Publications

 

Journal Articles

*Current or former Northwestern student author

^#Funded collaborator or student of funded collaborator

Waldeck A. R.*, Sageman B. B., and Jacobson A. D. (In prep) Radiogenic Sr isotopes ratios spanning Cretaceous Ocean Anoxic Event 2 record hydrothermal activity and ocean mixing.

Wan C.*, Kitch G. D.*, Sarvian N. L.*, Waldeck A. R.*, Hurtgen M. T., Sageman B. B., and Jacobson A. D. (Submitted) Stable Ca and Sr Isotope Records Reveal Variations in Coccolithophore Photosynthesis and Calcification Across the Paleocene-Eocene Thermal Maximum.

Pittman Cetiner J. E., Berelson W. M., Rollins N. E., Liu X., Pavia F. J., Waldeck A. R.*, Dong S., Fleger K., Barnhart H. A., Quinan M., Wani R. P., Rafter P. A., Jacobson A. D., Byrne R. H., Adkins J. F. (In review) Carbonate dissolution fluxes in deep-sea sediments as determined from in situ porewater profiles in a transect across the saturation horizon. Geochimica et Cosmochimica Acta.

Osburn, M. R., Selensky, M. J., Beddows, P. A., Jacobson, A. D., DeFranco, K. and Merediz-Alonso, G. (2023) Microbial biogeography of the eastern Yucatán carbonate aquifer. Applied and Environmental Microbiology, 89, e01682-23.1. 

Wang J.*, Jacobson A. D., Sageman B. B., and Hurtgen M. T. (2023) Application of the δ^44/40Ca-δ^88/86Sr multi-proxy to Namibian Marinoan cap carbonates. Geochimica et Cosmochimica Acta 353, 13-27.

Wang J.*, Tarhan L. G., Jacobson A. D., Oehlert A. M., and Planavsky N. J. (2023) The evolution of the marine carbonate factory. Nature 615, 265–269.

Jones M. M.*, Sageman B. B., Selby D., Jacobson A. D., Batenburg S. J., Riquier L., MacLeod K. G., Huber B. T., Bogus K. A., Tejada M. L. G., Kuroda J., and Hobbs R. W. (2023) Abrupt episode of mid-Cretaceous ocean acidification triggered by massive volcanism. Nature Geoscience 16, 169-174.

Kitch G. D.*, Jacobson A. D., Sageman B. B., Coccioni R., Chung-Swanson T.*, Ankney M. E., and Hurtgen M. T., (2022) Calcium isotope ratios of malformed foraminifera reveal biocalcification stress preceded Oceanic Anoxic Event 2. Communications Earth & Environment 3, 315.

Linzmeier B. J.*, Jacobson A. D., Sageman B. B., Hurtgen M. T., Ankney M. E., Masterson A., and Landman N. H. (2022) Isotope systematics of subfossil, historical, and modern Nautilus macromphalus from New Caledonia. PLoS One 17, e0277666.

Nelson C.*, Jacobson A. D., Kitch G. D., and Weisenberger T. (2022) Controls on riverine calcium isotope ratios during basalt weathering in the Skagafjörður watershed, Iceland. Geochimica et Cosmochimica Acta 333, 216-241.

Nelson C.*, Jacobson A. D., Kitch G. D.*, and Weisenberger T. B. (2021) Large calcium isotope fractionations by zeolite minerals from Iceland. Communications Earth & Environment 2, 206.

Erhardt A. M., Douglas G., Jacobson A. D., Wimpenny J., Yin Q.-Z., and Paytan A. (2021) Assessing sedimentary detrital Pb isotopes as a dust tracer in the Pacific Ocean. Paleoceanography and Paleoclimatology 36, e2020PA004144. DOI: 10.1029/2020PA004144.

Chakrabarti R., Surajit M., Jacobson A. D., Mills M., Romaniello S. J., and Vollstaedt H. (2021) Techniques, challenges, new developments, and the way forward for calcium isotope measurements. Chemical Geology 581, 120398, DOI: 10.1016/j.chemgeo.2021.120398.

Kitch G. D.*, Jacobson A. D., Hurtgen M. T., Sageman B. B., Harper D. T., and Zachos J. C. (2021) Calcium isotope composition of Morozovella Velascoensis over the Late Paleocene-Early Eocene. Geology 49, 723-727.

Wang J.*, Jacobson A. D., Sageman B. B., and Hurtgen M. T. (2021) Stable Ca and Sr isotopes support volcanically-triggered biocalcification crisis during Oceanic Anoxic Event 1a. Geology 49, 515-519.

Linzmeier B. J.*, Jacobson A. D., Sageman B. B., Hurtgen M. T., Ankney M. E., Petersen S. V., Tobin T. S., Kitch G. D., and Wang J. (2020) Calcium isotope evidence for environmental variability before and across the Cretaceous-Paleogene mass extinction. Geology 38, 34-38.

Wang J.*, Jacobson A. D., Zhang H., Ramezani J., Sageman B. B., Hurtgen M. T., Bowring S. A., and Shen S-Z. (2019) Coupled δ^44/40Ca, ⁸⁷Sr/⁸⁶Sr, and δ^88/86Sr geochemistry across the end-Permian mass extinction event. Geochimica et Cosmochimica Acta 262, 143-165.

Alkire M. B.^#, Jacobson A. D., Macdonald R. W., and Lehn G. O.* (2019) Assessing the contributions of meteoric water and sea ice meltwater in estuaries across the Canadian Arctic Archipelago. Estuaries and Coasts 42, 1226-1248.

Connolly C. T.^#, Khosh M. S.^#, Burkart G., Douglas T. A.^#, Holmes R. M., Jacobson A. D., Tank S. E., and McClelland J. W.^# (2018) Watershed slope as a predictor of fluvial dissolved organic matter and nitrate concentrations across geographical space and catchment size in the arctic. Environmental Research Letters DOI: 10.1088/1748-9326/aae35d.

