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Global Paleoclimate Indicators

Global paleoclimate indicators are the proxies sensitive to global paleoclimatic environment changes. They are mostly derived from marine sediments. Paleoclimate indicators derived from terrestrial sediments, on the other hand, are commonly influenced by local tectonic movements and paleogeographic variations. Factors governing the Earth's climate system include plate tectonics, which controls the configuration of continents, the interplay between the atmosphere and the ocean, and the Earth's orbital characteristics (Milankovitch cycles). Global paleoclimate indicators are established based on the information extracted from the analyses of geologic materials, including biological, geochemical and mineralogical data preserved in marine sediments. Indicators are generally grouped into three categories; paleontological, geochemical and lithological.

Paleontological indicators

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Sedimentary records are influenced by local topography and oceanic and atmospheric currents. Proxies of global climatic significance are, however, less ambiguous in paleotemperature interpretation. Marine biota have offered by far the most proxies for paleotemperature, of which the microfossils, because of their widespread, abundance and sensitive to latitudinal changes, have provided many primary important paleotemperature indicators. Identification of latitudinal indices species is usually the first attempt to tie their presence in sediments to paleotemperature fluctuations. Other properties of marine biota, including morphology, abundance, diversity, and geochemistry have also been successfully established as paleoclimate indicators. More complex statistical analyses (factor analysis, principal component, etc.) of biogeography have been able to link fauna assemblages to water masses for paleo-current reconstruction. List below are some key paleontological tools utilized by scientists to reconstruct paleotemperature history.[citation needed]

Foraminferals

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Because of their widespread distribution and abundance in sediments, forams have been the most extensively explored for their biological characters linked to paleoclimatic and paleoecologic reconstructions. Numerous reports have documented both planktonic and benthic forams as proxies for paleotemperature. These include the studies of morphological and biogeographical responses to surface temperature.[citation needed]

Morphology

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Size
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Investigations of planktonic foraminiferal population indicate that tropical species attain their largest test sizes in tropical waters, and polar species reach maximum sizes in polar waters. Species living in subtropical and subpolar waters decrease in test size with both increasing and decreasing temperature.[1]

The proloculus (the first chamber) sizes of benthic forams are affected by sea water temperature and their mean has been used as proxy for paleoclimatic investigations.[2]

Mean test diameters of the planktonic foraminifer Orbulina universa have been used to interpret sea surface temperature history in Somali Basin. R-mode factor and Q-mode cluster analyses define five significant factor assemblages and five clusters reflecting different environmental characteristics, including increased oxygenation, high surface productivity.[3]

Coiling direction
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A number of forams have been cited to have different coiling directions in response to surface temperature. Globierina pachyderma, for example, exhibits dominant population of right coiling direction in cold water vs. left in warm water,[4] and the ratio of these two forms have been utilized to estimate paleotemperature.[5][6] A similar dependency of coiling directions on temperatures has been reported for Muricohebergella delrioensis in Cretaceous sediments.[7]

Globigerina bulloides, a benthic foram, has been documented for its coiling directions related to seawater temperatures in surface sediments of the southern Indian Ocean.[8]

A similar relationship has been documented for another benthic foram Bulinina marginata.[9]

Species diversity

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Planktonic foraminiferal species diversity depends on available niches, which are in turn related to ocean circulation. By correlation with stable isotope records, maximum diversity has been found to occur after the initiation of a glaciation period.[10]

Biogeography

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Since the deep sea cores became available in the 1960s, paleoclimatic indices of planktonic foraminifera from marine sediments have been used for paleoclimatic reconstruction. Among the early pioneers to apply foraminifera latitudinal abundances, Ericson and Wollin (1968) succeeded in establishing the Pleistocene glacial and interglacial cycles based on the ratios of cold and warm water species in tropical sediments.[11] Similar work was extended to subantarctic region by Kennett (1970), who, based on subpolar cold and warm water planktonic foraminferal species, reconstructed paleoclimatic changes in the Pleistocene, consistent in trends with those established in the tropical region.[12]

