A complex multi-chamber magmatic system beneath a late Cenozoic volcanic field: evidence from CSDs and thermobarometry of clinopyroxene from a single nephelinite flow (Djbel Saghro, Morocco)

2008 ◽  
Vol 297 (1) ◽  
pp. 509-524 ◽  
Author(s):  
Julien Berger ◽  
Nasser Ennih ◽  
Jean-Paul Liégeois ◽  
Collin Nkono ◽  
Jean-Claude C. Mercier ◽  
...  
Keyword(s):  
Volcanic Field ◽  
Late Cenozoic ◽  
Magmatic System ◽  
Field Evidence

Late Cenozoic uplift of western Turkey: Improved dating of the Kula Quaternary volcanic field and numerical modelling of the Gediz River terrace staircase

2006 ◽  
Vol 51 (3-4) ◽  
pp. 131-171 ◽  
Author(s):  
Rob Westaway ◽  
Hervé Guillou ◽  
Sema Yurtmen ◽  
Anthony Beck ◽  
David Bridgland ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Volcanic Field ◽  
River Terrace ◽  
Late Cenozoic ◽  
Western Turkey ◽  
Gediz River

Geochemical constraints on the origin of late Cenozoic basalts in the Mt. Changbai volcanic field, NE China: evidence for crustal recycling

2019 ◽  
Vol 62 (17) ◽  
pp. 2125-2145 ◽  
Author(s):  
Ming Lei ◽  
Zhengfu Guo ◽  
Yutao Sun ◽  
Maoliang Zhang ◽  
Lihong Zhang ◽  
...  
Keyword(s):  
Volcanic Field ◽  
Late Cenozoic ◽  
Ne China ◽  
Crustal Recycling ◽  
Geochemical Constraints

Holocene isostasy and late Cenozoic development of landforms including Beaver and Radok Lake basins in the Amery Oasis, Prince Charles Mountains, Antarctica

1997 ◽  
Vol 9 (3) ◽  
pp. 299-306 ◽  
Author(s):  
D.A. Adamson ◽  
M.C.G. Mabin ◽  
J.G. Luly
Keyword(s):  
Sea Level ◽  
Late Cenozoic ◽  
Glacial Cycle ◽  
Ice Streams ◽  
Relative Sea Level ◽  
Field Evidence ◽  
North Eastern ◽  
Uplift Rates ◽  
Beaver Lake ◽  
Lambert Glacier

Geomorphological observations show no detectable uplift (i.e. falling relative sea level) of Amery Oasis since the establishment of relatively stable sea level during the mid-Holocene. The observations around the basin of Beaver Lake include an absence of raised shoreline features, the presence down to the present tidal limit of in situ ventifacts and residual landforms, the cliffed southern shoreline and adjacent shallow subhorizontal floor of Beaver Lake, and the composition of recent moraines on the basin's north eastern edge. This lack of Holocene uplift is consistent with low uplift rates observed from coastal oases of East Antarctica and suggests minor, rather than major, changes to the Antarctic ice sheet during the most recent Quaternary glacial cycle. The formation of Beaver basin is attributed to late Cenozoic glacial excavation by south flowing ice of the palaeo-Nemesis Glacier, initially eroding when relative sea level was higher than it is today. The basin containing Radok Lake was excavated by the palaeo-Battye Glacier probably when most effective during the numerous long cold periods of the late Cenozoic. The field evidence from landforms and the presence of marine fossil deposits suggests Amery Oasis was not overrun by erosive ice since at least the Pliocene, major ice streams such as Lambert Glacier flowing then, as now, around the oasis.

Geology and volcanology of San Venanzo volcanic field (Umbria, Central Italy)

2005 ◽  
Vol 142 (6) ◽  
pp. 683-698 ◽  
Author(s):  
VITTORIO ZANON
Keyword(s):  
Spatial Distribution ◽  
Central Italy ◽  
Volcanic Field ◽  
Tectonic Activity ◽  
Complex Morphology ◽  
Field Evidence ◽  
Field Investigations ◽  
Volcanic Deposits ◽  
Groundwater Reservoir ◽  
History Of

The purpose of this paper is to integrate, or even modify where necessary, the geo-volcanological setting outlined by other authors on the history of the small volcanic field of San Venanzo (Umbria, Central Italy). To attain this goal, new accurate field investigations were carried out in that area, coupled with detailed stratigraphic studies and laboratory analyses, to support field evidence with experimental results. The first objective was to stress the importance of a groundwater reservoir whose interaction with magma at various degrees was responsible not only for the explosive character of volcanism in that area, but also for the complex morphology of the volcanic deposits that are widely scattered on the underlying sedimentary basement. Another objective was to clarify the role played by tectonic activity in enhancing the fast and discontinuous ascent of batches of magma from the mantle to the surface, through two different sets of faults, opened by tectonic unrest into the crust, that were also responsible for the morphology and spatial distribution of volcanic centres. This was considered to be very important in consideration of the still-active stress field of the region. Finally, special attention was focused on the presence of a palaeosol between two eruptive sequences, as it most likely denoted a split in the volcanic activity of this site into two separate phases. This observation leads to the conclusion that, in spite of its eruptive characteristics, the small volcano of San Venanzo is not monogenic. For all of these topics, a number of conclusions have been drawn and they are reported with more data in the following sections of this paper.

scholarly journals Aspects of the petrology and geochemistry of the Huckleberry Ridge Tuff, Yellowstone

2021 ◽  
Author(s):  
◽  
Elliot Swallow
Keyword(s):  
Numerical Models ◽  
Volcanic Field ◽  
Fall Deposit ◽  
Magmatic System ◽  
Magmatic Complex ◽  
Isotopic Compositions ◽  
Stratigraphic Framework ◽  
System 2 ◽  
Geochemical Investigation ◽  
System 1

