- Johnson, D. L., Present, T. M., Li, M., Shen, Y. & Adkins, J. F, 2021. Carbonate associated sulfate (CAS) δ34S heterogeneity across the End-Permian Mass Extinction in South China. Earth and Planetary Science Letters 574, 117172. https://doi.org/10.1016/j.epsl.2021.117172
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Johnson, D.L., Grossman, E.L., Webb, S.M., Adkins, J.F., 2020. Brachiopod δ34SCAS microanalyses indicate a dynamic, climate-influenced Permo-Carboniferous sulfur cycle. Earth and Planetary Science Letters 546, 116428. https://doi.org/10.1016/j.epsl.2020.116428
- Y. Rosenthal, A.E. Holbourn, D.K. Kulhanek, the Expedition 363 Scientists. Western Pacific warm Pool. Proceedings of the International Ocean Discovery Program, 363, International Ocean Discovery Program, College Station, TX (2018), 10.14379/iodp.proc.363.2018
-
Pearson, P.N., IODP Expedition 363 Shipboard Scientific
Party, 2018. A deep-sea agglutinated foraminifer tube constructed with planktonic foraminifer shells of a single species. Journal of Micropalaeontology 37, 97–104. https://doi.org/10.5194/jm-37-97-2018
Johnson, D. L., Chau, T. H., Chesson, L. A., and Berg, G. E. (2023). Should tooth enamel be baked overnight prior to carbonate isotopic analysis?. Advances in Stable Isotope Techniques and Applications (ASITA) conference, Ottawa.
Johnson, D. L., Present, T. M., Li, M., Shen, Y. and Adkins, J. F (2021). Carbonate associated sulfate (CAS) δ34S heterogeneity across the End-Permian Mass Extinction in South China suggests frequent oscillations in sedimentary redox. AGU Fall Meeting, New Orleans.
Johnson, D. L., Gutierrez, M., Present, T. M., Peerthum,
Y., Marquez, R. T., and Adkins, J. F. (2020). Sedimentary Sulfur Cycling in
Deep Ocean Oxygenated Settings. The Weizmann-Caltech Symposium on The Carbon
Cycle, Rehovot.
Johnson, D. L., Gutierrez, M., Present, T. M., Peerthum,
Y., Marquez, R. T., and Adkins, J. F. (2019). Sedimentary Sulfur Cycling in
Deep Ocean Oxygenated Settings. AGU Fall Meeting, San Francisco.
Present, T.
M., Goldberg, S. L., Kast, E., Bergmann, K., Finnegan, S., Rae, J. W. B.,
Burke, A.,
Johnson, D. L., Fike, D. A.,
Fischer, W. W. and Cummins, R. (2019). Stability of Upper Ordovician to middle
Silurian marine sulfur isotopes recorded in brachiopod carbonate-associated
sulfate. AGU Fall Meeting, San Francisco.
Johnson,D. L., Gutierrez, M., Present,
T. M., and Adkins, J. F. (2019). Sedimentary
Sulfur Cycling in Deep Ocean Oxygenated Settings: Expedition 363 & Beyond.
IODP Expedition 363 Science Meeting, Qingdao.
Johnson,D. L., Grossman, E.L., Webb,
S. M., and Adkins, J. F. (2019). Single-brachiopod
δ34SCAS Indicates
a Dynamic, Climatically-Influenced Permo-Carboniferous S Cycle. Southern California Geobiology Symposium, Pasadena.
Adkins, J. F., Johnson, D. L., and Grossman, E. L. (2018). The Sulfur Isotope
Composition of Single-brachiopods and Modern Pore Waters to Constrain the
Permo-Carboniferous S cycle. AGU Fall
Meeting, Washington, D.C..
Gutierrez,
M., Johnson,D.
L., Present, T.M., and Adkins, J. F. (2018). Sedimentary Sulfur Cycling in Oxygenated Deep
Ocean Settings. Goldschmidt
Conference, Boston.
Johnson,D. L., Grossman, E.L., Webb,
S. M., and Adkins, J. F. (2018). Single-brachiopod
δ34SCAS Indicates
a Dynamic, Climatically-Influenced Permo-Carboniferous S Cycle. Goldschmidt Conference, Boston.
Johnson,D. L., Present, T. M.,
Fischer, W. W., Webb, S. M., and Adkins, J. F. (2015). Exploring Biogenic
Carbonates as Records of the Ancient Sulfur Cycle: A Case Study of Isotelus Trilobites
and Brachiopods from Anticosti Island, Quebec. Gordon Research Conference (Geobiology), Galveston.
Johnson,D. L., Fike, D. A., and Rose, C. V. (2014). Evaluating the Effects of Sediment Reworking
on the Sulfur Isotopic Composition of Aqueous and Mineral Sulfides.
AGU Fall Meeting, San Francisco.
Johnson,
D. L., Pierce,
E. L., Williams, T. J., Hemming, S. R., van de Flierdt,
T., Roy, M., Torfstein, A., and Gombiner,
J. (2012). Argon Concentrations of Fine-Grained Marine
Sediments near Wilkes
Land, Antarctica: Source Characterization and Implications for Ice Sheet Behavior during
the Middle Miocene.
AGU Fall Meeting,
San Francisco.
Duchesne, A.
E., Pierce, E. L., Williams, T., Hemming, S. R.,
Johnson, D. L., May, T., Gombiner, J., and Torfstein, A. (2012).
K/Ar Dating of Fine Grained Sediments Near Prydz Bay, Antarctica: East
Antarctic Ice Sheet Behavior During the Middle-Miocene Climate Transition. AGU Fall Meeting,
San Francisco.
Teaching & Mentoring Experience
Research Mentor
Mentor to Caltech
undergraduate Yashna Peerthum (Spring & Summer 2019)
Mentor to Caltech
undergraduate Melissa Gutierrez (Summer & Fall 2018)
Graduate Teaching Assistant
Ge 155: Paleoceanography (taught by Dr. Jess F.
Adkins), Winter 2019
Ge 101: Introduction
to Geology and Geochemistry (taught by Dr. Kenneth
A. Farley), Fall 2017
Ge 140a: Stable
Isotope Geochemistry (taught by Dr.
John M. Eiler), Winter 2017
Ge 1: Earth and
Environment (taught by Dr.
Paul D. Asimow), Spring 2016
Caltech Y RISE Program
Tutor (2015
– 2016)
Undergraduate Teaching Assistant
EPS 323: Biogeochemistry (taught by Dr. Alex Bradley), Spring 2014
Educational Outreach & Professional Development
Caltech Project for
Effective Teaching (CPET)
Completed Caltech Project for
Effective Teaching (CPET) Certificate of Interest in
University Teaching (2018-2019)
Caltech Science for
March
Assisted
with event planning and preparation (2018)
Presented
an ocean acidification outreach demonstration (2019)
Caltech Graduate Student
Council (GSC)
Led organization as Chair (Nov.
2017 – May 2018)
Served as
Treasurer (Jun. 2016 – May 2017) and Vice Chair (Jun. 2017 – Nov. 2017)
Organized
biannual Graduate Student-Faculty Colloquium as one of four co-chairs (Feb. 2018)
Public Talks
Johnson,D. L., Grossman, E.L., Webb, S. M., and Adkins, J. F. (2019). How an Ancient Ice Age Helped Enable Modern Global Warming. Caltech Reunion Weekend + Seminar Day Graduate Research Spotlight, Pasadena.
Popular Science Articles
Blog for the general public talking about my experiences on IODP Expedition 363
General science article written for the Caltech Letters science outreach website