When drilling cores, which recovered longer sediment columns than piston cores, came along, paleoclimatic reconstruction investigations were pushed back further in geological times. A climatic curve in the Oligocene was constructed in the Gulf of Mexico by using warm water indicators (Turborotalia pseudoampliapertura, Globoquadrina tripartita, Dentoglobigerina globularis, Dentoglobigerina baroemoenensis, “Globigerina” ciperoensis and Globigerinoides groups, and Cassigerinella chipolensis) and cold water indicators (Catapsydrax spp., Globorotaloides spp., Subbotina angiporoides group, Globigerina s. str., and the tenuitellids).[13] A more extensive geographic coverage was investigated by Spezzaferri in 1995, who analyzed samples from drilling cores in the Atlantic, Indian and South Pacific Oceans and identified and grouped foraminifera into warmer, cooler, warm-temperate and cool-temperate indices. A paleoclimatic curve in the Oligocene and Miocene transition period was established and the curve was supported by the isotope data.[14]

A more sophisticated approach to reconstruct paleoclimate involves using factor analysis. Thompson (1981) was able to relate six foraminiferal assemblages from core top samples to present water masses in the western North Pacific. A transfer function was generated to link the assemblages to sea surface temperatures. A paleotemperature curve for the past 150,000 years was reconstructed by applying this transfer function to old sediments in the cores.[15]

Similar technique has been applied to the Eocene and Oligocene sediments and the forams have been categorized in surface, intermediate and deep water-mass groups. Thus water-mass stratification, in addition to paleotemperature fluctuation has been reconstructed.[16]

Coccolith

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A 15-degree of latitude shift has been noted for the distribution of some selected species of Coccoliths between recent sediments and mid-Wisconsin glacier sediments of the North Atlantic.[17] Concentrations of coccoliths in marine sediments appear to be related to surface temperatures as well. This is demonstrated by the quantitative analysis of coccolith assemblages in the western Mediterranean Pleistocene sediments.[18]

Radiolarians

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Because of their resistant to cold water dissolution, which severely destroys the calcareous planktonic fossils at depth worldwide, Radiolarians has become one of the most commonly studied siliceous planktonic fossils for paleotemperature reconstruction. Study of Radiolarians in the North Pacific deep sea cores has revealed that increases in both species diversity and abundance correspond to major glaciation events of the last 16 million years. Changes in Radiolarian compositions are also evident to reflect in general sea surface temperature.[19]

By applying statistical analyses (Q-mode factor analysis), many quantitative studies of Radiolarian assemblages from surface sediments have established a transfer function which enables the estimation of paleo-sea surface temperature. For example, Pisias et al. (1997) were able to identify assemblages representative to the present Pacific biogeography and used these assemblages to predict sea surface temperature of the last glacier maximum.[20]

Diatoms

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Diatom species in polar and subpolar marine environments commonly display a narrow range of ecological preferences, in terms of sea surface temperature and sea ice conditions. An established relationship between diatom assemblages and their ecological preferences in surface sediments, could, therefore, be applied to sediments below the surface. For example, statistical analyses of diatom in the Antarctic Peninsula surface sediments have established diatom assemblages indicative to sea ice and open marine conditions, and these assemblages have been used as proxies for glacial and interglacial stages respectively in the Holocene sediments.[21]

Diatom studies of lacustrine sediments in Siberia and Mongolia demonstrate a close relationship during the last glacial maximum between planktonic diatom diversity and paleoclimate through the correlation with oxygen isotope records, which represent global ice volume changes.[22]

Dinoflagellates

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Investigation on dinoflagellate cyst in the Mediterranean Sea has identified warm and cold temperate dinocyst species and these species have been used to reconstruct the paleoclimate changes during the past 30,000 years.[23]

