scholarly journals Aging of basalt volcanic systems and decreasing CO<sub>2</sub> consumption by weathering

2019 ◽  
Vol 7 (1) ◽  
pp. 191-197 ◽  
Author(s):  
Janine Börker ◽  
Jens Hartmann ◽  
Gibran Romero-Mujalli ◽  
Gaojun Li
Keyword(s):  
Age Distribution ◽  
Aging Effect ◽  
Hydrothermal Activity ◽  
Volcanic Field ◽  
Critical Zone ◽  
Volcanic System ◽  
Reactive Material ◽  
Volcanic Fields ◽  
Basalt Weathering ◽  
Aging Function

Abstract. Basalt weathering is one of many relevant processes balancing the global carbon cycle via land–ocean alkalinity fluxes. The CO2 consumption by weathering can be calculated using alkalinity and is often scaled with runoff and/or temperature. Here, it is tested if the surface age distribution of a volcanic system derived by geological maps is a useful proxy for changes in alkalinity production with time. A linear relationship between temperature normalized alkalinity fluxes and the Holocene area fraction of a volcanic field was identified using information from 33 basalt volcanic fields, with an r2=0.93. This relationship is interpreted as an aging function and suggests that fluxes from Holocene areas are ∼10 times higher than those from old inactive volcanic fields. However, the cause for the decrease with time is probably a combination of effects, including a decrease in alkalinity production from material in the shallow critical zone as well as a decline in hydrothermal activity and magmatic CO2 contribution. The addition of fresh reactive material on top of the critical zone has an effect in young active volcanic settings which should be accounted for, too. A comparison with global models suggests that global alkalinity fluxes considering Holocene basalt areas are ∼60 % higher than the average from these models imply. The contribution of Holocene areas to the global basalt alkalinity fluxes is today however only ∼5 %, because identified, mapped Holocene basalt areas cover only ∼1 % of the existing basalt areas. The large trap basalt proportion on the global basalt areas today reduces the relevance of the aging effect. However, the aging effect might be a relevant process during periods of globally intensive volcanic activity, which remains to be tested.

scholarly journals Short Communication: Aging of basalt volcanic systems and decreasing CO<sub>2</sub> consumption by weathering

2018 ◽  
Author(s):  
Janine Börker ◽  
Jens Hartmann ◽  
Gibran Romero-Mujalli ◽  
Gaojun Li
Keyword(s):  
Age Distribution ◽  
Aging Effect ◽  
Hydrothermal Activity ◽  
Volcanic Field ◽  
Volcanic System ◽  
Co2 Consumption ◽  
Volcanic Fields ◽  
Basalt Weathering ◽  
Aging Function ◽  
Global Carbon

Abstract. Basalt weathering is one of many relevant processes balancing the global carbon cycle via land-ocean alkalinity fluxes. The CO2 consumption by weathering can be calculated using alkalinity and is often scaled with runoff and/or temperature. Here it is tested if information on the surface age distribution of a volcanic system is a useful proxy for changes in alkalinity production with time. A linear relationship between temperature normalized alkalinity fluxes and the Holocene area fraction of a volcanic field was identified, using information from 33 basalt volcanic fields, with an r2 = 0.91. This relationship is interpreted as an aging function and suggests that fluxes from Holocene areas are ~ 10 times higher than those from old inactive volcanic fields. However, the cause for the decrease with time is probably a combination of effects, including a decrease in alkalinity production from surface near material in the critical zone as well as a decline in hydrothermal activity and magmatic CO2 contribution. A comparison with global models suggests, that global alkalinity fluxes considering Holocene active basalt areas are ~ 70 % higher than the average from these models imply. The contribution of Holocene areas to the global basalt alkalinity fluxes is however only ~ 6 %, because identified, mapped Holocene basalt areas cover only ~ 1 % of the existing basalt areas. The large trap basalt proportion on the global basalt areas today reduces the relevance of the aging effect. However, the aging effect might be a relevant process during periods of globally, intensive volcanic activity, which remains to be tested.

scholarly journals 40Ar/39Ar and paleomagnetic constraints on the age and areal extent of the Picabo volcanic field: Implications for the Yellowstone hotspot

