Pierrick Roperch

French National Centre for Scientific Research | CNRS · Geosciences Rennes

The Cenozoic strata of the Xining Basin, NE Tibet, have provided crucial records for understanding the tectonic and paleo‐environmental evolution of the region. Yet, the age for the lower part of the sedimentary stratigraphy and consequently the early tectonic evolution of the basin remain debated. Here, we present the litho‐ and magnetostratigraph...

Knowledge of the tectonic history of the Pamir contributes to our understanding of both the evolution of collisional orogenic belts as well as factors controlling Central Asian aridification. It is, however, not easy to decipher the Mesozoic–Cenozoic tectonics of the Pamir due to extensive Neogene deformation in an orogen that remains largely under...

Schultz et al. (2021) interpreted the unusual silicate surface glasses found in the northeastern part of the Atacama Desert as products of a comet airburst that occurred about12 k.y. ago. This interpretation contradicts our conclusions (Roperch et al., 2017). On the basis of abundant field and laboratory evidence, our work suggested that the glasse...

In directional archaeomagnetic studies, it is rarely analysed whether the combustion structures display anisotropy of their thermoremanent magnetization (ATRM). It has been observed that, in specific cases like thin baked clays from the base of small hearths) archaeomagnetic directions can also be disturbed by the ATRM. We re-examine data from 56 c...

Paleogeographic maps are essential tools for understanding Earth system dynamics. They provide boundary conditions for climate and geodynamic modelling, for analysing surface processes and biotic interactions. However, the temporal and spatial distribution of key features such as seaways and mountain belts that govern climate changes and biotic int...

The Burma Terrane (Myanmar) played an important role in the India‐Asia collision and moved over 2000 km northward on the Indian Plate during the Cenozoic, before colliding with the Asian margin. However, the timing of this collision and its correlation to regional uplift phases, sedimentary provenance and basin development, remain poorly constraine...

The Burma Terrane (Myanmar) played an important role in the India‐Asia collision and moved over 2000 km northward on the Indian Plate during the Cenozoic, before colliding with the Asian margin. However, the timing of this collision and its correlation to regional uplift phases, sedimentary provenance and basin development, remain poorly constraine...

The timing and mechanisms of the Cretaceous sea incursions into Central Asia are still poorly constrained. We provide a new chronostratigraphic framework based on biostratigraphy and magnetostratigraphy together with detailed paleoenvironmental analyses of Cretaceous records of the proto‐Paratethys Sea fluctuations in the Tajik and Tarim basins. Th...

The Pamir orogen in Central Asia has formed by the amalgamation of several Gondwana-derived terranes and their accretion to the southern Eurasian margin in the Mesozoic. Later on, the crust of the Pamir orogen was strongly deformed and uplifted as a result of the Cenozoic India-Asia collision. The deformation of the Pamir orogen, which resulted in...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Convergence between the Indian and Asian plates has reshaped large parts of Asia, changing regional climate and biodiversity, yet geodynamic models fundamentally diverge on how convergence was accommodated since the India–Asia collision. Here we report palaeomagnetic data from the Burma Terrane, which is at the eastern edge of the collision zone an...

The proto‐Paratethys Sea covered a vast area extending from the Mediterranean Tethys to the Tarim Basin in western China during Cretaceous and early Paleogene. Climate modelling and proxy studies suggest that Asian aridification has been governed by westerly moisture modulated by fluctuations of the proto‐Paratethys Sea. Transgressive and regressiv...

The proto‐Paratethys Sea covered a vast area extending from the Mediterranean Tethys to the Tarim Basin in western China during Cretaceous and early Paleogene. Climate modelling and proxy studies suggest that Asian aridification has been governed by westerly moisture modulated by fluctuations of the proto‐Paratethys Sea. Transgressive and regressiv...

Paleogeographic reconstructions of terranes can greatly benefit from the provenance analysis of sediments. A series of Cenozoic basins provide key sedimentary archives for investigating the growth of the Tibetan Plateau, yet the provenance of the sediments in these basins has never been constrained robustly. Here we report sedimentary petrological...

