician Khabour Formation, the Upper Devonian to Lower Carboniferous Ora Shale Formation, and the lower shaly beds of the Upper Permian Chia Zairi Formation. The main target reservoirs are of Ordovician, Silurian, Carboniferous and Permian ages. Similar reservoirs have recently been reported for the Western Desert of Iraq, eastern Jordan and northern Saudi Arabia. In addition, two main regional seals (Lower Silurian shales and Permian evaporites) of northeastern Arabia extend over most of the Southwestern Desert, together with several other local seals. These considerations render the unexplored Paleozoic Southwestern Desert of Iraq prospective.
30
Stanley, Steven M. "Memoir 4: An Analysis of the History of Marine Animal Diversity." Paleobiology 33, S4 (2007): 1–55. http://dx.doi.org/10.1017/s0094837300019217.
Full textAbstract:
According to when they attained high diversity, major taxa of marine animals have been clustered into three groups, the Cambrian, Paleozoic, and Modern Faunas. Because the Cambrian Fauna was a relatively minor component of the total fauna after mid-Ordovician time, the Phanerozoic history of marine animal diversity is largely a matter of the fates of the Paleozoic and Modern Faunas. The fact that most late Cenozoic genera belong to taxa that have been radiating for tens of millions of years indicates that the post-Paleozoic increase in diversity indicated by fossil data is real, rather than an artifact of improvement of the fossil record toward the present.Assuming that ecological crowding produced the so-called Paleozoic plateau for family diversity, various workers have used the logistic equation of ecology to model marine animal diversification as damped exponential increase. Several lines of evidence indicate that this procedure is inappropriate. A plot of the diversity of marine animal genera through time provides better resolution than the plot for families and has a more jagged appearance. Generic diversity generally increased rapidly during the Paleozoic, except when set back by pulses of mass extinction. In fact, an analysis of the history of the Paleozoic Fauna during the Paleozoic Era reveals no general correlation between rate of increase for this fauna and total marine animal diversity. Furthermore, realistically scaled logistic simulations do not mimic the empirical pattern. In addition, it is difficult to imagine how some fixed limit for diversity could have persisted throughout the Paleozoic Era, when the ecological structure of the marine ecosystem was constantly changing. More fundamentally, the basic idea that competition can set a limit for marine animal diversity is incompatible with basic tenets of marine ecology: predation, disturbance, and vagaries of recruitment determine local population sizes for most marine species. Sparseness of predators probably played a larger role than weak competition in elevating rates of diversification during the initial (Ordovician) radiation of marine animals and during recoveries from mass extinctions. A plot of diversification against total diversity for these intervals yields a band of points above the one representing background intervals, and yet this band also displays no significant trend (if the two earliest intervals of the initial Ordovician are excluded as times of exceptional evolutionary innovation). Thus, a distinctive structure characterized the marine ecosystem during intervals of evolutionary radiation—one in which rates of diversification were exceptionally high and yet increases in diversity did not depress rates of diversification.Particular marine taxa exhibit background rates of origination and extinction that rank similarly when compared with those of other taxa. Rates are correlated in this way because certain heritable traits influence probability of speciation and probability of extinction in similar ways. Background rates of origination and extinction were depressed during the late Paleozoic ice age for all major marine invertebrate taxa, but remained correlated. Also, taxa with relatively high background rates of extinction experienced exceptionally heavy losses during biotic crises because background rates of extinction were intensified in a multiplicative manner; decimation of a large group of taxa of this kind in the two Permian mass extinctions established their collective identity as the Paleozoic Fauna.Characteristic rates of origination and extinction for major taxa persisted from Paleozoic into post-Paleozoic time. Because of the causal linkage between rates of origination and extinction, pulses of extinction tended to drag down overall rates of origination as well as overall rates of extinction by preferentially eliminating higher taxa having relatively high background rates of extinction. This extinction/origination ratchet depressed turnover rates for the residual Paleozoic Fauna during the Mesozoic Era. A decline of this fauna's extinction rate to approximately that of the Modern Fauna accounts for the nearly equal fractional losses experienced by the two faunas in the terminal Cretaceous mass extinction.Viewed arithmetically, the fossil record indicates slow diversification for the Modern Fauna during Paleozoic time, followed by much more rapid expansion during Mesozoic and Cenozoic time. When viewed more appropriately as depicting geometric—or exponential—increase, however, the empirical pattern exhibits no fundamental secular change: the background rate of increase for the Modern Fauna—the fauna that dominated post-Paleozoic marine diversity—simply persisted, reflecting the intrinsic origination and extinction rates of constituent taxa. Persistence of this overall background rate supports other evidence that the empirical record of diversification for marine animal life since Paleozoic time represents actual exponential increase. This enduring rate makes it unnecessary to invoke environmental change to explain the post-Paleozoic increase of marine diversity.Because of the resilience of intrinsic rates, an empirically based simulation that entails intervals of exponential increase for the Paleozoic and Modern Faunas, punctuated by mass extinctions, yields a pattern that is remarkably similar to the empirical pattern. It follows that marine animal genera and species will continue to diversify exponentially long into the future, barring disruption of the marine ecosystem by human-induced or natural environmental changes.
