Journal articles on the topic 'Fossil section'
To see the other types of publications on this topic, follow the link: Fossil section.
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 'Fossil section.'
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
Bogucki, Andriy, and Petro Voloshyn. "Engineering-geological characteristic of the rocks of the loess-soil series from the key section at Korshiv (Volhynian Upland)." Visnyk of the Lviv University. Series Geography, no. 42 (October 15, 2013): 11–21. http://dx.doi.org/10.30970/vgg.2013.42.1757.
Full textAbstract:
Korshiv key section is one of the best studied and most complete sections of periglacial loess-soil series of Volhyn-Podillia. There is total thickness of loess-soil series approximately is 30 meters in this section. This key section is stratotype of Korshiv fossil soil complex and Lutsk fossil soil. Pseudomorphs after the structures of cellular ice of several stages of Middle Pleistocene palaeocryogenesis were allocated here for the first time for Volhyn-Podillia. Detailed description of the section and the results of engineering-geological studies of rocks of all selected loess and palaeosoil horizons were done. Individual properties of selected stratigraphic horizons and their dependence on the paleogeographic conditions of sedimentation were displayed. Key words: loesses, fossil soils, palaeogeographical conditions, engineering-geological features, subsidence, Volhynian Upland.
2
Crimes, T. P., and Jiang Zhiwen. "Trace fossils from the Precambrian–Cambrian boundary candidate at Meishucun, Jinning, Yunnan, China." Geological Magazine 123, no. 6 (November 1986): 641–49. http://dx.doi.org/10.1017/s0016756800024158.
Full textAbstract:
AbstractThe Precambrian–Cambrian boundary candidate section at Meishucun, China, has yielded trace fossils which are abundant at some horizons. The earliest occur in Unit 3 of the Zhongyicun Member approximately 8 m above the lower selected stratotype reference point for the boundary and includeArenicolitessp.,Asteriacitessp.,Neonereites biserialis, N. uniserialisandSellaulichnus meishacunensis. The next trace-fossil-bearing horizon is in Unit 6 of the Zhongyicun Member whereCochlichnussp.,Monomorphichnussp.,Neonereites biserialisandN. uniserialisoccur. Immediately above, in Unit 7, areCruzianasp.,Didymaulichnus miettensis, Monomorphichnussp. andRusophycussp. In the Badaowan Member at the top of the section there areDidymaulichnussp. andTaphrhelminthopsis circularisin Unit 9,Arenicolitessp.,Diplocraterionsp.,Gordia molassica, Skolithossp. andT. circularisin Unit 11, andGordia meandria, ?Plagiogmussp.,Skolithossp. andT. circularisin Unit 12.Comparison of this trace-fossil distribution with that in key Precambrian–Cambrian boundary sections in other countries indicates that the ranges of a few trace fossils cross the boundary (e.g.Didymaulichnus, Neonereites, Planolites) but most appear only in the Cambrian. Different ichnogenera seem to appear at various levels above the boundary.ArenicolitesandAsteriacitesare among the first, whileTaphrhelminthopsis circularisis only encountered higher in all sequences. Some have only been recorded at much higher levels and relatively close to the first appearance of trilobites (e.g.Cruziana, Diplocraterion, Rusophycus). This suggests that the first appearance of specific trace fossils or groups of trace fossils may be valuable for locating the boundary in some sections and for correlating late Precambrian and early Cambrian strata.
3
Michalík, Jozef, and Vladimír Šimo. "A new spreite trace fossil from Lower Cretaceous limestone (Western Carpathians, Slovakia)." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 100, no. 04 (December 2009): 417–27. http://dx.doi.org/10.1017/s1755691009008068.
Full textAbstract:
ABSTRACTZavitokichnus fusiformisn. igen. et n. isp. occurs in Lower Cretaceous (Valanginian to Hauterivian) limestones of the Fatric Superunit in the Western Carpathians. Typical cross sections of this more or less spiral trace fossil are sometimes U–O–C–S-shaped. In cross-section the trace fossil passes from a simple linear form, and spreads to a wider rolled-up or rolled-out form and then it returns to a linear trace. Spreite-like lamellae are distinguishable on several cross-section examples. The trace fossil was produced by a deposit feeder and it might be classified as a fodinichnion.Z. fusiformisco-occurs with trace fossil associations ofZoophycos,Chondrites,Planolites,HormosiroideaandPalaeophycusin carbonate sediments of a deep-seated ramp along the margin of the Fatric intrashelf basin.
4
Bogucki, Andriy, and Petro Voloshyn. "Engineering-geological characteristic of the rocks of the loess-soil series from the key section Sharovechka (Podolian upland)." Visnyk of the Lviv University. Series Geography, no. 49 (December 30, 2015): 14–24. http://dx.doi.org/10.30970/vgg.2015.49.8510.
Full textAbstract:
Description and detailed engineering-geological characteristic of rocks of the loess-soil series of one of the most complete loess section of Podolian Upland were given. Sharovechka key section represents the main loess and palaeosol horizons of Lower, Middle and Upper Pleistocene. There is total thickness of loess-soil series approximately is 25 meters in this section. Horokhiv and Korshiv fossil soil complexes, Lutsk and Sokal fossil soils, and lower horizon of Lower Pleistocene loesses can be key horizons for all territory of Volhyn-Podillia. The monoliths were taken from all stratigraphic horizons of this section with the purpose of investigation of engineering-geological features including subsidence. The analysis of the distribution of composition and features indexes in loess and palaeosol succession demonstrates a significant difference between their certain horizons caused by peculiarities of paleogeographic conditions of their formation and diagenetic transformation. It was also deduced that the degree of contrast of parameters of composition and features of loess and palaeosol horizons in comparison with key loess sections of Volhynian Upland was much lower. Probably this was caused by the higher total content of clay in soils of certain stratigraphic horizons and by the direct overlay of different types of fossil soils at each other. Key words: loess, loess-soil series, key section, fossil soil, engineering-geological features.
5
Sullivan, Colleen A., and Sarah W. Keenan. "Experimental dissolution of fossil bone under variable pH conditions." PLOS ONE 17, no. 10 (October 13, 2022): e0274084. http://dx.doi.org/10.1371/journal.pone.0274084.
Full textAbstract:
Fossils exposed at the surface are an integral component of the paleontologic record and provide an archive of past life. However, it is widely known that fossils are not stable indefinitely upon exposure to surface conditions such as physical, chemical, and biological processes, and this last phase of taphonomy is poorly understood. Studies regarding the longevity of fossils subject to weathering, such as acidic precipitation, are absent in the literature. The goal of this study was to experimentally determine vertebrate fossil dissolution rates under variable pH conditions in a controlled laboratory setting. It was hypothesized that fossils would dissolve within acidic solutions and do so at an increasing rate when exposed to increasingly acidic solutions. The experiments were conducted on three fossil vertebrae in triplicate in closed reaction vessels at pH 4, 5, and 6. The fossils were completely submerged for 21 days in a tap water solution with the pH adjusted using 0.1N hydrochloric acid (HCl). Fossil dissolution was quantified by changes to: (1) fossil mass; (2) elemental chemistry of water and fossils with inductively coupled plasma mass spectrometry (ICP-MS); (3) fossil mineralogy with X-ray diffraction (XRD); and (4) histologic structures with thin section analyses. All fossils exhibited mass loss, which increased with decreasing pH conditions, and was greatest under pH 4 (477 to 803 mg loss). The elemental analyses with ICP-MS indicated an increase of both calcium (maximum increase of 315 ppm) and phosphorus (increase of 18 ppm) in aqueous solutions with increasing pH and a loss of those same elements from the fossils (maximum loss of 10 ppm Ca and 6 ppm P). XRD revealed loss of gypsum in all post-dissolution samples. Taken together, the results of ICP-MS and XRD suggest dissolution of the primary mineral phases, including hydroxylapatite, and secondary phases, particularly calcite and gypsum, resulting in an estimated mass loss at pH 4 of 23 to 28 mg per day. Thin section analysis showed degradation of both cortical and trabecular bone in all post-dissolution images, demonstrating physical changes to the fossils as a result of water-rock interactions. These findings constitute the first quantitative analysis of fossil dissolution rates and provide insights into this last stage of taphonomy, addressing a largely understudied potential bias in the vertebrate fossil record.
6
Hassani, Mohammad Javad. "Microbiostratigraphy, microfacies analysis and lateral basin evolution of Lower Cretaceous deposits in the south of Kerman region, SE Iran." Boletín de la Sociedad Geológica Mexicana 74, no. 2 (July 30, 2022): A240322. http://dx.doi.org/10.18268/bsgm2022v74n2a240322.
