Age distribution of cinder cones within the Bandas del Sur Formation, southern Tenerife, Canary Islands

2008 ◽  
Vol 146 (2) ◽  
pp. 161-172 ◽  
Author(s):  
JÖRG KRÖCHERT ◽  
ELMAR BUCHNER
Keyword(s):  
Rift Zone ◽  
Age Distribution ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Cinder Cones ◽  
The Third ◽  
Stratigraphic Position ◽  
Normal Magnetization ◽  
Reverse Magnetization ◽  
Volcanic Cycles

AbstractThe Quaternary Bandas del Sur Formation in the south of Tenerife comprises a complex sequence of pyroclastic rocks and lavas. In contrast to the NW- and NE-Rift zone on Tenerife, the S-Rift zone comprises a number of characteristics with respect to the morphological features, eruption cyclicity and the geochemistry of the volcanic deposits. Various flank eruptions of the Las Cañadas volcano associated with basaltic lavas and the formation of cinder cones within the Bandas del Sur are important volcanic units for understanding the explosive volcanic cycles during the Pleistocene on Tenerife. A number of palaeomagnetic studies, as well as major and trace element geochemistry and two radio-isotope dates (K–Ar), have been carried out on prominent cinder cones, in order to discover their stratigraphic position. Combining our results with previous K–Ar data, the cones and lavas can be subdivided into three stratigraphic units. The first unit contains cinder cones with reverse magnetization and Y/Nb ratios between 0.37 and 0.41. Cinder cones which belong to the second unit show normal magnetization and Y/Nb ratios of < 0.35. The third unit comprises cinder cones with normal magnetization and Y/Nb ratios of about 0.47. The first two units were constructed between c. 0.948–0.779 Ma and 0.323–0.300 Ma. These units define volcanic cycles ending in violent Plinian eruptions. The third and youngest unit possibly marks the beginning of a further volcanic cycle that started c. 0.095 Ma ago.

scholarly journals Pleistocene-Holocene Monogenetic Volcanism at Malko-Petropavlovsk Zone of Transverse Dislocations on Kamchatka: Geological Setting, Spatial, Geochemical Paticular Features and Potential Volcanic Hazards

2021 ◽  
Author(s):  
Olga Bergal-Kuvikas ◽  
Ilya Bindeman ◽  
Andrey Chugaev ◽  
Yulia Larionova ◽  
Alexander Perepelov ◽  
...  
Keyword(s):  
Volcanic Hazards ◽  
Trace Element Geochemistry ◽  
Monogenetic Volcanism ◽  
Element Geochemistry ◽  
Cinder Cones ◽  
Magma Plumbing System ◽  
Plumbing Systems ◽  
Moho Boundary ◽  
Monogenetic Volcanoes ◽  
Magma Plumbing

Abstract Based on government statistical data ~80% of the local Kamchatkan population (~250 ka people) live in the major cities on the coastal line of Avacha Gulf . It is the main transport seaway to Kamchatka , and and important Asia - North America air transport corridor. The Avacha Gulf is located in the Malko-Petropavlovsk zone of transverse dislocations (MPZ) on the extension of deep transform fault on the boundary between various ly aged slabs. Most of monogenetic cinder cones chaotic distributed in relation to the trench and belong to the long-living rupture zones of MPZ. Some of the monogenetic volcanoes are parasitic cones on the slopes of Koryaksky and Avachinsky stratovolcanoes and related with their magma plumbing systems. We here present new results of the geochemical and isotopic stud ies of monogenetic volcanism in MPZ. Based on whole rock and trace element geochemistry, Sr-Nd-Pb isotopic ratios of monogenetic volcanism, ­­ magmas were shown to sample the enriched mantle source with dominance decompression melting without significant inputs of the slab`s components. Calculations of the P, T conditions suggest magma residence of monogenetic cinder cones on the Moho boundary. That correlates with the geophysical observation of crustal discontinuity under the MPZ. Monogenetic cinder cones have an active magma plumbing system because during the Holocene time were several periods of activations. Presented results show necessary install continuous monitoring of environment changing around the Avacha Gulf and more serious attention from government and science. A more detailed investigation of MPZ will help degrease potential risks of eruptions from monogenetic volcanoes for human and infrastructures.