31
Bek, Jiří. "Paleozoic in situ spores and pollen. Lycopsida." Palaeontographica Abteilung B 296, no. 1-6 (December 11, 2017): 1–111. http://dx.doi.org/10.1127/palb/296/2017/1.
Full text
32
Begimbetov, Olzhas B., Abzal Zh Kenessary, Meyrimbek Koldey, Asylzhan B. Dauletov, Nurzhan S. Urekeshev, and Zhandos K. Sharipov. "Prospects for searching for hydrocarbon deposits in the Paleozoic complex of the South Torgai basin." Kazakhstan journal for oil & gas industry 4, no. 3 (October 15, 2022): 30–38. http://dx.doi.org/10.54859/kjogi108572.
Full textAbstract:
Intensive development of discovered oil and gas fields since the early 90s.of the last century, mainly associated with structural traps in Jurassic-Cretaceous complex, to date has led to a reduction in proven hydrocarbon reserves in the South Torgai sedimentary basin. The prospective potential for an increase in the resource base of the studied region can be focused within the deposits of pre-Mesozoic complex.
Historically it was believed that the South Torgai sedimentary basin has a two-deck structure: a sedimentary cover of the Mesozoic-Cenozoic age and an underlying crystalline-folded basement of the Paleozoic-Proterozoic complex. The oil and gas potential of the Paleozoic complex in the region has been proven by obtaining direct signs of oil and gas in the core, oil and gas shows, up to industrial oil flows on a limited number of areas within the weathering crust zones.
Analytical studies of recent years indicate a significant heterogeneity of the Paleozoic-Proterozoic complex, where promising structures of the Upper Paleozoic quasi-platform complex, represented by carbonate rocks, may be present. This article is focused on the analysis of a new and previously unexplored potential oil and gas complex of deeper-lying Paleozoic sediments that are of interest for setting up geological exploration.
Due to the confidentiality policy, the names of wells, fields, coordinates and other detailed information are hidden. The article was formed to demonstrate the concept of the prospects of the heterogeneous Paleozoic-Proterozoic complex.
33
Sivtsev, A. I., D. M. Petrov, and Z. E. Ivanova. "Prospects of Oil and Gas Potential of the Middle Paleozonic Deposits of Eastern Yakutia from Historical Viewpoint of Geological Development." IOP Conference Series: Earth and Environmental Science 988, no. 4 (February 1, 2022): 042031. http://dx.doi.org/10.1088/1755-1315/988/4/042031.
Full textAbstract:
Abstract The article considers the prospects of oil and gas potential of the Middle Paleozoic deposits of Eastern Yakutia. Based on the study of the peculiarities of bitumen content intervals of the Silurian-Devonian deposits of Selennyakhsky block, it was concluded about high oil and gas potential of the domanicoid Middle Paleozoic deposits of the Omulevsky terrain. Under favorable structural and tectonic conditions and immersion to shallow depths, Middle Paleozoic deposits can contain oil and gas deposits to clarify the most promising subsoil areas, the author’s version of the geological development history of Eastern Yakutia is proposed. The diagrams of the completenses of the main sedimentary complexes are compiled: Middle Devonian-Lower Carboniferous, Upper Paleozoic-Lower Mesozoic, Upper Jurassic-Lower Cretaceous and Upper Cretaceous-Cenozoic. Based on the constructed diagrams of the thicknesses of sedimentary complexes and the shown horizontal displacements, the Tastakhsky depression is identified as the most promising territory. It is assumed that there is a section of the Middle Paleozoic rift basin, slightly affected by the collision. Additionally, the prospects of oil and gas potential of the Upper Jurassic-Lower Cretaceous complex of deposits are substantiated and presented.
