First tephrostratigraphic results of the DEEP site record from Lake Ohrid (Macedonia and Albania)
First tephrostratigraphic results of the DEEP site record from Lake Ohrid (Macedonia and Albania)
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DOI：
10.5194/bg-13-2151-2016
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发表时间：
2016-01-01
期刊：
影响因子：
4.9
通讯作者：
Del Carlo, Paola
中科院分区：
文献类型：
--
作者：
Leicher, Niklas;Zanchetta, Giovanni;Del Carlo, Paola
为奥赫里德湖（马其顿和阿尔巴尼亚）的深海现场记录建立了一个覆盖海洋同位素阶段（MIS）1-15的火山灰地层记录。对从12个火山灰层（OH-DP-0115至OH-DP-2060）中提取的幼年碎片进行了主要元素分析（能量色散光谱（EDS）和波长色散光谱（WDS））。所有这些层的玻璃碎片的地球化学分析表明，在意大利火山省的起源。其中包括Y-3（OH-DP-0115，26.68-29.42 ka cal BP），坎帕尼亚期的斜镶英辉岩-Y-5（OH-DP-0169，39.6 +/- 0.1 ka）和X-6（OH-DP-0404，109 +/- 2 ka）来自坎帕尼亚火山，Pantelleria的P-11（OH-DP-0499，133.5 ± 2 ka），Vico B（OH-DP-0617，162 +/- 6 ka）来自Vico火山，Pozzolane Rosse（OH-DP-1817，457 +/- 2 ka）和Tufo di Bagni Albule（OH-DP-2060，527 +/- 2 ka），以及Sabatini火山区的Fall A（OH-DP-2010，496 +/- 3 ka）。此外，奥赫里德记录与地中海地区中-远缘档案的火山灰地层记录的比较允许识别其他不太知名的火山灰层的等同物，例如在Lago Grande di Monticchio和Sulmona Basin中识别的TM 24 a-POP 2（OH-DP-0404，102 +/- 2 ka），CF-V5-PRAD 3225（OH-DP-0624，ca. 163 +/- 22 ka），在Campo Felice盆地和亚得里亚海确定的SC 5（OH-DP-1955，493.1 +/- 10.9 ka），在Mercure盆地确定的，和在Acerno盆地采样的A11/12（OH-DP-2017，511 +/- 6 ka），其具体的火山源仍然缺乏约束。此外，一个cryptotephra（OH-DP-0027）的相关性的钾X射线荧光（XRF）强度从深度网站与那些从奥赫里德湖以前的研究短核心。在这些岩心中，钾的最大值是由玻璃碎片引起的，这与索玛-维苏威火山的Mercato火山灰（8.43-8.63 ka cal BP）有关。这里介绍的火山灰地层工作允许，第一次，意大利火山的中更新世火山灰地层学的一致部分的延伸，远至巴尔干半岛。奥赫里德湖记录的火山灰地层格架的建立为DEEP遗址序列的年龄-深度模型提供了重要的、独立的联系点，这是古气候和古环境重建的先决条件。此外，这个年龄-深度模型将有助于改进和重新评估其他记录中未注明日期和日期的火山灰层的年代学。因此，奥赫里德湖记录可能成为地中海中部火山灰地层学的模板，特别是迄今为止知之甚少和探索较低的中更新世时期。
A tephrostratigraphic record covering the Marine Isotope Stages (MIS) 1-15 was established for the DEEP site record of Lake Ohrid (Macedonia and Albania). Major element analyses (energy dispersive spectroscopy (EDS) and wavelength-dispersive spectroscopy (WDS)) were carried out on juvenile fragments extracted from 12 tephra layers (OH-DP-0115 to OH-DP-2060). The geochemical analyses of the glass shards of all of these layers suggest an origin in the Italian volcanic provinces. They include the Y-3 (OH-DP-0115, 26.68-29.42 ka cal BP), the Campanian Ignimbrite-Y-5 (OH-DP-0169, 39.6 +/- 0.1 ka), and the X-6 (OH-DP-0404, 109 +/- 2 ka) from the Campanian volcanoes, the P-11 of Pantelleria (OH-DP-0499, 133.5 +/- 2 ka), the Vico B (OH-DP-0617, 162 +/- 6 ka) from the Vico volcano, the Pozzolane Rosse (OH-DP-1817, 457 +/- 2 ka) and the Tufo di Bagni Albule (OH-DP-2060, 527 +/- 2 ka) from the Colli Albani volcanic district, and the Fall A (OH-DP-2010, 496 +/- 3 ka) from the Sabatini volcanic field. Furthermore, a comparison of the Ohrid record with tephrostratigraphic records of mid-distal archives related to the Mediterranean area allowed the recognition of the equivalents of other less known tephra layers, such as the TM24a-POP2 (OH-DP-0404, 102 +/- 2 ka) recognized in the Lago Grande di Monticchio and the Sulmona Basin, the CF-V5-PRAD3225 (OH-DP-0624, ca. 163 +/- 22 ka) identified in the Campo Felice Basin and the Adriatic Sea, the SC5 (OH-DP-1955, 493.1 +/- 10.9 ka) recognized in the Mercure Basin, and the A11/12 (OH-DP-2017, 511 +/- 6 ka) sampled at the Acerno Basin, whose specific volcanic sources are still poorly constrained. Additionally, one cryptotephra (OH-DP-0027) was identified by correlation of the potassium X-ray flourescence (XRF) intensities from the DEEP site with those from a short core of a previous study from Lake Ohrid. In these cores, a maximum in potassium is caused by glass shards, which were correlated with the Mercato tephra (8.43-8.63 ka cal BP) from Somma-Vesuvius. The tephrostratigraphic work presented here allows, for the first time, the extension of a consistent part of the Middle Pleistocene tephrostratigraphy of Italian volcanoes as far as the Balkans. The establishment of the tephrostratigraphic framework for the Lake Ohrid record provides important, independent tie points for the age-depth model of the DEEP site sequence, which is a prerequisite for palaeoclimatic and palaeoenvironmental reconstructions. Furthermore, this age-depth model will help to improve and re-evaluate the chronology of other, both undated and dated tephra layers from other records. Thus, the Lake Ohrid record may potentially become the template for the central Mediterranean tephrostratigraphy, especially for the hitherto poorly known and explored lower Middle Pleistocene period.