The Himalayan-Tibetan orogen is generally considered as the archetype for continent-continent collisional systems , being the result of the accretion of numerous terranes including notably the India-Asia collision. However, the geodynamic evolution of the India-Asia collision remains a controversial issue, as illustrated by the widely different com...

The Pamir orogen formed and uplifted in response to the amalgamation of the Gondwanan terranes in the Mesozoic followed by the Cenozoic India-Asia collision. The Pamir growth is held responsible for the disappearance of a large epicontinental sea and the desertification of Central Asia. More than 400 km of convergence has been inferred in the Pamir...

The establishment and evolution of the Asian monsoons and arid interior have been linked to uplift of the Tibetan Plateau, retreat of the inland proto-Paratethys Sea and global cooling during the Cenozoic. However, the respective role of these driving mechanisms remains poorly constrained. This is partly due to a lack of continental records coverin...

The northward indentation of the Pamir salient into the Tarim basin at the western syntaxis of the India-Asia collision zone is the focus of controversial models linking lithospheric to surface and atmospheric processes. Here we report on tectonic events recorded in the most complete and best-dated sedimentary sequences from the western Tarim basin...

The Cenozoic vegetation history of Central Myanmar is only sparsely documented and yet of great interest in the context of regional paleogeographic and climatic changes. The Kalewa section, situated in the Central Myanmar Basin and recently dated by our group (Myanmar Paleoclimate and Geodynamics research group), presents an excellent opportunity t...

Cenozoic collision between India and Eurasia produced the Himalayan-Tibetan orogen, which is commonly considered as the archetypical orogen for continent-continent collision systems. However, there is still no consensus on the amount and mechanism of post-collisional convergence, as well as on the roles of the numerous tectonic terranes comprising...

We describe extended occurrences of unusual silicate glass surface layers from the Atacama Desert (Chile). These glasses, found near the town of Pica at four localities separated by up to 70 km, are neither fulgurites, nor volcanic glasses, nor metallurgical slags related to anthropic activity, but show close similarities to other glasses that have...

Since the extrusion and rotation of the Indochina Peninsula following the India-Asia collision, the convergence of India relative to Myanmar has been highly oblique. This high obliquity has resulted in the strike-slip partitioning of the 1100-km long forearc basin of central Myanmar into individual pull-apart basins, as well as the early build-up o...

The Asian monsoons affect the lives of one third of the human population, yet the controls on monsoon intensity and longevity are not fully understood. Recent studies have highlighted that the South Asian monsoon is as old as the Eocene; early monsoonal intensity has been proposed to be driven by variations in atmospheric pCO2. This study proposes...

Variations of geomagnetic field in the Iberian Peninsula prior to roman times are poorly constrained. Here we report new archaeomagnetic results from four ceramic collections and two combustion structures recovered in two pre-roman (celtiberic) archaeological sites in central Spain. The studied materials have been dated by archaeological evidences...

En el norte de Chile, afloran fundidos vítreos y se interpreta y asocia su génesis al impacto de material extraterrestre. Se encuentran asociados a tierra cocida y/o cerámica y un nivel vegetal. Dos de estos sectores presentan morfologías llanas, conformados por depósitos de paleohumedales, y otros dos se encuentran en quebradas. La tierra cocida y...

The southernmost Andes of Patagonia and Tierra del Fuego present a prominent arc-shaped structure: the Patagonian Bend. Whether the bending is a primary curvature or an orocline is still matter of controversy. New paleomagnetic data have been obtained south of the Beagle Channel in 39 out of 61 sites. They have been drilled in Late Jurassic and Ear...

New paleomagnetic data from Permo-Triassic and Late Cretaceous rocks yield a consistent trend of vertical-axis-tectonic-rotations which are consistent with the Central Andean Rotation Pattern (CARP). However, three sites in the Tuina Formation and one site in the Purilactis Group record large rotations (80°). These mayor rotations are probably due...

The Magallanes fold and thrust belt (FTB) presents a large-scale curvature from N-S oriented structures north of 52°S to nearly E-W in Tierra del Fuego Island. We present a paleomagnetic and anisotropy of magnetic susceptibility (AMS) study from 85 sites sampled in Cretaceous to Miocene marine sediments. Magnetic susceptibility is lower than 0.0005...