Andrews M. G.* and Jacobson A. D. (2018) Controls on the solute geochemistry of subglacial discharge from the Russell Glacier, Greenland Ice Sheet determined by radiogenic and stable Sr isotope ratios. Geochimica et Cosmochimica Acta 239, 312-329.

Andrews M. G.*,  Jacobson A. D., Osburn M. R., and Flynn T. M. (2018) Dissolved carbon dynamics in meltwaters from the Russell Glacier, Greenland Ice Sheet. Journal of Geophysical Research-Biogeosciences 123, 2922-2940.

Kristall B.*, Jacobson A. D., Sageman B. B., and Hurtgen M. T. (2018) Coupled strontium-sulfur cycle modeling and the Early Cretaceous sulfur isotope record. Palaeogeography, Palaeoclimatology, Palaeoecology 496, 305-322.

Bush R. T.*, Berke M. A., and Jacobson A. D. (2017) Plant Water δD and δ¹⁸O of Tundra Species from West Greenland. Arctic, Antarctic, and Alpine Research 49, 341-358.

Lehn G. O.*, Jacobson A. D., Douglas T. A.^#, McClelland J. W. ^#, Barker A. ^#, and Khosh M. S. ^# (2017) Constraining seasonal active layer dynamics and chemical weathering reactions occurring in North Slope Alaskan watersheds with major ion and isotope (δ³⁴S_SO4, δ¹³C_DIC, ⁸⁷Sr/⁸⁶Sr, δ^44/40Ca, and δ^44/42Ca) measurements. Geochimica et Cosmochimica Acta 217, 399-420.

Andrews M. G.* and Jacobson A. D. (2017) The radiogenic and stable Sr isotope geochemistry of basalt weathering in Iceland: Role of hydrothermal calcite and implications for long-term climate regulation. Geochimica et Cosmochimica Acta 215, 247-262.

Khosh M. S.^#, McClelland J. W.^#, Jacobson A. D., Douglas T. A.^#, Barker A. J.^# and Lehn G. O.* (2017) Seasonality of dissolved nitrogen from spring melt to fall freeze-up in Alaskan Arctic tundra and mountain streams. Journal of Geophysical Research-Biogeosciences DOI: 10.1002/2016JG003377.

Alkire M. B.^#, Jacobson A. D., Lehn G. O.*, Macdonald R. W., and Rossi M. W. (2017) On the geochemical heterogeneity of rivers draining the Canadian Arctic Archipelago. Journal of Geophysical Research-Biogeosciences DOI: 10.1002/2016JG003723.  

Mills J. V.*, Gomes M. L.*, Kristall B.*, Sageman B. B., Jacobson A. D., and Hurtgen M. T. (2017) Massive volcanism, evaporite deposition, and the chemical evolution of the Early Cretaceous ocean. Geology 45, 475-478.

Kristall B.*, Jacobson A. D., and Hurtgen M. T. (2017) Modeling the Phanerozoic seawater radiogenic strontium isotope record: A case study of the Late Jurassic-Early Cretaceous. Palaeogeography, Palaeoclimatology, Palaeoecology 472, 163-176.

Holmden C., Jacobson A. D., Sageman B. B., and Hurtgen M. T. (2016) Response of the Cr isotope proxy to Cretaceous Ocean Anoxic Event 2 in a pelagic carbonate succession from the Western Interior Seaway. Geochimica et Cosmochimica Acta 186, 277-295.

Andrews M. G.*, Jacobson A. D., Lehn G. O.*, Horton T. W., and Craw D. (2016) Radiogenic and stable Sr isotope ratios (⁸⁷Sr/⁸⁶Sr, δ^88/86Sr) as tracers of chemical weathering and biogeochemical cycling in the Milford Sound region of Fiordland, New Zealand. Geochimica et Cosmochimica Acta 173, 284-303.

Alkire M.^#, Jacobson A. D., Lehn G. O.*, and MacDonald R. (2015) Small rivers could have big impact on Arctic Ocean. Eos, Transactions American Geophysical Union 96, DOI: 10.1029/2015EO034005.

Lemarchand D., Jacobson A. D., Cividini D., Chabaux F. (2015) The major ion, ⁸⁷Sr/⁸⁶Sr, and δ¹¹B geochemistry of groundwater in the Wyodak-Anderson Coal Bed aquifer (Powder River Basin, Wyoming, USA). Comptes Rendus Geoscience 347, 348-357.

Moore J. M.* and Jacobson A. D. (2015) Seasonally varying contributions to urban CO₂ in the Chicago, IL, USA region: Insights from a high-resolution CO₂ concentration and δ¹³C record. Elementa: Science of the Anthropocene DOI: 10.12952/journal.elementa.000052.

Lehn G. O.* and Jacobson A. D. (2015) Optimization of a ⁴⁸Ca–⁴³Ca double-spike MC-TIMS method for measuring Ca isotope ratios (δ^44/40Ca and δ^44/42Ca): limitations from filament reservoir mixing. Journal of Analytical Atomic Spectrometry 30, 1571-1581.

Jacobson A. D., Andrews M. G.*, Lehn G. O.*, and Holmden C. (2015) Silicate versus carbonate weathering in Iceland: New insights from Ca isotopes. Earth and Planetary Science Letters 416, 132-142.

Du Vivier A. D. C., Jacobson A. D., Lehn G. O.*, Selby D., Hurtgen M. T., and Sageman B. B. (2015) Ca isotope stratigraphy across the Cenomanian-Turonian OAE 2: links between volcanism, seawater geochemistry, and the carbonate fractionation factor. Earth and Planetary Science Letters 416, 121-131.

Barker A. J.^#, Douglas T. A.^#, Jacobson A. D., McClelland J. W.^#, Ilgen A. G., Khosh M. S.^#, Lehn G. O.*, and Trainor T. P. (2014) Late season mobilization of trace metals in small Alaskan Arctic watersheds as a proxy for permafrost active layer dynamics. Chemical Geology 381, 180-193.