Geosphere ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 716-735 ◽  
Author(s):  
Mark H. Anders ◽  
Victor J. DiVenere ◽  
Sidney R. Hemming ◽  
Joel Gombiner
Keyword(s):  
Migration Rate ◽  
Volcanic Field ◽  
Snake River Plain ◽  
Areal Extent ◽  
Volcanic System ◽  
Yellowstone Hotspot ◽  
The Past ◽  
Volcanic Fields ◽  
Silicic Volcanic ◽  
River Plain

Abstract The Picabo volcanic field is one of the key silicic volcanic fields in the time-transgressive track of the Yellowstone hotspot. The Picabo volcanic field is also one of the most poorly defined volcanic fields along the track of the Yellowstone hotspot. Determining the age and areal extent of the Picabo volcanic field ignimbrites is one of the primary objectives of this study. In our effort to correlate ignimbrites within the Picabo volcanic field as well as identify those from the neighboring Twin Falls and Heise volcanic fields, we present new petrographic, 40Ar/39Ar, and paleomagnetic data. With these data, we correlated several ignimbrites within the Picabo volcanic field. In some cases, we correlate units previously thought to be in the Picabo volcanic field to older volcanic fields. This includes the Picabo Tuff, which we suggest originates from the Twin Falls volcanic field rather from its namesake volcanic field. The first and best documented major silicic eruption of the volcanic field, the Arbon Valley Tuff, is also the largest ignimbrite in the Picabo volcanic field. There is disagreement as to whether the Arbon Valley Tuff is the result of a single ignimbrite eruption or multiple eruptions. We previously have suggested that the Arbon Valley Tuff is the result of two eruptions, one at 10.41 ± 0.01 Ma and the other at 10.22 ± 0.01 Ma (Anders et al., 2014). Those combining radiometric dates into a single eruption age report ages of 10.2 Ma, 10.27 ± 0.01 Ma, 10.34 ± 0.03 Ma, and 10.44 ± 0.27 Ma. We also suggest the final eruption of the Picabo volcanic field was the tuff of American Falls dated at 7.58 ± 0.02 Ma. Estimates of the location of Picabo volcanic field have been used to mark a major change in the migration rate of the Yellowstone–Snake River Plain silicic volcanic system. Based on our new data, we found only minor changes of the boundaries of the Picabo volcanic field from previous studies. Using the age of the Arbon Valley Tuff (10.41 Ma), we calculated an extension-corrected migration rate of 2.27 ± 0.2 cm/yr between the position of the Picabo volcanic field and that of the Yellowstone volcanic field over the past ∼10 m.y. This estimate is close to the extension corrected 2.38 ± 0.21 cm/yr value based on the migration of the hotspot deformation field. These rates are consistent with independent estimates of North American plate velocity over the past 10 m.y. and therefore consistent with a fixed reference frame for the Yellowstone hotspot. These results stand in contrast with several recent models for the evolution of the Yellowstone–Snake River Plain volcanic system. We also discovered a new ignimbrite from the Heise volcanic field, the 4.37 ± 0.08 Ma tuff of Birch Creek Sinks, in core from the U.S. Geological Survey (USGS) borehole 2-2A, which now represents the youngest outflow ignimbrite of the Heise volcanic field. Although recently, several intracaldera ignimbrites younger than 4 Ma have been identified in the volcanic field, the age range of outflow ignimbrites from the Heise volcanic field is now extended from 6.66 Ma to at least 4.37 Ma.

Eruptive frequency of the Bora-Baricha-Tullu Moye (BBTM) volcanic system in the Central Main Ethiopian Rift

2021 ◽  
Author(s):  
Amdemichael Zafu Tadesse ◽  
Karen Fontijn ◽  
Abate Assen Melaku ◽  
Ermias Filfilu Gebru ◽  
Victoria Smith ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Volcanic Eruptions ◽  
Volcanic Field ◽  
Tectonic Activity ◽  
Explosive Eruptions ◽  
Ethiopian Rift ◽  
Rift System ◽  
Diagnostic Features ◽  
Volcanic System ◽  
Main Ethiopian Rift

&lt;p&gt;The Main Ethiopian Rift (MER) is the northern portion of the East African Rift System and separates the Eastern and Western plateaus of Ethiopia. The recent volcanic and tectonic activity is largely focused within the rift basin along a 20 km wide zone on the rift floor. Large silicic volcanic complexes are aligned along this central rift axis but their eruptive histories are not well constrained.&lt;/p&gt;&lt;p&gt;The Bora-Baricha-Tullu Moye (BBTM) volcanic field is situated in the central Main Ethiopian Rift and has a different appearance than the other MER volcanic systems. The BBTM constitutes several late Quaternary edifices, the major ones are: Tullu Moye, Bora and Baricha. In addition, there are multiple smaller eruptive vents (e.g. Oda and Dima), cones, and domes across the ca. 20 X 20 km wide area. Currently, there is very little information on the frequency and magnitude of past volcanic eruptions. We present a new dataset of field observations, componentry, petrography, geochronology (&lt;sup&gt;40&lt;/sup&gt;Ar/&lt;sup&gt;39&lt;/sup&gt;Ar), and glass major and trace element chemistry. The data are assessed as potential fingerprints to assign diagnostic features and correlate units across the area, and establish a tephrostratigraphic framework for the BBTM volcanic field.&lt;/p&gt;&lt;p&gt;Two large-volume and presumably caldera-forming eruptions are identified, the younger of which took place at 100 ka. The volcanic products exposed in the BBTM area show that the volcanic field has undergone at least 20 explosive eruptions since then. The post-caldera eruptions have comenditic (Tullu Moye) and pantelleretic (Bora and Baricha) magma compositions. Other smaller edifices such as Oda and Dima also erupted pantelleritic magmas, and only differ slightly in composition than tephra of Bora and Baricha. Tullu Moye had two distinct explosive eruptions that dispersed tephra up to 14 km away and on to the eastern plateau. Bora and Baricha together had at least 8 explosive eruptions. Their deposits can be distinguished by their light grey color and unique lithic components. Oda had 7 eruptions, the most recent of which generated a pyroclastic density current that travelled up to 10 km away from the vent. Dima experienced at least 3 eruptions, generating tephra with a bluish-grey colour.&lt;/p&gt;&lt;p&gt;This mapping and compositional analysis of the deposits from the BBTM in the MER indicates that the region has been more active in the last 100 ka than previously thought, which has implications for hazards assessments for the region.&lt;/p&gt;

scholarly journals Structural controls on the location, geometry and longevity of an intraplate volcanic system: the Tuatara Volcanic Field, Great South Basin, New Zealand

2020 ◽  
Vol 177 (5) ◽  
pp. 1039-1056
Author(s):  
Thomas B. Phillips ◽  
Craig Magee
Keyword(s):  
Volcanic Field ◽  
Auckland Volcanic Field ◽  
Seismic Section ◽  
Volcanic System ◽  
Seismic Reflection Data ◽  
Content Type ◽  
Reflection Data ◽  
3D Geometry ◽  
Plumbing Systems ◽  
Supplementary Material

Intraplate volcanism is widely distributed across the continents, but the controls on the 3D geometry and longevity of individual volcanic systems remain poorly understood. Geophysical data provide insights into magma plumbing systems, but, as a result of the relatively low resolution of these techniques, it is difficult to evaluate how magma transits highly heterogeneous continental interiors. We use borehole-constrained 2D seismic reflection data to characterize the 3D geometry of the Tuatara Volcanic Field located offshore New Zealand's South Island and investigate its relationship with the pre-existing structure. This c. 270 km2 field is dominated by a dome-shaped lava edifice, surrounded and overlain by c. 69 volcanoes and >70 sills emplaced over 40 myr from the Late Cretaceous to Early Eocene (c. 85–45 Ma). The Tuatara Volcanic Field is located above a basement terrane boundary represented by the Livingstone Fault; the recently active Auckland Volcanic Field is similarly located along-strike on North Island. We suggest that the Livingstone Fault controlled the location of the Tuatara Volcanic Field by producing relief at the base of the lithosphere, thereby focussing lithospheric detachment over c. 40 myr, and provided a pathway that facilitated the ascent of magma. We highlight how observations from ancient intraplate volcanic systems may inform our understanding of active intraplate volcanic systems, including the Auckland Volcanic Field.Supplementary material: Interpreted seismic section showing well control on stratigraphic interpretation is available at https://doi.org/10.6084/m9.figshare.c.5004464

scholarly journals Shallow Magmatic Hydrothermal Eruption in April 2018 on Ebinokogen Ioyama Volcano in Kirishima Volcano Group, Kyushu, Japan

Geosciences ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 183 ◽  
Author(s):  
Yasuhisa Tajima ◽  
Setsuya Nakada ◽  
Fukashi Maeno ◽  
Toshio Huruzono ◽  
Masaaki Takahashi ◽  
...  
Keyword(s):  
Hydrothermal System ◽  
Hydrothermal Activity ◽  
Volcanic Field ◽  
Multiple Systems ◽  
Geothermal Activity ◽  
Hydrothermal Eruption ◽  
Kirishima Volcano ◽  
Geophysical Observation ◽  
Under The Volcano ◽  
Fluid Pressurization

The Kirishima Volcano Group is a volcanic field ideal for studying the mechanism of steam-driven eruptions because many eruptions of this type occurred in the historical era and geophysical observation networks have been installed in this volcano. We made regular geothermal observations to understand the hydrothermal activity in Ebinokogen Ioyama Volcano. Geothermal activity resumed around the Ioyama from December 2015. A steam blowout occurred in April 2017, and a hydrothermal eruption occurred in April 2018. Geothermal activity had gradually increased before these events, suggesting intrusion of the magmatic component fluids in the hydrothermal system under the volcano. The April 2018 eruption was a magmatic hydrothermal eruption caused by the injection of magmatic fluids into a very-shallow hydrothermal system as a bottom–up fluid pressurization, although juvenile materials were not identifiable. Additionally, the upwelling of mixed magma–meteoric fluids to the surface as a kick was observed just before the eruption to cause the top–down flashing of April 2018. A series of events was generated in the shallower hydrothermal regime consisting of multiple systems divided by conductive caprock layers.

scholarly journals Hydrothermal Activity in the Southwest Yellowstone Plateau Volcanic Field

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
S. Hurwitz ◽  
R. B. McCleskey ◽  
D. Bergfeld ◽  
S. E. Peek ◽  
D. D. Susong ◽  
...  
Keyword(s):  
Hydrothermal Activity ◽  
Volcanic Field

scholarly journals Age and mantle sources of Quaternary basalts associated with “leaky” transform faults of the migrating Anatolia-Arabia-Africa triple junction

Geosphere ◽  
2020 ◽  
Author(s):  
Michael A. Cosca ◽  
Mary Reid ◽  
Jonathan R. Delph ◽  
Gençalioğlu Kuşcu Gonca ◽  
Janne Blichert-Toft ◽  
...  
Keyword(s):  
Partial Melting ◽  
Fault Zone ◽  
Triple Junction ◽  
Lithospheric Mantle ◽  
Seismic Imaging ◽  
Plate Boundary ◽  
Volcanic Field ◽  
Plate Boundaries ◽  
Transform Faults ◽  
Volcanic Fields