34
Sepkoski, J. John. "Crustacean biodiversity through the marine fossil record." Contributions to Zoology 69, no. 4 (2000): 213–22. http://dx.doi.org/10.1163/18759866-06904001.
Full textAbstract:
Approximately 2,600 genera of marine crustaceans have been recognized in the fossil record, and crustaceans constitute the major component of marine arthropod diversity from the mid- Paleozoic to the Recent. Despite problems of sporadic fossil preservation and/or taxonomic ambiguity, some general statements can be made about the history of crustacean biodiversity, based on global taxonomic data bases. Ostracodes were the first major group to radiate, attaining high diversity during the Ordovician Period with other members of the Paleozoic evolutionary fauna; rates of extinction and responses to mass extinctions were also similar to those of groups within the Paleozoic fauna. Malacostracans and barnacles (cirripedes), the two other crustacean groups with important fossil records, had minor diversity throughout the Paleozoic Era. Both groups experienced diversification from the mid-Mesozoic to Recent with lower extinction rates, as characteristic members of the Modern evolutionary fauna.
35
SEILACHER, ADOLF, and COPELAND MACCLINTOCK. "Crinoid Anchoring Strategies for Soft-Bottom Dwelling." PALAIOS 20, no. 3 (June 1, 2005): 224–40. http://dx.doi.org/10.2110/palo.2003.p03-70.
Full textAbstract:
Abstract During the geologic history of crinoids, many groups have modified their distal stems to function as anchors in soft sediments, but more so in the Paleozoic than in later times. Major strategies were passively implanting anchors, cirral root systems, coils, and stemless reclining. In Paleozoic roots, the stereom usually consists of crystallographically individualized ossicles, but articulations may be hidden by a tough cuticle that protected the living tissue of immersed parts and stiffened them with cortical stereom. Post-Paleozoic representatives produced similar anchoring structures by different fabricational pathways, including non-articulated root systems.
36
Blake, Daniel B., and Dan R. Elliott. "Ossicular homologies, systematics, and phylogenetic implications of certain North American Carboniferous asteroids (Echinodermata)." Journal of Paleontology 77, no. 3 (May 2003): 476–89. http://dx.doi.org/10.1017/s002233600004419x.
Full textAbstract:
Emphereaster missouriensis new genus and species, Ambigaster, new genus, and Delicaster, new genus are assigned to the Carboniferous asteroid family Neopalaeasteridae Schuchert. The neopalaeasterids are similar to but separable from the Carboniferous Monasteridae, Calliasterellidae, and Fandasteridae, n. fam., in ambulacral and other characters. The several families indicate that late Paleozoic asteroids were diverse although poorly documented.Similarities between late Paleozoic stem-group and post-Paleozoic crown-group asteroids allow argumentation on ossicular homologies. In species with only a single row of arm marginals, an earlier suggestion that certain disk ossicles are superomarginals is rejected. Enlarged proximal adambulacrals fill space on the actinal surface whereas actinal ossicles, generally lacking in Paleozoic asteroids, provide the space-filling service in crown-group asteroids.The body wall beyond the ambulacral column and accessory ossicles traditionally have been stressed in the classification of asteroids of all ages. Because of body wall homoplasies, many older taxonomic concepts do not identify monophyletic late Paleozoic clades, nor do they indicate the derivation of the crown group. Ambulacral characters in contrast are conservative through long periods of geologic time, improving phylogenetic resolution as more taxonomic data become available. Now-available ambulacral skeletal data for certain Carboniferous genera suggest membership in lineages basal to the post-Paleozoic crown group.Emphereaster missouriensis and most neopalaeasterids are stoutly constructed suggesting a defensive mechanism against durophagous chondrichthyan fish that co-occur with the holotype of Emphereaster. Abundant sponge spicules within the disk of the holotype suggest it fed on sponges, a prey type widely exploited by living asteroids.