Full textAbstract:
Detailed microbiostratigraphy and basin evolution of the Lower Cretaceous deposits in the Rayen area, south of Kerman Region, SE Iran are investigated for the first time in two sections. The section no. 1 is 324.6m in thickness and comprises five lithostratigraphic units. The section no. 2 is 218 m in thickness and includes three lithostratigraphic units. The identified fauna and flora include 41 benthic foraminifera and 11 calcareous algae species. The identified assemblage indicates that the marine strata in both sections were deposited during the Barremian to Albian. The microfacies analyses carried out on 22 carbonate and 2 clastic microfacies indicate that the deposits in the section no. 1 were deposited on a homoclinal carbonate ramp, whereas in the section no. 2 they were deposited on a rimmed carbonate shelf. Generally, the Cretaceous deposit in the two studied sections represent different sedimentary models and fossil content indicating different basin evolution histories. The paleogeographic setting of the studied area on the south eastern margin of the Central-East Iranian Microcontinent and the active tectonic history during the Mesozoic suggest that the syndepositional tectonism influenced the basement’s morphology and resulted in changes in the fossil diversity and sedimentary nature of adjacent sedimentary basins.
7
Gladenkov, Andrey Yu. "Study of marine Paleogene diatom assemblages from the Kamchatka region: results of the last decade." Issues of modern algology (Вопросы современной альгологии), no. 1(28) (2022): 117–22. http://dx.doi.org/10.33624/2311-0147-2022-1(28)-117-122.
Full textAbstract:
Review of results obtained on fossil diatom assemblages studied from marine Paleogene sections in Kamchatka region in the last decade are presented. The first data for Kamchatka on direct correlation of Eocene diatom assemblages with complexes of calcareous plankton (the Il’pinskii Peninsula stratigraphic section, northeast Kamchatka), and on correlation of Oligocene diatom assemblages with the magnetostratigraphic scale (the Kvachina Bay section, west Kamchatka) are emphasized.
8
LI, DA, HONG-FEI LING, SHAO-YONG JIANG, JIA-YONG PAN, YONG-QUAN CHEN, YUAN-FENG CAI, and HONG-ZHEN FENG. "New carbon isotope stratigraphy of the Ediacaran–Cambrian boundary interval from SW China: implications for global correlation." Geological Magazine 146, no. 4 (March 26, 2009): 465–84. http://dx.doi.org/10.1017/s0016756809006268.
Full textAbstract:
AbstractThe Yangtze Platform preserves relatively thick carbonate successions and excellent fossil records across the Ediacaran–Cambrian boundary interval. The intensely studied Meishucun section in East Yunnan was one of the Global Stratotype Section candidates for the Precambrian–Cambrian boundary. However, depositional breaks were suspected in the section and the first appearance of small shelly fossils could not be verified. The Laolin section located in NE Yunnan is more continuous and shows great potential for global correlation of carbon isotope features across the Precambrian–Cambrian boundary. However, the stratigraphic framework and correlations were controversial. We studied and systematically sampled the Laolin section and present here new carbon isotope data for this section. The Laolin section consists of, in ascending order, the Baiyanshao dolostone of the Dengying Formation, the Daibu siliceous dolostone, Zhongyicun dolomitic phosphorite, lower Dahai dolostone and upper Dahai limestone of the Zhujiaqing Formation, and the black siltstone of the Shiyantou Formation. Our data reveal a large negative δ13C excursion (−7.2‰, L1′) in the Daibu Member, which matches the previously published data for the Laolin section, and a large positive excursion (+3.5‰, L4) in the Dahai Member, which was not shown in the published data. The excursion L1′ correlates well with the similarly large negative excursion near the first appearance of small shelly fossils in Siberia and Mongolia. Similar magnitude excursions are also known from Morocco and Oman, for which there are no robust fossil constraints but from where volcanic ash beds have been dated precisely at 542 Ma, thus confirming a global biogeochemical event near the Ediacaran–Cambrian boundary. Our data also indicate that deposition was more continuous at the Laolin section compared with the Meishucun section, where there are no records of a comparable negative excursion near the Ediacaran–Cambrian boundary, nor any comparable positive excursion in the Dahai Member. Therefore, the Laolin section has proven potential to be a supplementary Global Stratotype Section for the Ediacaran–Cambrian boundary on the Yangtze Platform.
9
O'NEIL, GRETCHEN R., LYDIA S. TACKETT, and MICHAEL B. MEYER. "THE ROLE OF SURFICIAL BIOTURBATION IN THE LATEST EDIACARAN: A QUANTITATIVE ANALYSIS OF TRACE FOSSIL INTENSITY IN THE TERMINAL EDIACARAN–LOWER CAMBRIAN OF CALIFORNIA." PALAIOS 37, no. 12 (December 29, 2022): 703–17. http://dx.doi.org/10.2110/palo.2021.050.
Full textAbstract:
ABSTRACT Bioturbating activities have played a vital role in shaping the marine ecosystem throughout metazoan history, influencing the abundance and preservation potential of body fossil-producing taxa and driving major environmental and geochemical changes. The earliest trace making behaviors arose during the late Ediacaran Period (∼ 560–541 Ma), disrupting the substrate previously occupied by dominantly sessile organisms. Simple dwelling and grazing behaviors exploited the organic-rich matgrounds, expanding into the underutilized microbial mat ecosystem. In the western United States, trace assemblages from Ediacaran–Cambrian boundary-spanning deposits document a thriving trace-maker ecosystem. One boundary-spanning deposit in this region, the lower member of the Wood Canyon Formation, crops out along the California-Nevada boundary and contains both trace and body fossil assemblages. The Chicago Pass section of the lower Wood Canyon Formation contains a suite of dominantly simple Ediacaran traces, which become commonplace in the upper part of the stratigraphic section, documenting the onset of prevalent trace-making behaviors in this region. While traces have been previously described from this locality, the addition of the complex trace Lamonte trevallis and quantification of trace fossil density of simple Ediacaran traces provides a more comprehensive ichnological view of the Chicago Pass section. Although Chicago Pass does not yield abundant tubicolous body fossils, as are found elsewhere in the region, the low diversity ichnoassemblages document both burgeoning surficial trace making groups and mat-targeted mining in the latest Ediacaran. The behaviors present at Chicago Pass are similar to those of the Dengying Formation in South China, and highlight the need for petrographic-based trace fossil studies. Additionally, studies of Nama Group trace fossils of the same age from Namibia report higher diversity and complexity in trace-making activities than what has been observed at Chicago Pass, but with similar, low Ediacara biota body fossil diversity. If Ediacara biota diversity is anticorrelated with trace-making behaviors, Chicago Pass represents a low-complexity end-member of the same phenomenon observed in Namibia. The effect of surface sediment disruption on the sessile Ediacaran communities may have been decoupled from complexity of the traces, more so influenced by the presence of general trace-making behaviors in aggregate, including simple traces.
10
Bogucki, Andriy, and Petro Voloshyn. "Engineering-geological characteristic of the rocks of the loess-soil series from the key section Boyanychi (Volhynian Upland)." Visnyk of the Lviv University. Series Geography, no. 47 (November 27, 2014): 18–29. http://dx.doi.org/10.30970/vgg.2014.47.813.
Full textAbstract:
Boyanychi key section is one of the most complete, most famous and best studied sections of periglacial loess-soil series of Volhyn-Podillia. An almost complete history of the formation of rocks for the last 600 000 years is represented here. There is total thickness of loess-soil series approximately is 25 meters in this section. This key section is stratotype of Sokal fossil soil. Pseudomorphs after the structures of cellular ice of Boyanychi palaeocryogenesis stage were allocated here for the first time for Volhyn-Podillia and individual significance of this stage was substantiated as one of the most ancient in the Pleistocene. Boyanychi key section was studied by the use of practically all methods which apply for the investigation of Pleistocene deposits (in particular, micromorphological, palaeocryogenic, palaeomagnetic, engineering-geological, palaeontological, methods of absolute dating of deposits etc.). Detailed description of the section and the results of engineering-geological studies of rocks of all selected loess and palaeosoil horizons were done. Individual properties of selected stratigraphic horizons and their dependence on the paleogeographic conditions of sedimentation were displayed. Key words: loesses, fossil soils, palaeogeographical conditions, palaeocryogenesis, engineeringgeological features, subsidence, Volhynian Upland.
11
Dolezych, Martina, and Lutz Reinhardt. "First evidence for the conifer Pinus, as Pinuxylon selmeierianum sp. nov., during the Paleogene on Wootton Peninsula, northern Ellesmere Island, Nunavut, Canada." Canadian Journal of Earth Sciences 57, no. 1 (January 2020): 25–39. http://dx.doi.org/10.1139/cjes-2018-0163.
Full textAbstract:
We describe a new fossil wood species of pine, Pinuxylon selmeierianum sp. nov., for a piece of petrified wood encased within a concretion that was recovered in marine, fine-grained sandstones of the Paleogene Eureka Sound Group on Wootton Peninsula, Ellesmere Island. The fossil wood is allochthonous, having drifted in from a nearby landmass. Within the fossil wood genus Pinuxylon Gothan, 1905, Pinuxylon selmeierianum sp. nov. shares anatomical characteristics with the haploxylon sections Parrya Mayr, 1890 and Strobus Little and Critchfield, 1969. The new species is most closely related to the extant Pinus lambertiana Douglas, 1827, a species belonging to section Strobus. Our study provides the first evidence for a fossil Pinus Linné, 1753 on Wootton Peninsula, supporting the idea that Pinus was an “Arctic conifer”, and providing insights into Paleogene vegetation at high latitudes.