The Anatolia (Eurasia), Arabia, and Africa tec­tonic plates intersect in southeast Turkey, near the Gulf of İskenderun, forming a tectonically active and unstable triple junction (the A3 triple junction). The plate boundaries are marked by broad zones of major, dominantly left-lateral transform faults including the East Anatolian fault zone (the Anato­lia-Arabia boundary) and the Dead Sea fault zone (the Arabia-Africa boundary). Quaternary basalts occur locally within these “leaky” transform fault zones (similar to those observed within oceanic transform faults), providing evidence that mantle melting, basalt genesis, and eruption are linked to crustal deformation and faulting that extends into the upper mantle. We investigated samples of alkaline basalt (including basanite) from the Toprakkale and Karasu volcanic fields within a broad zone of transtension associated with these plate-boundary faults near the İskenderun and Amik Basins, respectively. Toprakkale basalts and basanites have 40Ar/39Ar plateau ages ranging from 810 ± 60 ka to 46 ± 13 ka, and Karasu volcanic field basalts have 40Ar/39Ar plateau ages ranging from 2.63 ± 0.17 Ma to 52 ± 16 ka. Two basanite samples within the Toprak­kale volcanic field have isotopic characteristics of a depleted mantle source, with 87Sr/86Sr of 0.703070 and 0.703136, 143Nd/144Nd of 0.512931 and 0.512893, 176Hf/177Hf of 0.283019 and 0.282995, 206Pb/204Pb of 19.087 and 19.155, and 208Pb/204Pb of 38.861 and 38.915. The 176Hf/177Hf ratios of Toprakkale basalts (0.282966–0.283019) are more radiogenic than Karasu basalts (0.282837–0.282965), with some overlap in 143Nd/144Nd ratios (0.512781–0.512866 vs. 0.512648–0.512806). Toprakkale 206Pb/204Pb ratios (19.025 ± 0.001) exhibit less variation than that observed for Karasu basalts (18.800–19.324), and 208Pb/204Pb values for Toprakkale basalts (38.978– 39.103) are slightly lower than values for Karasu basalts (39.100–39.219). Melting depths estimated for the basalts from both volcanic fields gener­ally cluster between 60 and 70 km, whereas the basanites record melting depths of ~90 km. Depth estimates for the basalts largely correspond to the base of a thin lithosphere (~60 km) observed by seismic imaging. We interpret the combined radio­genic isotope data (Sr, Nd, Hf, Pb) from all alkaline basalts to reflect partial melting at the base of the lithospheric mantle. In contrast, seismic imaging indicates a much thicker (&gt;100 km) lithosphere beneath southern Anatolia, a substantial part of which is likely subducted African lithosphere. This thicker lithosphere is adjacent to the surface loca­tions of the basanites. Thus, the greater melting depths inferred for the basanites may include par­tial melt contributions either from the lithospheric mantle of the attached and subducting African (Cyprean) slab, or from partial melting of detached blocks that foundered due to convective removal of the Anatolian lithosphere and that subsequently melted at ~90 km depth within the asthenosphere. The Quaternary basalts studied here are restricted to a broad zone of transtension formed in response to the development of the A3 triple junction, with an earliest erupted age of 2.63 Ma. This indicates that the triple junction was well established by this time. While the current posi­tion of the A3 triple junction is near the Amik Basin, faults and topographic expressions indicate that inception of the triple junction began as early as 5 Ma in a position farther to the northeast of the erupted basalts. Therefore, the position of the A3 triple junction appears to have migrated to the southwest since the beginning of the Pliocene as the Anatolia-Africa plate boundary has adjusted to extrusion (tectonic escape) of the Anatolia plate. Establishment of the triple junction over the past 5 m.y. was synchronous with rollback of the Afri­can slab beneath Anatolia and associated trench retreat, consistent with Pliocene uplift in Cyprus and with the current positions of plate boundaries. The A3 triple junction is considered to be unstable and likely to continue migrating to the southwest for the foreseeable geologic future.

scholarly journals Stratigraphy of Architectural Elements of a Buried Monogenetic Volcanic System

2019 ◽  
Vol 11 (1) ◽  
pp. 581-616 ◽  
Author(s):  
Alan Bischoff ◽  
Andrew Nicol ◽  
Jim Cole ◽  
Darren Gravley
Keyword(s):  
Geothermal Energy ◽  
Sedimentary Basin ◽  
Sedimentary Basins ◽  
Volcanic Field ◽  
Plumbing System ◽  
Volcanic System ◽  
Architectural Elements ◽  
Stratigraphic Framework ◽  
Cone Type ◽  
Geological Evolution