37
Syverson, V. J., and Tomasz K. Baumiller. "Temporal trends of predation resistance in Paleozoic crinoid arm branching morphologies." Paleobiology 40, no. 3 (2014): 417–27. http://dx.doi.org/10.1666/13063.
Full textAbstract:
The rise of durophagous predators during the Paleozoic represents an ecological constraint imposed on sessile marine fauna. In crinoids, it has been suggested that increasing predation pressure drove the spread of adaptations against predation. Damage to a crinoid's arms from nonlethal predation varies as a function of arm branching pattern. Here, using a metric for resilience to predation (“expected arm loss,” EAL), we test the hypothesis that the increase in predation led to more predation-resistant arm branching patterns (lower EAL) among Paleozoic crinoids. EAL was computed for 230 genera of Paleozoic crinoids and analyzed with respect to taxonomy and time. The results show significant variability among taxa. Camerates, especially monobathrids, display a pattern of increasingly convergent and predation-resistant arm morphologies from the Ordovician through the Devonian, with no significant change during the Mississippian. In contrast, the mean EAL among cladids follows no overall trend through the Paleozoic. Regenerating arms are known to be significantly more common in camerates than in other Paleozoic taxa; if regeneration is taken as a proxy for nonlethal interactions with durophagous predators, this indicates that nonlethal predation occurred more often among camerates throughout the Early and Middle Paleozoic. In addition, frequency of injury among camerates is inversely correlated with EAL and positively correlated with infestation by parasitic snails. From this we conclude that decreasing EAL signals a selective pressure in favor of resistance to grazing predation in camerates but not in other subclasses before the Mississippian, with an apparent relaxation in this constraint after the late Devonian extinctions.
38
Isaev, Valery I., Margarita F. Galieva, Anna O. Aleeva, Galina A. Lobova, Vitaly I. Starostenko, and Alexander N. Fomin. "Paleotemperature modeling of hydrocarbon generation centers and their role in the formation of «Paleozoic» oil deposits (Ostaninskoe field, Tomsk region)." Georesursy 23, no. 1 (March 30, 2021): 2–16. http://dx.doi.org/10.18599/grs.2021.1.1.
Full textAbstract:
Study and exploration of the pre-Jurassic oil and gas complex in Western Siberia is one of the aspects of hydrocarbon raw-material base development. The main scope of this study is to locate the source of Paleozoic hydrocarbons. The problem of modeling and assessing the role of Paleozoic-Mesozoic hydrocarbon generation centers in the formation of «Paleozoic» oil deposits in the section of the Ostaninskoe oil and gas condensate field (Tomsk region) is solved. In the formation of the oil and gas content of the pre-Jurassic basement two reservoirs are involved: the weathering crust and the roof of the bed-rock Paleozoic. The first was formed during the period of 213–208 Ma, and the second is genetically determined by epigenetic processes in the weathering crust. Potential hydrocarbon sources for the weathering crust and bed-rock Paleozoic reservoirs are Domanic type rocks in the crystalline basement: Larinskaya S1lr, Mirnaya D1mr, Chuzikskaya D2cz, Chaginskaya D3cg Formations, as well as Tyumenskaya J1-2tm and Bazhenovskaya J3bg Formations in sedimentary cover. To perform joint paleotemperature modeling of sedimentary basins of the «modern» Jurassic-Cretaceous and Paleozoic «paleobasins», the Ostaninskaya 438P well was selected, which is due to the presence of measured temperatures both in the Jurassic sections and in the pre-Jurassic formations, as well as fluid inflows from the pre-Jurassic horizons into the well. At the first step, the solution of the inverse problem of geothermics was obtained using reservoir temperatures and vitrinite reflectance measurements from the Mesozoic deposits: density of deep heat flow from the base of sedimentary section was determined, which is characterized by a quasi-constant value from the Jurassic to the present. The second step was to solve the inverse problem using vitrinite reflectance measurements from Paleozoic sediments. As a result, the heat flow value was obtained for the key moments of geodynamic history of the stratigraphic section, starting from the Silurian. By solving direct problems of geothermics with the given values of heat flow, the structural-tectonic and thermal history of four Paleozoic potential oil source formations (as well as Jurassic – Bazhenov and Tyumen Formations) has been retraced. The controversial aspects of the heat transfer model in the section of the Ostaninskoe field are considered. It has been established that the Tyumen and Bazhenov oil sources (most likely Bazhenov) are syngenetic (in terms of generation, accumulation and preservation time) for the weathering crust and the Paleozoic reservoirs. The role of the Chaginskaya Formation as gas source is insignificant.
