Tephrostratigraphical investigation of lake sediments and a peat bog in Northeastern China since 20,000 years

The Holocene ◽  
2016 ◽  
Vol 27 (5) ◽  
pp. 765-778
Author(s):  
Hongli Zhao ◽  
Jiaqi Liu ◽  
Valerie A Hall ◽  
Xiaoqiang Li

This is a detailed tephrostratigraphical investigation of late Quaternary deposits in the Longgang and Changbaishan Volcanic Fields of northeastern China. A total of 45 reference samples which were collected from either side of the Chinese/Korean border showed very similar geochemical characteristics to the Millennium eruption of Tianchi Volcano. Through comparing the published data of the glass shards detected in Gushantun with these reference samples, further description is that the glass shards in the sediment of Gushantun came from the Tianchi Volcano eruption in AD 1702, 1668, and 1597. A basaltic tephra layer found in the sediment of Hanlongwan associated with an eruption of the Jinlongdingzi Volcano which happened in 1500–2100 cal. yr BP by comparing with the published data from Sihailongwan and Xiaolongwan. Tianchi and Jinlongdingzi Volcano are both active and erupted several times during the historical period. Reference samples and the tephra layers detected in Hanlongwan, Sihailongwan, Gushantun, Erlongwan, and Xiaolongwan can be used as marker horizons beyond the Longgang Volcanic Field and Changbaishan Volcanic Field, including, for example, in Japan, Korea, nearby coastal area of Russia, and marine records.

1977 ◽  
Vol 7 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Henry W. Smith ◽  
Rose Okazaki ◽  
Charles R. Knowles

Reference samples of three prominent pumice units of Glacier Peak tephra collected east of the volcano within a distance of 100 km are similar petrographically to units described by earlier workers. Glass shards isolated from these samples were analyzed by electron microprobe to determine the content of Ca, Fe, and K. Resulting data, plus those published for two other references samples, provide a basis for attributing certain outlying tephra layers from 14 locations in eastern Washington, Idaho, Wyoming, and Montana to eruptions of Glacier Peak. Ten of the samples have properties of both Glacier Peak tephra and Mount St. Helens set J tephra, but proportions of Ca:Fe:K in glass shards indicate that 9 of the 10 outlying samples came from Glacier Peak, whereas one is assigned to Mount St. Helens set J. The remaining six outlying samples, all from southeastern Washington, contain cummingtonite phenocrysts and are chemically similar to some parts of Mount St. Helens tephra sets that are older than 12,000 BP.


2020 ◽  
pp. SP510-2020-83
Author(s):  
Haiquan Wei ◽  
Bo Zhao ◽  
Zhengquan Chen ◽  
Hongmei Yu

AbstractThe Changbaishan volcanic field located on the Gaima (Gaema, Gaiman) Plateau witnessed plateau-forming eruptions along with the uplift of the Gaima Plateau. The Tianchi basaltic lava shield volcano was formed at the main peak of Changbaishan, with cone construction eruptions that formed a huge and steep trachytic composite cone on the gentle lava shield. At the peak of the Millennium Eruption (ME), height of the eruption column (HB) reached 25 km and the bulk volume of tephra was about 120 km3. The ME eventually formed Tianchi caldera, after which several eruptions occurred, albeit of a much smaller scale.The magmas involved in the shield-forming eruptions are characterized by both alkalic series trachybasalt and basaltic trachyandesite and subalkalic tholeiite and basaltic andesite. In the cone-construction and ignimbrite-forming eruption stages, the magma is completely composed of alkalic series trachyte and comendite. The largest negative Eu anomalies observed in ME magmas indicate that plagioclase was strongly crystallized and differentiated.


2012 ◽  
Vol 47 ◽  
pp. 150-159 ◽  
Author(s):  
Jinhui Yin ◽  
A.J. Timothy Jull ◽  
George S. Burr ◽  
Yonggang Zheng

2016 ◽  
Vol 13 (7) ◽  
pp. 2151-2178 ◽  
Author(s):  
Niklas Leicher ◽  
Giovanni Zanchetta ◽  
Roberto Sulpizio ◽  
Biagio Giaccio ◽  
Bernd Wagner ◽  
...  

Abstract. 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.


2015 ◽  
Vol 12 (18) ◽  
pp. 15411-15460 ◽  
Author(s):  
N. Leicher ◽  
G. Zanchetta ◽  
R. Sulpizio ◽  
B. Giaccio ◽  
B. Wagner ◽  
...  

