Papers by Gabriel Gutierrez-Alonso
A post-collisional batholith from Southern Iberia rooted in the Earth's mantle: Los Pedroches batholith
Lithos, Oct 1, 2023
The unique Cambro-Ordovician silicic large igneous province of NW Gondwana: Catastrophic melting of a thinned crust
Gondwana Research, Jun 1, 2022
Solid Earth, Jul 8, 2020
The collision between Gondwana and Laurussia that formed the latest supercontinent, Pangea, occur... more The collision between Gondwana and Laurussia that formed the latest supercontinent, Pangea, occurred during Devonian to early Permian times and resulted in a largescale orogeny that today transects Europe, northwest Africa, and eastern North America. This orogen is characterized by an "S" shaped corrugated geometry in Iberia. The northern curve of the corrugation is the well-known and studied Cantabrian (or Ibero-Armorican) Orocline and is convex to the east and towards the hinterland. Largely ignored for decades, the geometry and kinematics of the southern curvature, known as the Central Iberian curve, are still ambiguous and hotly debated. Despite the paucity of data, the enigmatic Central Iberian curvature has inspired a variety of kinematic models that attempt to explain its formation but with little consensus. This paper presents the advances and milestones in our understanding of the geometry and kinematics of the Central Iberian curve from the last decade with particular attention to structural and paleomagnetic studies. When combined, the currently available datasets suggest that the Central Iberian curve did not undergo regional differential vertical-axis rotations during or after the latest stages of the Variscan orogeny and did not form as the consequence of a single process. Instead, its core is likely a primary curve (i.e., inherited from previous physiographic features of the Iberian crust), whereas the curvature in areas outside the core is dominated by folding interference from the Variscan orogeny or more recent Cenozoic (Alpine) tectonic events.
Journal of Iberian Geology, Nov 2, 2017
Your article is protected by copyright and all rights are held exclusively by Springer Internatio... more Your article is protected by copyright and all rights are held exclusively by Springer International Publishing AG. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Post-collisional batholiths do contribute to continental growth
Earth and Planetary Science Letters, Feb 1, 2023
La transición entre las zonas externas e internas en el orógeno Varisco: niveles estructurales y partición de la deformación
Geological Society of America Bulletin, Sep 23, 2021
International Geology Review, Oct 27, 2020
In this work, we present new U-Pb, Sm-Nd geochronology, major and trace-element and isotopic comp... more In this work, we present new U-Pb, Sm-Nd geochronology, major and trace-element and isotopic composition (Nd, Sr, Pb, O) for the Goryachegorsk alkaline-mafic igneous rocks from the Kuznetsk Alatau (Siberia, Russian Federation). The age obtained using U-Pb in zircon, ~ 265 Ma, is considered to represent the crystallization age of Goryachegorsk intrusion in Late Permian times. LILE and HFSE composition, and isotope signatures indicate the heterogeneity of magmatic sources and the mixing of IAB-and OIB-like magmas. We interpret that this intrusion is characterized by the superposition of PREMA + EM 2 mantle plume magmas and other magmas derived from the melting of accretion-collision complexes from the Paleo Asian ocean margin. Mixing of mantle sources and continental crust resulted in variations of Nd-isotope composition (ε Nd (t) ~ 1.7-6.8) and lead isotope composition (206 Pb/ 204 Pb in 19.29, 207 Pb/ 204 Pb in 15.58, 208 Pb/ 204 Pb in 37.74), as well as an increase of 87 Sr/ 86 Sr (t) ~ 0.7049-0.7068 and δ 18 О 8.5-9.6 ‰, SMOW in igneous rocks. Additional geochronological data on the Kuznetsk Alatau alkaline mafic province suggest its origin at different times during the Paleozoic: at the Cambrian-Ordovician boundary (~ 510-480 Ma); Early-Middle Devonian (~ 410-385 Ma); and Late Permian (~ 266-262 Ma). Geochemical similarity between the regional alkaline magmatism emplaced at different ages provides insights into periodic mantle plume-lithosphere interaction over a time span of ca. 250 Ma.
