A volcanic source of variation

Studies have found that the Permian is another important stratum for petroleum exploration except the Jurassic coal measures within Turpan–Hami Basin recently. However, the knowledge of the depositional environments and its petroleum geological significances during the Middle–Late Permian is still limited. Based on the analysis about the sedimentological features of the outcrop and the geochemical characteristics of mudstones from the Middle Permian Taerlang Formation and Upper Permian Quanzijie Formation in the Taoshuyuanzi profile, northwest Turpan–Hami Basin, this paper makes a detailed discussion on the Middle–Late Permian paleoenvironment and its petroleum geological significances. The Middle–Upper Permian delta–lacustrine depositional system was characterized by complex vertical lithofacies assemblages, which were primarily influenced by tectonism and frequent lake-level variations in this area. The Taerlang Formation showed a significant lake transgression trend, whereas the regressive trend of the Quanzijie Formation was relatively weaker. The provenance of Taerlang and Quanzijie Formations was derived from the rift shoulder (Bogda Mountain area now) to the north and might be composed of a mixture of andesite and felsic volcanic source rocks. The Lower Taerlang Formation was deposited in a relatively hot–dry climate, whereas the Upper Taerlang and Quanzijie Formations were deposited in a relatively humid climate. During the Middle–Late Permian, this area belonged to an overall semi-saline water depositional environment. The paleosalinity values showed stepwise decreases from the Lower Taerlang Formation to the Upper Quanzijie Formation, which was influenced by the changes of paleoclimate in this region. During the Middle–Late Permian, the study area was in an overall anoxic depositional environment. The paleoenvironment with humid climate, lower paleosalinity, anoxic condition, and semi-deep to deep water during the deposition of the Upper Taerlang Formation was suitable for the accumulation of mudstones with higher TOC values.

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Isotopic tracing of volcanic source regions from Hawaii: decoupling of gaseous from lithophile magma components

Earth and Planetary Science Letters ◽

10.1016/0012-821x(96)00126-4 ◽

1996 ◽

Vol 144 (1-2) ◽

pp. 185-198 ◽

Cited By ~ 50

Author(s):

P.J. Valbracht ◽

H. Staudigel ◽

M. Honda ◽

I. McDougall ◽

G.R. Davies

Keyword(s):

Isotopic Tracing ◽

Source Regions ◽

Volcanic Source

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The Characteristics of OSL Signal from Quartz Grains Extracted from Modern Sediments in Japan

Geochronometria ◽

10.2478/v10003-010-0020-6 ◽

2010 ◽

Vol 37 (-1) ◽

pp. 13-19 ◽

Cited By ~ 15

Author(s):

Kayoko Tokuyasu ◽

Kazuhiro Tanaka ◽

Sumiko Tsukamoto ◽

Andrew Murray

Keyword(s):

Source Rock ◽

Sedimentary Rocks ◽

Fast Component ◽

Source Rocks ◽

Complex Mixtures ◽

Coastal Sediments ◽

Component Ratio ◽

Source Areas ◽

Volcanic Source ◽

Quartz Grains

The Characteristics of OSL Signal from Quartz Grains Extracted from Modern Sediments in Japan Quartz grains from sediments in Japan are derived from complex mixtures of sources, including volcanic, plutonic, metamorphic and sedimentary rocks. We have measured the OSL signal of quartz grains from modern coastal sediments derived from different source rocks and compared these characteristics with the likely source. Each sample shows a different combination of various OSL components. It is concluded that the source rock affects the characteristics of the OSL components from quartz grains in Japanese sediments. By comparing the LM-OSL signals from volcanic sources with those from various source rocks, it can be deduced that quartz which has a higher fast component ratio is more suitable for dating. We also conclude that volcanic source areas should be avoided.

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Self-sustained vibrations in volcanic areas extracted by Independent Component Analysis: a review and new results

Nonlinear Processes in Geophysics ◽

10.5194/npg-18-925-2011 ◽

2011 ◽

Vol 18 (6) ◽

pp. 925-940 ◽

Cited By ~ 4

Author(s):

E. De Lauro ◽

S. De Martino ◽

M. Falanga ◽

M. Palo

Keyword(s):