12
Armentrout, John M. "Biostratigraphic signature of sequence boundaries, maximum flooding surfaces, condensed sections, and depositional systems tracts – with examples from the gulf of mexico plio-pleistocene." Paleontological Society Special Publications 6 (1992): 9. http://dx.doi.org/10.1017/s2475262200005694.
Full textAbstract:
The primary horizons utilized in sequence stratigraphic analysis are the sequence boundary, and the maximum flooding surface which occurs within the condensed section in areas of low sediment accumulation rates. These regionally correlative surfaces can be identified on seismic reflection profiles, on wireline logs, in stratigraphic sections, and from checklists of fossil abundance and diversity. Both surfaces are time-transgressive but nevertheless can be used as correlation horizons for partitioning depositional cycles into discrete phases of relative sea-level rise and fall. Sediments deposited during rising and falling phases of sea-level form depositional systems tracts that consist of all correlative deposits of lowstand, of transgressive or of highstand phases of relative sea level.The sequence boundary is an unconformity formed during relative lowering of and during lowstand of sea level. The unconformity correlates into basinal areas of continuous sedimentation where the age of the unconformity is determined biostratigraphically. The unconformity surface is usually recognized because of erosional truncation of underlying strata and the onlap of overlying strata of the next sequence. The sequence boundary may be represented by a marked shift in biofacies assemblages from deeper below to shallower above. It may be marked also by an increase in reworked or displaced fossils, and by a decrease in both fossil abundance and diversity due to rapid accumulation of sediment in the shallow water, high-energy environments associated with the erosional unconformity.The maximum flooding surface is defined by, and can be identified by, the most landward onlap of marine strata immediately below the progradational unit with downlapping onto the flooding surface. The precise age of this surface will vary along any basin margin because of the interplay of sediment supply and accommodation space. Away from the locus of major input of sediment this surface is a clay-rich condensed section formed by slow accumulation of sediment. This interval is often represented by significant increase in fossil abundance and by the deepest-water biofacies assemblage of the transgressive-regressive cycle. Despite their lateral variabilities, the seismic, lithologic and biostratigraphic signatures of the condensed section and of the associated maximum flooding surface are generally the most easily recognized and precisely dated regional correlative surfaces.Within the axis of the depocenter, the highstand systems tract typically consists of forestepping coarsening-upward cycles deposited above the maximum flooding surface and below the sequence boundary. Fossil assemblages of the highstand systems tract reflect shallowing upward neritic conditions, with intervals in which faunal abundance decreases upwards. Transgressive systems tracts are backstepping coarsening-upward cycles deposited above the regional transgressive surface and below the maximum flooding surface. Fossil assemblages in transgressive systems tracts show deepening-upward biofacies and an increase in faunal abundance upward. Lowstand systems tracts are most significant seaward of the shelf-edge, and consist of depositional thicks with low fossil abundance. These lowstand systems tracts are separated by highly fossiliferous condensed sections containing the distal aspects of the transgressive and highstand systems tracts.Identification of each sequence boundary and its correlative conformity, and of each maximum flooding surface is achieved by careful recognition of patterns of stratal terminations, by correlation of those stratal surfaces of discontinuity with measured sections or wireline logs, and by biostratigraphic correlation between these sections and logs. If the discontinuity surfaces correlate throughout the depositional basin or subbasin, they should be considered sequence boundaries and maximum flooding surfaces. If the surfaces are limited to local areas and are not coeval, they are probably local discontinuities associated with local structural events or with autocyclic shifting of sediment accumulation.
13
Erbajeva, M. A., A. A. Shchetnikov, A. Yu Kazansky, G. G. Matasova, F. I. Khenzykhenova, I. A. Filinov, O. D. Ts Namzalova, and I. O. Nechaev. "New pleistocene key section Ulan-Zhalga of the Western Transbaikalia." Доклады Академии наук 488, no. 3 (September 26, 2019): 277–81. http://dx.doi.org/10.31857/s0869-56524883277-281.
Full textAbstract:
The currant paper presents the preliminary results of the multidisciplinary study of the new Pleistocene section Ulan-Zhalga (51°29′40.75″ С, 107°20′18.11″ В) discovered in the Western Transbauikalaia in 2017. On the base of the paleontological, paleomagmetic, and lithological data the early, middle and late Pleistocene sediments were recognized in the section. The analysis of the rich small mammal fossils resulted in to trace the paleoenvironmental and climatic changes in the region during the Quaternary. The unique alternation of the 19 faunistic horizons and 11 fossil soils in the whole section, the high correlation of the paleomagnetic and paleontological data allow us to refer the studied section Ulan-Zhalga to addition new late Cenozoic Key section of the south Eastern Siberia. The new geological and paleontological data would be important for paleogeographical reconstruction and biostratigraphic analysis.
14
Gingras, Murray K., John W. F. Waldron, Chris E. White, and Sandra M. Barr. "The evolutionary significance of a Lower Cambrian trace-fossil assemblage from the Meguma terrane, Nova Scotia." Canadian Journal of Earth Sciences 48, no. 1 (January 2011): 71–85. http://dx.doi.org/10.1139/e10-086.
Full textAbstract:
We report a diverse assemblage of trace fossils from the Lower(?) Cambrian High Head member of the Church Point Formation near Yarmouth, Nova Scotia. Based on the presence of sharp-based beds, load casts, and flute casts, along with other sedimentological criteria, the strata are interpreted to have a turbidite origin. Other characteristics, including wrinkle structures and high fidelity of trace-fossil preservation, suggest that the inter-episode biotope was influenced by the presence of biomats. The trace-fossil assemblage includes (in approximate order of abundance) Planolites , Helminthopsis , Oldhamia , Chondrites , Gordia , Cladichnus , Psammichnites gigas , Treptichnus , Phycodes , Lorenzinia , Palaeophycus , and Teichichnus . Trace fossils are increasingly abundant upwards in the section, but they are ultimately mitigated by an increase in (inferred) sedimentation rates. The trace-fossil assemblage, which bears many similarities to other Lower Cambrian locales (e.g., Puncoviscana Formation of northwest Argentina, Chapel Island Formation of southeastern Newfoundland), and the distribution of ichnofossils strongly support an earliest Cambrian age for the studied strata. More importantly, evolutionary trends can be interpreted from the trace-fossil assemblage, namely (1) an increase in size and diversity of animals in deep water; (2) an expansion of motile strategies used to coexist with biomats; and, (3) increasingly complex mining strategies below the sediment-biomat interface.
15
Smith, Ian R., and Don Butler. "The Bunya in Queensland's Forests." Queensland Review 9, no. 2 (November 2002): 31–38. http://dx.doi.org/10.1017/s1321816600002932.
Full textAbstract:
Much publicity has been given over the past decade to the discovery of the Wollemi pine (Wollemia nobilis) north of Sydney and its status as a ‘living fossil’. It is not generally realised that the bunya (Araucaria bidwillii), a unique part of Queensland's forests, has a similar status. The tree is the last surviving species of the section Bunya of the genus Araucaria. This section was more diverse and widespread during the Mesozoic, (Table 1), with some species having cone morphology similar to A. bidwillii appearing during the Jurassic with fossils extending into the northern hemisphere.
16
Brasier, Martin D., Mordeckai Magaritz, Richard Corfield, Luo Huilin, Wu Xiche, Ouyang Lin, Jiang Zhiwen, B. Hamdi, He Tinggui, and A. G. Fraser. "The carbon- and oxygen-isotope record of the Precambrian–Cambrian boundary interval in China and Iran and their correlation." Geological Magazine 127, no. 4 (July 1990): 319–32. http://dx.doi.org/10.1017/s0016756800014886.
Full textAbstract:
AbstractThe fossiliferous section at Meishucun of Yunnan, China, is a candidate stratotype section for the Precambrian–Cambrian boundary. Early diagenetic dolomites and phosphorites have been sampled across the boundary interval here, and in the correlated section at Maidiping in Sichuanand Valiabad in Iran, for comparison of their carbon and oxygen isotopes. This is the first such study that is calibrated by biostratigraphy in the interval from the earliest (pre-Tommotian) skeletal fossils to trilobites. Although negative oxygen isotopes indicate a diagenetic signal in the Zhongyicun Member and basal Badaowan Member phosphorites, two carbon-isotope cycles are clearly present and can be correlated in dolomitic rocks between the two sections. The first appearance datum (FAD) of the earliest skeletal assemblage (zone I, Marker A), FAD of diverse micromolluscs (zone II, Marker B) and FAD of Chinese trilobites (zones IV, V) and Marker C appear at similar points on the carbon-isotope curve in the two Chinese sections. Integrated carbon-isotope and early skeletal fossil biostratigraphy is shown to have the potential to correlate further afield, with sections in Iran, as well as with India, Siberia, Morocco and Australia. We suggest that a distinctive positive excursion provides a global marker for the interval between Marker B and C in China and just below the Tommotian Stage of Siberia.