Melin A. D., Crowley B. E., Brown S. T., Wheatley P. V., Moritz G. L., Tuh Yit Yu F., Bernard H., DePaolo D. J., Jacobson A. D., and Dominy N. J. (2014) Calcium and carbon stable isotope ratios as paleodietary indicators. American Journal of Physical Anthropology 154, 633-643.

Li D.*, Jacobson A. D., and McInerney D. (2014) A reactive-transport model for examining tectonic and climatic controls on chemical weathering and atmospheric CO₂ consumption in granitic regolith. Chemical Geology 365, 30-42.

Lehn G. O.*, Jacobson A. D., and Holmden C. (2013) Precise analysis of Ca isotope ratios (δ^44/40Ca) using an optimized ⁴³Ca-⁴²Ca double-spike MC-TIMS method. International Journal of Mass Spectrometry 351, 69-75.

Moore J.*, Jacobson A. D., Holmden C., and Craw D. (2013) Tracking the relationship between mountain uplift, silicate weathering, and long-term CO₂ consumption with Ca isotopes: Southern Alps, New Zealand. Chemical Geology 341, 110-127.

Ryu J.-S.* and Jacobson A. D. (2012) CO₂ evasion from the Greenland Ice Sheet: A new carbon-climate feedback. Chemical Geology 320-321, 80-95.

Ryu J.-S.*, Jacobson A. D., Holmden C., Lundstrom C. C., and Zhang Z. (2011) The major ion, δ^44/40Ca, δ^44/42Ca, and δ^26/24Mg, geochemistry of granite weathering at pH = 1 and T = 25°C: power-law processes and the relative reactivity of minerals. Geochimica et Cosmochimica Acta 75, 6004-6026.

Jacobson A. D., Zhang Z.*, Lundstrom C. C., and Huang F. (2010) Behavior of Mg isotopes during dedolomitization in the Madison Aquifer, South Dakota. Earth and Planetary Science Letters 297, 446-452.

Jacobson A. D. and Wu L.* (2009) Microbial dissolution of calcite at T = 28°C and ambient P_CO2. Geochimica et Cosmochimica Acta 73, 2314-2331.

Jacobson A. D. and Holmden C. (2008) δ⁴⁴Ca evolution in a carbonate aquifer and its bearing on the equilibrium isotope fractionation factor for calcite. Earth and Planetary Science Letters 270, 349-353.

Wu L.*, Jacobson A. D., and Hausner M. (2008) Characterization of elemental release during microbe-granite interactions at T = 28°C. Geochimica et Cosmochimica Acta 72, 1076-1095.

Gierlowski-Kordesch E. H., Jacobson A. D., Blum J. D., and Valero Garces B. L. (2008) Watershed reconstruction of a Paleocene–Eocene lake basin using Sr isotopes in carbonate rocks. Geological Society of American Bulletin 120, 85-95.

Wu L.*, Jacobson A. D., Chen H.-C., Hausner M. (2007) Characterization of elemental release during microbe basalt interactions. Geochimica et Cosmochimica Acta 71, 2224-2239.

Jacobson A. D. and Holmden C. (2006) Calcite dust and the atmospheric supply of Nd to the Japan Sea. Earth and Planetary Science Letters 244, 418-430.

Chamberlain C. P., Waldbauer J. R., and Jacobson A. D. (2005) Strontium, hydrothermal systems and steady-state chemical weathering in active mountain belts. Earth and Planetary Science Letters 238, 351-366.

Jacobson A. D. and Wasserburg G. J. (2005) Anhydrite and the Sr isotope evolution of groundwater in a carbonate aquifer. Chemical Geology 214, 331-250.

Jacobson A. D. (2004) Has the atmospheric supply of dissolved calcite dust to seawater influenced the evolution of marine ⁸⁷Sr/⁸⁶Sr ratios over the past 2.5 million years? Geochemistry, Geophysics, Geosystems (G3) DOI: 10.1029/2004GC000750.

Jacobson A. D. and Blum J. D. (2003) Relationship between mechanical erosion and atmospheric CO₂ consumption in the New Zealand Southern Alps. Geology 31, 865-868.

Jacobson A. D., Blum J. D., Chamberlain C. P., Craw D., and Koons P. O. (2003) Climatic and tectonic controls on chemical weathering in the New Zealand Southern Alps. Geochimica et Cosmochimica Acta 67, 29-46.

Jacobson A. D., Blum J. D., and Walter L. M. (2002) Reconciling the elemental and Sr isotope composition of Himalayan weathering fluxes: Insights from the carbonate geochemistry of stream waters. Geochimica et Cosmochimica Acta 66, 3417-3429.

Jacobson A. D., Blum J. D., Chamberlain C. P., Poage M. A., and Sloan V. F. (2002) Ca/Sr and Sr isotope systematics of a Himalayan glacial chronosequence: Carbonate versus silicate weathering rates as a function of landscape surface age. Geochimica et Cosmochimica Acta 66, 13-27.

Jacobson A. D. and Blum J. D. (2000) Ca/Sr and ⁸⁷Sr/⁸⁶Sr geochemistry of disseminated calcite in Himalayan silicate rocks from Nanga Parbat: Influence on river water chemistry. Geology 28, 463- 466.

Blum J. D., Gazis, C. A., Jacobson A. D., and Chamberlain C. P. (1998). Carbonate versus silicate weathering in the Raikhot Watershed within the High Himalayan Crystalline Series. Geology 26, 411-414.

 

Abstracts

*Northwestern student author

^#Funded collaborator or student of funded collaborator

Wan C.*, Podrecca L. G.*, Waldeck A. R., Selby D., Sageman B. B., and Jacobson A. D. (2024) Calcium and osmium isotope records across Cretaceous OAE1a and OAE2 suggest similar biological responses in the global carbonate factory. American Geophysical Union Fall Meeting, Washington, D. C.

Wan C.*, Clemente J. N., Podrecca L. G.*, Jacobson A. D., Nielsen S. G., and Sageman B. B. (2024) Unusual pattern of deep ocean anoxia during Oceanic Anoxic Event 1a revealed by novel thallium isotope analysis. American Geophysical Union Fall Meeting, Washington, D. C.