<p>Silicic (i.e. dacitic-rhyolitic) magmatic systems have the potential to generate large, explosive caldera-forming eruptions which have global effects and consequences. How, and over what timescale, magma accumulates and is stored in the upper crust are key aspects in understanding such systems and their associated hazards. The absence of such eruptions in the historical record, however, has forced understanding of these systems to be developed through numerical models or the study of the deposits in the geological record. Numerical models primarily focus on the long-term generation but instantaneous eruption of single magma (i.e. melt-dominant) bodies. In contrast, the stratigraphic and geochemical nature of eruption deposits often show features more consistent with complex magmatic systems comprising multiple melt-dominant bodies that may have formed rapidly but erupted episodically. Further studies of past eruption deposits are valuable, therefore, in reconstructing silicic magmatic systems and highlighting the nature of melt-dominant body generation and storage.  To this end, this thesis examines the 2.08 Ma, ∼2,500 km³ Huckleberry Ridge Tuff (HRT), Yellowstone Plateau volcanic field (YPVF), U.S.A, the deposit of the first and largest of three caldera-forming eruptions in the YPVF. The HRT comprises an initial fall deposit followed by three ignimbrite members (A, B and C) with a second fall deposit between members B and C. Despite emanating from an archetypal silicic volcanic field, minimal previous work has been undertaken on the geochemical nature of the HRT but it is thought to conform to traditional, unitary magma body ideas. A revised stratigraphic framework, detailing an episodic and prolonged initial fall deposit, identification of a weeks-months time gap between members A and B, and a similar but longer years-decades hiatus in activity between members B and C provides the context for this geochemical investigation. A large sample suite representative of the diverse range of physical characteristics of clasts and material found in the HRT was analysed. In situ micro-analysis of matrix glass (major and trace elements) and crystals (major elements) in the initial fall deposit are coupled with major and trace element, and isotopic compositions of single silicic clasts (i.e. pumice/fiamme) from all three ignimbrite members, supplemented by in situ analysis of their crystals and groundmass glass. These data are used to reconstruct the silicic magmatic system. Furthermore, major and trace element, andisotopic compositions of rare mafic (i.e. basaltic to andesitic) material found in members A and B provide an insight into the thermal and chemical drivers of HRT silicic volcanism.  This macro- and micro-analytical investigation using multiple techniques reveals remarkable complexity within the large-scale HRT magmatic complex. Four geochemically distinct magmatic systems are differentiated on single clast elemental and isotopic characteristics that are further reflected in crystal and glass compositions. Two of these systems (1 and 2) were active in the initial fall deposit and member A. Magmatic system 1 is volumetrically dominant in the HRT and is characterised by moderate-high Ba single clast (450-3540 ppm) and glass (100-3360 ppm) compositions, in contrast to the distinctly low-Ba (≤250 ppm single clast, <65 ppm glass Ba contents) magmatic system 2. Both these magmatic systems exhibit clustered glass compositions, indicating multiple, laterally-adjacent melt-dominant bodies were present, and shared moderate isotopic compositions (e.g. ⁸⁷Sr/⁸⁶SrAC = 0.70950-0.71191) are explicable by a multi-stage partial melting-fractional crystallisation petrogenesis. The time break between members A and B is associated with mixing and mingling within magmatic system 1, related to a renewed influx of mafic material, and a cessation of activity of system 2, which is absent from member B. The time break between members B and C reflects significant changes within the magmatic complex. Magmatic system 2 is rejuvenated and melt-dominant bodies associated with two new magmatic systems (3 and 4) are formed, with at least system 3 comprising multiple bodies. These latter two magmatic systems strongly differ in their elemental characteristics (system 3: high SiO₂ [75-78 wt% SiO₂]; system 4: dacite-rhyolite [66-75 wt% SiO₂]). Despite this, they have similar and highly radiogenic (e.g. ⁸⁷Sr/⁸⁶SrAC = 0.72462-0.72962) isotopic compositions indicating shared extensive incorporation of Archean crust. They also contrast in their relation to mafic compositions, with system 4 associated with olivine tholeiitic compositions erupted prior to and following the HRT in the YPVF. In contrast, system 3, like systems 1 and 2, is associated with high-Ba, high-Zr mafic compositions found co-erupted in HRT members A and B. These compositions are similar to lava flows erupted further west at the Craters of the Moon field, and are interpreted as representing partial melts from regions in the lithospheric mantle enriched by high-T, P fluids emanating from the subducted Farallon slab.  Overall, the HRT magmatic complex was remarkably heterogeneous. Two contemporaneous mafic root zones drove four silicic magmatic systems, episodically active throughout the eruption. At least three of these systems comprised multiple laterally-adjacent melt-dominant bodies. Intra-eruption time breaks are associated with broad-scale reorganisation of the magmatic complex. This complexity highlights the utility of a detailed, systematic, multi-technique geochemical investigation, within a stratigraphic framework, of the deposits of large silicic caldera-forming eruptions, and breaks new ground in the understanding of such systems.</p>

40Ar/39Ar and U–Pb dating of the Fish Canyon magmatic system, San Juan Volcanic field, Colorado: Evidence for an extended crystallization history

2007 ◽  
Vol 236 (1-2) ◽  
pp. 134-166 ◽  
Author(s):  
O. Bachmann ◽  
F. Oberli ◽  
M.A. Dungan ◽  
M. Meier ◽  
R. Mundil ◽  
...  
Keyword(s):  
Volcanic Field ◽  
San Juan ◽  
Magmatic System

Evolution of a magmatic system during continental extension: The Mount Taylor Volcanic Field, New Mexico

1990 ◽  
Vol 95 (B12) ◽  
pp. 19327 ◽  
Author(s):  
Frank V. Perry ◽  
W. Scott Baldridge ◽  
Donald J. DePaolo ◽  
Muhammad Shafiqullah
Keyword(s):  
New Mexico ◽  
Volcanic Field ◽  
Magmatic System ◽  
Continental Extension
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