Detailed view into the dynamics of the late Miocene glaciation episode that accompanied terrestrial evolution

Author(s): Tzanova, Alexandrina; Herbert, Timothy; Lawrence, Kira T.; Peterson, Laura; Kelly, Christopher S.
Author Affiliation(s): Primary:
Brown University, Earth, Environmental and Planetary Science, Providence, RI, United States
Other:
Central Connecticut State University, Geology, United States
Lafayette College, United States
Luther College, United States
Volume Title: AGU 2015 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2015; American Geophysical Union 2015 fall meeting, San Francisco, CA, Dec. 14-18, 2015. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: We focus on the period of ∼ 9-5 Ma when an episode of notably cool temperatures corresponds to evidence of high latitude Northern Hemisphere glaciation and mid-latitude terrestrial evolution. Alkenone-based sea surface temperatures (SST) from six globally distributed sites: ODP Sites 907 and 982 in the North Atlantic, ODP Site 1088 in the South Atlantic and ODP Sites 883, 884 and 887 in the North Pacific, and the Monte dei Corvi marine section in the Mediterranean unequivocally establish a dramatic, late Miocene cold episode that persisted over approximately 2.5 Myr. In this work we establish the timing and synchronization of temperature decrease as well as rebound at orbital timescales. All sites were notably warmer than their modern annual average at ∼9 Ma and exhibit sustained cooling beginning at ∼8 Ma. SSTs rebound close to ∼5.9 Ma at most locations suggesting that the cooling trend that began in the late Miocene slowed down or even reversed in some locations in the Pliocene. The newly reconstructed SSTs highlight the role of cooling and an increase in equator to pole temperature gradients in terrestrial evolution at this pivotal time.
Year of Publication: 2015
Research Program: ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Arctic Ocean; Atlantic Ocean; Cores; Detroit Seamount; East Pacific; Emperor Seamounts; Leg 145; Leg 162; Leg 177; Marine sediments; North Atlantic; North Pacific; Northeast Pacific; Northwest Pacific; Norwegian Sea; ODP Site 1088; ODP Site 883; ODP Site 884; ODP Site 887; ODP Site 907; ODP Site 982; Ocean Drilling Program; Pacific Ocean; Rockall Bank; Sediments; South Atlantic; West Pacific
Coordinates: N691459 N691459 W0124154 W0124154
N573100 N573100 W0155200 W0155200
S410810 S410810 E0133346 E0133346
Record ID: 2016062606
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