Climatic influences on the Paleogene evolution of alkenones

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doi: 10.1002/2013PA002576
Author(s): Brassell, Simon C.
Author Affiliation(s): Primary:
Indiana University, Department of Geological Sciences, Bloomington, IN, United States
Volume Title: Paleoceanography
Source: Paleoceanography, 29(3), p.255-272. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. NSF Grant EAR-9909857. 165 refs.; illus., incl. 3 tables
Summary: Application of the alkenone paleotemperature proxy (UK'37) for marine sediments is typically constrained by three factors: (i) an absence of alkatrienones in sediments deposited where ocean temperatures exceed ∼28°C, (ii) loss of alkenones in thermally altered sediments, and (iii) poor preservation of alkenone signals due to oxidative degradation. In addition, there appears to be a temporal limit on the occurrence of alkatrienones, which are conspicuously absent in all alkenone-containing sediments from the early Aptian to the immediate aftermath of the Early Eocene Climatic Optimum (EECO) when they first appeared in Arctic Ocean sediments. Compilation of reported and previously unpublished alkenone distributions for the Paleogene coupled with assessment of co-occurring calcareous nannoplankton genera within the Noelaerhabdaceae provide evidence that evolutionary developments in alkenone occurrences include biosynthetic responses likely triggered by climate change. The timing of emergence of alkatrienones post-EECO and their subsequent appearance at all latitudes during the middle Eocene accompanies expansion of the calcareous nannoplankton genus Reticulofenestra coincident with significant climate-driven changes in oceanic conditions, including (i) modification of trophic structure associated with weakened thermal stratification, (ii) higher productivity facilitated by enhanced nutrient influx, and (iii) changes in seasonality, initially at high latitudes, related to greater latitudinal temperature gradients. Collectively, these changes would serve to favor eurythermal/eurytrophic algae, like Reticulofenestra, with a biomechanism to store energy through production of lipid bodies rich in alkenones during episodes of higher nutrient availability. This ability likely enhanced the viability of this marine haptophyte when nutrients were limiting, ultimately ensuring its evolutionary success. Abstract Copyright (2014), . American Geophysical Union. All Rights Reserved.
Year of Publication: 2014
Research Program: DSDP Deep Sea Drilling Project
IODP Integrated Ocean Drilling Program
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Alkenones; Arctic Coring EXpedition; Arctic Ocean; Atlantic Ocean; Biomarkers; Campbell Plateau; Cape Verde Basin; Ceara Rise; Cenozoic; Climate change; DSDP Site 277; DSDP Site 336; DSDP Site 356; DSDP Site 357; DSDP Site 367; DSDP Site 494; DSDP Site 511; DSDP Site 513; DSDP Site 516; DSDP Site 588; DSDP Site 608; DSDP Site 612; Deep Sea Drilling Project; East Pacific; Eocene; Equatorial Atlantic; Equatorial Pacific; Expedition 302; IPOD; Iceland-Faeroe Ridge; Integrated Ocean Drilling Program; Ketones; Leg 130; Leg 150; Leg 151; Leg 154; Leg 177; Leg 184; Leg 189; Leg 199; Leg 29; Leg 38; Leg 39; Leg 41; Leg 67; Leg 71; Leg 72; Leg 90; Leg 94; Leg 95; Lomonosov Ridge; Lord Howe Rise; Marine environment; Microfossils; Nannofossils; Noelaerhabdaceae; North Atlantic; North Pacific; Northeast Atlantic; Northeast Pacific; Northwest Atlantic; Northwest Pacific; Norwegian Sea; ODP Site 1090; ODP Site 1148; ODP Site 1172; ODP Site 1219; ODP Site 803; ODP Site 903; ODP Site 913; ODP Site 925; ODP Site 929; Ocean Drilling Program; Oligocene; Ontong Java Plateau; Organic compounds; Pacific Ocean; Paleoclimatology; Paleoenvironment; Paleogene; Paleotemperature; Plantae; Reticulofenestra; Rio Grande Rise; South Atlantic; South China Sea; South Pacific; Southwest Pacific; Tasman Sea; Tertiary; West Pacific
Coordinates: N384912 N384913 W0724625 W0724626
N875100 N875600 E1393300 E1361000
N752921 N752921 W0065648 W0065648
N632103 N632104 W0074716 W0074717
Record ID: 2014035274
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom