Figure 7 : Summary of global climate through the mid-to-late
Miocene. (a) Sea surface temperature estimates from Sunbird-1, fellow
low latitude ODP sites 850 (Zhang et al. , 2014) and 761
(Sosdian and Lear, 2020), mid latitude Northern Hemisphere ODP
site 1021 (LaRiviere et al., 2012), and mid-latitude Southern
Hemisphere site 1125 (Herbert et al., 2016), and high-latitude
Northern Hemisphere ODP Site 982 (Herbert et al. , 2016). ODP Site
761 data is displayed on an alternative axis as SST anomalies relative
to the baseline average from 16.0 – 15.5 Ma. (b) pCO2reconstructions, with Y axis on a log scale, of Sosdian et al.(2018) applying the CCD reconstruction of Pälike et al. (2012)
and the δ11BSW scenario ofGreenop et al. (2017), and Stoll et al. (2019) applying
temperature estimates from Bolton et al. (2016) and Zhang
et al. (2013). Confidence intervals (95%) are displayed as dashed
lines and error bars respectively. (c) Composite benthic
δ18O record showing data that have been smoothed by a
locally weighted function over 20 kyr (blue curve) and 1 Myr (red curve)
(Westerhold et al. , 2020). Blue, yellow, and gray panels indicate
intervals of ice sheet expansion across the Mid Miocene Climate
Transition (MMCT) associated with CO2 decline, the
steepening of latitudinal temperature gradeints in the absence of a
CO2 trend, and the Late Miocene Cooling (LMC).
5 Conclusions
Our Sunbird-1 sea surface temperature estimates from LA-ICP-MS Mg/Ca
analyses are in good agreement with those using the
δ18O paleo-thermometer on glassy foraminifera,
supporting the use of LA-ICP-MS micro-analysis across multiple specimens
for reconstructing paleotemperatures. This analytical technique has
allowed the reconstruction of reliable Mg/Ca derived paleotemperatures
using foraminifera whose bulk trace element ratios demonstrate
diagenetic contamination by authigenic coatings. This finding opens the
potential for Mg/Ca paleothermometry on other challenging time
intervals, and locations, where contaminant coatings have previously
inhibited the geochemical analysis of primary foraminiferal calcite. We
present new sea surface temperature records from planktic foraminiferal
Mg/Ca for the south west Indian Ocean between 13.5 Ma and 9.5 Ma.
Absolute estimates of 24-31⁰C suggest that sea surface temperature was
relatively constant through the interval, although our record also
suggests two intervals of regional cooling and freshening of surface
waters at 11.8 and 10.7 Ma. The late Miocene represented a key interval
in the transition of Earth’s climate to its modern state, including the
development of stronger latitudinal temperature gradients. Our new
temperature record suggests that different mechanisms may have been
responsible for this cooling. The initial cooling from
~10 Ma at mid to high latitudes in both hemispheres was
not associated with significant cooling at low latitudes. On the other
hand, the late Miocene cooling between ~7.5 and 5.5 Ma
was global in nature and associated with a drawdown in
pCO2. Further work should therefore explore the
mechanisms responsible for the enhanced polar amplification between 10
and 7.5 Ma, and the possibility of carbon cycle feedbacks contributing
to the subsequent late Miocene Cooling.
Acknowledgments, Samples, and Data
This study uses samples from the Sunbird-1 core provided by BG-Group.
All data from this study can be found in Table 1 and Supplementary
Tables S1 to S11,and aredeposited in the Zenodo online data repository
http://doi.org/10.5281/zenodo.4472994. We thank Alexandra Nederbragt and
Anabel Morte-Rodeñas for laboratory assistance. We thank the reviewers
and editor for their insightful comments that improved the manuscript.
This research was supported by NERC iCASE studentship BW/22003105
(M.G.N.), and NE/L009633/1 grant to C.H.L.
References
Anand, P., Elderfield, H., & Conte, M. H. (2003). Calibration of Mg/Ca
thermometry in planktonic foraminifera from a sediment trap time series.Paleoceanography, 18 (2).
https://doi.org/10.1029/2002PA000846
Aze, T., Ezard, T. H., Purvis, A., Coxall, H. K., Stewart, D. R., Wade,
B. S., & Pearson, P. N. (2011). A phylogeny of Cenozoic macroperforate
planktonic foraminifera from fossil data. Biological Reviews,
86 (4), 900-927. https://doi.org/10.1111/j.1469-185X.2011.00178.x
Backman, J., Raffi, I., Rio, D., Fornaciari, E., & Pälike, H. (2012).
Biozonation and biochronology of Miocene through Pleistocene calcareous
nannofossils from low and middle latitudes. Newsletters on
Stratigraphy, 45 (3), 221-244. 10.1127/0078-0421/2012/0022
Badger, M. P., Lear, C. H., Pancost, R. D., Foster, G. L., Bailey, T.