Ostracods

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Using ostracod crustaceans as palaeoclimate proxies has been well established for the Quaternary. Not only their indicator species, but also the trace element and stable isotope geochemistry of their shells have been documented as evidence of past climate fluctuations.[24]

Geochemical Indicators

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Isotope

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Oxygen

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Its isotope fractionation is linked to water temperature and its isotope ratios from a variety of sources have been widely used to reconstruct paleoclimate. Oxygen isotope in calcium carbonates has become the most widely applied as geothermometer for estimating ancient ocean temperatures. The most successful applications of isotope paleoclimatology have been the study of foraminifera from deep-sea sediments. For instance, Shackleton and Kennett (1975) have established the Cenozoic paleotemperature history based on analyzing oxygen isotope composition of both planktonic and benthic foraminifera in the Antarctic region.[25] Since the variations in the 18O/16O ratio in marine fossil records are global, the oxygen isotope stratigraphy has been used for chronological correlation.[26]

Carbon

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Stable carbon isotope composition is another widely used proxy for interpreting paleoenvironment conditions. The Surface temperature fluctuation from the Paleocene to Miocene has been established based on carbon isotope data from foraminifera in Antarctic region.[25] The organic matter preserved in sediments records paleoecosystems, and its carbon isotope composition has been also utilized to reconstruct paleoclimatic evolution. For example, Rogers and Koons (1969) have reported that the carbon isotope ratios, derived from organic matter in Quaternary marine sediments in the Gulf of Mexico, correlate well with Pleistocene climate changes.[27]

Chen et al. (2011) have documented ancient climate fluctuations since the last glacial maximum based on soil samples in Tibet.[28] Other sources for organic carbon isotope used as proxies for paleoenvironment reconstruction include lacustrine deposits for lake level variations,[29] fossilized vertebrates for precipitation fluctuations,[30] oil shales for paleoecological and paleoclimate conditions.[31]

Biomarkers

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Lipid:In marine sediments, a stable lipid called IP25 (Ice Proxy with 25 carbon atoms), which is biosynthesized by sea-ice dwelling diatom, has been found to be generally related to spring sea-ice cover in the Arctic region, Thus this proxy could be used to reconstruct sea-ice coverage.[32] A different biomarker, IPSO25 (Ice Proxy Southern Ocean with 25 carbon atoms) has been documented as a useful proxy for the sea-ice cover in the Antarctic region.[33]

Lithological indicators

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Ice-rafted debris

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Among all the lithological indicators, ice-rafted debris (IRD) is the most useful tool to reconstruct paleoclimate. High concentrations of IRD evidence the glacial intervals during which icebergs likely traveled far from Polar Regions。In the South Pacific, IRD has been used as proxy for glaciation in the Cenozoic and a glaciation history has been established for the Subantarctic region. The history is also supported by the foraminifera species diversity data.[34]

In the western Arctic Ocean, investigation of ice-rafted debris has identified at least six glacial intervals in the last 1 million years. [35] Deep-sea cores with high rates of sedimentation allow high resolution analyses of IRD. In the North Pacific, records of IRD have delineated interstadials (short time thermal event during glacial interval), which could be correlated with the similar events in the North Atlantic.[36]

Marine carbonates

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Carbonate in marine sediments predominantly comes from calcifying organisms, with a minor contribution from diagenesis and precipitation. Biogenic calcium carbonate has two polymorphs; calcite by foraminifera and coccolith and aragonite by corals and pteropods. While the distribution of foraminifera is generally global, that of corals is subtropical to tropical. Hence the distribution of fossil corals is commonly used as proxy for paleolatitudes. Kiessling et al. (1999) have compiled a database for the “Phanerozoic reefs” including their paleopostions for paleoclimatological reconstructions [37] Maillet et al. (2021), based on the distribution of Carboniferous coral reefs demonstrated the warm paleoclimatic conditions during the Mississippian, characterized by the wide spread of coral reefs on the supercontinent of Pangea, and this is followed by early Pennsylvanian cooling, marked by rare occurrence of coral reefs.[38]