Independent Component Analysis ◽

Seismic Waves ◽

Volcanic Tremor ◽

Component Analysis ◽

Independent Component ◽

Common Source ◽

Magma Flow ◽

Volcanic Source ◽

Non Linear ◽

Low Dimensionality

Abstract. We investigate the physical processes associated with volcanic tremor and explosions. A volcano is a complex system where a fluid source interacts with the solid edifice so generating seismic waves in a regime of low turbulence. Although the complex behavior escapes a simple universal description, the phases of activity generate stable (self-sustained) oscillations that can be described as a non-linear dynamical system of low dimensionality. So, the system requires to be investigated with non-linear methods able to individuate, decompose, and extract the main characteristics of the phenomenon. Independent Component Analysis (ICA), an entropy-based technique is a good candidate for this purpose. Here, we review the results of ICA applied to seismic signals acquired in some volcanic areas. We emphasize analogies and differences among the self-oscillations individuated in three cases: Stromboli (Italy), Erebus (Antarctica) and Volcán de Colima (Mexico). The waveforms of the extracted independent components are specific for each volcano, whereas the similarity can be ascribed to a very general common source mechanism involving the interaction between gas/magma flow and solid structures (the volcanic edifice). Indeed, chocking phenomena or inhomogeneities in the volcanic cavity can play the same role in generating self-oscillations as the languid and the reed do in musical instruments. The understanding of these background oscillations is relevant not only for explaining the volcanic source process and to make a forecast into the future, but sheds light on the physics of complex systems developing low turbulence.

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Tilt offset associated with local seismicity: the Mt. Etna January 9, 2001 seismic swarm.

Open Geosciences ◽

10.1515/geo-2016-0045 ◽

2016 ◽

Vol 8 (1) ◽

pp. 514-522 ◽

Cited By ~ 2

Author(s):

Salvatore Gambino

Keyword(s):

Local Stress ◽

Tectonic Structure ◽

Local Seismicity ◽

Seismic Swarm ◽

Long Baseline ◽

Volcanic Source ◽

Active Tectonic ◽

Mt Etna ◽

Measured Deformation ◽

2001 Eruption

AbstractOn the 9th of January 2001 a seismic swarm on the southeastern flank of Mt. Etna at 3.5 km beside sea level (b.s.l.), caused co-seismic variations on short and long baseline tiltmeters of the Mt. Etna permanent tilt network.Taking account of the geometry and mechanism of the active tectonic structure obtained by seismological studies, the theoretical tilt linked to the faulting source was calculated at multiple different recording stations. It was found that the amount of measured deformation exceeded that which was generated seismically, indicating that much of the deformation along the fault was aseismic.The 9 January 2001 episode represents a shear response to a local stress caused by a volcanic source that acted in the period preceding the 2001 eruption. Tilt data also suggest a marked slip of 70-140 cm along the fault, probably due to the presence of fluids.

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Sensitivity analysis for volcanic source modeling quality assessment and model selection

Computers & Geosciences ◽

10.1016/j.cageo.2012.03.008 ◽

2012 ◽

Vol 44 ◽

pp. 52-59 ◽

Cited By ~ 128

Author(s):

Flavio Cannavó

Keyword(s):

Sensitivity Analysis ◽

Model Selection ◽

Quality Assessment ◽

Source Modeling ◽

Volcanic Source

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Astronomical dating of two Pliocene alkaline volcanic ash layers in the Capo Rossello area (southern Sicily, Italy): implications for the beginning of the rifting in the Sicily Channel

BSGF - Earth Sciences Bulletin ◽

10.2113/gssgfbull.180.2.95 ◽

2009 ◽

Vol 180 (2) ◽

pp. 95-104 ◽

Cited By ~ 1

Author(s):

Antonio Caruso ◽

Paolo Censi ◽

Pietro Aricò ◽

Carmelina Meli ◽

Mario Sprovieri

Keyword(s):

High Resolution ◽

Late Pleistocene ◽

Volcanic Activity ◽

Volcanic Ash ◽

South Coast ◽

Sedimentary Sequences ◽

Volcanic Source ◽

Sicily Channel ◽

The One ◽

Middle Pliocene

Abstract Two volcaniclastic ash layers (AL1 and AL2) are intercalated throughout the middle Pliocene sedimentary sequences of Punta Piccola and Capo Rossello exposed along the south coast of Sicily (Italy). Astronomical calibration of the Punta Piccola section provided an age of 2.676 Ma for the deposition of the AL1 layer. The high-resolution bio-cyclostratigraphy of the Capo Rossello section, in combination with detailed correlations with previously astronomically calibrated coeval sequences, provided an age of 2.225 Ma for the deposition of the AL2 layer. Mineralogical, petrographical and geochemical results from the two volcaniclastic layers suggest a Na-alkaline differentiated magmatism for the volcanic source, similar to the one which formed the alkaline rocks of the island of Pantelleria (Sicily Channel). These results indicate that isolated volcanic activity and/or early differentiated magmatic events may have occurred in the area of the Sicily channel well before the well-known late Pleistocene volcanic activity.

