DOI: 10.1016/j.palaeo.2016.03.019
论文题名: Daily growth and tidal rhythms in Miocene and modern giant clams revealed via ultra-high resolution LA-ICPMS analysis — A novel methodological approach towards improved sclerochemistry
作者: Warter V. ; Müller W.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
卷: 465 起始页码: 362
结束页码: 375
语种: 英语
英文关键词: Daily cycles
; Image processing
; Miocene
; Tidal periodicity
; Tridacna spp.
; Ultra-high resolution LA-ICPMS
英文摘要: We present a novel approach for ultra-high resolution laser-ablation inductively-coupled-plasma mass spectrometry (LA-ICPMS) analysis, which not only allows us to clearly resolve < 10 μm (daily) compositional variability in B/Ca, Mg/Ca, Sr/Ca and Ba/Ca, but also to detect long-term tidal and seasonal cycles in both Miocene and modern Tridacna (giant clam) shells. Daily element/Ca variability preserved within microscopically visible growth increments is resolved by utilizing the combined capabilities of a rotating rectangular aperture (spot size on target 4 × 50 μm), the rapid signal washout of a Laurin two-volume laser ablation cell and slow compositional profiling (≤ 1.5 μm/s). Striking co-variation between oscillating cycles in B/Ca, Mg/Ca, Sr/Ca and Ba/Ca is discernible, yet also tantalizingly, sub-daily shifts between these element/Ca ratios can be observed. In comparison to a lower-resolution, seasonally-resolved δ18O–Mg/Ca record (Warter et al., 2015), the ~ 10–20 μm element/Ca cycles are determined to be daily in origin, and a further ~ 14–15 day cyclicity is superimposed on the daily cycles. The latter is interpreted to reflect (Miocene) tidal periodicity. Changes in pixel intensity during thin section observation associated with micro- and macroscopically visible low and high density bands have been quantified via image processing analysis. This reveals close correspondence to the measured trace elemental cyclicity, indicating a coupling between the geochemical composition of the shell and the incremental growth pattern. A comparison between the elemental and image processing results reveals that ultra-high-resolution LA-ICPMS analysis surpasses the latter in detecting environmental rhythms, including daily and tidal cycles. Highly-resolved LA-ICPMS analysis is a viable alternative to nanoSIMS and opens up routine investigation of long-term (deep-time) paleoenvironmental records at daily resolution. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68063
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey, United Kingdom
Recommended Citation:
Warter V.,Müller W.. Daily growth and tidal rhythms in Miocene and modern giant clams revealed via ultra-high resolution LA-ICPMS analysis — A novel methodological approach towards improved sclerochemistry[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01,465