R., Leng, M. J., & Abels, H. A. (2013). CO2 drawdown following the
middle Miocene expansion of the Antarctic Ice Sheet.Paleoceanography, 28 (1), 42-53.
https://doi.org/10.1002/palo.20015
Barker, S., Greaves, M., & Elderfield, H. (2003). A study of cleaning
procedures used for foraminiferal Mg/Ca paleothermometry.Geochemistry, Geophysics, Geosystems, 4 (9).
https://doi.org/10.1029/2003GC000559
Bemis, B. E., Spero, H. J., Bijma, J., & Lea, D. W. (1998).
Reevaluation of the oxygen isotopic composition of planktonic
foraminifera: Experimental results and revised paleotemperature
equations. Paleoceanography, 13 (2), 150-160.
https://doi.org/10.1029/98PA00070
Bertlich, J., Nürnberg, D., Hathorne, E. C., De Nooijer, L. J., Mezger,
E. M., Kienast, M., et al. (2018). Salinity control on Na incorporation
into calcite tests of the planktonic foraminifera Trilobatus
sacculifer–evidence from culture experiments and surface sediments.Biogeosciences (BG), 15 (20), 5991-6018.
http://dx.doi.org/10.5194/bg-2018-164
Boyer, T. P., Antonov, J. I., Baranova, O. K., Coleman, C., Garcia, H.
E., Grodsky, A., et al. (2013). World Ocean Database 2013.
Boyle, E., & Keigwin, L. (1985). Comparison of Atlantic and Pacific
paleochemical records for the last 215,000 years: Changes in deep ocean
circulation and chemical inventories. Earth and Planetary Science
Letters, 76 (1), 135-150. http://doi.org/0012-821x/85/$03.30
Boyle, E. A. (1983). Manganese carbonate overgrowths on foraminifera
tests. Geochimica et Cosmochimica Acta, 47 (10), 1815-1819.
https://doi.org/10.1016/0016-7037(83)90029-7
Broecker, W. S., Peng, T.-H., & Beng, Z. (1982). Tracers in the
Sea : Lamont-Doherty Geological Observatory, Columbia University.
Chen, P., Yu, J., & Jin, Z. (2017). An evaluation of benthic
foraminiferal U/Ca and U/Mn proxies for deep ocean carbonate chemistry
and redox conditions. Geochemistry, Geophysics, Geosystems .
Article in Press. http://doi.org/10.1002/2016GC006730
Coggon, R. M., Teagle, D. A., Smith-Duque, C. E., Alt, J. C., & Cooper,
M. J. (2010). Reconstructing past seawater Mg/Ca and Sr/Ca from
mid-ocean ridge flank calcium carbonate veins. Science,
327 (5969), 1114-1117. http://doi.org/10.1126/science.1182252
Cramer, B., Miller, K., Barrett, P., & Wright, J. (2011). Late
Cretaceous–Neogene trends in deep ocean temperature and continental ice
volume: reconciling records of benthic foraminiferal geochemistry (δ18O
and Mg/Ca) with sea level history. Journal of Geophysical
Research: Oceans (1978–2012), 116 (C12).
https://doi.org/10.1029/2011JC007255
Cramwinckel, M. J., Huber, M., Kocken, I. J., Agnini, C., Bijl, P. K.,
Bohaty, S. M., et al. (2018). Synchronous tropical and polar temperature
evolution in the Eocene. Nature, 559 (7714), 382-386.
http://doi.org/10.1038/s41586-018-0272-2
Creech, J. B., Baker, J. A., Hollis, C. J., Morgans, H. E. G., & Smith,
E. G. C. (2010). Eocene sea temperatures for the mid-latitude southwest
Pacific from Mg/Ca ratios in planktonic and benthic foraminifera.Earth and Planetary Science Letters, 299 (3–4), 483-495.
http://dx.doi.org/10.1016/j.epsl.2010.09.039
de Nooijer, L. J., Hathorne, E. C., Reichart, G.-J., Langer, G., &
Bijma, J. (2014). Variability in calcitic Mg/Ca and Sr/Ca ratios in
clones of the benthic foraminifer Ammonia tepida. Marine
Micropaleontology, 107 , 32-43.
https://doi.org/10.1016/j.marmicro.2014.02.002
de Nooijer, L. J., van Dijk, I., Toyofuku, T., & Reichart, G. J.