Oolitic limestone

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Marine carbonate ooids are formed in warm, supersaturated, shallow, highly agitated marine water intertidal environments, and their presence in geological records provides a key role in paleoclimatic and paleogeographic reconstructions. Huang et al. (2017), for example, based on the distribution of Permian ooids and glaciomarine diamictites, have repositioned the Baoshan Block in southwestern China, with respect to other Gondwana continents.[39]

References

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  1. ^ Hecht, Alan D. (25 June 1976). "Size Variations in Planktonic Foraminifera: Implications for Quantitative Paleoclimatic Analysis". Science. 192 (4246): 1330–1332. Bibcode:1976Sci...192.1330H. doi:10.1126/science.192.4246.1330. PMID 17739837.
  2. ^ Nigam, Rajiv; Rao, Aradhana S. (1 May 1987). "Proloculus size variation in recent benthic Foraminifera: Implications for paleoclimatic studies". Estuarine, Coastal and Shelf Science. 24 (5): 649–655. Bibcode:1987ECSS...24..649N. doi:10.1016/0272-7714(87)90104-1.
  3. ^ Gupta, A. K. (1 July 1997). "Paleoceanographic and paleoclimatic history of the Somali Basin during the Pliocene-Pleistocene; multivariate analyses of benthic foraminifera from DSDP Site 241 (Leg 25)". The Journal of Foraminiferal Research. 27 (3): 196–208. doi:10.2113/gsjfr.27.3.196.
  4. ^ Ericson, David B. (24 July 1959). "Coiling Direction of Globigerina pachyderma as a Climatic Index". Science. 130 (3369): 219–220. Bibcode:1959Sci...130..219E. doi:10.1126/science.130.3369.219. PMID 17816141. S2CID 29077070.
  5. ^ Kellogg, Thomas B. (1976). "Late Quaternary Climatic Changes: Evidence from Deep-Sea Cores of Norwegian and Greenland Seas". In Cline, R. M.; Hays, James D. (eds.). Investigation of Late Quaternary Paleoceanography and Paleoclimatology. Geological Society of America. pp. 77–110. ISBN 978-0-8137-1145-4.
  6. ^ Thompson, Peter R.; Shackleton, Nicholas J. (October 1980). "North Pacific palaeoceanography: late Quaternary coiling variations of planktonic foraminifer Neogloboquadrina pachyderma". Nature. 287 (5785): 829–833. Bibcode:1980Natur.287..829T. doi:10.1038/287829a0. S2CID 4321896.
  7. ^ Desmares, Delphine; Crognier, Nemo; Bardin, Jérémie; Testé, Marc; Beaudoin, Bernard; Grosheny, Danièle (March 2016). "A new proxy for Cretaceous paleoceanographic and paleoclimatic reconstructions: Coiling direction changes in the planktonic foraminifera Muricohedbergella delrioensis" (PDF). Palaeogeography, Palaeoclimatology, Palaeoecology. 445: 8–17. Bibcode:2016PPP...445....8D. doi:10.1016/j.palaeo.2015.12.021.
  8. ^ Malmgren, Björn A.; Kennett, James P. (1978). "Late Quaternary Paleoclimatic Applications of Mean Size Variations in Globigerina bulloides d'Orbigny in the Southern Indian Ocean". Journal of Paleontology. 52 (6): 1195–1207. JSTOR 1303930.
  9. ^ Collins, Laurel S. (June 1990). "The correspondence between water temperature and coiling direction in Bulimina". Paleoceanography. 5 (3): 289–294. Bibcode:1990PalOc...5..289C. doi:10.1029/PA005i003p00289.