Waldeck A. R.*, Olsen E. K., Leapaldt H. C., McCormick M. L., Kump L. R., Jacobson A. D., and Ingalls M. (2024) Paired calcium (δ^44/40Ca) and dual clumped (Δ₄₇-Δ₄₈) isotope geochemistry of a summer whiting event at Fayetteville Green Lake, NY. American Geophysical Union Fall Meeting, Washington, D. C.

Ulrich R. N., Lucarelli J. K., Waldeck A. R.*, Tashjian A., Tarique M., Purgstaller B., Goetschl K. E., Ni P., Eagle R. A., Blättler C., Dietzel M., Jacobson A. D., Tipper E., and Tripati A. K.Cation isotope (δ^7/6Li, δ^26/24Mg, and δ^44/40Ca) and concentration (Li/Ca, Mg/Ca) investigations into the transformation of synthetic amorphous calcium magnesium carbonates (ACMC) at different temperatures. American Geophysical Union Fall Meeting, Washington, D. C.

Wan C.*, Kitch G. D., Sarvian N. L., Waldeck A. R., Sageman B. B., and Jacobson A. D. (2024) Combined Stable Ca, Sr, and O Isotope Records Reveal Coccolithophore Calcification Stress Before and Across the PETM. V. M. Goldschmidt Conference, Chicago, IL.

Chen J.*, Wan C.* , Waldeck A. R., Huber B., Jacobson A. D., and Sageman B. B. (2024) Biocalcification stress and a foraminiferal extinction at the Aptian-Albian Boundary. V. M. Goldschmidt Conference, Chicago, IL.

Waldeck A. R.*, Jacobson A. D., Sageman B. B., Linzmeier B. J., Kitch G. D., Sarvian N. L., Wan C. and Hurtgen M. (2024) Radiogenic Sr isotope ratios spanning Cretaceous OAE2 record hydrothermal activity and ocean mixing. V. M. Goldschmidt Conference, Chicago, IL.

Žurovec O., Magee R., Rateau F., McDermott F, Jacobson A. D., Bryson M. (2024) Towards sustainable crop production: Assessing the agro-environmental impacts and carbon sequestration potential of various soil amendments, ERW24, Yale University, New Haven, CT.

Jacobson A. D., Wang J., Jones M. M., Coccioni R., Petersen S. V., and Sageman B. B. (2024) High-Precision Ca Isotope Measurements Reveal Potential Biomineralization Crises During Major Carbon Cycle Perturbations. North American Paleontological Convention, Ann Arbor, MI.

Wang J., Jacobson A. D., Sageman B. B., and Hurtgen M. T. (2024) Biocalcification crisis indicated by stable Ca and Sr isotopes during OAE1a. North American Paleontological Convention, Ann Arbor, MI.

Chen J.*, Wan C.*, Waldeck, A. R., Huber, B., Jacobson A. D., and Sageman B. B. (2024) Biocalcification stress and faunal turnover at the Aptian-Albian Boundary. North American Paleontological Convention, Ann Arbor, MI.

Wan C.*, Kitch G. D., Sarvian N. L., Waldeck A. R.*, Sageman B. B., and Jacobson A. D. (2024) Combined O, Ca, and Sr isotope records reveal coccolithophore feedbacks across the Paleocene Eocene Thermal Maximum. North American Paleontological Convention, Ann Arbor, MI.

Wan C.*, Waldeck A. R.*, Wang J., Sarvian N. L.*, Kitch G. D., Cui Y., Hurtgen M. T., Sageman B. B., and Jacobson A. D. (2023) Multiple calcium isotope records constrain global ocean acidification across the Paleocene-Eocene Thermal Maximum. American Geophysical Union Fall Meeting, San Francisco, CA.

Small D.*, Waldeck A. R.*, Jacobson A. D., Sageman B. B., and Linzmeier B. J.(2023) Assessing Cretaceous Pycnodonte Oysters as Calcium Isotope Archives. American Geophysical Union Fall Meeting, San Francisco, CA.

Linzmeier B. J., Kita N. K., Kitajima K., Ankney M. E., Jacobson, A. D., and Valley, J.W. (2023) Advancing in-situ microanalytical calcium isotope geochemistry by SIMS. Geological Society of America Annual Meeting, Pittsburgh, PA.

Waldeck A. R.*, Jacobson A. D., Sageman B. B., and Hurtgen M. T. (2022) Ca and Sr isotopes in a southern Mexico carbonate platorm. American Geophysical Union Fall Meeting, Chicago, IL.

Small D.*, Waldeck A. R.*, Jacobson A. D., Sageman B. B., Linzmeier B. J. (2022) Assessing the variability of stable calcium isotopes in Cretaceous carbonate oyster fossils. American Geophysical Union Fall Meeting, Chicago, IL.

Wang J., Tarhan L. G., Jacobson A. D., Oehlert A. M., and Planavsky N. J. (2022) The evolution of the marine carbonate factory. American Geophysical Union Fall Meeting, Chicago, IL.

Wang J., Tarhan L. G., Jacobson A. D., Oehlert A. M., and Planavsky N. J. (2022) The evolution of the marine carbonate factory. Geological Society of America Annual Meeting, Denver, CO.

Sarvian N. L.*, Jacobson A. D., Chung-Swanson T., Hurtgen M. T., Osburn M. R., and Bergmann K. D. (2022) Constraining the Shuram δ¹³C Excursion with the δ^44/40Ca-δ^88/86Sr multi-proxy. V. M. Goldschmidt Conference, Honolulu, HI.

Nelson C.*, Jacobson A. D., and Weisenberger T. B.^# (2022) Investigating basalt weathering in the Icelandic highlands with Ca and C isotopes. V. M. Goldschmidt Conference, Honolulu, HI.