17
Honarmand, Atusa, Mohamad Vahidinia, Mohamad Hosein Mahmudy Gharaie, and Meysam Shafiee Ardestani. "Biostratigraphy of Upper Cretaceous planktonic foraminifera of the Abtalkh Formation in an east-west transect, Kopet-Dagh Basin, northeastern Iran." Micropaleontology 66, no. 4 (2020): 285–300. http://dx.doi.org/10.47894/mpal.66.4.02.
Full textAbstract:
The Upper Cretaceous Abtalkh Formation of the Kopet-Dagh Basin (northeastern Iran) was studied in four stratigraphic sections (Bahadorkhan, Hammam Galeh, Type section and Shorab). All sections display limestones, shales and calcareous shales. The Bahadorkhan section is approximately 480 m thick. We identified 32 planktonic foraminifera species belonging to 13 genera in 6 biozones: 1. Dicarinella asymetrica Total Range Zone, 2. Globotruncanita elevata Partial Range Zone, 3. Contusotruncana plummerae Interval Zone, 4. Radotruncana calcarata Total Range Zone, 5. Globotruncanella havanensis Partial Range Zone and Globotruncana aegyptiaca Interval Zone. Based on foraminiferal biostratigraphy, the Bahadorkhan section was dated to the latest Santonian to late Campanian. This study identifies 11 genera and 25 species of planktonic foraminifera in the 1500m thick Hammam Galeh section, spanning 7 biozones: 1. Dicarinella asymetrica Total Range Zone, 2. Globotruncanita elevata Partial Range Zone, 3. Contusotruncana plummerae Interval Zone, 4. Radotruncana calcarata Total Range Zone, 5. Globotruncanella havanensis Partial Range Zone, 6. Globotruncana aegyptiaca Interval Zone, 7. Gansserina gansseri Interval Zone. Latest Santonian to late Campanian ages have been established for the Abtalkh Formation. The type locality of the Abtalkh Formation is 750mthick and contains 31 planktonic foraminiferal species belonging to 12 genera. Based on this fossil content, we identified 6 biozones. The age of the formation is estimated to be the latest Santonian to late Campanian, as for the Bahadorkhan type section. The Shorab section of the Abtalkh Formation is 990m thick. In this section, 19 species belonging to 10 genera were identified, as were 5 biozones: 1. Globotruncanita elevata Partial Range Zone, 2. Contusotruncana plummerae Interval Zone, 3. Radotruncana calcarata Total Range Zone, 4. Globotruncanella havanensis Partial Range Zone, 5. Globotruncana aegyptiaca Interval Zone. Based on this fossil assemblage, the Shorab section dates to the early to late Campanian.
18
Martin, Anthony J., Dorothy Stearns, Meredith J. Whitten, Melissa M. Hage, Michael Page, and Arya Basu. "First known trace fossil of a nesting iguana (Pleistocene), The Bahamas." PLOS ONE 15, no. 12 (December 9, 2020): e0242935. http://dx.doi.org/10.1371/journal.pone.0242935.
Full textAbstract:
Most species of modern iguanas (Iguania, Iguanidae) dig burrows for dwelling and nesting, yet neither type of burrow has been interpreted as trace fossils in the geologic record. Here we describe and diagnose the first known fossil example of an iguana nesting burrow, preserved in the Grotto Beach Formation (Early Late Pleistocene, ~115 kya) on San Salvador Island, The Bahamas. The trace fossil, located directly below a protosol, is exposed in a vertical section of a cross-bedded oolitic eolianite. Abundant root traces, a probable land-crab burrow, and lack of ghost-crab burrows further indicate a vegetated inland dune as the paleoenvironmental setting. The trace fossil matches dimensions and overall forms of burrows made by modern iguanas, and internal structures indicate active backfilling consistent with modern iguana nesting burrows. The trace fossil is also located on an island with a modern native species of rock iguana (Cyclura riyeli riyeli), suggesting a presence of iguanas on San Salvador since the Late Pleistocene. This nesting burrow may provide a search image for more fossil iguana burrows in The Bahamas and other places with long-established iguana species and favorable geological conditions for preserving their burrows.
19
Kremin, Nadiya. "Micromorphological structure of Korshiv fossil soil complex of Halych 2D key section." Visnyk of the Lviv University. Series Geography, no. 47 (November 27, 2014): 157–63. http://dx.doi.org/10.30970/vgg.2014.47.920.
Full textAbstract:
The general lithologic and micromorphological descriptions of korshiv fossil soil complex of Halych 2D key section were conducted. The features of formation of differentiated genetic profile based on the analysis of main features of microstructure of korshiv soil complex were revealed. Interpretation of natural conditions of the formation of korshiv fossil soil complex during the Pleistocene was performed. The reasons which suggest the forest and forest steppe conditions of the formation of korshiv soils of the first and second phases were analyzed. Key words: micromorphological structure, shlif, soil horizon, fossil soil, loess.
20
Feduccia, Alan. "Cretaceous Reverie: Review of Birds of Stone: Chinese Avian Fossils from the Age of Dinosaurs by Luis M. Chiappe and Meng Qingjin1." Open Ornithology Journal 11, no. 1 (February 12, 2018): 27–33. http://dx.doi.org/10.2174/1874453201811010027.
Full textAbstract:
Birds of Stone contains a portfolio of outstanding photographs of the spectacularly preserved Jehol bird fossils, from the Chinese Lower Cretaceous, and other pertinent vertebrate fossils of varying ages, along with comments on each fossil. The book nicely illustrates a range of species of the radiation of enantiornithines (opposite birds), the dominant Mesozoic landbirds, as well as the ornithuromorphs, the Mesozoic antecedents of the modern neornithine birds. Although the first section of the book is fairly straight forward, the second section, on bird origins and their early evolution is one-sided, presenting only the popular paleontological view and omits discussion of controversial subjects. Examples are the highly speculative presence of dinosaur protofeathers and improbable scenarios of flight origins. There are no citations of the numerous credible opposing views in the literature.
21
Wu, Meng-Xiao, Jian Huang, Tao Su, Zhe-Kun Zhou, and Yao-Wu Xing. "Fraxinus L. (Oleaceae) fruits from the early Oligocene of Southwest China and their biogeographic implications." Fossil Imprint 77, no. 2 (2022): 287–98. http://dx.doi.org/10.37520/fi.2021.021.
Full textAbstract:
Two new fossil taxa of the ash tree, namely F. zlatkoi Meng-Xiao Wu et J.Huang sp. nov. and Fraxinus cf. honshuensis Tanai et Onoe were reported from the early Oligocene of the Lühe flora, Yunnan Province, Southwest China. The fruit traits were used to assign the proposed species to the genus Fraxinus. These traits were a flattened and symmetrical shape, a single seed located in the base of the fruit and veins parallel to the long axis of each fruit. The new species have low length to width ratio and an obovate seed. Our fossils represent the oldest records of Fraxinus in the low latitude region of the Northern Hemisphere. These fossils provide evidence that Section Dipetalae and Section Ornus had appeared in Southwest China by the early Oligocene.
22
LINDSAY-KAUFMAN, AMELIA, STEPHANIE A. ROSBACH, LAUREN S. WRIGHT, EMILY L. V. EDWARDS, SEYED HAMID VAZIRI, MAHMOUD REZA MAJIDIFARD, TARA SELLY, MARC LAFLAMME, and JAMES D. SCHIFFBAUER. "DESCRIBING DIFFICULT SHELL-HASH ASSEMBLAGES FROM THE LOWER CAMBRIAN SOLTANIEH FORMATION, ALBORZ MOUNTAINS, NORTHERN IRAN." PALAIOS 37, no. 7 (July 26, 2022): 374–91. http://dx.doi.org/10.2110/palo.2021.031.
Full textAbstract:
ABSTRACT The fossil record spanning the latest Ediacaran and earliest Cambrian is characterized by the proliferation of small, mineralized organisms that comprise the well-known and abundant deposits of small shelly fauna. Many of these fossils are tubular or conical forms with simple morphologies, and thus present difficulties in both taxonomic and phylogenetic interpretation. This study investigates a community of poorly preserved shelly tubicolous organisms in two fossiliferous slabs from the Soltanieh Formation, northern Iran. Analysis of the taphonomy of this fossil assemblage using thin-section petrography, scanning electron microscopy, and energy dispersive X-ray spectroscopy, suggests a two-part preservational pathway involving phosphatic replacement of the shell wall and separate, diagenetically later infillings of void space with either phosphatic or calcium carbonate cements. In parallel with the taphonomic study and given the difficulty in assigning the observed fossils taxonomically, morphometrics of the shelly organisms were also explored. Biometric measurements were collected from high-resolution photomosaic images of the slab-surface fossils, as well as from a three-dimensional volume of the interior of one of the slabs generated via X-ray tomographic microscopy. Statistical analysis of these measurements revealed a separation of the fossils into two morphologically distinct groups of conical and tubular forms, which we characterize respectively as ‘conomorphs' and ‘tubomorphs'. Based on previous studies of fossils from the Soltanieh Fm., we can offer tentative generic-level assignment to Anabarites and Cambrotubulus to at least some of the fossils present, though these are dependent on views in thin section rather than morphometric distinction. Cumulatively, we provide a conservative, taxonomy-free approach for detailing the morphology and preservation of poorly preserved fossils from the Ediacaran–Cambrian transition.