The Lower Silurian Osmundsberg K-bentonite. Part I: stratigraphic position, distribution, and palaeogeographic significance

1998 ◽  
Vol 135 (1) ◽  
pp. 1-13 ◽  
Author(s):  
STIG M. BERGSTRÖM ◽  
WARREN D. HUFF ◽  
DENNIS R. KOLATA
Keyword(s):  
Northern Ireland ◽  
Source Area ◽  
Thickness Variation ◽  
Trace Element Geochemistry ◽  
Large Magnitude ◽  
Element Geochemistry ◽  
Thickness Increase ◽  
Lower Silurian ◽  
Stratigraphic Position ◽  
The One

A large number of Lower Silurian (Llandovery) K-bentonite beds have been recorded from northwestern Europe, particularly in Baltoscandia and the British Isles, but previous attempts to trace single beds regionally have yielded inconclusive results. The present study suggests that based on its unusual thickness, stratigraphic position and trace element geochemistry, one Telychian ash bed, the Osmundsberg K-bentonite, can be recognized at many localities in Estonia, Sweden and Norway and probably also in Scotland and Northern Ireland. This bed, which is up to 115 cm thick, is in the lower–middle turriculatus Zone. The stratigraphic position, thickness variation and geographic distribution of the Osmundsberg K-bentonite are illustrated by means of 12 selected Llandovery successions in Sweden, Estonia, Norway, Denmark, Scotland and Northern Ireland. In Baltoscandia, the Osmundsberg K-bentonite shows a trend of general thickness increase in a western direction suggesting that its source area was located in the northern Iapetus region between Baltica and Laurentia. Because large-magnitude ash falls like the one that produced the Osmundsberg K-bentonite last at most a few weeks, such an ash bed may be used as a unique time-plane for a variety of regional geological and palaeontological studies.

Stratigraphy, structure and geochemistry of Archaean supracrustal rocks from Oqaatsut and Naajaat Qaqqaat, north-east Disko Bugt, West Greenland

1999 ◽  
pp. 65-78
Author(s):  
Henrik Rasmussen ◽  
Lars Frimodt Pedersen
Keyword(s):  
Tectonic Setting ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
West Greenland ◽  
North West ◽  
North East ◽  
Metavolcanic Rocks ◽  
Arc Setting ◽  
Area North ◽  
Back Arc

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Rasmussen, H., & Frimodt Pedersen, L. (1999). Stratigraphy, structure and geochemistry of Archaean supracrustal rocks from Oqaatsut and Naajaat Qaqqaat, north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 65-78. https://doi.org/10.34194/ggub.v181.5114 _______________ Two Archaean supracrustal sequences in the area north-east of Disko Bugt, c. 1950 and c. 800 m in thickness, are dominated by pelitic and semipelitic mica schists, interlayered with basic metavolcanic rocks. A polymict conglomerate occurs locally at the base of one of the sequences. One of the supracrustal sequences has undergone four phases of deformation; the other three phases. In both sequences an early phase, now represented by isoclinal folds, was followed by north-west-directed thrusting. A penetrative deformation represented by upright to steeply inclined folds is only recognised in one of the sequences. Steep, brittle N–S and NW–SE striking faults transect all rock units including late stage dolerites and lamprophyres. Investigation of major- and trace-element geochemistry based on discrimination diagrams for tectonic setting suggests that both metasediments and metavolcanic rocks were deposited in an environment similar to a modern back-arc setting.

REGIONAL TRACE ELEMENT GEOCHEMISTRY OF ZIRCONS IN THE JURASSIC VOLCANIC ARC OF THE SOUTHWEST U.S

2016 ◽  
Author(s):  
Jennifer A. Laughlin ◽  
◽  
Joseph L. Wooden ◽  
A.P. Barth ◽  
John T. Shukle ◽  
...  
Keyword(s):  
Trace Element ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Volcanic Arc

PATTERNS OF TRACE ELEMENT GEOCHEMISTRY IN CULTURED NEOGLOBOQUADRINA PACHYDERMA CRUST CALCITE

2020 ◽  
Author(s):  
Caitlin M. Livsey ◽  
◽  
Catherine V. Davis ◽  
Jennifer S. Fehrenbacher ◽  
Claudia Benitez-Nelson ◽  
...  
Keyword(s):  
Trace Element ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Neogloboquadrina Pachyderma
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