Sarvian N. L.*, Jacobson A. D., Hurtgen M. T., Osburn M. R., and Bergmann K. D. (2021) Application of the δ^44/40Ca-δ^88/86Sr multi-proxy to the Shuram carbon isotope excursion. V. M. Goldschmidt Conference, Lyon, France.

Nelson C.*, Jacobson A. D., Kitch G. D.*, and Weisenberger T. B.# (2021) Ca-O bonding controls the Ca isotope geochemistry of hydrothermal zeolites from Iceland. V. M. Goldschmidt Conference, Lyon, France.

Kitch G. D.*, Jacobson A. D., Coccioni R., Chung-Swanson T*., Hurtgen M. T., and Sageman B. B., (2021) Bulk carbonate and foraminiferal calcium isotope ratios indicate calcification stress preceded Oceanic Anoxic Event 2. V. M. Goldschmidt Conference, Lyon, France.

Kitch G. D.*, Jacobson A. D., Coccioni R., Harper D. T., Chung-Swanson T*., Hurtgen M. T., Sageman B. B., and Zachos J. C. (2020) Foraminiferal calcium isotope response to carbon cycle perturbations: comparison of the Paleocene-Eocene Thermal Maximum to Ocean Anoxic Event 2. Fall American Geophysical Union Conference, San Francisco, CA.

Wang J.*, Kitch G. A.*, Linzmeier B. J., Jacobson A. D., Sageman B. B., and Hurtgen M. T. (2020) Calcium isotope variability across ancient candidate ocean acidification events. Geological Society of America Annual Meeting, Online.

Sarvian N. L.*, Jacobson A. D., Osburn M. R., Maloof A. C., and Hurtgen M. T. (2020) Stable Sr Isotopes and the Neoproterozoic carbonate cycle. Geological Society of America Annual Meeting, Online.

Wang J.*, Jacobson A. D., Sageman B. B., and Hurtgen M. T. (2020) Stable Ca and Sr isotopes indicate biocalcification crisis during OAE1a. V. M. Goldschmidt Conference, Honolulu, HI.

Nelson C.*, Jacobson A. D., and Weisenberger T. B. (2020) Ca isotope study of hyaloclastite weathering in the Icelandic highlands. V. M. Goldschmidt Conference, Honolulu, HI.

Kitch G. D*., Jacobson A. D., Hurtgen M. T., Sageman B. B., Harper D. T., and Zachos J. C. (2020) Calcium isotope response of Morozovella spp. to Paleocene-Eocene Ocean Acidification. V. M. Goldschmidt Conference, Honolulu, HI.

Sarvian N. L.*, Jacobson A. D., Hurtgen M. T., Osburn M. R., and Maloof A. C. (2020) Radiogenic and stable Sr isotope records preceding the Sturtian snowball earth event. V. M. Goldschmidt Conference, Honolulu, HI.

Jones M. M., Sageman B. B., Selby D. S., Jacobson A. D., Huber B. T., Batenburg S. J., Riquier L., Hasegawa T., Petrizzo M. R., MacLeod K. G., Hobbs R. W., and Bogus K. A. (2019) Volcanically initiated shoaling of the marine calcite compensation depth during Oceanic Anoxic Event 2 (~94 Ma). Fall American Geophysical Union Conference, San Francisco, CA.

Linzmeier B. J.*, Jacobson A. D., Sageman B. B., Hurtgen M. T., Ankney M. E., Petersen S. V., and Landman N. H. (2019) Calibrating cephalopod isotope responses using Nautilus macromphalus from New Caledonia. Geological Society of America Annual Meeting, Phoenix, AZ.

Kitch G. A.*, Jacobson A. D., Hurtgen M. T., Sageman B. B., Harper D. T., and Zachos J. C. (2019) Calcium isotope composition of Morozovella Velascoensis over the Paleocene Eocene Thermal Maximum. 13^th International Conference on Paleoceanography, Sydney, Australia.

Kitch G. A.*, Jacobson A. D., Ankney M. E., Masterson A. L., Hurtgen M. T., and Sageman B. B. (2019) Calcium isotope composition (δ^44/40Ca) of bulk carbonate spanning Ocean Anoxic Event 2: kinetic effects or diagenesis? V. M. Goldschmidt Conference, Barcelona, Spain.

Nelson C.*, Jacobson A. D., and Weisenberger T. B. (2019) Large fractionation of Ca isotopes by zeolite minerals from Iceland. V. M. Goldschmidt Conference, Barcelona, Spain.

Linzmeier B. J.*, Jacobson A. D., Sageman B. B., Hurtgen M. T., Ankney M. E., Petersen S. V., and Tobin T. S. (2019) Calcium isotope evidence for environmental change before and across the K-Pg extinction. V. M. Goldschmidt Conference, Barcelona, Spain.

Sarvian N. L.*, Hurtgen M. T., Jacobson A. D., and Maloof A. C. (2019) Stable strontium isotope (δ^88/86Sr) record of pre-Sturtian carbonate rocks spanning a large δ¹³C anomaly. V. M. Goldschmidt Conference, Barcelona, Spain.

Jones M. M., Petersen S. V., Sageman B. B., Selby D., Jacobson A. D., Singer B. S., and Jicha B. R. (2019) Thermal and paleoceanographic responses to OAE2 from Δ₄₇ geochemistry and a refined chronostratigraphy. V. M. Goldschmidt Conference, Barcelona, Spain.

Linzmeier B. J.*, Jacobson A. D., Sageman B. B., Hurtgen M. T., Ankney M. E., and Landman N. H. (2018) Using sub-fossil and historic Nautilus to test potential links between calcium isotope fractionation and pCO₂. Geological Society of America Annual Meeting, Indianapolis, IN.

Linzmeier B. J.*, Jacobson A. D., Sageman B. B., Hurtgen M. T., Ankney M. E., Petersen S. V., and Tobin T. S. (2018) Linking Deccan volcanism and the bolide impact with Ca isotope stratigraphy from the Late Maastrichtian of Seymour Island, Antarctica. V. M. Goldschmidt Conferece, Boston, MA.