Abstract. A~tephrostratigraphic record covering the Marine Isotope Stages (MIS) 1–15 was established for the DEEP site record of Lake Ohrid (Macedonia/Albania). Major element analyses (SEM-EDS/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 from the Italian Volcanic Provinces. They include: the Y-3 (OH-DP-0115, 26.68–29.42 cal ka 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 the Pantelleria Island (OH-DP-0499, 129 ± 6 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 TM24-a/POP2 (OH-DP-0404, 101.8 ka) from the Lago Grande di Monticchio and the Sulmona basin, the CF-V5/PRAD3225 (OH-DP-0624, ca. 162 ka) from the Campo Felice basin/Adriatic Sea, the SC5 (OH-DP-1955, 493.1 ± 10.9 ka) from the Mercure basin, and the A11/12 (OH-DP-2017, 511 ± 6 ka) from the Acerno basin, whose specific volcanic sources are still poorly constrained. Additionally, one cryptotephra (OH-DP-0027) was identified by correlation of the potassium XRF intensities from the DEEP site with those from short cores of previous studies 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 cal ka BP) from Somma-Vesuvius. With the tephrostratigraphic work, a consistent part of the Middle Pleistocene tephrostratigraphic framework of Italian volcanoes was for the first time extended as far as to 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 paleoclimatic and -environmental 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 is candidate to become the Rosetta stone for the central Mediterranean tephrostratigraphy, especially for the hitherto poorly known and explored lower Middle Pleistocene period.


2020 ◽  
Vol 105 (12) ◽  
pp. 1830-1840 ◽  
Author(s):  
Yi Sun ◽  
Axel K. Schmitt ◽  
Lucia Pappalardo ◽  
Massimo Russo

Abstract Initial excess protactinium (231Pa) is a frequently suspected source of discordance in baddeleyite (ZrO2) geochronology, which limits accurate U/Pb dating, but such excesses have never been directly demonstrated. In this study, Pa incorporation in late Holocene baddeleyite from Somma-Vesuvius (Campanian Volcanic Province, central Italy) and Laacher See (East Eifel Volcanic Field, western Germany) was quantified by U-Th-Pa measurements using a large-geometry ion microprobe. Baddeleyite crystals isolated from subvolcanic syenites have average U concentrations of ~200 ppm and are largely stoichiometric with minor abundances of Nb, Hf, Ti, and Fe up to a few weight percent. Measured (231Pa)/(235U) activity ratios are significantly above the secular equilibrium value of unity and range from 3.4(8) to 14.9(2.6) in Vesuvius baddeleyite and from 3.6(9) to 8.9(1.4) in Laacher See baddeleyite (values within parentheses represent uncertainties in the last significant figures reported as 1σ throughout the text). Crystallization ages of 5.12(56) ka (Vesuvius; MSWD = 0.96, n = 12) and 15.6(2.0) ka (Laacher See; MSWD = 0.91, n = 10) were obtained from (230Th)/(238U) disequilibria for the same crystals, which are close to the respective eruption ages. Applying a corresponding age correction indicates average initial (231Pa)/(235U)0 of 8.8(1.0) (Vesuvius) and 7.9(5) (Laacher See). For reasonable melt activities, model baddeleyite-melt distribution coefficients of DPa/DU = 5.8(2) and 4.1(2) are obtained for Vesuvius and Laacher See, respectively. Speciation-dependent (Pa4+ vs. Pa5+) partitioning coefficients (D values) from crystal lattice strain models for tetra- and pentavalent proxy ions significantly exceed DPa/DU inferred from direct analysis of 231Pa for Pa5+. This is consistent with predominantly reduced Pa4+ in the melt, for which D values similar to U4+ are expected. Contrary to common assumptions, baddeleyite-crystallizing melts from Vesuvius and Laacher See appear to be dominated by Pa4+ rather than Pa5+. An initial disequilibrium correction for baddeleyite geochronology using DPa/DU = 5 ± 1 is recommended for oxidized phonolitic melt compositions.


1980 ◽  
Vol 13 (2) ◽  
pp. 160-171 ◽  
Author(s):  
Alan N. Federman ◽  
Steven N. Carey

AbstractFive widespread tephra layers are found in late Quaternary sediments (0–130,000 yr B.P.) of the Eastern Mediterranean Sea. These layers have been correlated among abyssal cores and to their respective terrestrial sources by electron-probe microanalysis of glass and pumice shards. Major element variations are sufficient to discriminate unambiguously between the five major layers. Oxygen isotope stratigraphy in one of the cores studied was used to data four of the five layers. Two of the widespread layers are derived from explosive eruptions of the Santorini volcanic complex: the Minoan Ash (3370 yr B.P.) and the Acrotiri Ignimbrite (18,000 yr B.P.). An additional layer, found in one core only, is most likely correlated to the Middle Pumice Series of Santorini (approximately 100,000 yr B.P.). Two layers are correlated to deposits on the islands of Yali and Kos and date to 31,000 and 120,000 yr B.P., respectively. One layer originated from the Neapolitan area of Italy 38,000 yr B.P.