(2017). The Impacts of Seawater Mg/Ca and Temperature on Element
Incorporation in Benthic Foraminiferal Calcite. Geochemistry,
Geophysics, Geosystems, 18 (10), 3617-3630.
http://doi.org/10.1002/2017GC007183Delaney, M. L., Be, A. W. H.,
& Boyle, E. A. (1985). Li, Sr, Mg, and Na in foraminiferal calcite
shelss from laboratory culture sediment traps, and sediment cores.Geochim. Cosmochim. Acta, 49 (6), 1327-1341.
https://doi.org/10.1016/0016-7037(85)90284-4
Detlef, H., Sosdian, S. M., Kender, S., Lear, C. H., & Hall, I. R.
(2019). Multi-elemental composition of authigenic carbonates in benthic
foraminifera from the eastern Bering Sea continental margin
(International Ocean Discovery Program Site U1343). Geochimica et
Cosmochimica Acta . https://doi.org/10.1016/j.gca.2019.09.025
Dickson, J. A. D. (2002). Fossil Echinoderms As Monitor of the Mg/Ca
Ratio of Phanerozoic Oceans. Science, 298 (5596), 1222-1224.
http://doi.org/10.1126/science.1075882
Eggins, S., De Deckker, P., & Marshall, J. (2003). Mg/Ca variation in
planktonic foraminifera tests: implications for reconstructing
palaeo-seawater temperature and habitat migration. Earth and
Planetary Science Letters, 212 (3), 291-306.
https://doi.org/10.1016/S0012-821X(03)00283-8
Eggins, S. M., Sadekov, A., & De Deckker, P. (2004). Modulation and
daily banding of Mg/Ca in Orbulina universa tests by symbiont
photosynthesis and respiration: a complication for seawater thermometry?Earth and Planetary Science Letters, 225 (3), 411-419.
https://doi.org/10.1016/j.epsl.2004.06.019
Evans, D. and Müller, W. (2012). Deep time foraminifera Mg/Ca
paleothermometry: Nonlinear correction for secular change in seawater
Mg/Ca. Paleoceanography, 27(4).https://doi.org/10.1029/2012PA002315
Evans, D., Erez, J., Oron, S. and Müller, W., (2015a). Mg/Ca-temperature
and seawater-test chemistry relationships in the shallow-dwelling large
benthic foraminifera Operculina ammonoides. Geochimica et Cosmochimica
Acta, 148, pp.325-342. https://doi.org/10.1016/j.gca.2014.09.039
Evans, D., Bhatia, R., Stoll, H., & Müller, W. (2015b). LA‐ICPMS Ba/Ca
analyses of planktic foraminifera from the Bay of Bengal: Implications
for late Pleistocene orbital control on monsoon freshwater flux.Geochemistry, Geophysics, Geosystems, 16 (8), 2598-2618.
https://doi.org/10.1002/2015GC005822
Evans, D., Brierley, C., Raymo, M. E., Erez, J., & Müller, W. (2016).
Planktic foraminifera shell chemistry response to seawater chemistry:
Pliocene-Pleistocene seawater Mg/Ca, temperature and sea level change.Earth and Planetary Science Letters . Article in Press.
http://doi.org/10.1016/j.epsl.2016.01.013
Evans, D., & Müller, W. (2018). Automated Extraction of a Five‐Year
LA‐ICP‐MS Trace Element Dataset of Ten Common Glass and Carbonate
Reference Materials: Long‐Term Data Quality, Optimisation and Laser Cell
Homogeneity. Geostandards and Geoanalytical Research .
https://doi.org/10.1111/ggr.12204
Evans, D., Sagoo, N., Renema, W., Cotton, L. J., Müller, W., Todd, J.
A., et al. (2018). Eocene greenhouse climate revealed by coupled clumped
isotope-Mg/Ca thermometry. Proceedings of the National Academy of
Sciences of the United States of America, 115 (6), 1174-1179. Article.
http://doi.org/10.1073/pnas.1714744115
Evans, D., Wade, B. S., Henehan, M., Erez, J., & Müller, W. (2016).
Revisiting carbonate chemistry controls on planktic foraminifera Mg /
Ca: Implications for sea surface temperature and hydrology shifts over
the Paleocene-Eocene Thermal Maximum and Eocene-Oligocene transition.Climate of the Past, 12 (4), 819-835. Article.
http://doi.org/10.5194/cp-12-819-2016
Farrell, J. W., Raffi, I., Janecek, T. R., Murray, D. W., Levitan, M.,
Dadey, K. A., et al. (1995). 35. LATE NEOGENE SEDIMENTATION PATTERNS IN
THE EASTERN EQUATORIAL PACIFIC OCEAN1.