Holmden C., Jacobson A. D., Sageman B. B., Hurtgen M. T., and Dickson A. (2018) Deciphering the unexpected response of the Cr isotope proxy to OAE 2. V. M. Goldschmidt Conference, Boston, MA.

Hurtgen M. T., Wang J.*, Jacobson A. D., and Sageman B. B. (2017) Radiogenic and stable Sr isotope records reveal changes in chemical weathering and carbonate burial rates following Marinoan glaciation. Geological Society of America Annual Meeting, Seattle, WA.

Wang J.*, Jacobson A. D., Zhang H., Ramezani J., Sageman B. B., Hurtgen M. T., Bowring S. A., and Shen S.-Z. (2017) Ca and Sr isotope records support ocean acidification during end-Permian mass extinction. Fall American Geophysical Union Conference, New Orleans, LA.

Kitch G. A.*, Jacobson A. D., Hurtgen M. T., Sageman B. B., Harper D. T., and Zachos J. C. (2017) Calcium isotope (δ^44/40Ca) composition of Morozovella Velascoensis during the Paleocene Eocene Thermal Maximum ocean acidification event. Fall American Geophysical Union Conference, New Orleans, LA.

Jacobson A. D. and Andrews M. G.* (2017) The impact of subsurface silicate weathering on the long-term C cycle. V. M. Goldschmidt Conference, Paris, France.

Andrews M. G.*, Jacobson A. D., Osburn M. R., and Flynn T. M. (2017) Microbial CO₂ production at the Greenland Ice Sheet margin. V. M. Goldschmidt Conference, Paris, France.

Holmden C., Jacobson A. D., Hurtgen M. T., and Sageman B. B. (2017) A Cr isotope fingerprint of submarine LIP volcanism. V. M. Goldschmidt Conference, Paris, France.

Fernandez N. M., Druhan J. L., Potrel A., and Jacobson A. D. (2016) Surface area dependence of calcium isotopic reequilibration in carbonates: Implications for isotopic signatures in the weathering zone. Fall American Geophysical Union Conference, San Francisco, CA.

Alkire M. B.^#, Jacobson A. D., Lehn G. O.*, Macdonald R. W., and Rossi M. W. (2016) Geochemical heterogeneity of rivers draining the Canadian Arctic Archipelago. Fall American Geophysical Union Conference, San Francisco, CA.

Wang J.*, Jacobson A. D., Zhang H., Ramezani J., Sageman B. B., Hurtgen M. T., Bowring S. A., and Shen S.-Z. (2016) A Permo-Triassic Ca isotope record from Meishan, China. V. M. Goldschmidt Conference, Yokohama, Japan.

Andrews M. G.* and Jacobson A. D. (2016) Radiogenic and stable Sr isotope ratios as tracers of silicate and carbonate weathering in Iceland. V. M. Goldschmidt Conference, Yokohama, Japan.

Sageman B. B., Hurtgen M. T., Jacobson A. D., and Selby D. (2015) Multi-proxy study of Ocean Anoxic Event 2 (Cenomanian-Turonian) yields new perspective on the drivers for Mesozoic anoxic events. Fall American Geophysical Union Conference, San Francisco, CA.

Kristall B.*, Hurtgen M. T., Sageman B. B., and Jacobson A. D. (2015) The Early Cretaceous sulfur isotope record: new data, revised ages, and updated modeling. Fall American Geophysical Union Conference, San Francisco, CA.

Andrews M. G.* and Jacobson A. D. (2015) Seasonal variation and controls on subglacial riverine CO₂ concentrations from a small catchment, west Greenland Ice Sheet. Fall American Geophysical Union Conference, San Francisco, CA.

Jacobson A. D., Lehn G. O.*, Du Vivier A. D. C., Selby D., Hurtgen M. T., and Sageman B. B. (2014) Ca isotope evidence for changes in the carbonate geochemistry of seawater across OAE 2. Fall American Geophysical Union Conference, San Francisco, CA.

Holmden C., Jacobson A. D., Hurtgen M. T., and Sageman B. B. (2014) Marine carbonate δ⁵³Cr values reflect inputs from LIP volcanism during OAE 2. Fall American Geophysical Union Conference, San Francisco, CA.

Andrews M. G.*, Jacobson A. D., and Lehn G. O.* (2014) Stable strontium isotopes (δ^88/86Sr) as a tracer of Sr sources and biogeochemical cycling in two catchments draining Fiordland, New Zealand. Fall American Geophysical Union Conference, San Francisco, CA.

Lehn G. O.*, Jacobson A. D., Douglas T. A.^#, McClelland J. W.^#, Khosh M. S.^#, and Barker A. J.^# (2014) Seasonal variability of riverine geochemistry (⁸⁷Sr/⁸⁶Sr, δ¹³C_DIC, δ^44/40Ca, and major ions) in permafrost watersheds on the North Slope of Alaska. Fall American Geophysical Union Conference, San Francisco, CA.

Hurtgen M. T., Mills J. V.*, Gomes M. L.*, Kristall B.*, Sageman B. B., and Jacobson A. D. (2014) Massive volcanism, evaporite deposition, and the chemical evolution of the Cretaceous ocean. Fall Geological Society of America Meeting, Vancouver, Canada.

Holmden C., Jacobson A. D., Sageman B. B., and Hurtgen M. T. (2014) Response of the Cr isotope proxy to Ocean Anoxic Event 2. V. M. Goldschmidt Conference, Sacramento, CA.

Melin A. D., Crowley B. E., Moritz G. L., Jacobson A. D., and Dominy N. J. (2013) Calcium and carbon stable isotope ratios as paleodietary indicators. American Association of Physical Anthropologists, Calgary, Alberta Canada.

Mills J. V.*, Gomes M. L., Sageman B. B., Jacobson A. D., and Hurtgen M. T. (2013) Reinterpreting the early Cretaceous sulfur isotope records: implications for the evolution of seawater chemistry. Fall American Geophysical Union Conference, San Francisco, CA.