39
Kammer, Thomas W., and William I. Ausich. "Demise of the middle Paleozoic crinoid fauna: gradual or mass extinction?" Paleontological Society Special Publications 6 (1992): 156. http://dx.doi.org/10.1017/s2475262200007164.
Full textAbstract:
There are essentially three major crinoid faunas of the Paleozoic: 1) the lower Paleozoic (Ordovician) fauna dominated by disparids and diplobathrid camerates; 2) the middle Paleozoic (Silurian-middle Mississippian) fauna dominated by monobathrid camerates, cladids, and flexibles; and 3) the upper Paleozoic (middle Mississippian-Permian) fauna dominated by cladids. Change from the middle Paleozoic fauna to the late Paleozoic fauna, at or near the Osagean-Meramecian boundary, was characterized by Laudon (1948) as “one of the most remarkable faunal breaks in the entire Paleozoic era”. The monobathrids that had reached their zenith in the Osagean (Tournaisian-Visean) became a very minor component of late Paleozoic faunas. Conventional thinking has implied that a mass extinction of crinoids occurred at the Osagean-Meramecian boundary.We have biostratigraphically subdivided the late Osagean and early Meramecian into four zones (times A-D, oldest to youngest, all within the Gnathodustexanus zone) in order to study the origination and extinction of all crinoid species during the changeover from the middle to upper Paleozoic faunas. Rather than a mass extinction, a monotonic turnover of species fits a pattern of gradual extinction as extinctions outpaced originations. Data are based on 216 species (taxonomically updated) from 69 localities and are as follows:The pattern of originations and extinctions for monobathrids is very similar to the pattern for all crinoid species.The above data have maximum diversity during Time B of the late Osagean followed by declining diversity in times C and D into the early Meramecian. Late Meramecian crinoid faunas (after time D) were less diverse with a maximum of about 45 species. The gradual decline of crinoids across the Osagean-Meramecian boundary cannot be explained as sampling bias (Signor-Lipps effect), because ranges of crinoids thought to be extinct at the boundary are extended into the early Meramecian as well as disappearing at various tinles prior to the boundary.The decline in diversity and the monotonic turnover of species are hypothesized to be the result of habitat reduction as the Eastern Interior Basin of North America was gradually infilled with clastic sediments at the end of the Acadian Orogeny. Most notable in this regard was the smothering of the Keokuk Limestone carbonate bank. Changes in sea level also contributed to habitat reduction. Lowering of sea level at the end of the Osagean caused restriction of open marine environments. A transgression in the early Meramecian was followed by shoaling and restriction during deposition of the late Meramecian Salem and St. Louis limestones.
40
Lemieux, Y., R. I. Thompson, P. Erdmer, A. Simonetti, and R. A. Creaser. "Detrital zircon geochronology and provenance of Late Proterozoic and mid-Paleozoic successions outboard of the miogeocline, southeastern Canadian Cordillera." Canadian Journal of Earth Sciences 44, no. 12 (December 1, 2007): 1675–93. http://dx.doi.org/10.1139/e07-048.
