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| 1 | The westward lithospheric drift,its role on the subduction and transform zones surrounding Americas:Andean to cordilleran orogenic types cyclicity显示文摘We investigate the effect of the westerly rotation of the lithosphere on the active margins that surround the Americas and find good correlations between the inferred easterly-directed mantle counterflow and the main structural grain and kinematics of the Andes and Sandwich arc slabs.In the Andes,the subduction zone is shallow and with low dip,because the mantle flow sustains the slab;the subduction hinge converges relative to the upper plate and generates an uplifting doubly verging orogen.The Sandwich Arc is generated by a westerly-directed SAM(South American) plate subduction where the eastward mantle flow is steepening and retreating the subduction zone.In this context,the slab hinge is retreating relative to the upper plate,generating the backarc basin and a low bathymetry single-verging accretionary prism.In Central America,the Caribbean plate presents a more complex scenario:(a) To the East,the Antilles Arc is generated by westerly directed subduction of the SAM plate,where the eastward mantle flow is steepening and retreating the subduction zone.(b) To the West,the Middle America Trench and Arc are generated by the easterly-directed subduction of the Cocos plate,where the shallow subduction caused by eastward mantle flow in its northern segment gradually steepens to the southern segment as it is infered by the preexisting westerly-directed subduction of the Caribbean Plateau.In the frame of the westerly lithospheric flow,the subduction of a divergent active ridge plays the role of introducing a change in the oceanic/continental plate’s convergence angle,such as in NAM(North American)plate with the collision with the Pacific/Farallon active ridge in the Neogene(Cordilleran orogenic type scenario).The easterly mantle drift sustains strong plate coupling along NAM,showing at Juan de Fuca easterly subducting microplate that the subduction hinge advances relative to the upper plate.This lower/upper plate convergence coupling also applies along strike to the neighbor continental strike slip fault systems where subduction was terminated(San Andreas and Queen Charlotte).The lower/upper plate convergence coupling enables the capture of the continental plate ribbons of Baja California and Yakutat terrane by the Pacific oceanic plate,transporting them along the strike slip fault systems as para-autochthonous terranes.This Cordilleran orogenic type scenario,is also recorded in SAM following the collision with the Aluk/Farallon active ridge in the Paleogene,segmenting SAM margin into the eastwardly subducting Tupac Amaru microplate intercalated between the proto-LiquineOfqui and Atacama strike slip fault systems,where subduction was terminated and para-autochthonous terranes transported.In the Neogene,the convergence of Nazca plate with respect to SAM reinstalls subduction and the present Andean orogenic type scenario. | Eugenio Aragon Fernando D'Eramo Marco Cuffaro Carlo Doglioni Eleonora Ficini Lucio Pinotti Silvina Nacif Manuel Demartis Irene Hernando Tomas Fuentes | 2020 | Geoscience Frontiers2020，11，4： | 2 |
| 2 | Ore-Forming Fluids of Vein-Type Fluorite Deposits of the Cerro Aspero Batholith, Southern Cordoba Province, Argentina显示文摘 | Jorge Coniglio Roberto Xavier Lucio Pinotti Fernando D’ERAMO | 2000 | International Geology Review2000，，4： | 1 |