Abstract Large volumes of magma emplaced and deposited within sedimentary basins can have an impact on the architecture and geological evolution of these basins. Over the last decade, continuous improvement in techniques such as seismic volcano-stratigraphy and 3D visualisation of igneous bodies has helped increase knowledge about the architecture of volcanic systems buried in sedimentary basins. Here, we present the complete architecture of the Maahunui Volcanic System (MVS), a middle Miocene monogenetic volcanic field now buried in the offshore Canterbury Basin, South Island of New Zealand. We show the location, geometry, size, and stratigraphic relationships between 25 main intrusive, extrusive and sedimentary architectural elements, in a comprehensive volcano-stratigraphic framework that explains the evolution of the MVS from emplacement to complete burial in the host sedimentary basin. Understanding the relationships between these diverse architectural elements allows us to reconstruct the complete architecture of the MVS, including its shallow (<3 km) plumbing system, the morphology of the volcanoes, and their impact in the host sedimentary basin during their burial. The plumbing system of the MVS comprises saucer-shaped sills, dikes and sill swarms, minor stocks and laccoliths, and pre-eruptive strata deformed by intrusions. The eruptive and associated sedimentary architectural elements define the morphology of volcanoes in the MVS, which comprise deep-water equivalents of crater and cone-type volcanoes. After volcanism ceased, the process of degradation and burial of volcanic edifices formed sedimentary architectural elements such as inter-cone plains, epiclastic plumes, and canyons. Insights from the architecture of the MVS can be used to explore for natural resources such as hydrocarbons, geothermal energy and minerals in buried and active volcanic systems elsewhere.

scholarly journals Quaternary basaltic volcanic fields of the American Southwest

Geosphere ◽  
2021 ◽  
Author(s):  
Greg A. Valentine ◽  
Michael H. Ort ◽  
Joaquín A. Cortés
Keyword(s):  
Regional Scale ◽  
Plate Boundary ◽  
Poisson Model ◽  
Volcanic Field ◽  
American Southwest ◽  
Order Estimate ◽  
Recurrence Rates ◽  
Data Set ◽  
The North ◽  
Volcanic Fields

The southwestern United States contains numerous monogenetic basaltic volcanoes distributed in intraplate volcanic fields. We review, on a regional scale, our current understanding of the Quaternary basalts with a focus on aspects pertinent to hazard assessment, such as physical volcanology and geochronology, while also summarizing the several petrogenetic concep­tual models that have been proposed for the range of local tectonic settings in the region. We count 2229 volcanoes in 37 volcanic fields (including the Pinacate volcanic field, which is mostly in northern Sonora, Mexico). Volcanic landforms are dominantly scoria cones and ramparts with attendant lava fields that have a spectrum of ‘a’ā and blocky to pāhoehoe morphologies, while a small percentage of the volcanoes are maars and tuff cones. Explosive eruption styles that were driven mainly by magmatic volatiles, where they have been studied in detail, included Hawaiian, Strombolian, violent Strombolian, and sub-Plinian activity. The latter two have resulted in sub­stantial fallout deposits that can be traced tens of kilometers from source vents. Phreatomagmatic styles have produced pyroclastic current (mainly pyroclastic surges), ballistic, and fallout deposits. These eruption styles pose hazards to humans when they occur in populated areas and to air travel and regional infrastructure even in sparsely populated areas. All but one of the major volcanic fields (fields that contain ~100 or more Quaternary volcanoes) together form a northwest-southeast–trending band, which we suggest may reflect an influence of plate-boundary-related shearing on melt segregation in the upper mantle along with other factors; this view is consistent with recent global positioning system (GPS) and structural geologic data indicating the influence of dextral motion along the North America-Pacific plate boundary deep inside the Southwest. Of the 2229 Quaternary volcanoes identified, ~548 (25%) have been dated, and only ~15% have been dated with methods such as 40Ar/39Ar and cosmogenic surface exposure methods that are considered optimal for young basalts. Acknowledging the large uncertainty due to the poor geochronological data coverage, we use a simple Poisson model to pro­vide a first-order estimate of recurrence rates of monogenetic volcanoes on the scale of the region as a whole; recurrence rates using our compiled age data set range from 3.74 × 10−4 yr−1 to 8.63 × 10−4 yr−1. These values are only based on dated and mapped volcanoes, respectively, and do not account for undated and buried volcanoes or other uncertainties in the volcano count. The time between monogenetic eruptions in the Southwest is similar to the repose times of some polygenetic volcanoes, which suggests that the regional hazard is potentially commensurate with the hazard from a reawakening stratovolcano such as those in the Cascade Range. Notable in our review is that only a few volcanoes have been the subject of physical volcanological characterization, interpretation, and detailed petrologic study that may elu­cidate factors such as magma generation, ascent (including time scales), and controls on eruption style.

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