Динамика внедрения базит-ультрабазитовых тел на глубинных уровнях аккреционно-коллизионных систем... more Динамика внедрения базит-ультрабазитовых тел на глубинных уровнях аккреционно-коллизионных систем (ольхонский регион, западное прибайкалье)
Geodinamika i Tektonofizika, Oct 12, 2022
Mineralogical and geochemical study was performed on peridotite xenolith hosted by amygdaline bas... more Mineralogical and geochemical study was performed on peridotite xenolith hosted by amygdaline basalts of Lanzarote Island (Canary archipelago). Their modal composition corresponds to harzburgite. Remarkably, the petrographic composition of the rocks is marked by presence of plagioclase. The isochron shows the age of 267±35 Ma, which might be the initial stage of opening a fragment of the Atlantic Ocean. The peridotites were apparently derived in the magmatic chamber formed by "underplating" triggered by interaction of mantle substrate with the lower crust material.
Lithos, 2017
The Marbella Conglomerate (Betic Cordilleras, SW Spain) is a poorly sorted and polymictic rock of... more The Marbella Conglomerate (Betic Cordilleras, SW Spain) is a poorly sorted and polymictic rock of vaguely constrained Late Carboniferous age interlayered within a sandy sequence. It contains variable amounts of pebbles of quartzite, gneiss, deformed granitoid, schist, aplite, dacite and other volcanic rocks among others, which makes it a potential target for detrital zircon provenance studies. In order to decipher provenance we combined U-Pb SHRIMP and LA-ICP-MS analyses on zircons obtained from single pebbles of deformed rocks (schist, granitoids) and detrital zircons from the sandy sequence, respectively. The age spectra of the detrital zircons indicates that at least the sedimentation took place soon after the start of the Permian according to the youngest detrital zircon age (≈286 Ma), and it involved the denudation of terranes with rocks bearing Paleoproterozoic, Neoproterozoic, Cambro-Ordovician, Devonian and Carboniferous zircon age clusters. In contrast with the Permian age of the detrital zircons from the sandstones, igneous (ca. 532 and 516 Ma) and metamorphic (ca. 356 Ma) U-Pb SHRIMP Concordia ages were obtained from the pebbles. The different age clusters observed could be correlated to igneous, metamorphic and detrital rocks from an already eroded terrane similar to the Ossa-Morena Zone of the Iberian Variscan Belt. Therefore, we propose that most of the sedimentation of the Marbella Conglomerate took place along the western border of the Paleotethys at the north margin of Gondwana during the dismantling of the Variscan orogenic edifice and/or the Neotethys ocean opening and the birth of the Cimmerian ribbon continent.
The collision between Gondwana and Laurussia that formed the latest supercontinent, Pangea, occur... more The collision between Gondwana and Laurussia that formed the latest supercontinent, Pangea, occurred during Devonian to early Permian times and resulted in a largescale orogeny that today transects Europe, northwest Africa, and eastern North America. This orogen is characterized by an "S" shaped corrugated geometry in Iberia. The northern curve of the corrugation is the well-known and studied Cantabrian (or Ibero-Armorican) Orocline and is convex to the east and towards the hinterland. Largely ignored for decades, the geometry and kinematics of the southern curvature, known as the Central Iberian curve, are still ambiguous and hotly debated. Despite the paucity of data, the enigmatic Central Iberian curvature has inspired a variety of kinematic models that attempt to explain its formation but with little consensus. This paper presents the advances and milestones in our understanding of the geometry and kinematics of the Central Iberian curve from the last decade with particular attention to structural and paleomagnetic studies. When combined, the currently available datasets suggest that the Central Iberian curve did not undergo regional differential vertical-axis rotations during or after the latest stages of the Variscan orogeny and did not form as the consequence of a single process. Instead, its core is likely a primary curve (i.e., inherited from previous physiographic features of the Iberian crust), whereas the curvature in areas outside the core is dominated by folding interference from the Variscan orogeny or more recent Cenozoic (Alpine) tectonic events.
Detrital zircon ages and provenance of a Cambrian succession in the Sierra Albarrana Domain (SW Iberian Massif)
Lithos, 2022
This study presents the first U-Pb geochronological data on detrital zircon grains from the metas... more This study presents the first U-Pb geochronological data on detrital zircon grains from the metasedimentary successions of the Sierra Albarrana Domain (SW Iberian Massif) obtained by SHRIMP and LA-ICP-MS. We provide new information on the Maximum Depositional Ages (MDA) during the middle Cambrian through a systematic study, together with age comparisons of the successions, using Kernel Density Estimates (KDE) diagrams, Cumulative Age Distributions (CADs) and the Kolmogorov–Smirnov (K-S) test. On the other hand, the U-Pb zircon data presented in this study have been compared with all the existing data from detrital zircon grains in Neoproterozoic and Cambrian rocks of the Iberian Massif (20 samples, 2706 U–Pb zircon ages). For the comparison, in addition to the KDEs, CADs and K-S test, we apply 3D multidimensional scaling techniques (3D-MDS). The results, together with the geochemical and isotopic characterisation from previous studies, suggest that this domain is likely to be part of the autochthonous section of the Central Iberian Zone (CIZ). Zircon age patterns indicate a probable sedimentary provenance from the Saharan Metacraton with, or without, minor input from the Tuareg Shield. The most important local detrital source corresponds to Cadomian magmatism developed during a magmatic event (535–515 Ma) followed by back-arc extension and early Paleozoic rifting (535–460 Ma). The remaining Mesoproterozoic, Paleoproterozoic and Archean zircon grains would have been provided by the Paleoproterozoic basement and/or the older continental crust recycled in the western sections of the Gondwana margin
International Journal of Earth Sciences, Apr 28, 2017
Ledesma pluton that also yielded an age of ca. 343 Ma. (2) Devonian-Silurian zircon xenocrysts wi... more Ledesma pluton that also yielded an age of ca. 343 Ma. (2) Devonian-Silurian zircon xenocrysts with scattered ages between ca. 390 and 432 Ma. (3) Middle Cambrian-Ordovician (ca. 450-511 Ma). (4) Ediacaran-Cryogenian zircon ages (ca. 540-840 Ma). (5) Mesoproterozoic to Archaean zircon (900-2700 Ma). The abundance of Carboniferousinherited zircon shows that crustal recycling/cannibalization may often happen at a fast pace in orogenic scenarios with only short lapses of quiescence. In our case study, it seems plausible that a "crustal layer" of ca. 340 Ma granitoids/ migmatites was recycled, partially or totally, only 15-20 My after its emplacement.
IOP conference series, Sep 19, 2019
Contrasting metamorphism in adjacent terranes is distinctive of large-scale tectonic events that ... more Contrasting metamorphism in adjacent terranes is distinctive of large-scale tectonic events that include both collisional and rifting scenarios. When one of those terranes is characterized by the presence of high-pressure rocks, it is more likely to be related to collisional settings, and commonly in locations close to the suture. This contribution shows an example of the aforementioned situation in the Variscan orogenic belt of NW Iberia, where a tectonic slice with high-pressure metamorphism is above rocks that underwent Barrovian metamorphism. The two involved terranes are known as lower allochthon and parautochthon, respectively. The lower allochthon recorded the continental subduction (blueschist-and eclogite-facies conditions; [1,2]) of the most external part of the north Gondwana passive margin during the late Devonian (ca. 370-365 Ma; [1, 3]) at the beginning of the Variscan collision, followed by a buoyancy-driven exhumation triggered by the extensional collapse of the orogenic pile. Contrarily, the underlying parautochthon underwent crustal thickening, resulting in a medium-pressure Barrovian-type metamorphism that possibly was followed by a higher temperature/lower pressure Buchan-type metamorphism that may be related to tectonic exhumation and/or erosion [cf. 4].
IOP conference series, Dec 1, 2017
Understanding global-scale orogenic processes related to supercontinents, and their relationship ... more Understanding global-scale orogenic processes related to supercontinents, and their relationship to the secular evolution of the Earth's lithosphere, represent important challenges for Earth scientists today. The record of these processes is preserved in the microstructures, mineral assemblages and mineral compositions of lithospheric rocks exhumed to the Earth's surface. Given a well-characterized microstructural evolution, thermodynamic modelling is the key to quantifying changes in pressure and temperature, with the rate of these changes being provided by rock-forming and accessory mineral-based geochronology. Thus, metamorphic rocks provide Pressure-Temperature-time-deformation (P-T-t-d) data that help to parameterize orogenic processes. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Gondwanan basement terranes of the Variscan–Appalachian orogen: Baltican, Saharan and West African hafnium isotopic fingerprints in Avalonia, Iberia and the Armorican Terranes
Tectonophysics, Jun 1, 2016
Abstract Iberia, Avalonia and the “Armorican” terranes form key constituents of the Variscan–Appa... more Abstract Iberia, Avalonia and the “Armorican” terranes form key constituents of the Variscan–Appalachian orogen, but their Neoproterozoic origins along the northern Gondwanan margin continue to be strongly debated. Here, we present a new detrital zircon U–Pb–Hf dataset from Neoproterozoic–Silurian sedimentary sequences in NW Iberia and Avalonia, in conjunction with the comprehensive existing datasets from potential source cratons, to demonstrate that the provenance of each terrane is relatively simple and can be traced back to three major cratons. The enigmatic Tonian–Stenian detrital zircons in autochthonous Iberian rocks were derived from the Saharan metacraton in the latest Neoproterozoic–early Cambrian. Avalonia is commonly considered to have been derived from the Amazonian margin of Gondwana, but the hafnium isotopic characteristics of the detrital zircon grains in early Neoproterozoic rocks bear much stronger similarities to Baltica. The hafnium isotopic array also suggests the early Avalonian oceanic arc was built on a sliver of “Grenvillian-type crust” (~ 2.0–1.0 Ga) possibly of Baltican affinity at ~ 800 Ma, prior to accretion with a continental margin at ~ 640 Ma. The Upper Allochthon of Iberia is frequently linked to the West African Craton in the late Neoproterozoic–early Cambrian, however the hafnium isotopic array presented here does not support this connection; rather it is more similar to the hafnium array from Avalonia. The Armorican terranes have strong detrital zircon isotopic links to the West African Craton during the late Neoproterozoic–Cambrian.
IOP conference series, Dec 1, 2017
The advent of a large amount of more precise U-Pb age data on Variscan granitoids from NW Iberia ... more The advent of a large amount of more precise U-Pb age data on Variscan granitoids from NW Iberia in recent years has provided a more focused picture of the magmatic history of the Western European Variscan belt (WEVB). Based on these data, three main pulses of magmatic activity seem to be well established.
Geoheritage, Jul 27, 2016
The Alejico coalbeds represent a well-preserved Carboniferous fossils site characterised by the p... more The Alejico coalbeds represent a well-preserved Carboniferous fossils site characterised by the presence of tree trunks in life position and parallel to bedding. The area, located near the Picos de Europa National Park (Spain), between the León and Asturias provinces, lacks of any kind of preservation directives, thus being influenced by weathering, erosion and anthropogenic destruction. We present a photogrammetric study carried out through terrestrial and UAV-assisted technology in order to collect digital 3D information for fossil analysis and future preservation. A general overview of the steep wall of the outcrop and a detailed section of the fossil forest have been implemented into a reliable and accurate point cloud. Qualitative and quantitative information was obtained from a georeferenced high-resolution digital 3D model used for the characterisation of the different outcrop features, which aimed specially at the fossil conservation. The results p r o v i d e u s e f u l i n f o r m a t i o n o n t h e n a t u r e a n d paleoenvironment of carboniferous forests with important implication for scientific and educational interests. These technologies provide new possibilities for better preservation and diffusion of geologic heritage locations prone to be damaged, and enables public awareness for the protection of fossil sites with high scientific and cultural value.
Lithosphere, Aug 24, 2015
The Variscan orogen provides the European record of the late Paleozoic continental collisions tha... more The Variscan orogen provides the European record of the late Paleozoic continental collisions that culminated with formation of the supercontinent Pangea. An S-shaped pair of isoclinal coupled oroclines characterizes the Variscan orogen of the Iberian Massif. Though oroclines are common features of the world's orogenic belts, the mechanisms that drive oroclinal formation, and the manner in which these continental-scale vertical-axis folds of orogens are accommodated are poorly understood. The northerly Cantabrian and the southerly Central Iberian oroclines are structurally continuous and pericontemporaneous, suggesting that they formed in the same fashion. Exposures of the Ediacaran Narcea Slates within the so-called Narcea antiform trace a 150-km-long arcuate belt around the 180° Cantabrian orocline. In the western flank of the Narcea antiform, the Narcea Slates are characterized by a penetrative steep to vertical, rough to slaty cleavage (S1) and subparallel 2-km-wide reverse shear zones with a penetrative fabric (S2) that are postdated by asymmetric meso-to outcrop-scale verticalaxis folds (plunge >65°) with a dominant vergence toward the oroclinal hinge; i.e., fold geometry is dominantly dextral (Z-shaped) in the southern limb of the Cantabrian orocline and dominantly sinistral (S-shaped) in its northern limb. Axial planes are consistently steeply dipping, but they are typically oriented at a high angle to S1/S2 and are therefore variable in strike about the orocline hinge. Vertical-axis folds affecting the Narcea Slates are of the appropriate scale and geometry to be interpreted as parasitic structures developed in response to a component of flexural shear within the limbs of the forming Cantabrian orocline. A model of formation of the Iberian coupled oroclines by buckling accommodating significant orogen-parallel shortening along an initially linear Iberian Variscan belt is therefore supported, providing new insight into the complexities associated with the final stages of Pangean amalgamation.
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Papers by Gabriel Gutierrez-Alonso