23
Gallagher, W. B. "Oligotrophic oceans and minimalist organisms: collapse of the Maastrichtian marine ecosystem and Paleocene recovery in the Cretaceous-Tertiary sequence of New Jersey." Netherlands Journal of Geosciences - Geologie en Mijnbouw 82, no. 3 (August 2003): 225–31. http://dx.doi.org/10.1017/s0016774600020813.
Full textAbstract:
AbstractThe inner Atlantic Coastal Plain of New Jersey reveals exposures of fossiliferous Maastrichtian and Danian deposits. Recent fossil discoveries in this interval are here reported, and placed in the context of Cretaceous/Tertiary (K/T) faunal changes. The exposure at the Inversand Pit at Sewell (New Jersey) is the last active marl mine in the region, and stands as an important reference section for the many significant discoveries of vertebrate fossils produced by the marl mining industry at its zenith. Changes in planktonic populations across the K/T boundary are related to Maastrichtian/Danian marine ecosystem community reorganisation, by demonstrating changes in abundance of dominant marine invertebrates in successive fossil assemblages. Marine invertebrates with non-planktotrophic larval stages were briefly the commonest fossils preserved in the Danian sediments of this region. Late surviving examples of Cretaceous fauna now restricted to the Indo-Pacific region may imply biogeographic changes linked to the K/T mass extinction event.
24
Archer, Allen W., John H. Calder, Martin R. Gibling, Robert D. Naylor, Donald R. Reid, and Winton G. Wightman. "Invertebrate trace fossils and agglutinated foraminifera as indicators of marine influence within the classic Carboniferous section at Joggins, Nova Scotia, Canada." Canadian Journal of Earth Sciences 32, no. 12 (December 1, 1995): 2027–39. http://dx.doi.org/10.1139/e95-156.
Full textAbstract:
The sea cliffs at Joggins, Nova Scotia, are the most extensive and continuous Carboniferous section in eastern North America. Although the section has been considered to have formed within a nonmarine depositional basin, paleobiological information indicates that parts of the section were deposited in brackish water. The occurrence of a trace-fossil assemblage, which includes Cochlichnus, Kouphichnium, and Treptichnus, is part of an assemblage of biogenic structures that apparently reflects paleodeposition within fluvial systems that may have experienced distal marine influences. Presence of agglutinated foraminifera characteristic of brackish-water environments supports this interpretation. This information provides new evidence of brackish-water conditions at Joggins such as those now being widely recognized in other Carboniferous coal-bearing sections.
25
Berneker, Erik, and Gerd Geyer. "The Oued Boutergui section, western Anti-Atlas: Cambrian stratigraphy, fossil distribution, and depositional history." Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1990, no. 7 (August 17, 1990): 385–403. http://dx.doi.org/10.1127/njgpm/1990/1990/385.
Full text
26
PRUSS, SARA B., JONATHAN L. PAYNE, and SOPHIE WESTACOTT. "TAPHONOMIC BIAS OF SELECTIVE SILICIFICATION REVEALED BY PAIRED PETROGRAPHIC AND INSOLUBLE RESIDUE ANALYSIS." PALAIOS 30, no. 8 (August 1, 2015): 620–26. http://dx.doi.org/10.2110/palo.2014.105.
Full textAbstract:
Abstract Silicification is an important mode of fossil preservation but the extent to which silicified material represents an unbiased sampling of the total fossil assemblage within a given rock sample remains poorly quantified. Here, we use paired analyses of thin sections and acid-extracted silicified specimens from the same samples to examine the biases introduced during silicification of Lower Triassic Virgin Limestone carbonates preserved in the Muddy Mountains of southern Nevada. Bivalves dominate most thin sections in the point count data, but rarely silicify completely enough to be recognized in residue. Echinoderms and gastropods are less abundant in thin section but dominate the residues. The abundances of these groups in thin section and residue are only weakly correlated. These findings suggest that although silicification generally captures relative trends in proportional abundance of higher taxa among samples, the silicification process can be taxonomically biased. Given the biases that can occur during silicification, it should not be assumed that silicified collections present a pristine picture of taxonomic or paleoecologic composition. Petrographic analysis has the potential to illuminate the reliability of paleontological data based on silicified collections.
27
Hill, RS. "Araucaria (Araucariaceae) species from Australian tertiary sediments — a micromorphological study." Australian Systematic Botany 3, no. 2 (1990): 203. http://dx.doi.org/10.1071/sb9900203.
Full textAbstract:
The cuticular micromorphology of four existing and four new species of Araucaria from Australian Tertiary sediments is examined using scanning electron microscopy. Scanning electron microscopy is very useful for distinguishing species, but less successful for determining the affinities of the fossil species within the genus. Two fossil species, A. balcombensis Selling and A. hastiensis Bigwood & Hill, are closely related to the extant South American species A. araucana (Molina) K. Koch (section Columbea). Five fossil species, A. lignitici Cookson & Duigan, A. planus R. Hill, sp. nov., A. prominens R. Hill, sp. nov., A. readiae R. Hill & Bigwood and A. uncinatus R. Hill, sp. nov., are assigned to section Eutacta, but their affinities within that section are uncertain. One fossil species, A. fimbriatus R. Hill, sp. nov., cannot be placed into a section with confidence. The presence of A. balcombensis and A. hastiensis in south-eastern Australia in the early Tertiary, along with species of Nothofagus in a subgenus now restricted to South America, suggests that there may have been early Tertiary forests in Australia similar to the Araucaria araucana–Nothofagus associations found today near the tree line in the Andes. The presence of at least three Araucaria species at the late Oligocene-early Miocene Monpeelyata deposit suggests that complex araucarian forests similar to those found today in New Caledonia may have been more widespread in the region in the past.
28
Hussain, Salah. "Microfacies Characterizations and Paleoenvironment of Upper Part of Qamchuqa Formation from Chwarqauran Section, Sulaimaniyia Area, Kurdistan Region, Iraq." Iraqi Geological Journal 54, no. 1B (February 28, 2021): 102–11. http://dx.doi.org/10.46717/igj.54.1b.9ms-2021-02-27.
Full textAbstract:
The Qamchuqa Formation was studied in Chwarqauran section, Sulaimanyia, Kurdistan region, Northeastern Iraq. The lithology of the formation contains limestone throughout the whole section except for one bed of dolomite at the Middle part. Twenty-four slides were prepared from 24 rock samples that were taken from this section to discriminate the petrography and fossil content. The petrographic study shows four main microfacies including lime mudstone, wackestone, packstone, and floatstone. Additionally, there are four sub microfacies: bioclast wackestone, miliolid wackestone, bioclast packstone and orbitolinid packstone. However, the fossil content shows the abundance of benthic foraminifera against the planktonic. All the microfacies indicate facies zone 7, 8 and 9A which reflect deposition in the platform interior between the tidal flat to the mid ramp and back reef environment
29
KOUCHINSKY, ARTEM, STEFAN BENGTSON, VLADIMIR PAVLOV, BRUCE RUNNEGAR, ANATOLIJ VAL'KOV, and EDWARD YOUNG. "Pre-Tommotian age of the lower Pestrotsvet Formation in the Selinde section on the Siberian platform: carbon isotopic evidence." Geological Magazine 142, no. 4 (July 2005): 319–25. http://dx.doi.org/10.1017/s0016756805000865.
Full textAbstract:
Carbon isotopic data from the Selinde section in the southeastern part of the Siberian platform area are correlated with the reference isotopic profile from the Lower Cambrian stratotype sections of the Lena–Aldan region, but also show additional δ13C excursions unrecognized there. The chemostratigraphic correlation suggests that the geological and fossil record of the lower Pestrotsvet Formation in the Selinde section has a deeper history than the stratotype region. This conclusion is important for both constraining the age of the earliest Cambrian marine transgression on the Siberian platform and providing a clearer understanding of the pace and order of early Cambrian geochemical and biological events.
30
McKenna, Malcolm C., and Jason A. Lillegraven. "Biostratigraphic deception by the Devil, salting fossil kollinbrains into the Poobahcene section of central Myroaming." Palaeontographica Abteilung A 277, no. 1-6 (October 30, 2006): 1–17. http://dx.doi.org/10.1127/pala/277/2006/1.
Full text
31
Stefenon, V. M., O. Gailing, and R. Finkeldey. "Phylogenetic Relationship Within Genus Araucaria (Araucariaceae) Assessed by Means of AFLP Fingerprints." Silvae Genetica 55, no. 1-6 (December 1, 2006): 45–52. http://dx.doi.org/10.1515/sg-2006-0007.
Full textAbstract:
Abstract Highly polymorphic AFLP markers were applied to analyse the phylogenetic relationships of seven species from three sections within genus Araucaria (Araucariaceae) with cladistic and phenetic approaches. The objectives of the study were to compare the intrageneric relationships within Araucaria assessed by AFLP markers with the classification according to chloroplast DNA sequences and morphological characters. The AMOVA revealed 48% of the variation among species. The results of the principal coordinate analysis revealed three distinct groups: (1) A. angustifolia and A. araucana (= section Araucaria), (2) A. bidwillii (= section Bunya) and (3) A. cunninghamii, A. heterophylla, A. rulei and A. scopulorum (= section Eutacta). In the cladistic and phenetic analyses, phylogenetic trees were subdivided into two sister clades, one comprising the samples from section Eutacta, the other one was divided again into two sister clades corresponding to sections Araucaria and Bunya. These results are congruent with a previous phylogenetic study of the family Araucariaceae based on rbcL sequences and with the classification of genus Araucaria based on morphological characters. Both rbcL sequence data and AFLP analyses do not support section Bunya as one of the oldest sections within genus Araucaria, as suggested by the fossil record. The utility of AFLP markers for phylogenetic analyses is discussed.
32
Oliver, William. "James Hall and Fossil Corals." Earth Sciences History 6, no. 1 (January 1, 1987): 99–105. http://dx.doi.org/10.17704/eshi.6.1.71587105082520h5.
Full textAbstract:
During his long career, James Hall named and described over 250 species and several genera of fossil corals, mostly of Middle Silurian to Middle Devonian age. Hall's principal coral works were published in 1843, 1877, 1882-84, and (with G. B. Simpson) 1887. Sporadic work on corals continued to 1898, the year of his death. In spite of shortcomings, his four main contributions provided the taxonomic base for much of the later work on Helderberg, Onondaga and Hamilton corals in New York and adjacent areas. Beginning in 1868, George B. Simpson was one of Hall's many assistants. He began as illustrator, became a describer of corals and bryozoans, and ultimately co-author of the 1887 work. His own study of Paleozoic coral genera, based on thin section analyses, began the post-Hall era of coral work in eastern North America.
33
Bogucki, Andriy, Andriy Yatsyshyn, Roman Dmytruk, and Olena Tomeniuk. "Solonske section and the perspectives of the cognition of Loyeva level." Visnyk of the Lviv University. Series Geography, no. 50 (December 28, 2016): 54–66. http://dx.doi.org/10.30970/vgg.2016.50.8677.
Full textAbstract:
New geological and geomorphological investigations carried out in different parts of the Fore-Carpathian region of the Dnister River basin gave an opportunity to distinguish at least four separate different-age levels (terraces) within the Loyeva level (sixth terrace): Torhanovychi, Dubrivka, Susidovychi and Biskovychi. In the Solonske section the alluvial and cover loess-soil sediments from the Lower to Upper Pleistocene of the total thickness of about 30 m are revealed. Loess-soil series of the investigated section represents a number of loess and palaeosol horizons from modern soil (MIS 1), which is developed on the Horokhiv fossil soil complex (MIS 5), to the soil with spot-medallions (MIS 17–19). The last one was formed above the permafrost and obviously can be correlated with one of the soils of fossil soil complex of Zahvizdia type. A very thick (almost 10-meter) stratum of deposits that, apparently, have a limnic origin is underlying this soil. Alluvial deposits, which are directly under the limnic stratum, are composed of the channel and flood-plain facies and represent one of the identified separate levels of the Loyeva level (the sixth over-floodplain terrace of the Dnister River). In Solonske section two levels of the development of palaeocryogenic structures like spot-medallions are revealed (above the Lutsk fossil soil (MIS 9) and over one of the soils of fossil soil complex of Zahvizdia type). Undoubtedly, under the conditions of the proper further investigations of the section, Solonske can become a key point for Pleistocene not only for Fore-Carpathians. It will be important in determining the time of the formation of different-age levels of the Loyeva level. Key words: loess-soil series, alluvium, terrace, palaeocryogenesis, spot-medallions, Pleistocene, Loyeva level, Dnister, Fore-Carpathians.
34
Lundberg, Jan C. "Fossil fuels policy action: A special section for correspondence and controversy." Population and Environment 13, no. 3 (March 1992): 225–28. http://dx.doi.org/10.1007/bf01256418.
Full text
35
Celis, Sergio A., Francisco J. Rodríguez-Tovar, and Andrés Pardo-Trujillo. "The Phycosiphon record in the Ladrilleros-Juanchaco section (Miocene, Colombian Pacifi c): palaeoecological implications." Spanish Journal of Palaeontology 33, no. 2 (December 13, 2018): 277. http://dx.doi.org/10.7203/sjp.33.2.13603.
Full textAbstract:
Miocene rocks of the Ladrilleros-Juanchaco section, located on the NW margin of South America, contain a high diverse and abundant trace fossil assemblage. The relative abundance of Phycosiphon, together with its morphological variations, provides new insights into the environmental conditions. Detailed outcrop stratigraphic, ichnological, and geochemical analyses carried out in the section focused on the trace fossil assemblages (distribution, relative abundance), ichnofabric index, and, especially, in the general ichnological features of Phycosiphon . In addition, the detailed photographic documentation and the use of the digital image treatment technique facilitate the precise study of particular ichnological properties. Based on the stratigraphic analysis of the section, together with the abundance, size and distribution of the specimens of Phycosiphon , as well as the analysis of total organic carbon, the record of Phycosiphon is proved as related to the food content in the sediment, and then as a proxy in the study of ancient environments.
36
Yatsyshyn, Andriy, Andriy Bogucki, Roman Dmytruk, Olena Tomeniuk, Maria Łanczont, and Teresa Madeyska. "Loess covers on the terraces in the lower course of Svicha River." Visnyk of the Lviv University. Series Geography, no. 50 (December 28, 2016): 412–26. http://dx.doi.org/10.30970/vgg.2016.50.8729.
Full textAbstract:
The Fore-Carpathians part of Svicha River valley partially covers Morshyn and Zalissia Uplands and Stryi-Zhydachiv depression. Within the Svicha and Sukil' river valleys, there are well-developed different-age terraces with thick stratified loess covers. The investigation of the last ones can help to define nomenclature and age of the terraces. The loess covers of the third (Kolodiiv) and the fourth (Mariampil) terraces, which are represented by Pidberezhzhia and Mizhrichchia sections accordingly, are characterised in detail in the article. Pidberezhzhia section represents a sequence of alluvial and covering deposits of the third (Kolodiiv) over-floodplain terrace of Svicha River, which is developed on its right bank. The terrace is stretched out in the form of a narrow (about 2 km) strip from the village Zarichchia to the village Novoselytsia. It is separated from the Svicha riverbed by the system of different-altitude floodplain levels and the first and second over-floodplain terraces. The boundaries between them are morphologically distinct, the exceeding of the surface of the Kolodiiv terrace above the water level in the riverbed of Svicha reaches 10 m or even more. Covering loess-soil series on the terrace has a capacity of more than 6 m and begins with the Horokhiv fossil soil complex. Mizhrichchia section represents the fourth (Mariampil) over-floodplain terrace, which to the north of Mizhrichchia village forms a scarp to the riverbed of the Svicha River, about 20 m in height. The terrace on this part of the valley of the river covers small areas and it is developed between the villages of Zarichchia and Mali Didushychi. Almost along its length, the terrace directly scarps to the riverbed. On the opposite side, where the rear seam is, it borders on the fifth (Galician) over-floodplain terrace, which forms a scarp about 10 m in height. Loess cover on the fourth terrace is up to 14 m thick. There are welldeveloped Dubno fossil soil (MIS 3) and Horokhiv fossil soil complex (MIS 5) and a thick sequence of hydromorphic deposits, which obviously correspond to the Korshiv fossil soil complex (MIS 7) in loesspaleosol series. The studied Pleistocene covers allow us to reliably identify Mariampil and Kolodiiv terraces of the Svicha River, as well as outline the nomenclature of the remaining terraces of the adjacent sections of the Zalissia and Morshyn Uplands and Stryi-Zhydachiv depression. Key words: river terrace, loess-soil covers, Dubno fossil soil, Horokhiv and Korshiv fossil soil complexes, Fore-Carpathians, Zalissia and Morshyn Uplands.
37
Tasch, Paul. "Geology and Zoology — A Symbiosis Darwin's Beagle Voyage and Galapagos Experience." Earth Sciences History 4, no. 2 (January 1, 1985): 98–112. http://dx.doi.org/10.17704/eshi.4.2.q635v04120qw08g7.