Fehrenbacher, J. S., & Martin, P. A. (2014). Exploring the dissolution
effect on the intrashell Mg/Ca variability of the planktic foraminifer
Globigerinoides ruber. Paleoceanography, 29 (9), 854-868.
https://doi.org/10.1002/2013PA002571
Fehrenbacher, J. S., Spero, H. J., Russell, A. D., Vetter, L., &
Eggins, S. (2015). Optimizing LA-ICP-MS analytical procedures for
elemental depth profiling of foraminifera shells. Chemical
Geology, 407-408 , 2-9.
http://doi.org/10.1016/j.chemgeo.2015.04.007
Foster, G. L., Lear, C. H., & Rae, J. W. B. (2012). The evolution of
pCO2, ice volume and climate during the middle Miocene. Earth and
Planetary Science Letters, 341–344 (0), 243-254.
http://dx.doi.org/10.1016/j.epsl.2012.06.007
Foster, G. L., & Rae, J. W. (2015). Reconstructing Ocean pH with Boron
Isotopes in Foraminifera. Annual Review of Earth and Planetary
Sciences (0).
https://www.annualreviews.org/doi/full/10.1146/annurev-earth-060115-012226#_i63
Geerken, E., De Nooijer, L. J., Van DIjk, I., & Reichart, G.-J. (2018).
Impact of salinity on element incorporation in two benthic foraminiferal
species with contrasting magnesium contents. Biogeosciences,
15 (7), 2205-2218. https://doi.org/10.5194/bg-15-2205-2018
Gray, W. R., & Evans, D. (2019). Nonthermal influences on Mg/Ca in
planktonic foraminifera: a review of culture studies and application to
the Last Glacial Maximum. Paleoceanography and Paleoclimatology,
34 (3), 306-315. https://doi.org/10.1029/2018PA003517
Gray, W. R., Weldeab, S., Lea, D. W., Rosenthal, Y., Gruber, N., Donner,
B., & Fischer, G. (2018). The effects of temperature, salinity, and the
carbonate system on Mg/Ca in Globigerinoides ruber (white): A global
sediment trap calibration. Earth and Planetary Science Letters,
482 , 607-620. Article. http://doi.org/10.1016/j.epsl.2017.11.026
Greenop, R., Foster, G. L., Wilson, P. A., & Lear, C. H. (2014). Middle
Miocene climate instability associated with high‐amplitude CO2
variability. Paleoceanography, 29 (9), 845-853.
https://doi.org/10.1002/2014PA002653
Greenop, R., Hain, M. P., Sosdian, S. M., Oliver, K. I. C., Goodwin, P.,
Chalk, T. B., et al. (2017). A record of Neogene seawater δ11B
reconstructed from paired δ11B analyses on benthic and planktic
foraminifera. Climate of the Past, 13 (2), 149-170. Article.
https://doi.org/10.5194/cp-13-149-2017
Guillong, M., L. Meier, D., Allan, M., A. Heinrich, C., & Yardley, B.
(2008). SILLS: A MATLAB-based program for the reduction of laser
ablation ICP-MS data of homogeneous materials and inclusions (Vol. 40).
Hasenfratz, A. P., Martínez-García, A., Jaccard, S. L., Vance, D.,
Wälle, M., Greaves, M., & Haug, G. H. (2016). Determination of the
Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca
temperatures for Mn-rich contaminant phases. Earth and Planetary
Science Letters . http://dx.doi.org/10.1016/j.epsl.2016.10.004
Hasiuk, F.J. and Lohmann, K.C., 2010. Application of calcite Mg
partitioning functions to the reconstruction of paleocean Mg/Ca.
Geochimica et Cosmochimica Acta, 74(23), pp.6751-6763.
https://doi.org/10.1016/j.gca.2010.07.030
Henehan, M. J., Rae, J. W. B., Foster, G. L., Erez, J., Prentice, K. C.,
Kucera, M., et al. (2013). Calibration of the boron isotope proxy in the
planktonic foraminifera Globigerinoides ruber for use in palaeo-CO2
reconstruction. Earth and Planetary Science Letters, 364 ,
111-122. https://doi.org/10.1016/j.epsl.2012.12.029
Herbert, T. D., Lawrence, K. T., Tzanova, A., Peterson, L. C.,
Caballero-Gill, R., & Kelly, C. S. (2016). Late Miocene global cooling
and the rise of modern ecosystems. Nature Geoscience .
https://doi.org/10.1038/ngeo2813
Hines, B. R., Hollis, C. J., Atkins, C. B., Baker, J. A., Morgans, H. E.
