Climatic influences on the Paleogene evolution of alkenones
| Online Access: |
Get full text doi: 10.1002/2013PA002576 |
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| 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 Compilation of reported and previously unpublished alkenone distributions for the Paleogene coupled with assessment of co-occurring calcareous nannoplankton genera within the Noelaerhabdaceae provide evidence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 |