Full textAbstract:
Darwin's South American fossil collections yielded many insights. in one section he recorded the gradual vertical change in shell characteristics of fossil oysters. The giant fossil vertebrates brought the realization that several were precursors of living species. Contrary to accepted Catastrophism Theory, he inferred that all taxa found fossilized did not become extinct together since the living agouti, among others, had fossil precursors. He envisioned the way an existing molluscan fauna and its sedimentary matrix could be transformed into fossiliferous rocks reminiscent of the Tertiary, and also speculated about the kinds of fossils that the Galapagos biota would yield in some future rock column. Volcanic islands (Galapagos Archipelago and others) were linked in Darwin's thought to the appearance of "peculiar" taxa inhabiting these "mere spots" in the sea. Were these migrants from the nearest continents? If so, why were they so distinctive while carrying the imprint of their place of origin? If not, how did these four-legged and other terrestrial creatures get to the islands? Were the archipelagos ever united to the continents? Gradually Darwin was led to a continent-archipelago-continent concept. Continents were elevated archipelagos. (He had the Andean volcanoes in mind.) Archipelagos were submerged remnants of continents. He incorporated into this concept the rise and extinction of species: elevation of archipelagos were the "best nurseries" for appearance of new taxa, while subsidence of continents generally led to extinction of extant forms.
38
Sketel, Michael, Jenny McGuire, Julia Schap, and Rachel Short. "Describing a Newly Excavated Packrat Midden Near Natural Trap Cave, Wyoming to Help Assess Biases in Fossil Microfaunal Accumulation." Bulletin of the Florida Museum of Natural History 60, no. 2 (February 16, 2023): 117. http://dx.doi.org/10.58782/flmnh.dsqo9692.
Full textAbstract:
Microfauna communities resulting from packrat accumulation provide crucial information about how natural communities respond to environmental changes. However, fossil accumulation mechanisms can be complex, making it difficult to interpret these community responses. Natural Trap Cave (NTC) is an open-mouth cave with an 85-foot drop that often lies unseen by passing animals, making it a major location for fossil accumulation. NTC, located in the Bighorn Mountains of Wyoming, has accumulated a paleontological record of the local community’s biota dating back to the Late Pleistocene, 25,000 years ago. The rim of the cave’s mouth is home to packrat middens located directly above the major deposits of microvertebrate (<5 kg) fossils. It is hypothesized that middens along the rim have accumulated seeds, bones, teeth, and bird pellets from the local communities over time and have periodically washed into the cave below. We seek to assess the bias in microvertebrate community composition introduced by packrat accumulation. We identified bones and teeth collected from a 9-section grid of a modern midden located adjacent to the cave, which allow us to see which species dominate the NTC environment. We calculate species evenness, richness, and relative abundances using MNI. To assess local bias resulting from packrat accumulation, we compare the modern midden with live-and camera-trap data of small mammal communities. To assess which NTC fossils result from packrat accumulation, we compare the modern midden with fossil material from within the cave, ranging in age from 2 to 20 ka. Once we understand these biases present in the fossil accumulation, we can associate species’ relative abundances with changes in climate, such as drought, increasing temperatures, and flooding. By knowing how climate has affected NTC species’ abundances through time, we will be prepared to aid in conservation efforts by predicting how species numbers will be affected by future climate change.
39
Benchimol, R. E., K. Cooper, Kronberg B.I., and M. Powell. "Reconnaissance study of macrofossils from the upper purus river - Western Amazônia." Acta Amazonica 16 (1986): 327–36. http://dx.doi.org/10.1590/1809-43921986161336.
Full textAbstract:
Fossils of wood, bone and teeth found along the Upper Purus River οf Amazonia. were studied using conventional microscopy and scanning electron microscopy. Mass spectometry was also used to investigate minor and trace element signatures of bone samples.The microsopy studies showed that there was little alteration of original textures. In the fossil wood samples, identified In thin section as tropical hardwood trees, the replacement of the original material with siderite suggests that fossilization occured in shallow sediments in which interstitial waters were saturated with respect to iron carbenate. In samples of both fossilized bone and wood, precipitation of secondary iron phases was commonly observed in cracks and voids. Other secondary phases Included silica, iron oxides, manganese carbonate. The intimate assοciation οf these secondary phases with the original biological structures could be evidence for a microbiological role in the formation of these phases. The similarity in rare earth element (REE) signatures for 2 fossil bone samples from different modern locations indicates their having shared similar diagenetic histories.The virtually complete preservation of original textures suggests that microscοpic studies could be useful in classifying fossil and even in identifying original materials. Rare carth signatures in fossilized bone may reflect ground water compositions at the time of fossilization.
40
PAULSON, DENNIS R., and MILEN MARINOV. "Zootaxa 20th Anniversary Celebration: Odonata section." Zootaxa 4979, no. 1 (May 28, 2021): 218–21. http://dx.doi.org/10.11646/zootaxa.4979.1.21.
Full textAbstract:
During the two decades (2001–2020) of the journal’s existence, 346 papers on Odonata were published in Zootaxa. These papers contributed 317 new extant taxa, 26 new fossil taxa, and 106 new larval descriptions. By the end of the period, papers in Zootaxa were contributing slightly more than half of all descriptions of new extant taxa. Research was published from all over the world but predominantly from the American and Asian tropics, and authors from 42 countries contributed papers.
41
Bubík, Miroslav, Juraj Franců, Helena Gilíková, Jiří Otava, and Lilian Švábenická. "Upper Cretaceous to Lower Miocene of the Subsilesian Unit (Western Carpathians, Czech Republic): stratotypes of formations revised." Geologica Carpathica 67, no. 3 (June 1, 2016): 239–59. http://dx.doi.org/10.1515/geoca-2016-0016.
Full textAbstract:
Abstract Type sections/areas for all four formations distinguished in the sedimentary succession of the Subsilesian Unit on Czech territory were revisited and described. New data on lithology, sedimentology, fossil record, biostratigraphy, heavy-minerals and geochemical proxies are based on observations and analysis of these sections. The historical type section of the Frýdek Formation was destroyed during railway construction in 19th century. Outcrops of Campanian to Maastrichtian marls and sandstones on the southwestern slope of “Castle hill” at Frýdek, are proposed as a new type section. The Ostravice riverbed in Frýdlant nad Ostravicí was originally designated as the type area, not mentioning the particular section. This area, even when supplemented with Sibudov Creek, does not show all typical facies of the formation. The outcrops range from lowermost Eocene to Eocene-Oligocene transition. In the original description of the Menilite Formation Glocker mentioned several localities in the area covering the Ždanice, Subsilesian and Silesian units, not mentioning the principal one. The single sections, each not exceeding a thickness of 2 m, are not sufficient to be a type section. Instead of that, we propose the area between Paršovice and Bystřice pod Hostýnem, covering the historical localities, as the type area. The type locality of the Ženklava Formation is an outcrop in an unnamed creek in Ženklava according to the original definition. It seems to be reasonable to extend the type section to the whole 500 m long section of the creek with the outcrops that better illustrate the lithological variability of the formation. New biostratigraphic data allow assignment to late Egerian (Eggenburgian?).
42
Pei, Liang, and Liying Sun. "Study on Di-Phase Membrane Device with DZ272(DDD) for Purification Behavior of Divalent Cobalt Ions in Slops." Toxics 10, no. 9 (September 19, 2022): 546. http://dx.doi.org/10.3390/toxics10090546.
Full textAbstract:
A novel Di-phase membrane device with DZ272 (DDD) containing a replenishing feed section and replenishing resolving section for the purification behavior of Co(II) has been studied. The replenishing feed section was composed of feed solution and Di-isooctylphosphinic acid (DZ272) as the carrier in fossil oil, and the replenishing resolving section was composed of DZ272 as the carrier in fossil oil and HCl as the resolving agent. The effects of the voluminal ratio of the membrane solution and feed solution (O/F), pH, initial molarity of Co(II) and ionic strength in the feed solution, voluminal ratio of membrane solution and resolving agent (O/S), molarity of H2SO4 solution and DZ272 molarity in the replenishing resolving section on purification of Co(II) were considered. The benefits of DDD compared to the traditional membrane device, system stability, reuse of the membrane solution and retention of the membrane section were also studied. Experimental results indicated that the optimal purification conditions of Co(II) were obtained, as H2SO4 molarity was 2.00 mol/L, DZ272 molarity was 0.120 mol/L, O/S was 3:1 in the replenishing resolving section, O/F was 1:8 and pH was 5.20 in the replenishing feed section. The ions intensity in the replenishing feed section had no apparent effect on purification behavior of Co(II). When the initial Co(II) molarity was 3.00 × 10−4 mol/L, the purification percentage of Co(II) achieved 93.6% in 200 min. The kinetic equation was deduced in light of the law of mass diffusivity and interfacial chemistry.
43
Mandang, Y. I., Andianto, and H. Oktariani. "Paleobotany collections: fossil woods available at the Bandung Geological Museum." IOP Conference Series: Earth and Environmental Science 948, no. 1 (December 1, 2021): 012002. http://dx.doi.org/10.1088/1755-1315/948/1/012002.