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Integrated interpretation of reflection seismic and aeromagnetic data in a marine geological complex area: a case study.

10.5194/egusphere-egu2020-1226 ◽

2020 ◽

Author(s):

Silvana Fais ◽

Emile Eduard Klingele ◽

Raffaele Tocco ◽

Giuseppe Casula

Keyword(s):

Magnetic Anomaly ◽

Tectonic Evolution ◽

Analytical Signal ◽

Western Mediterranean ◽

Aeromagnetic Data ◽

Reflection Seismic ◽

Magnetic Pattern ◽

Volcanic Source ◽

Integrated Interpretation ◽

Seismic Sections

This paper presents an integrated seismic and aeromagnetic approach applied in the geological complex area of the Cagliari Gulf in the southern Sardinian margin (Western Mediterranean). The investigated area represents the southern extreme part of the main branch of the Sardinian Rift (SR) (Western Mediterranean) that is made up here of a sub-basin bounded by approximately NW faults. The study was also integrated by complementary information deduced from the GNSS network in southern Sardinia.The aim of this study was to give a contribution on the knowledge of the tectonic evolution and volcanism of the investigated area. For this purpose we used an integrated interpretation of two-dimensional reflection seismic sections and aeromagnetic data. In the same area a well drilled for oil prospection was used for calibrating the seismic interpretation up to approximately 1.8 sec.. It is worth noting that the interpretation of the seismic data can be problematic in structurally complex areas where volcanic formations occur, but it can be assisted effectively by magnetic interpretation.&#160;An interesting magnetic pattern represented by a strong, well-localized positive magnetic anomaly extending N-S for approximately 35 km is present in the western part of the Gulf. Its width in the W-E direction is of almost 20 km. The anomaly seems to be linked with the magnetic anomalies that characterize the southern Sardinian Rift in correspondence to the Campidano Graben. In fact, a set of localized high-gradient anomalies generally corresponding to the Oligo-Miocene andesitic calc-alkaline complexes is present in this Graben. The aeromagnetic interpretation was carried out to explain the origin of the above strong elongated magnetic anomaly that has never been quantitatively interpreted. In this work, this anomaly has been interpreted by means of Euler deconvolution, the analytical signal and by a delineation technique based on the maxima of the radial horizontal derivative of the total magnetic field.&#160;The geological knowledge of the area by means of earlier studies also on land contributed to give a petrographic meaning to the magnetic sources, while by the magnetic and seismic integrated interpretation it was possible to carry out a spatial reconstruction of the volcanic source body and to give an useful contribution to the knowledge on the volcano-tectonic evolution of the area. Recently the area of the Gulf of Cagliari was affected in its western sector by a weak earthquake with hypocenter at around 10 km of depth, localized by Istituto Nazionale di Geofisica e Vulcanologia (INGV). The results of this study also provided new elements of knowledge which have contributed to understand this seismic event.Acknowledgements: This work was partially supported by FIR (Fondi integrativi per la Ricerca) funded by the University of Cagliari (Italy) and by RAS/FBS (grant number: F71/17000190002) grants for funding.

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Operational evaluation of volcanic source terms (volcanic ash and SO2) from inverse modelling for aviation

10.5194/egusphere-egu2020-4889 ◽

2020 ◽

Author(s):

Mariëlle Mulder ◽

Delia Arnold ◽

Christian Maurer ◽

Marcus Hirtl

Keyword(s):

Source Term ◽

Dispersion Model ◽

Meteorological Data ◽

A Priori ◽

Radar Data ◽

Particle Dispersion ◽

Volcanic Emissions ◽

Volcanic Source ◽

Computational Resources ◽

Different Sources

An operational framework is developed to provide timely and frequent source term updates for volcanic emissions (ash and SO2). The procedure includes running the Lagrangian particle dispersion model FLEXPART with an initial (a priori) source term, and combining the output with observations (from satellite, ground-based, etc. sources) to obtain an a posteriori source term. This work was part of the EUNADICS-AV (eunadics-av.eu), which is a continuation of the work developed in the VAST project (vast.nilu.no). The aim is to ensuring that at certain time intervals when new observational and meteorological data is available during an event, an updated source term is provided to analysis and forecasting groups. The system is tested with the Grimsv&#246;tn eruption of 2011. Based on a source term sensitivity test, one can find the optimum between a sufficiently detailed source term and computational resources. Because satellite and radar data from different sources is available at different times, the source term is generated with the data that is available the earliest after the eruption started and data that is available later is used for evaluation.

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