Du Vivier A. D. C., Jacobson A. D., Lehn G. O.*, Selby D., and Sageman B. B. (2013) Perturbation to the marine Ca isotope cycle across Oceanic Anoxic Event 2. V. M. Goldschmidt Conference, Florence, Italy.

Moore J.*, Jacobson A. D., Holmden C., and Craw D. (2013) Detection of non-stoichiometric silicate mineral dissolution in rivers draining alpine glaciers using δ^44/40Ca. V. M. Goldschmidt Conference, Florence, Italy.

Erhardt A. M., Chein C-T., Jacobson A. D., Moy C. M., Muhs D. R., and Paytan A. (2013) Characterizing the Pb isotopic contribution of dust to seawater. V. M. Goldschmidt Conference, Florence, Italy.

Jacobson A. D. (2012) Climate change through time: how did we get here, and where are we going? David and Lucile Packard Foundation Annual Meeting, Monterey, CA.

Lehn G. O.*, Jacobson A. D., Douglas T. A.#, McClelland J. W.^#, Khosh M. S.^#, Barker A. J.^#, and Holmden C. (2012) A multiproxy approach (⁸⁷Sr/⁸⁶Sr, δ⁴⁴Ca, δ¹³CDIC) for tracking seasonal changes in permafrost dynamics. V. M. Goldschmidt Conference, Montreal, Canada.

Moore J. and Jacobson A. D. (2012) Quantifying carbon cycling via continuous measurement of atmospheric CO₂ concentrations and δ¹³C in Chicago, IL. Fall American Geophysical Union Conference, San Francisco, CA.

Barker A. J.^#, Douglas T. A.^#, Jacobson A. D., McClelland J. W.^#, Ilgen G., Khosh M. S.^#, Lehn G. O.*, and Trainor T. P. (2012) Influence of permafrost active layer dynamics on trace metals in two small Alaskan Arctic rivers. Fall American Geophysical Union Conference, San Francisco, CA.

Khosh M. S.^#, McClelland J. W.^#, Douglas T. A., Jacobson A. D., Lehn G. O.*, and Barker A. J.^# (2012) Seasonal dynamics of particulate organic carbon and nitrogen in Alaskan Arctic streams and rivers. Fall American Geophysical Union Conference, San Francisco, CA.

Bowden W. B., Khosh M. S.^#, Waldvogel G., Gooseff M. N., Wolheim W. M., Whittinghill K. A., Wlostowki A. N., Jacobson A. D., McClelland J. W.^#, Douglas T. A.^#, Lehn G. O.*, and Barker A. J.^# (2012) Seasonal asynchrony in terrestrial nutrient production and demand drives nutrient delivery to Arctic streams. Fall American Geophysical Union Conference, San Francisco, CA.

Moore J., Reed M. E., and Jacobson A. D. (2012) Finding the rhythm of Chicago’s urban metabolism. North Central Geological Society of America Meeting, Dayton, Ohio.

Reed M. E., Moore J., and Jacobson A. D. (2012) Carbon cycling in an urban environment. North Central Geological Society of America Meeting, Dayton, Ohio.

Jacobson A. D. and Ryu J.-S.* (2011) CO₂ evasion from the Greenland ice sheet: a new carbon climate feedback. V. M. Goldschmidt Conference, Prague, Czech Republic.

Douglas T. A.^#, Jacobson A. D., McClelland J. W.^#, Barker A. J.^#, Khosh M. S.^#, and Lehn G. O.* (2011) Permafrost active layer dynamics inferred from major element geochemical signatures in six Arctic Alaskan rivers. V. M. Goldschmidt Conference, Prague, Czech Republic.

Douglas T. A.^#, Jacobson A. D., McClelland J. W.^#, Barker A. J.^#, Khosh M. S.^#, and Lehn G. O.* (2011) Permafrost and active layer dynamics inferred from major element geochemical signatures in six Arctic Alaskan rivers. The Fourth Interagency Conference on Research in the Watersheds, 26-30 September 2011, Fairbanks, AK.

Moore J.* and Jacobson A. D. (2011) Measuring the concentration and carbon isotope composition of atmospheric CO₂ in an urban setting using cavity ring-down spectroscopy. American Chemical Society National Meeting, Denver, CO.

Lehn G. O.*, Jacobson A. D., Douglas T. A.^#, McClelland J. W.^#, Khosh M. S.^#, and Barker A.^# (2011) Seasonal variability of major ions and δ¹³C_DIC in permafrost watersheds of Arctic Alaska. Fall American Geophysical Union Conference, San Francisco, CA.

Barker A. J.^_#, Douglas T. A.^#, Jacobson A. D., McClelland J. W.^#, Ilgen G., Khosh M. S.^#, Lehn G. O.*, and Trainor T. P. (2011) Influence of permafrost active layer dynamics on race metals in two small Alaskan Arctic rivers. Fall American Geophysical Union Conference, San Francisco, CA.

Khosh M. S.^#, McClelland J. W.^#, Douglas T. A.^#, Jacobson A. D., Barker A.^#, and Lehn G. O.* (2011) Dissolved nitrogen seasonal dynamics in Alaskan Arctic streams and rivers. Fall American Geophysical Union Conference, San Francisco, CA.

Ryu J.-S.* and Jacobson A. D. (2010) CO₂ evasion from the Greenland ice sheet. Fall American Geophysical Union Conference, San Francisco, CA.

Moore J.*, Jacobson A. D., Holmden C., and Craw D. (2010) Ca isotopes reveal weak control of tectonic uplift on long-term climate change. Fall American Geophysical Union Conference, San Francisco, CA.

Li D. D.*, Jacobson A. D., and McInerney D. J. (2010) A mathematical model for examining tectonic and climatic controls on chemical weathering and CO₂ consumption. Fall American Geophysical Union Conference, SanFrancisco, CA.