  10. ^ Ottens, Janneke J.; Nederbragt, Alexandra J. (April 1992). "Planktic foraminiferal diversity as indicator of ocean environments". Marine Micropaleontology. 19 (1–2): 13–28. Bibcode:1992MarMP..19...13O. doi:10.1016/0377-8398(92)90019-G.
  11. ^ Ericson, David B.; Wollin, Goesta (13 December 1968). "Pleistocene Climates and Chronology in Deep-Sea Sediments: Magnetic reversals give a time scale of 2 million years for a complete Pleistocene with four glaciations". Science. 162 (3859): 1227–1234. doi:10.1126/science.162.3859.1227. PMID 17756330.
  12. ^ Kennett, James P. (February 1970). "Pleistocene paleoclimates and foraminiferal biostratigraphy in subantarctic deep-sea cores". Deep Sea Research and Oceanographic Abstracts. 17 (1): 125–140. Bibcode:1970DSRA...17..125K. doi:10.1016/0011-7471(70)90092-6.
  13. ^ Spezzaferri, Silvia; Premoli Silva, Isabella (February 1991). "Oligocene planktonic foraminiferal biostratigraphy and paleoclimatic interpretation from Hole 538A, DSDP Leg 77, Gulf of Mexico". Palaeogeography, Palaeoclimatology, Palaeoecology. 83 (1–3): 217–263. Bibcode:1991PPP....83..217S. doi:10.1016/0031-0182(91)90080-B.
  14. ^ Spezzaferri, Silvia (March 1995). "Planktonic foraminiferal paleoclimatic implications across the Oligocene-Miocene transition in the oceanic record (Atlantic, Indian and South Pacific)". Palaeogeography, Palaeoclimatology, Palaeoecology. 114 (1): 43–74. Bibcode:1995PPP...114...43S. doi:10.1016/0031-0182(95)00076-X.
  15. ^ Thompson, Peter R. (1981). "Planktonic foraminifera in the Western North Pacific during the past 150 000 years: Comparison of modern and fossil assemblages". Palaeogeography, Palaeoclimatology, Palaeoecology. 35: 241–279. Bibcode:1981PPP....35..241T. doi:10.1016/0031-0182(81)90099-7.
  16. ^ Keller, Gerta (August 1983). "Paleoclimatic analyses of middle Eocene through Oligocene planktic foraminiferal faunas". Palaeogeography, Palaeoclimatology, Palaeoecology. 43 (1–2): 73–94. Bibcode:1983PPP....43...73K. doi:10.1016/0031-0182(83)90049-4.
  17. ^ McIntyre, Andrew (8 December 1967). "Coccoliths as Paleoclimatic Indicators of Pleistocene Glaciation". Science. 158 (3806): 1314–1317. Bibcode:1967Sci...158.1314M. doi:10.1126/science.158.3806.1314. PMID 17801859. S2CID 29899719.
  18. ^ Flores, J. A.; Sierro, F. J.; Francés, G.; Vázquez, A.; Zamarren˜o, I. (1 February 1997). "The last 100,000 years in the western Mediterranean: sea surface water and frontal dynamics as revealed by coccolithophores". Marine Micropaleontology. 29 (3): 351–366. Bibcode:1997MarMP..29..351F. doi:10.1016/S0377-8398(96)00029-1.
  19. ^ Kamikuri, Shin-ichi; Nishi, Hiroshi; Motoyama, Isao (June 2007). "Effects of late Neogene climatic cooling on North Pacific radiolarian assemblages and oceanographic conditions". Palaeogeography, Palaeoclimatology, Palaeoecology. 249 (3–4): 370–392. Bibcode:2007PPP...249..370K. doi:10.1016/j.palaeo.2007.02.008.