G., & Strong, P. C. (2017). Reduction of oceanic temperature gradients
in the early Eocene Southwest Pacific Ocean. Palaeogeography,
Palaeoclimatology, Palaeoecology, 475 , 41-54.
https://doi.org/10.1016/j.palaeo.2017.02.037
Holland, K., Branson, O., Haynes, L. L., Hönisch, B., Allen, K. A.,
Russell, A. D., et al. (2020). Constraining multiple controls on
planktic foraminifera Mg/Ca. Geochimica et Cosmochimica Acta,
273 , 116-136. Article. https://doi.org/10.1016/j.gca.2020.01.015
Hollis, C., Dunkley Jones, T., Anagnostou, E., Bijl, P., Cramwinckel,
M., Cui, Y., et al. (2019). The DeepMIP contribution to PMIP4:
methodologies for selection, compilation and analysis of latest
Paleocene and early Eocene climate proxy data, incorporating version 0.1
of the DeepMIP database. Geoscientific Model Development
Discussions, 2019 , 1-98.
http://dx.doi.org/10.5194/gmd-12-3149-2019
Hollis, C., Hines, B., Littler, K., Villasante-Marcos, V., Kulhanek, D.,
Strong, C., et al. (2015). The Paleocene–Eocene Thermal Maximum at DSDP
Site 277, Campbell Plateau, southern Pacific Ocean.
https://doi.org/10.5194/cp-11-1009-2015
Hönisch, B., Allen, K. A., Lea, D. W., Spero, H. J., Eggins, S. M.,
Arbuszewski, J., et al. (2013). The influence of salinity on Mg/Ca in
planktic foraminifers–Evidence from cultures, core-top sediments and
complementary δ18O. Geochimica et Cosmochimica Acta, 121 ,
196-213. https://doi.org/10.1016/j.gca.2013.07.028
Horita, J., Zimmermann, H., & Holland, H. D. (2002). Chemical evolution
of seawater during the Phanerozoic: Implications from the record of
marine evaporites. Geochimica et Cosmochimica Acta, 66 (21),
3733-3756. https://doi.org/10.1016/S0016-7037(01)00884-5
Huang, Y., Clemens, S. C., Liu, W., Wang, Y., & Prell, W. L. (2007).
Large-scale hydrological change drove the late Miocene C4 plant
expansion in the Himalayan foreland and Arabian Peninsula.Geology, 35 (6), 531-534. https://doi.org/10.1130/G23666A.1
Hut, G. (1987). Consultants’ group meeting on stable isotope reference
samples for geochemical and hydrological investigations.
Jiang, S., Wise, S., & Wang, Y. (2007). Cause of the middle/late
Miocene carbonate crash: dissolution or low productivity. Paper
presented at the Proceedings of the Ocean Drilling Program. Scientific
Results.
Jochum, K. P., Weis, U., Stoll, B., Kuzmin, D., Yang, Q., Raczek, I., et
al. (2011a). Determination of reference values for NIST SRM 610–617
glasses following ISO guidelines. Geostandards and Geoanalytical
Research, 35 (4), 397-429.
https://doi.org/10.1111/j.1751-908X.2011.00120.x
Jochum, K.P., Wilson, S.A., Abouchami, W., Amini, M., Chmeleff, J.,
Eisenhauer, A., Hegner, E., Iaccheri, L.M., Kieffer, B., Krause, J. and
McDonough, W.F., (2011b). GSD‐1G and MPI‐DING reference glasses for in
situ and bulk isotopic determination. Geostandards and Geoanalytical
Research, 35(2), pp.193-226.
https://doi.org/10.1111/j.1751-908X.2010.00114.x
Keller, G. (1985). Depth stratification of planktonic foraminifers in
the Miocene ocean. The Miocene ocean: paleoceanography and
biogeography, 163 , 177-196.
Keller, G., & Barron, J. A. (1987). Paleodepth distribution of Neocene
deep‐sea hiatuses. Paleoceanography, 2 (6), 697-713.
https://doi.org/10.1029/PA002i006p00697
Kısakürek, B., Eisenhauer, A., Böhm, F., Garbe-Schönberg, D., & Erez,
J. (2008). Controls on shell Mg/Ca and Sr/Ca in cultured planktonic
foraminiferan, Globigerinoides ruber (white). Earth and Planetary
Science Letters, 273 (3-4), 260-269.
https://doi.org/10.1016/j.epsl.2008.06.026
Knorr, G., Butzin, M., Micheels, A., & Lohmann, G. (2011). A warm
Miocene climate at low atmospheric CO2 levels. Geophysical
Research Letters, 38 (20). https://doi.org/10.1029/2011GL048873
Koho, K., de Nooijer, L., & Reichart, G. (2015). Combining benthic
foraminiferal ecology and shell Mn/Ca to deconvolve past bottom water
oxygenation and paleoproductivity. Geochimica et Cosmochimica
Acta, 165 , 294-306. https://doi.org/10.1016/j.gca.2015.06.003
LaRiviere, J. P., Ravelo, A. C., Crimmins, A., Dekens, P. S., Ford, H.