Full textAbstract:
Abstract Indonesia is a country which has plants species diversity. The form of ancient plants that grew in the past are recorded as fossil woods. Several fossil woods from regions in Indonesia were collected and became exhibition collections at the Bandung Geological Museum. These fossil woods on display requires biology identity to provide more information to visitors. Identification of species of fossil woods were carried out based on the anatomical features on the smoothed cross-section. Observations were carried out by a loop hand (a magnification of 10 times and a digital loop (with a magnification of 16 times). The fossil woods anatomy features observed included vessel cells, parenchyma cells, rays cells, and the presence of resin channels. The fossil specimen which had unclear anatomy features compared by detailed description of wood anatomy available at the library and collections of wood samples owned by the Xylarium Bogoriense. The fossil woods species are Canarioxylon sp., Terminalioxylon sp., Anisopteroxylon sp., Dipterocarpoxylon sp., Dryobalanoxylon sp., Hopenium/Hopeoxylon sp., Shoreoxylon sp., Kompassioxylon sp., and Xanthophyllum sp. The mostly fossil woods species resvectively belonging to the Dipterocarpaceae, Combretaceae, Polygalaceae, Burseraceae, and Leguminosae. The fossil woods member of Dipterocarpaceae family are conspicuously characterized with the presence of resin canals.
44
Bogucki, Andriy, Petro Voloshyn, Nadiya Kremin, and Olena Tomeniuk. "Engineering-geological characteristic of the rocks of the loess-soil series of the key section Pidvolochysk (Podolian Upland)." Visnyk of the Lviv University. Series Geography, no. 50 (December 28, 2016): 45–53. http://dx.doi.org/10.30970/vgg.2016.50.8676.
Full textAbstract:
Key section Pidvolochysk is located in the quarry of the currently inactive brick factory. It represents the Upper and Middle Pleistocene loess-soil series as well as some fossil paleocryogenic forms of the Khmelnytsky Plateau of the Podolian Upland. The ice-wedge casts of the Final Pleistocene (Krasyliv) palaeocryogenic stage are presented here especially intensely. One of them is studied on the engineering-geological aspect. In particular, it has been defined, that the loess filler of ice-wedge cast, in contradistinction to loesses that contain it, is loose and subsiding. This is of great importance for the engineering-geological evaluation of the properties of loess-soil strata. Key section Pidvolochysk is well stratified. Two Upper Pleistocene loess horizons (MIS 2, 4) and the upper horizon of Middle Pleistocene loesses (MIS 6) are disclosed here. Besides loess horizons, Dubno fossil soil (MIS 3) and Horokhiv fossil soil complex (MIS 5), as well as delluvial-solifluctional stratum above Dubno, are developed here. The engineering-geological properties of the loess and palaeosol horizons, including their subsidence, have been studied in detail. Individual characteristics of distinct stratigraphic horizons are given. It can be used during the engineering-geological research in the areas of distribution of Pleistocene loess-soil series. Key words: loess-soil series, key section, Pleistocene, palaeocryogenesis, engineering-geological features, Podolian Upland.
45
Lavoie, C., S. A. Elias, and S. Payette. "Holocene fossil beetles from a treeline peatland in subarctic Quebec." Canadian Journal of Zoology 75, no. 2 (February 1, 1997): 227–36. http://dx.doi.org/10.1139/z97-029.
Full textAbstract:
We analyzed the fossil insect fauna of a palsa peatland located 10 km south and east of the treeline in subarctic Quebec (57°45′N, 76°15′W) to detect any changes in the species composition during the Holocene epoch and to infer past environmental conditions in the study area. A minimum of 802 beetle individuals were recovered from a 2-m peat section, representing 51 taxa (18 identified to the species level) and 8 families. Trechus crassiscapus, Eucnecosum brunnescens, and Olophrum rotundicolle were the most common species found in the peat. The insect assemblage was quite stable through the study interval (5850–1950 BP). The formation of the palsa (where the peat section was excavated) occurred probably after 1950 BP, raising the soil surface above water level and preventing additional peat accumulation. The proportion of boreal forest species in the faunal assemblage is high (88%). The only arctic (tundra) species found were Amara alpina and Pterostichus arcticola. Many species were out of their modern distribution range, but since collection localities are scarce in subarctic Quebec, the modern range of these species may extend to the study site. A mutual climatic range analysis, employing beetles identified to the species level, showed that the mean July temperature of the study area between 5850 and 1950 BP was possibly 2.8–5.5 °C higher than during the 20th century. This assertion is supported by other paleoecological data (pollen and charcoal remains) suggesting a cooling trend in the study area after 2000 BP. However, since the last 2000 years are missing from the sampled peat section, it was not possible to quantify the impact of the cooling trend on the beetle fauna.
46
Ćosović, Vlasta, Katica Drobne, Bojan Ogorelec, Alan Moro, Mladen Koić, Ivan Šoštarko, Alceo Tarlao, and Giorgio Tunis. "Decastronema barattoloi (DE CASTRO), characteristic fossil of the Palaeocene and the Eocene peritidal sediments from the Adriatic carbonate platform." Geologia Croatica 61, no. 2-3 (December 25, 2008): 321–32. http://dx.doi.org/10.4154/gc.2008.24.
Full textAbstract:
The renewed deposition in the Palaeogene and the oldest part of the non-interrupted Palaeocene succession is characterized by the presence of Decastronema barattoloi (DE CASTRO), cyanobacterial tubes originally described in the Apennines. The reinterpretation of limestones from several sections located in the Kras region (NW part of the AdCP: Basovizza, Dolenja vas, Sopada, ?ebulovica) confi rmed the presence of these microfossils in peritidal sediments of Danian age (SBZ 1). The Cuisian (Late Lower Eocene) sediments, from eastern Istria (Brnjci section), Cres Island (Koroma?na Cove section) and Ravni kotari (Benkovac–Korlat section) contain individuals of this species in great numbers. The cyanobacterial tubes are scattered in laminated, fi ne grained mudstones and wackestones, immediately above the Cretaceous sediments (occasionally above bauxites or breccias). The Decastronema-bearing sediments pass upward into the Foraminiferal limestones of Cuisian age (SBZ 11, based on conical agglutinated foraminifera and alveolinids), allowing the age determination of the cyanobacterial remnants. The Palaeocene specimens are minute (up to about 180 ?m long), thick walled tubes that occur with the index fossil Bangiana hanseni DROBNE. The Eocene forms accompanied by ostracods, pelecypods, and miliolid and rotaliid foraminifera are segmented tubes, up to 400 mm long and usually thin walled.
47
Sandy, Michael R. "Preparation of serial sections." Paleontological Society Special Publications 4 (1989): 146–56. http://dx.doi.org/10.1017/s2475262200005086.
Full textAbstract:
Serial sectioning (also referred to as serial grinding) is used to investigate the internal structures of three-dimensional (rock or fossil). In this process series of sections are ground or cut in sequence through a specimen to reveal its internal structures. The specimen is ground down against an abrasive surface (e.g., abrasive powder on a sheet of steel or a rotating diamond wheel on a lathe) or cut with a saw blade. The details of each section can be recorded by drawing or photography. A permanent record of each surface can be made by taking acetate peels and mounting them in glass slides (Wilson and Palmer, this volume, Chapter 13). Serial section information can be digitized and reconstructed in three-dimensions using computer techniques (Chapman, this volume, Chapter 15).
48
Benammi, Mouloud, Elina Aidona, Gildas Merceron, George D. Koufos, and Dimitris S. Kostopoulos. "Magnetostratigraphy and Chronology of the Lower Pleistocene Primate Bearing Dafnero Fossil Site, N. Greece." Quaternary 3, no. 3 (July 26, 2020): 22. http://dx.doi.org/10.3390/quat3030022.
Full textAbstract:
This paper aims to contribute to the stratigraphic and geochronological evaluation of the primate bearing Dafnero fossil site of Northern Greece by means of lithostratigraphic, paleomagnetic and paleontological analyses. The 60 m thick fossiliferous deposits of fluviatile origin are recognized as representing a typical braided-river sequence unconformably overlying molassic sediments. Rock magnetic investigations indicate the presence of both medium and low coercivity minerals. Paleomagnetic sampling of the Dafnero sediments yielded a stable magnetic remanence, and the characteristic remanent magnetization directions pass reversal test with dual polarity. Based on calibration from mammal fossils, the normal polarity magnetozone N1 located in the upper third of the studied section could correlate with chron C2n (the Olduvai subchron), suggesting that the fossil horizon is within C2r with an extrapolated age of 2.4–2.3 Ma and rather closer to the upper age limit. The results allow the re-calibration of several middle Villafranchian assemblages of S. Balkans and the correlation of the corresponding mammal fauna with the environmental shifts of Praetiglian, as it is recorded in climatostratigraphic data from the Black Sea.
49
Mai, Hartmut, Katharina v. Salis Perch-Nielsen, Helmut Willems, and Ton Romein. "Fossil Coccospheres from the K/T Boundary Section from Geulhemmerberg, the Netherlands." Micropaleontology 43, no. 3 (1997): 281. http://dx.doi.org/10.2307/1485829.
Full text
50
Basile, Angelo. "Preface to special section: WHEC 2013 – H 2 production from fossil fuels." International Journal of Hydrogen Energy 39, no. 32 (October 2014): 18583–84. http://dx.doi.org/10.1016/j.ijhydene.2014.10.002.
Full text