Full textAbstract:
The Kootenay Arc has been interpreted as the western limit of autochthonous continental margin strata, west of which occur Paleozoic to Mesozoic rocks of uncertain paleogeographic origin. Recent mapping has demonstrated stratigraphic linkage between the Kootenay Arc strata and rocks farther west. A U–Pb study of detrital zircons using laser ablation – multicollector – inductively coupled plasma – mass spectrometry (LA–MC–ICP–MS) was undertaken in the upper succession of the Monashee complex mantling gneiss and in mid-Paleozoic strata of the Chase Formation exposed in the northern Kootenay Arc area and adjacent outboard strata. The predominance of >1.75 Ga zircon matches well with basement domains of the western buried North American craton and indicates that most of the grains were derived from a source of North American affinity. Zircon between 1.00 and 1.30 Ga demonstrates a Neoproterozoic source of possible “Grenville” affinity. Additional populations in the Chase Formation are mid-Paleozoic, Ediacaran, 800–1000 Ma, and 1400–1750 Ma. We interpret them to have been derived from exposed sources of Proterozoic continental crust and (or) proximal late Neoproterozoic and middle Paleozoic magmatic sources. The investigated Proterozoic and Paleozoic successions confirm sedimentologic and depositional relationships with the ancestral North American margin, and as such are interpreted to represent outboard extensions of the Cordilleran miogeoclinal succession.
41
Wilson, Mark A., and Timothy J. Palmer. "The earliest Gastrochaenolites (Early Pennsylvanian, Arkansas, USA): An upper Paleozoic bivalve boring?" Journal of Paleontology 72, no. 4 (July 1998): 769–72. http://dx.doi.org/10.1017/s0022336000040464.
Full textAbstract:
Borings of the ichnogenus Gastrochaenolites have been found in limestone cobbles of the Morrowan (Early Pennsylvanian) Cane Hill Member of the Hale Formation in northwestern Arkansas. They were likely excavated by lithophagid bivalves, thus extending the earliest record of obligate bivalve boring back from the Triassic into the upper Paleozoic. These borings are herein referred to as G. anauchen n. ichnosp. Lithophagid borings may be rare in the upper Paleozoic because of the absence or scarcity of suitable substrates, such as scleractinian corals or carbonate hardgrounds. Additional upper Paleozoic bivalve borings will likely be discovered in other carbonate-rich rocky shore deposits.
42
Korobkin, V. V., A. Ye Chaklikov, and Zh S. Tulemissova. "Tectonic zoning of paleozoids of Kazakhstan and its oil and gas-bearing regions." Kazakhstan journal for oil & gas industry 4, no. 1 (May 16, 2022): 39–49. http://dx.doi.org/10.54859/kjogi107854.
Full textAbstract:
The article deals with the issues of tectonic zoning of the Paleozoic and Mesozoic-Cenozoic structures of Kazakhstan. The principles of tectonic zoning are outlined, on the basis of which the zoning and indexation of tectonic units of the territory of Kazakhstan was carried out. For this, various data of complex geological and geophysical analysis of Paleozoids were used, including tectonic, structural, stratigraphic, lithological-paleogeographic, petrographic, geodynamic and other studies.
A geological and tectonic scheme (model) is proposed that reflects the main tectonic units that make up the structural framework of the Paleozoids of Kazakhstan, consisting of a crystalline basement on which the formation of sedimentary oil and gas basins took place. The main tectonic units of the earth's crust of the territory under consideration are identified and characterized, and the mosaic-block structure of the complexes is shown. The characteristic of the complex multi-stage evolution of the paleozoids of Kazakhstan and its oil and gas regions is given.
43
Erwin, Douglas H. "Carboniferous-Triassic gastropod diversity patterns and the Permo-Triassic mass extinction." Paleobiology 16, no. 2 (1990): 187–203. http://dx.doi.org/10.1017/s0094837300009878.