L., Lyle, M., & Wara, M. W. (2012). Late Miocene decoupling of oceanic
warmth and atmospheric carbon dioxide forcing. Nature, 486 (7401),
97. https://doi.org/10.1038/nature11200
Lear, C. H., Coxall, H. K., Foster, G. L., Lunt, D. J., Mawbey, E. M.,
Rosenthal, Y., et al. (2015). Neogene ice volume and ocean temperatures:
Insights from infaunal foraminiferal Mg/Ca paleothermometry.Paleoceanography . https://doi.org/10.1002/2015PA002833
Lear, C. H., Mawbey, E. M., & Rosenthal, Y. (2010). Cenozoic benthic
foraminiferal Mg/Ca and Li/Ca records: Toward unlocking temperatures and
saturation states. Paleoceanography, 25 (4).
https://doi.org/10.1029/2009pa001880
Lear, C. H., Rosenthal, Y., & Slowey, N. (2002). Benthic foraminiferal
Mg/Ca-paleothermometry: A revised core-top calibration. Geochimica
et Cosmochimica Acta, 66 (19), 3375-3387.
https://doi.org/10.1016/S0016-7037(02)00941-9
LeGrande, A. N., & Schmidt, G. A. (2006). Global gridded data set of
the oxygen isotopic composition in seawater. Geophysical Research
Letters, 33 (12). https://doi.org/10.1029/2006GL026011
Lemarchand, D., Gaillardet, J., Lewin, E., & Allegre, C. (2002). Boron
isotope systematics in large rivers: implications for the marine boron
budget and paleo-pH reconstruction over the Cenozoic. Chemical
Geology, 190 (1), 123-140.
https://doi.org/10.1016/S0009-2541(02)00114-6
Longerich, H. P., Jackson, S. E., & Günther, D. (1996).
Inter-laboratory note. Laser ablation inductively coupled plasma mass
spectrometric transient signal data acquisition and analyte
concentration calculation. Journal of analytical atomic
spectrometry, 11 (9), 899-904.
https://doi.org/10.1039/JA9961100899
Lübbers, J., Kuhnt, W., Holbourn, A. E., Bolton, C. T., Gray, E., Usui,
Y., et al. (2019). The middle to late Miocene “Carbonate Crash” in the
equatorial Indian Ocean. Paleoceanography and Paleoclimatology,
34 (5), 813-832. https://doi.org/10.1029/2018PA003482
Lunt, D. J., Flecker, R., Valdes, P. J., Salzmann, U., Gladstone, R., &
Haywood, A. M. (2008). A methodology for targeting palaeo proxy data
acquisition: A case study for the terrestrial late Miocene. Earth
and Planetary Science Letters, 271 (1), 53-62.
https://doi.org/10.1016/j.epsl.2008.03.035
Lyle, M., Dadey, K. A., & Farrell, J. W. (1995). 42. The Late Miocene
(11–8 Ma) Eastern Pacific Carbonate Crash: evidence for reorganization
of deep-water Circulation by the closure of the Panama Gateway.1995 Proceedings of the Ocean Drilling Program, Scientific
Results, 138 .
Mayk, D., Fietzke, J., Anagnostou, E., & Paytan, A. (2020).
LA-MC-ICP-MS study of boron isotopes in individual planktonic
foraminifera: A novel approach to obtain seasonal variability patterns.Chemical Geology, 531 . Article.
https://doi.org/10.1016/j.chemgeo.2019.119351
Müller, P. J., Kirst, G., Ruhland, G., Von Storch, I., & Rosell-Melé,
A. (1998). Calibration of the alkenone paleotemperature index U 37 K′
based on core-tops from the eastern South Atlantic and the global ocean
(60 N-60 S). Geochimica et Cosmochimica Acta, 62 (10), 1757-1772.
https://doi.org/10.1016/S0016-7037(98)00097-0
Nairn, M. (2018). Mid-Late Miocene climate constrained by a new
Laser Ablation ICP-MS set up. Cardiff University,
Nürnberg, D., Bijma, J., & Hemleben, C. (1996). Assessing the
reliability of magnesium in foraminiferal calcite as a proxy for water
mass temperatures. Geochimica et Cosmochimica Acta, 60 (5),
803-814.
Pagani, M., Freeman, K. H., & Arthur, M. A. (1999). Late Miocene
Atmospheric CO<sub>2</sub>
Concentrations and the Expansion of
C<sub>4</sub> Grasses.Science, 285 (5429), 876-879.
https://doi.org/10.1126/science.285.5429.876
Pearson, P. N., & Burgess, C. E. (2008). Foraminifer test preservation
and diagenesis: comparison of high latitude Eocene sites.Geological Society, London, Special Publications, 303 (1), 59-72.
https://doi.org/10.1144/SP303.5
Pearson, P. N., Ditchfield, P. W., Singano, J., Harcourt-Brown, K. G.,
Nicholas, C. J., Olsson, R. K., et al. (2001). Warm tropical sea surface
temperatures in the Late Cretaceous and Eocene epochs. Nature,
413 (6855), 481-487. https://doi.org/10.1038/35097000
Pena, L., Calvo, E., Cacho, I., Eggins, S., & Pelejero, C. (2005).