| 3 | Mantle derived crystal-poor rhyolitic ignimbrites:Eruptive mechanism from geochemical and geochronological data of the Piedra Parada caldera,Southern Argentina显示文摘Trace elements, isotopic modeling and U-Th-Pb SHRIMP zircon age constraints are used to reconstruct the eruption history and magmatic processes of the Piedra Parada Caldera. In the early Eocene, the crystal-poor Barda Colorada ignimbrite(BCI), having >>15% micro-porphyritic crystals with respect to magmatic components, erupted a volume estimated in more than 300 km^3. The Piedra Parada caldera is located in the Patagonian Andes foreland, at the southern end of the calderas field of the Pilcaniyeu Volcanic Belt(PVB). This belt is related to an extensional tectonic setting as a result of the collision of the Farallon-Aluk ridge with South America, which enabled the development of a transform ocean/continental plate margin followed by the detachment of the Aluk plate and the opening of a slab window. The BCI extra-caldera Plateau is a >100 m thick deposit, having a lower unit with high silica(Si O_2> 76 wt.%),potassium poor rhyolitic composition(trondhjemitic like magma), and an upper unit with normal to high potassium rhyolitic composition(granitic like magma). A trace elements modeling of the BCI units shows that the BCI lower and upper units did not evolve from fractionation or immiscibility in the shallow magma reservoir. The BCI also have a primitive isotopic signature(initial87 Sr/86 Sr =0.7031-0.7049 and ε_(Nd)= +3.4 to +3.65). Thus, tectonic, compositional and isotopic constraints suggest the fast ascent of high silica magmas to a shallow reservoir, and point to an upper mantle origin for these rhyolitic magmas in a transitional(Orogenic-Anorogenic) tectono-magmatic setting. U-Th-Pb SHRIMP zircon crystallization ages of the Syn-caldera stage BCI units(56 -51.5 Ma) show a protracted life of 5 Ma for this caldera reservoir. The age of 52.9 ± 0.3 Ma is considered the best fit for the possible maximum age for the caldera collapse. The Late-caldera magmatism has trachyandesitic and rhyolitic compositions.The trace element modeling suggests that these rhyolites evolve from the trachyandesites and do not evolve from the BCI residual magma. The trachyandesites have U-Th-Pb SHRIMP zircon crystallization ages of 52 ± 1 Ma, suggesting that the caldera eruption was triggered by the arrival of the trachyandesitic magma. | Eugenio Aragon Antonio Castro Juan Diaz-Alvarado Lucio Pinotti Fernando D'eramo Manuel Demartis Jorge Coniglio Irene Hernando Carmen Rodriguez | 2018 | Geoscience Frontiers2018，9，5： | 0 |
| 4 | The Farallon-Aluk ridge collision with South America:Implications for the geochemical changes of slab window magmas from fore- to back-arc显示文摘一条分叉的海洋山脉的碰撞可以演变为二个结束案例:在海洋地板 subduction 的连续性,或在 subducted 板的分开。北 Patagonia 活跃的板边缘有在新生代时间,它受到了二分叉的山脉碰撞的唯一的状况,代表结束成员之一的每一个。晚第三纪 Antarctica-Nazca 分叉的山脉碰撞作为一个连续海洋地板 subduction 系统演变,支持在在背弧的弧轴,在在先弧的山脉海洋地板的部分的 obduction,和玄武岩的火山作用的 magmatic 中断。相反, Paleogene Farallon-Aluk 分叉的山脉碰撞演变为变换边缘,与分开并且 Aluk 板和一扇大平板窗户的发展下沉。作为在以前的盒子中,这碰撞在弧轴支持了 magmatic 中断,但是 tectono-magmatic 情形改变了到传播了到以前的在先弧的 postorogenic synextensional 火山作用(暗岩,安山岩,流纹岩) 并且以前的背弧(bimodal ignimbrite 骤发,暗岩) 。这个平板窗户 synextensional 火山作用的地球化学向以前的背弧向以前的在先弧,和 MORB-OIB-like 暗岩显示出更多的象 MORB 一样暗岩。相反,孤立的 undeformable 与对平板窗户和 extensional 政体的地壳变动的回答,在以前的背弧的外壳的块被 OIB 类型暗岩盖住在以后高举。主要元素证明平板窗户暗岩到达 TiO2 价值直到 3 wt% ,作为与弧岩浆的 1.5 wt% 的最高的价值相比。而且, MgO 关于(FeOt + Al2O3 ) 比率帮助关于地壳变动的块把平板窗户岩浆变化与以前的在先弧区分开来到以前的背弧并且也。象 Nb 和 Ta 那样的 HFS 元素的更高的内容也帮助把这个平板窗口与弧岩浆并且也区分开来,到把平板窗口岩浆变化与以前的在先弧区分开来到以前的背弧和地壳变动的块设置。平板窗口 magmatism 的同位素作文给外壳的来源从 MORB 显示出一个迥异的同时代的数组,由于 extensional 设置作为延长存储和 homogenization 的缺乏的后果解释了。 | Eugenio Aragón Lucio Pinotti Fernando D'Eramo Antonio Castro Osvaldo Rabbia Jorge Coniglio Manuel Demartis Irene Hernando Claudia E.Cavarozzi Yolanda E.Aguilera | 2013 | Geoscience Frontiers2013，4，4： | 0 |
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