Lehn G. O.*, Jacobson A. D., Douglas T. A.^#, McClelland J. W.^#, Khosh M. S.^#, and Barker A.^# (2010) Seasonal changes in the major ion and δ¹³CDIC geochemistry of Arctic Alaskan rivers. Fall American Geophysical Union Conference, San Francisco, CA.

Douglas T. A.^#, Barker A.^#, Jacobson A. D., McClelland J. W.^#, Khosh M. S.^#, and Lehn G. O.* (2010) Major element concentrations in six Alaskan arctic rivers from melt to freeze-up. Fall American Geophysical Union Conference, San Francisco, CA.

Khosh M. S.^#, McClelland J. W.^#, Douglas T. A.^#, Jacobson A. D., Lehn G. O.*, and Barker A.^# (2010) Quantifying and characterizing dissolved organic matter and nutrients in the headwaters of Alaskan North Slope rivers. Fall American Geophysical Union Conference, San Francisco, CA.

Ryu J.-S.*, Jacobson A. D., Holmden C., Lundstrom C. C., and Zhang Z.* (2009) The elemental, δ⁴⁴Ca, and δ²⁶Mg geochemistry of granite weathering at pH = 1 and T = 25°C. Fall American Geophysical Union Conference, San Francisco, CA.

Moore J.*, Jacobson A. D., Holmden C., and Craw D. (2009) Ca isotopes, chemical weathering, and geomorphic controls on long-term climate, Fall American Geophysical Union Conference, San Francisco, CA.

Jacobson A. D. (2009) Calcium isotopes, Earth’s long-term climate, and chemical weathering in active mountain belts. David and Lucile Packard Foundation Annual Meeting, Monterey, CA.

Moore J.*, Jacobson A. D., Holmden C., and Craw D. (2009) δ⁴⁴Ca traces chemical weathering of hydrothermal calcite in the Southern Alps of New Zealand. V. M. Goldschmidt Conference, Davos, Switzerland.

Jacobson A. D. (2008) Using calcium isotopes to track Earth’s ancient and modern carbon cycle. 1st Annual French American Frontiers of Science Symposium sponsored by the National Academy of Science and the Kavli Foundation, Roscoff, France.

Zhang Z.*, Jacobson A. D., and Lundstrom C. (2008) δ²⁶Mg evolution during water-rock interaction in a carbonate aquifer. Fall American Geophysical Union Conference, San Francisco, California.

Lemarchand D., Cividini D., and Jacobson A. D. (2008) An isotopic view of rapid exchange reactions and long-term weathering: a window to reaction pathways and time of water and solutes transfer. Spring European Geosciences Union Meeting, Vienna, Austria.

Flaum J. A.*, Jacobson A. D., and Sageman B. B. (2007) The atmospheric supply of terrestrial authigenic phosphate minerals to open marine sediments. Fall American Geophysical Union Conference, San Francisco, California.

Wu L.*, Jacobson A. D., Chen H.-C., and Hausner M. (2007) Characterization of elemental release during interaction of bacteria with basalt and granite. V. M. Goldschmidt Conference, Cologne, Germany.

Jacobson A. D. and Holmden C. (2007) δ⁴⁴Ca evolution during water-rock interaction in a carbonate aquifer. V. M. Goldschmidt Conference, Cologne, Germany.

Wu L.*, Jacobson A. D., and Hausner M. (2006) Characterization of elemental release during microbe-basalt interactions. Fall American Geophysical Union Conference, San Francisco, California.

Wu L.*, Chen H.-C., Jacobson A. D., and Hausner M. (2006) Microbially mediated dissolution of granite and fluorapatite. Biofilm Systems VI, Amsterdam, Netherlands.

Wu L.*, Chen H.-C., Jacobson A. D., and Hausner M. (2006) Contribution of microorganisms to granite and fluorapatite dissolution. American Society for Microbiology 106th Annual Meeting, Orlando, Florida.

Lemarchand D., Cividini D., Chabaux F., and Jacobson A. D. (2006) Tracing water/rock interactions in groundwater systems by B isotopes. European Geosciences Union, Vienna, Austria.

Gierlowski-Kordesch E. H., Jacobson A. D., Blum J. D., and Valero Garces B. L. (2006) Carbonates in provenance studies. 17th International Sedimentological Congress, Fukuoka, Japan.

Jacobson A. D. and Holmden C. (2005) The role of calcite dust in marine geochemical cycles. Fall American Geophysical Union Conference, San Francisco, California.

Jacobson A. D., Blum J. D., and Chamberlain C. P. (2004) Atmospheric CO₂ consumption in uplifting mountain ranges: New Insight from the New Zealand Southern Alps (INVITED). Fall American Geophysical Union Conference, San Francisco, CA.

Jacobson A. D., Blum J. D., and Walter L. M. (2000) Partitioning contributions from carbonate vs. silicate weathering in the Himalaya. Fall American Geophysical Union Conference, San Francisco, CA.

Jacobson A. D. and Blum J. D. (1999) The geochemistry of disseminated calcite in high Himalayan silicate rocks. Proceedings of the 5th International Symposium on Geochemistry of the Earth’s Surface, Rejkavik, Iceland.

Jacobson A. D. (1999) Chemical weathering in the Himalayan Mountains of northern Pakistan: implications for the global carbon and strontium cycles. Science to Achieve Results (STAR) Graduate Fellowship Conference IV: Emerging Environmental Issues, Arlington, VA.

Jacobson A. D. and Blum, J. D. (1998) Strontium isotope systematics of a Himalayan glacial chronosequence. V. M. Goldschmidt Conference, Toulouse, France.

Jacobson A. D. (1998) The strontium isotope systematics of a Himalayan glacial chronosequence: implications for the global carbon cycle and climate change. Science to Achieve Results (STAR) Graduate Fellowship Conference III: Emerging Environmental Issues, Arlington, VA.

Gazis C. A., Blum J. D., Jacobson A. D., and Chamberlain C. P. (1998) Controls on the strontium isotope geochemistry of the Indus River in northern Pakistan. Fall American Geophysical Union Conference, San Francisco, CA.