  20. ^ Pisias, Nicklas G.; Roelofs, Adrienne; Weber, Mysti (June 1997). "Radiolarian-based transfer functions for estimating mean surface ocean temperatures and seasonal range". Paleoceanography. 12 (3): 365–379. Bibcode:1997PalOc..12..365P. doi:10.1029/97PA00582.
  21. ^ Taylor, F; Whitehead, J; Domack, E (February 2001). "Holocene paleoclimate change in the Antarctic Peninsula: evidence from the diatom, sedimentary and geochemical record". Marine Micropaleontology. 41 (1–2): 25–43. Bibcode:2001MarMP..41...25T. doi:10.1016/S0377-8398(00)00049-9.
  22. ^ Karabanov, Eugene; Williams, Douglas; Kuzmin, Mikhail; Sideleva, Valentina; Khursevich, Galina; Prokopenko, Alexander; Solotchina, Emilia; Tkachenko, Lilia; Fedenya, Svetlana; Kerber, Eugene; Gvozdkov, Alexander; Khlustov, Oleg; Bezrukova, Elena; Letunova, Polina; Krapivina, Svetlana (July 2004). "Ecological collapse of Lake Baikal and Lake Hovsgol ecosystems during the Last Glacial and consequences for aquatic species diversity". Palaeogeography, Palaeoclimatology, Palaeoecology. 209 (1–4): 227–243. Bibcode:2004PPP...209..227K. doi:10.1016/j.palaeo.2004.02.017.
  23. ^ Rouis-Zargouni, Imene; Turon, Jean-Louis; Londeix, Laurent; Essallami, Latifa; Kallel, Néjib; Sicre, Marie-Alexandrine (January 2010). "Environmental and climatic changes in the central Mediterranean Sea (Siculo–Tunisian Strait) during the last 30ka based on dinoflagellate cyst and planktonic foraminifera assemblages". Palaeogeography, Palaeoclimatology, Palaeoecology. 285 (1–2): 17–29. Bibcode:2010PPP...285...17R. doi:10.1016/j.palaeo.2009.10.015.
  24. ^ Horne, David J.; Holmes, Jonathan A.; Rodriguez-Lazaro, Julio; Viehberg, Finn A. (2012). Ostracoda as Proxies for Quaternary Climate Change. Developments in Quaternary Sciences. Vol. 17. pp. 305–315. doi:10.1016/B978-0-444-53636-5.00018-4. ISBN 978-0-444-53636-5.
  25. ^ a b Shackleton, N.J.; Kennett, J.P. (1975). "Paleotemperature History of the Cenozoic and the Initiation of Antarctic Glaciation: Oxygen and Carbon Isotope Analyses in DSDP Sites 277, 279 and 281". Initial Reports of the Deep Sea Drilling Project, 29. Vol. 29. doi:10.2973/dsdp.proc.29.117.1975.
  26. ^ Grossman, E.L.; Joachimski, M.M. (2020). "Oxygen Isotope Stratigraphy". Geologic Time Scale 2020. pp. 279–307. doi:10.1016/B978-0-12-824360-2.00010-3. ISBN 978-0-12-824360-2. S2CID 241419002.
  27. ^ Rogers, M. A.; Koons, C. B. (1969). "Organic Carbon Delta C13 Values from Quarternary Marine Sequences in the Gulf of Mexico: A Reflection of Paleotemperature Changes". Gulf Coast Association of Geological Societies Transactions. 19: 529–534.
  28. ^ Chen, Lingkang; Lai, Xulong; Zhao, Yinbing; Chen, Haixia; Ni, Zhongyun (December 2011). "Organic carbon isotope records of paleoclimatic evolution since the last glacial period in the Tangjia region, Tibet". Journal of Earth Science. 22 (6): 704–717. doi:10.1007/s12583-011-0221-6. S2CID 130293173.
  29. ^ Liu, Weiguo; Li, Xiangzhong; An, Zhisheng; Xu, Liming; Zhang, Qingle (June 2013). "Total organic carbon isotopes: A novel proxy of lake level from Lake Qinghai in the Qinghai–Tibet Plateau, China". Chemical Geology. 347: 153–160. Bibcode:2013ChGeo.347..153L. doi:10.1016/j.chemgeo.2013.04.009.