Identification and removal of Mn‐Mg‐rich contaminant phases on
foraminiferal tests: Implications for Mg/Ca past temperature
reconstructions. Geochemistry, Geophysics, Geosystems, 6 (9).
https://doi.org/10.1029/2005GC000930
Petersen, J., Barras, C., Bézos, A., La, C., De Nooijer, L. J., Meysman,
F. J. R., et al. (2018). Mn/Ca intra- and inter-test variability in the
benthic foraminifer Ammonia tepida. Biogeosciences, 15 (1),
331-348. Article. https://doi.org/10.5194/bg-15-331-2018
Pisias, N., & Mix, A. (1988). Aliasing of the geologic record and
the search for long-period Milankovitch cycles (Vol. 3).
Pound, M. J., Haywood, A. M., Salzmann, U., Riding, J. B., Lunt, D. J.,
& Hunter, S. J. (2011). A Tortonian (Late Miocene, 11.61–7.25Ma)
global vegetation reconstruction. Palaeogeography,
Palaeoclimatology, Palaeoecology, 300 (1), 29-45.
https://doi.org/10.1016/j.palaeo.2010.11.029
Raffi, I., Wade, B.S., Pälike, H., Beu, A.G., Cooper, R., Crundwell,
M.P., Krijgsman, W., Moore, T., Raine, I., Sardella, R. and Vernyhorova,
Y.V. (2020). The Neogene Period. In Geologic Time Scale 2020, (pp.
1141-1215). Elsevier.https://doi.org/10.1016/B978-0-12-824360-2.00029-2.
Raitzsch, M., & Hönisch, B. (2013). Cenozoic boron isotope variations
in benthic foraminifers. Geology, 41 (5), 591-594.
https://doi.org/10.1130/g34031.1
Raitzsch, M., Kuhnert, H., Hathorne, E. C., Groeneveld, J., & Bickert,
T. (2011). U/Ca in benthic foraminifers: A proxy for the deep‐sea
carbonate saturation. Geochemistry, Geophysics, Geosystems,
12 (6). https://doi.org/10.1029/2010GC003344
Rathmann, S., Hess, S., Kuhnert, H., & Mulitza, S. (2004). Mg/Ca ratios
of the benthic foraminifera Oridorsalis umbonatus obtained by laser
ablation from core top sediments: Relationship to bottom water
temperature. Geochemistry, Geophysics, Geosystems, 5 (12).
https://doi.org/10.1029/2004gc000808
Reichart, G.-J., Jorissen, F., Anschutz, P., & Mason, P. R. (2003).
Single foraminiferal test chemistry records the marine environment.Geology, 31 (4), 355-358.
https://doi.org/10.1130/0091-7613(2003)031<0355:SFTCRT>2.0.CO;2
Rosenthal, Y., Boyle, E. A., & Slowey, N. (1997). Temperature control
on the incorporation of magnesium, strontium, fluorine, and cadmium into
benthic foraminiferal shells from Little Bahama Bank: Prospects for
thermocline paleoceanography. Geochimica et Cosmochimica Acta,
61 (17), 3633-3643.
Rousselle, G., Beltran, C., Sicre, M.-A., Raffi, I., & De Rafélis, M.
(2013). Changes in sea-surface conditions in the Equatorial Pacific
during the middle Miocene–Pliocene as inferred from coccolith
geochemistry. Earth and Planetary Science Letters, 361 , 412-421.
http://dx.doi.org/10.1016/j.epsl.2012.11.003
Russell, A. D., Hönisch, B., Spero, H. J., & Lea, D. W. (2004). Effects
of seawater carbonate ion concentration and temperature on shell U, Mg,
and Sr in cultured planktonic foraminifera. Geochimica et
Cosmochimica Acta, 68 (21), 4347-4361.
https://doi.org/10.1016/j.gca.2004.03.013
Sadekov, A., Eggins, S. M., De Deckker, P., & Kroon, D. (2008).
Uncertainties in seawater thermometry deriving from intratest and
intertest Mg/Ca variability in Globigerinoides ruber.Paleoceanography, 23 (1).
https://doi.org/10.1029/2007pa001452
Sadekov, A. Y., Eggins, S. M., & De Deckker, P. (2005).
Characterization of Mg/Ca distributions in planktonic foraminifera
species by electron microprobe mapping. Geochemistry, Geophysics,
Geosystems, 6 (12). https://doi.org/10.1029/2005GC000973
Schiebel, R., & Hemleben, C. (2017). Planktic Foraminifers in the
Modern Ocean .
Schlitzer, R., Ocean Data View, odv.awi.de,
(2018).
