气候变化领域集成服务门户(CCPortal): Late miocene to holocene high-resolution eastern equatorial pacific carbonate records: Stratigraphy linked by dissolution and paleoproductivity

CCPortal

DOI	10.5194/cp-15-1715-2019
	Late miocene to holocene high-resolution eastern equatorial pacific carbonate records: Stratigraphy linked by dissolution and paleoproductivity
	Lyle M.; Joy Drury A.; Tian J.; Wilkens R.; Westerhold T.
发表日期	2019
ISSN	18149324
起始页码	1715
结束页码	1739
卷号	15 期号:5
英文摘要	Coherent variation in CaCO3 burial is a feature of the Cenozoic eastern equatorial Pacific. Nevertheless, there has been a long-standing ambiguity in whether changes in CaCO3 dissolution or changes in equatorial primary production might cause the variability. Since productivity and dissolution leave distinctive regional signals, a regional synthesis of data using updated age models and high-resolution stratigraphic correlation is an important constraint to distinguish between dissolution and production as factors that cause low CaCO3. Furthermore, the new chronostratigraphy is an important foundation for future paleoceanographic studies. The ability to distinguish between primary production and dissolution is also important to establish a regional carbonate compensation depth (CCD). We report late Miocene to Holocene time series of XRF-derived (X-ray fluorescence) bulk sediment composition and mass accumulation rates (MARs) from eastern equatorial Pacific Integrated Ocean Drilling Program (IODP) sites U1335, U1337, and U1338 and Ocean Drilling Program (ODP) site 849, and we also report bulkdensity-derived CaCO3 MARs at ODP sites 848, 850, and 851. We use physical properties, XRF bulk chemical scans, and images along with available chronostratigraphy to intercorrelate records in depth space. We then apply a new equatorial Pacific age model to create correlated age records for the last 8 Myr with resolutions of 1-2 kyr. Large magnitude changes in CaCO3 and bio-SiO2 (biogenic opal) MARs occurred within that time period but clay deposition has remained relatively constant, indicating that changes in Fe deposition from dust is only a secondary feedback to equatorial productivity. Because clay deposition is relatively constant, ratios of CaCO3 % or biogenic SiO2 % to clay emulate changes in biogenic MAR. We define five major Pliocene-Pleistocene low CaCO3 % (PPLC) intervals since 5.3 Ma. Two were caused primarily by high bio-SiO2 burial that diluted CaCO3 (PPLC-2, 1685-2135 ka, and PPLC-5, 4465-4737 ka), while three were caused by enhanced dissolution of CaCO3 (PPLC-1, 51-402 ka, PPLC-3, 2248-2684 ka, and PPLC-4, 2915-4093 ka). Regional patterns of CaCO3 % minima can distinguish between low CaCO3 caused by high diatom bio-SiO2 dilution versus lows caused by high CaCO3 dissolution. CaCO3 dissolution can be confirmed through scanning XRF measurements of Ba. High diatom production causes lowest CaCO3 % within the equatorial high productivity zone, while higher dissolution causes lowest CaCO3 percent at higher latitudes where CaCO3 production is lower. The two diatom production intervals, PPLC-2 and PPLC-5, have different geographic footprints from each other because of regional changes in eastern Pacific nutrient storage after the closure of the Central American Seaway. Because of the regional variability in carbonate production and sedimentation, the carbonate compensation depth (CCD) approach is only useful to examine large changes in CaCO3 dissolution. © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	calcium carbonate; carbonate; Cenozoic; chronostratigraphy; dissolution; Holocene; Miocene; Ocean Drilling Program; paleoceanography; paleoproductivity; Pliocene-Pleistocene boundary; stratigraphic correlation; Pacific Ocean; Pacific Ocean (East); Pacific Ocean (Equatorial); Bacillariophyta
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146778
作者单位	College of Earth, Ocean, and Atmospheric Science, Oregon State University, 104 CEOAS Admin Bldg, Corvallis, OR 97331, United States; MARUM - Center for Marine Environmental Sciences, University of Bremen, Leobener Strasse, Bremen, 28359, Germany; Laboratory of Marine Geology, Tongji University, Siping Road 1239, Shanghai, 200092, China; University of Hawaii, School of Ocean and Earth Science and Technology, Honolulu, HI 96822, United States; University College London, Earth Sciences, London, WC1E 6BS, United Kingdom
推荐引用方式 GB/T 7714	Lyle M.,Joy Drury A.,Tian J.,et al. Late miocene to holocene high-resolution eastern equatorial pacific carbonate records: Stratigraphy linked by dissolution and paleoproductivity[J],2019,15(5).
APA	Lyle M.,Joy Drury A.,Tian J.,Wilkens R.,&Westerhold T..(2019).Late miocene to holocene high-resolution eastern equatorial pacific carbonate records: Stratigraphy linked by dissolution and paleoproductivity.Climate of the Past,15(5).
MLA	Lyle M.,et al."Late miocene to holocene high-resolution eastern equatorial pacific carbonate records: Stratigraphy linked by dissolution and paleoproductivity".Climate of the Past 15.5(2019).