DOI: 10.5194/cp-14-321-2018
Scopus记录号: 2-s2.0-85043533370
论文题名: Reinforcing the North Atlantic backbone: Revision and extension of the composite splice at ODP Site 982
作者: Drury A.J. ; Westerhold T. ; Hodell D. ; Röhl U.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2018
卷: 14, 期: 3 起始页码: 321
结束页码: 338
语种: 英语
Scopus关键词: benthic foraminifera
; climate forcing
; cooling
; marine isotope stage
; Miocene
; Ocean Drilling Program
; oxygen isotope
; paleoclimate
; Pliocene
; sea surface temperature
; stable isotope
; stratigraphy
; Atlantic Ocean
; Atlantic Ocean (Equatorial)
; Atlantic Ocean (North)
; Mediterranean Sea
; Morocco
英文摘要: Ocean Drilling Program (ODP) Site 982 represents a key location for understanding the evolution of climate in the North Atlantic over the past 12g Ma. However, concerns exist about the validity and robustness of the underlying stratigraphy and astrochronology, which currently limits the adequacy of this site for high-resolution climate studies. To resolve this uncertainty, we verify and extend the early Pliocene to late Miocene shipboard composite splice at Site 982 using high-resolution XRF core scanning data and establish a robust high-resolution benthic foraminiferal stable isotope stratigraphy and astrochronology between 8.0 and 4.5g Ma. Splice revisions and verifications resulted in g 1/4 g 11g m of gaps in the original Site 982 isotope stratigraphy, which were filled with 263 new isotope analyses. This new stratigraphy reveals previously unseen benthic δ18O excursions, particularly prior to 6.65g Ma. The benthic δ18O record displays distinct, asymmetric cycles between 7.7 and 6.65g Ma, confirming that high-latitude climate is a prevalent forcing during this interval. An intensification of the 41g kyr beat in both the benthic δ13C and δ18O is also observed g 1/4 g 6.4g Ma, marking a strengthening in the cryosphere-carbon cycle coupling. A large g 1/4 g 0.7g ‰ double excursion is revealed g 1/4 g 6.4-6.3g Ma, which also marks the onset of an interval of average higher δ18O and large precession and obliquity-dominated δ18O excursions between 6.4 and 5.4g Ma, coincident with the culmination of the late Miocene cooling. The two largest benthic δ18O excursions g 1/4 g 6.4-6.3g Ma and TG20/22 coincide with the coolest alkenone-derived sea surface temperature (SST) estimates from Site 982, suggesting a strong connection between the late Miocene global cooling, and deep-sea cooling and dynamic ice sheet expansion. The splice revisions and revised astrochronology resolve key stratigraphic issues that have hampered correlation between Site 982, the equatorial Atlantic and the Mediterranean. Comparisons of the revised Site 982 stratigraphy to high-resolution astronomically tuned benthic δ18O stratigraphies from ODP Site 926 (equatorial Atlantic) and Ain el Beida (north-western Morocco) show that prior inconsistencies in short-term excursions are now resolved. The identification of key new cycles at Site 982 further highlights the requirement for the current scheme for late Miocene marine isotope stages to be redefined. Our new integrated deep-sea benthic stable isotope stratigraphy and astrochronology from Site 982 will facilitate future high-resolution late Miocene to early Pliocene climate research. © Author(s) 2018. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109587
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany; Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, United Kingdom
Recommended Citation:
Drury A.J.,Westerhold T.,Hodell D.,et al. Reinforcing the North Atlantic backbone: Revision and extension of the composite splice at ODP Site 982[J]. Climate of the Past,2018-01-01,14(3)