Seki, O., Schmidt, D., Schouten, S., C. Hopmans, E., Sinninghe-Damste,
J., & D. Pancost, R. (2012). Paleoceanographic changes in the
Eastern Equatorial Pacific over the last 10 Myr (Vol. 27).
Sexton, P. F., Wilson, P. A., & Pearson, P. N. (2006). Microstructural
and geochemical perspectives on planktic foraminiferal
preservation:“Glassy” versus “Frosty”. Geochemistry,
Geophysics, Geosystems, 7 (12).
https://doi.org/10.1029/2006GC001291
Sosdian, S. M., Greenop, R., Hain, M. P., Foster, G. L., Pearson, P. N.,
& Lear, C. H. (2018). Constraining the evolution of Neogene ocean
carbonate chemistry using the boron isotope pH proxy. Earth and
Planetary Science Letters, 498 , 362-376.
https://doi.org/10.1016/j.epsl.2018.06.017
Sosdian, S.M. and Lear, C.H. (2020). Initiation of the Western Pacific
Warm Pool at the Middle Miocene Climate Transition?Paleoceanography and Paleoclimatology, 35(12) , e2020PA003920.
https://doi.org/10.1029/2020PA003920
Stewart, D. R. M., Pearson, P. N., Ditchfield, P. W., & Singano, J. M.
(2004). Miocene tropical Indian Ocean temperatures: evidence from three
exceptionally preserved foraminiferal assemblages from Tanzania.Journal of African Earth Sciences, 40 (3), 173-189.
https://doi.org/10.1016/j.jafrearsci.2004.09.001
Stoll, H. M., Guitian, J., Hernandez-Almeida, I., Mejia, L. M., Phelps,
S., Polissar, P., et al. (2019). Upregulation of phytoplankton carbon
concentrating mechanisms during low CO2 glacial periods and implications
for the phytoplankton pCO2 proxy. Quaternary Science Reviews,
208 , 1-20. https://doi.org/10.1016/j.quascirev.2019.01.012
Super, J. R., Thomas, E., Pagani, M., Huber, M., O’Brien, C., & Hull,
P. M. (2018). North Atlantic temperature and p CO2 coupling in the
early-middle Miocene. Geology, 46 (6), 519-522.
https://doi.org/10.1130/G40228.1
Thil, F., Blamart, D., Assailly, C., Lazareth, C. E., Leblanc, T.,
Butsher, J., & Douville, E. (2016). Development of laser ablation
multi-collector inductively coupled plasma mass spectrometry for boron
isotopic measurement in marine biocarbonates: New improvements and
application to a modern Porites coral. Rapid Communications in
Mass Spectrometry, 30 (3), 359-371. Article.
https://doi.org/10.1002/rcm.7448
van Hinsbergen, D. J., de Groot, L. V., van Schaik, S. J., Spakman, W.,
Bijl, P. K., Sluijs, A., et al. (2015). A paleolatitude calculator for
paleoclimate studies. PloS one, 10 (6).
https://doi.org/DOI:10.1371/journal.pone.0126946
Vetter, L., Kozdon, R., Mora, C. I., Eggins, S. M., Valley, J. W.,
Hönisch, B., & Spero, H. J. (2013). Micron-scale intrashell oxygen
isotope variation in cultured planktic foraminifers. Geochimica et
Cosmochimica Acta, 107 , 267-278.
https://doi.org/10.1016/j.gca.2012.12.046
von der Heydt, A., & Dijkstra, H. A. (2006). Effect of ocean gateways
on the global ocean circulation in the late Oligocene and early Miocene.Paleoceanography, 21 (1).
https://doi.org/10.1029/2005pa001149
Wade, B. S., Pearson, P. N., Berggren, W. A., & Pälike, H. (2011).
Review and revision of Cenozoic tropical planktonic foraminiferal
biostratigraphy and calibration to the geomagnetic polarity and
astronomical time scale. Earth-Science Reviews, 104 (1), 111-142.
https://doi.org/10.1016/j.earscirev.2010.09.003
Yu, J., & Elderfield, H. (2008). Mg/Ca in the benthic
foraminifera< i> Cibicidoides
wuellerstorfi</i> and< i>
Cibicidoides mundulus</i>: Temperature versus
carbonate ion saturation. Earth and Planetary Science Letters,
276 (1), 129-139. https://doi.org/10.1016/j.epsl.2008.09.015
Zachos, J. C., Stott, L. D., & Lohmann, K. C. (1994). Evolution of
early Cenozoic marine temperatures. Paleoceanography, 9 (2),
353-387. https://doi.org/10.1029/93PA03266
Zhang, Y. G., Pagani, M., & Liu, Z. (2014). A 12-Million-Year
Temperature History of the Tropical Pacific Ocean. Science,
344 (6179), 84-87. https://doi.org/10.1126/science.1246172