2021 ◽  
Author(s):  
◽  
Matthew Thomas Stevens

<p>The Coromandel Volcanic Zone (CVZ) was the longest-lived area of volcanism in New Zealand hosting the commencement of large explosive rhyolitic and ignimbrite forming eruptions. The NW trending Coromandel Peninsula is the subaerial remnant of the Miocene-Pliocene CVZ, which is regarded as a tectonic precursor to the Taupo Volcanic Zone (TVZ), currently the most dynamic and voluminous rhyolitic volcanic centre on Earth. This study presents new single glass shard major and trace element geochemical analyses for 72 high-silica volcanic tephra layers recovered from well-dated deep-sea sediments of the SW Pacific Ocean by the Ocean Drilling Program (ODP) Leg 181. ODP Site 1124, ~720 km south and east from the CVZ, penetrated sediments of the Rekohu Drift yielding an unprecedented record of major explosive volcanic eruptions owing to the favourable location and preservation characteristics at this site. This record extends onshore eruptive sequences of CVZ explosive volcanism that are obscured by poor exposure, alteration, and erosion and burial by younger volcanic deposits. Tephra layers recovered from Site 1124 are well-dated through a combination of biostratigraphic and palaeomagnetic methods allowing the temporal geochemical evolution of the CVZ to be reconstructed in relation to changes in the petrogenesis of CVZ arc magmas from ~ 10 to 2 Ma. This thesis establishes major and trace element geochemical "fingerprints" for all Site 1124-C tephras using well-established (wavelength dispersive electron probe microanalysis) and new (laser ablation inductively coupled plasma mass spectrometry) in situ single glass shard microanalytical techniques. Trace element analysis of Site 1124-C glass shards (as small as 20 um) demonstrate that trace element signatures offer a more specific, unequivocal characterisation for distinguishing (and potentially correlating) between tephras with nearly identical major element compositions. The Site 1124-C core contains 72 unaltered Miocene-Pliocene volcanic glass-shard-bearing laminae > 1 cm thick that correspond to 83 or 84 geochemical eruptive units. Revised eruptive frequencies based on the number of geochemical eruptive units identified represent at least one eruption every 99 kyr for the late Miocene and one per 74 kyr for the Pliocene. The frequency of tephra deposition throughout the history of the CVZ has not been constant, rather reflecting pulses of major explosive eruptions resulting in closely clustered groups of tephra separated by periods of reduced activity, relative volcanic quiescence or non-tephra deposition. As more regular activity became prevalent in the Pliocene, it was accompanied by more silicic magma compositions. Rhyolitic volcanic glass shards are characterised by predominantly calc-alkaline and minor high-K enriched major element compositions. Major element compositional variability of the tephras deposited between 10 Ma and 2 Ma reveals magma batches with pre-eruptive compositional gradients implying a broad control by fractional crystallisation. Trace element characterisation of glass shards reveals the role of magmatic processes that are not readily apparent in the relatively homogeneous major element compositions. Multi-element diagrams show prominent negative Sr and Ti anomalies against primitive mantle likely caused by various degrees of plagioclase and titanomagnetite fractional crystallisation in shallow magma chambers. Relative Nb depletion, characteristic of arc volcanism, is moderate in CVZ tephras. HFSEs (e.g. Nb, Zr, Ti) and HREEs (e.g. Yb, Lu) remain immobile during slab fluid flux suggesting they are derived from the mantle wedge. LILE (e.g. Rb, Cs, Ba, Sr) and LREE (e.g. La, Ce) enrichments are consistent with slab fluid contribution. B/La and Li/Y ratios can be used as a proxy for the flux of subducting material to the mantle wedge, they suggest there is a strong influence from this component in the generation of CVZ arc magmas, potentially inducing melting. CVZ tephra show long-term coherent variability in trace element geochemistry. Post ~ 4 Ma tephras display a more consistent, less variable, chemical fingerprint that persists up to and across the CVZ/TVZ transition at ~ 2 Ma. Initiation of TVZ volcanism may have occurred earlier than is presently considered, or CVZ to TVZ volcanism may have occurred without significant changes in magma generation processes.</p>


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