Full textAbstract:
Paleozoic and post-Paleozoic marine faunas are strikingly different in composition. Paleozoic marine gastropods may be divided into archaic and modern groups based on taxonomic composition, ecological role, and morphology. Paleozoic assemblages were dominated by pleurotomariids (Eotomariidae and Phymatopleuridae), the Pseudozygopleuridae, and, to a lesser extent, the Euomphalidae, while Triassic assemblages were dominated by the Trochiina, Amberleyacea, and new groups of Loxonematoidea and Pleurotomariina. Several new groups of caenogastropods appeared as well. Yet the importance of the end-Permian mass extinction in generating these changes has been questioned. As part of a study of the diversity history of upper Paleozoic and Triassic gastropods, to test the extent to which taxonomic and morphologic trends established in the late Paleozoic are continued after the extinction, and to determine the patterns of selectivity operating during the extinction, I assembled generic and morphologic diversity data for 396 genera in 75 families from the Famennian through the Norian stages. Within this interval, gastropod genera underwent an adaptive radiation during the Visean and Namurian, largely of pleurotomariids, a subsequent period of dynamic stability through the Leonardian, a broad-based decline during the end-Permian mass extinction, and a two-phase post-extinction rebound during the Triassic. The patterns of generic diversity within superfamily-level clades were analyzed using Q-mode factor analysis and detrended correspondence analysis.The results demonstrate that taxonomic affinity, previous clade history, generic age, and gross morphology did not determine survival probability of genera during the end-Permian extinction, with the exception of the bellerophontids, nor did increasing diversity within clades or expansion of particular morphologies prior to the extinction facilitate survival during the extinction or success after it. The pleurotomariids diversified during the Lower Permian, but were heavily hit by the extinction. Similarly, trochiform and turriculate morphologies, among those which Vermeij (1987) has identified as having increased predation resistance, were expanding in the late Paleozoic, but suffered similar extinction rates to other nondiversifying clades. Survival was a consequence of broad geographic and environmental distribution, as was the case during background periods.
44
Buitrón-Sánchez, Blanca Estela, Francisco Javier Cuen-Romero, Rogelio Monreal, and Iván Manuel Cuadros-Mendoza. "Diversity of Crinozoa (Echinodermata: Eocrinoidea, Blastoidea, Crinoidea) from the Paleozoic of MexicoDiversity of Crinozoa (Echinodermata: Eocrinoidea, Blastoidea, Crinoidea) from the Paleozoic of Mexico." Revista Mexicana de Ciencias Geológicas 39, no. 1 (March 30, 2022): 43–53. http://dx.doi.org/10.22201/cgeo.20072902e.2022.1.1665.
Full textAbstract:
Paleozoic outcrops in Mexico containing echinoderms are located to the north, center and south of the country, mainly in the states of Baja California, Sonora, Chihuahua, Tamaulipas, Coahuila, Hidalgo, Puebla, Guerrero, Oaxaca, and Chiapas. These rocks correspond to marine carbonates deposited in warm shallow environments, with an approximate age of 541 to 251 Ma. Also containing a varied and diverse biota made up of phylloid algae, foraminifera (fusulinids), coralline sponges, corals, bryozoans, brachiopods, mollusks, trilobites and echinoderms. In order to know the diversity of Crinozoa from the Paleozoic of Mexico, an analysis of the species documented for the country was carried out, with the objective of contributing to the knowledge of the biostratigraphy and paleogeography of Mexico. The methodology consisted of a detailed analysis of bibliographic sources with information on echinoderms from the Paleozoic of Mexico. Cambrian eocrinoids (Gogia, and Ubaghsicystis) are distributed mainly in Sonora. Crinoid plates from the Carboniferous and Permian, particularly morphospecies of the genera Cyclocaudex, Cyclocrista, Heterostelechus, Lamprosterigma, Mooreanteris, Pentagonopternix, Preptopremnum, and Pentaridica, are widely distributed throughout the country. Analysis of the Mississippian-Permian biota indicates that the cosmopolitan distribution of the fauna studied in this work is due to the connections between the seas of western North America and eastern Asia. The Late Permian benthic fauna of Sonora was widely dispersed in the Tethyan realm, which stretched from western North America to North Africa and Asia. The comprehensive study of Paleozoic marine stratigraphic successions and their biotic content provided information on faunal migrations regarding the Paleozoic carbonate facies. It also contributed to reconstructing the geographical, climatological, and ecological characteristics of the Paleozoic of Mexico.
45
Bandel, Klaus, and Luis Arturo Quinzio-Sinn. "Paleozoic trace fossil from the Cordillera Costal near Concepción, connected to a review of the Paleozoic history of central Chile." Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 211, no. 1-2 (January 29, 1999): 171–200. http://dx.doi.org/10.1127/njgpa/211/1999/171.
