U–Pb ages were obtained on single detrital zircon grains separated from six samples of Neoproterozoic and Lower Palaeozoic sedimentary and volcanosedimentary rocks from NW Iberia using the laser ablation microprobe-inductively coupled plasma mass spectrometry (LAM-ICP-MS) method. Precambrian greywackes yielded abundant zircons with Neoproterozoic (800–640 Ma) and Mesoproterozoic (0.9–1.2 Ga) ag...

The chemistry of primitive arc rocks provides a window into compositional variability in the mantle wedge, as well slab-derived inputs to subduction-related magmatism. However, long-term cycling elements between Earth's internal and external reservoirs, key unknown is importance retaining mobile within subduction system, through metasomatism mantle. To address these questions, we have analysed ...

[1] Shear-wave splitting observations at several subduction systems show trench-parallel fast directions in the fore-arc mantle. The presence of B-type olivine fabric in the mantle wedge may provide an explanation for this pattern of anisotropy under low-temperature and hydrated conditions. Sensitivity tests are shown that provide insights into the distribution and magnitude of B-type fabric us...

Volcanic rocks along the Panama Canal present a world-class opportunity to examine the relationship between arc magmatism, tectonic forcing, wet and dry magmas, and volcanic structures. Major and trace element geochemistry of Canal volcanic rocks indicate a significant petrologic transition at 21-25 Ma. Oligocene Bas Obispo Fm. rocks have large negative Nb-Ta anomalies, low HREE, fluid mobile e...

Chaldoran area in NW of Iran has Mesozoic oceanic crust basement. The studied rocks of this region can be divided into three groups: ophiolitic gabbros and pillow lavas, ophiolitic volcanoclastics and Eocene lava flows. Ophiolitic mafic rocks show continental volcanic arc natures and Eocene lava flow shows OIB-like nature. During the Mesozoic,the Chaldoran region was situated in the active cont...

The area of study is located 120 Km north-east of Shahrood city. In terms of structure and geological classification, this area is located in the northern part of central Iran zone. Granitoids of Troud ranging from monzonite to granite. The main minerals of granitoids are quartz, plagioclase, and orthose. The accessory minerals are biotite, hornblende, sphene, and opaque minerals. Various textu...

Most subduction zones on Earth are oblique, i.e., the angle between plate convergence vector and trench notably differs from 90°. Therefore, modeling understanding strain partitioning in forearc, development of extensional basins back-arc region diachronous transition to collision require a 3D approach. Here, we assess how oblique oceanic subsequent associated mantle flow around subducted litho...

The Neotethyan subduction and collision with the Asian, Indian, Australian plates is evidenced by a giant Andean-type arc system remarkable igneous belt along southwestern Eurasian margin. However, southward extent, cause, of poorly understood. Here, zircon U-Pb dating whole-rock geochemical study two groups Eocene (50−48 Ma) mafic intrusions from Tangse, North Sumatra, helps to unravel story. ...

Originally studied for designing min cost connecting grid (in distribution, transportation, communication applications) to connect a set of cities. Under arc lengths > 0 min cost connecting network will bea spanning tree (ST). Earliest algo. (Boruvka's) dates back to 1926! Undirected, connected G = (N A c). To nd an uncon-strained MCST in G. c arbitrary. Constrained MCST problems (typical const...

Hydrogen atomic pair ions, i.e., H(+) and H(-) ions, are produced by plasma-assisted catalytic ionization using a porous nickel plate. Positive ions in a hydrogen plasma generated by dc arc discharge are irradiated to the porous plate, and pair ions are produced from the back of the irradiation plane. It becomes clear that the production quantity of pair ions mainly depends on the irradiation c...