  30. ^ Hatzell, Garrett (1 July 2015). Paleoclimate Implications from Stable Isotope Analysis of Sedimentary Organic Carbon and Vertebrate Fossils from the Cedar Mountain Formation, UT, U.S.A. (Thesis).
  31. ^ Yavuz Pehlivanli, Berna; Koç, Şükrü; Sari, Ali (November 2014). "Carbon isotope (δ13C) characteristics of middle Miocene Çayirhan oil shales (Beypazari, Ankara/Turkey): Implications on paleoenvironment and paleoclimate". Fuel. 135: 427–434. doi:10.1016/j.fuel.2014.07.012.
  32. ^ Stoynova, Vera; Shanahan, Timothy M.; Hughen, Konrad A.; de Vernal, Anne (November 2013). "Insights into Circum-Arctic sea ice variability from molecular geochemistry". Quaternary Science Reviews. 79: 63–73. Bibcode:2013QSRv...79...63S. doi:10.1016/j.quascirev.2012.10.006.
  33. ^ Lamping, Nele; Müller, Juliane; Hefter, Jens; Mollenhauer, Gesine; Haas, Christian; Shi, Xiaoxu; Vorrath, Maria-Elena; Lohmann, Gerrit; Hillenbrand, Claus-Dieter (29 October 2021). "Evaluation of lipid biomarkers as proxies for sea ice and ocean temperatures along the Antarctic continental margin" (PDF). Climate of the Past. 17 (5): 2305–2326. Bibcode:2021CliPa..17.2305L. doi:10.5194/cp-17-2305-2021. S2CID 240248345.
  34. ^ Margolis, Stanley V.; Kennett, James P. (4 December 1970). "Antarctic Glaciation during the Tertiary Recorded in Sub-Antarctic Deep-Sea Cores". Science. 170 (3962): 1085–1087. Bibcode:1970Sci...170.1085M. doi:10.1126/science.170.3962.1085. PMID 17777827. S2CID 31920337.
  35. ^ Bischof, Jens; Clark, David L.; Vincent, Jean-Serge (December 1996). "Origin of ice-rafted debris: Pleistocene paleoceanography in the western Arctic Ocean". Paleoceanography. 11 (6): 743–756. Bibcode:1996PalOc..11..743B. doi:10.1029/96PA02557.
  36. ^ Hewitt, Antony T.; McDonald, Darcy; Bornhold, Brian D. (15 December 1997). "Ice-rafted debris in the North Pacific and correlation to North Atlantic climatic events". Geophysical Research Letters. 24 (24): 3261–3264. Bibcode:1997GeoRL..24.3261H. doi:10.1029/97GL03264.
  37. ^ Wolfgang Kiessling, Erik Flügel; Golonka, Jan (1999). "Paleoreef Maps: Evaluation of a Comprehensive Database on Phanerozoic Reefs". AAPG Bulletin. 83 (10): 1552–1587.
  38. ^ Maillet, Marine; Huang, Wen-Tao; Li, Xiao; Yang, Zhen-Yuan; Guan, Chang-Qing; Zhang, Yong-Li; Gong, En-Pu; Ueno, Katsumi; Samankassou, Elias (January 2021). "Late Pennsylvanian carbonate platform facies and coral reef: new insights from southern China (Guizhou Province)". Facies. 67 (1): 3. doi:10.1007/s10347-020-00613-w. PMC 7678634. PMID 33239835.
  39. ^ Huang, Hao; Jin, Xiaochi; Li, Fei; Shen, Yang (June 2017). "Permian oolitic carbonates from the Baoshan Block in western Yunnan, China, and their paleoclimatic and paleogeographic significance". International Journal of Earth Sciences. 106 (4): 1341–1358. Bibcode:2017IJEaS.106.1341H. doi:10.1007/s00531-016-1400-6. S2CID 133150093.
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