Full text
46
Shi, Yu, Xi Jun Liu, and Zuo Hai Feng. "Formation Age of the Qinling Complex and the early Paleozoic Tectonic Event." Advanced Materials Research 734-737 (August 2013): 60–70. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.60.
Full textAbstract:
The Qinling orogenic belt (QOB) located between the North China Craton (NCC) and the South China Craton (SCC) is composed of the Northern Qinling Belt (NQB) and the Southern Qinling Belt (SQB). This study presents new geochemical data, zircon U-Pb ages and Hf isotopes from two rocks from the Qinling complex in the NQB. LA-ICP-MS zircon U-Pb dating results suggest that the Qinling complex was formed in early Neoproterozoic and experienced the early Paleozoic metamorphism. HighεHf(t) values of 9.0-12.0 for the early Paleozoic zircons indicated that there is mantle-derived magma intruding into the Qinling complex in the early Paleozoic.
47
Reid, R. Pamela. "Discovery of Triassic phylloid algae: possible links with the Paleozoic." Canadian Journal of Earth Sciences 23, no. 12 (December 1, 1986): 2068–71. http://dx.doi.org/10.1139/e86-191.
Full textAbstract:
Triassic phylloid algae have recently been discovered in a reef in the southern Yukon. These plate-like algae are the primary frame builders in a few small patches in the upper section of the reef, where they are associated with fossils and sedimentary structures suggesting deposition in very shallow water. A vague, porous microstructure in some of the algae suggests affinities with Paleozoic codiacean phylloid algae, but preservation is too poor to permit definite classification. Nevertheless, the indication that phylloid algae did not become extinct at the end of the Paleozoic, as formerly supposed, increases the possibility of finding missing evolutionary links between Paleozoic phylloid algae and their modern counterparts.
48
Han, Wenxue, Shizhen Tao, Guoyi Hu, Weijiao Ma, Dan Liu, Ziqi Feng, and Weilong Peng. "Light hydrocarbon geochemical characteristics and their application in Upper Paleozoic, Shenmu gas field, Ordos Basin." Energy Exploration & Exploitation 35, no. 1 (November 26, 2016): 103–21. http://dx.doi.org/10.1177/0144598716679962.
Full textAbstract:
Light hydrocarbon has abundant geochemical information, but there are few studies on it in Shenmu gas field. Taking Upper Paleozoic in Shenmu gas field as an example, authors use gas chromatography technology to study light hydrocarbon systematically. The results show that (1) The Shenmu gas field is mainly coal-derived gas, which is mixed by partial oil-derived gas due to the experiment data. (2) Based on K1, K2 parameter and Halpern star chart, the Upper Paleozoic gas in Shenmu gas field belongs to the same petroleum system and the depositional environment of natural gas source rocks should be homologous. (3) The source rocks are mainly from terrestrial higher plant origins and belong to swamp facies humic due to methyl cyclohexane index and Mango parameter intersection chart, which excluded the possibility of the Upper Paleozoic limestone as source rocks. (4) The isoheptane ranges from 1.45 to 2.69 with an average of 2.32, and n-heptane ranges from 9.48 to 17.68% with an average of 11.71%, which is below 20%. The maturity of Upper Paleozoic gas in Shenmu gas field is low-normal stage, which is consistent with Ro data. (5) The Upper Paleozoic natural gas in the Shenmu gas field did not experience prolonged migration or secondary changes, thus can be analyzed by light hydrocarbon index precisely.
49
Brand, Uwe, Alyssa M. Davis, Kristen K. Shaver, Nigel J. F. Blamey, Matt Heizler, and Christophe Lécuyer. "Atmospheric oxygen of the Paleozoic." Earth-Science Reviews 216 (May 2021): 103560. http://dx.doi.org/10.1016/j.earscirev.2021.103560.
Full text
50
Nemyrovska, Tamara I. "PALEOZOIC CONODONT STUDIES IN UKRAINE." Collection of Scientific Works of the Institute of Geological Sciences of the NAS of Ukraine 10 (December 15, 2017): 124–36. http://dx.doi.org/10.30836/igs.2522-9753.2017.142182.
Full text