The Magallanes fold and thrust belt (FTB) presents a large-scale curvature from N-S oriented structures north of 52°S to nearly E-W in Tierra del Fuego Island. We present a paleomagnetic and anisotropy of magnetic susceptibility (AMS) study from 85 sites sampled in Cretaceous to Miocene marine sediments. Magnetic susceptibility is lower than 0.0005...

In this paper we show the results of a paleomagnetic study carried out along the western Andes of central Chile from 30° to 36°S. Whereas paleomagnetic analysis from Jurassic to Late Cretaceous rocks in the Pampean flat slab segment shows small or non significant clockwise vertical-axis rotations, results obtained in Late Jurassic to Neogeone rocks...

Additional paleomagnetic data are necessary to improve geomagnetic models of secular variation during the Holocene, especially from the southern hemisphere. In most of the Andean volcanoes from Ecuador to the Chilean central volcanic zone, very well dated lava flows are rare. In contrast, andesitic to basaltic pyroclastic density current (PDC) depo...

The Illapel Plutonic Complex (IPC), located in the Coastal Range of central Chile (31°-33° S), is composed of different lithologies, ranging from gabbros to trondhjemites, including diorites, tonalites and granodiorites. U/Pb geochronological data shows that the IPC was amalgamated from, at least, four different magmatic pulses between 117 and 90 M...

Partial self-reversed thermoremanent magnetizations (SRTRMs) were observed in samples of baked soils, hearths and ceramics from the Rumipamba archeological site near Quito (Ecuador) and ceramics from sites near the town of Esmeraldas (Ecuador). The SRTRMs were recognized at room temperature on few samples but cooling the samples in liquid nitrogen...

To improve geomagnetic models of secular variation during the Holocene, it is necessary to bring new data, especially from the southern hemisphere. In most of the Andean volcanoes from Ecuador to the Chilean central volcanic zone, very well dated lava flows are not numerous. In contrast, pyroclastic flows (PF) often contain charcoal facilitating th...

During the Paleozoic, South America, Arabia, Africa and East and West Antarctica were part of the Gondwana supercontinent. By the mid‐Cretaceous, South Atlantic opening was under way, and East‐Antarctica and the Antarctic Peninsula acted as a single plate. However the connection between the Antarctic Peninsula and Patagonia is still subject of deba...

New paleomagnetic data presented here from 61 sites in Paleozoic, Mesozoic and Cenozoic igneous and sedimentary rocks from the Antarctic Peninsula and the South Shetland Islands constrain the relative motion of the Antarctic Peninsula since the mid-Cretaceous and allow the quantification of tectonic rotation between the different blocks recognized...

We report a combined study of anisotropy of low field magnetic susceptibility (AMS) and paleomagnetism from 16 sites in a sedimentary sequence of Eocene–early Oligocene red beds in southern Peru. Incipient tectonic strain is recorded during the early stages of deformation. Nonhorizontal magnetic lineation in geographic coordinate suggests either no...

The northern North Atlantic and its adjacent continental margins have specific and uncommon features: location of the ridge on a major mantle plume, a history of ridge jump and extinction, and intraplate deformation on the margins (inverted basins and compressional domes). Reconstructions of the opening of the North Atlantic on the basis of two rig...

We discuss the relationships between Andean shortening, plate velocities at the trench, and slab geometry beneath South America. Although some correlation exists between the convergence velocity and the westward motion of South America on the one hand, and the shortening of the continental plate on the other hand, plate kinematics neither gives a s...

El Teniente porphyry copper deposit, the world’s greatest intrusion-related Cu–Mo ore body, is hosted within basaltic–andesitic volcanic and gabbroic rocks (mafic complex). This ore body is strongly affected by multiple events of alteration/mineralization with pervasive potassic and chloritic alteration and coetaneous with associated copper mineral...

Very few archeomagnetic results are available for the southern hemisphere and more data are needed to better constrain the global geomagnetic field models over the past few millenias. We will present new paleomagnetic results from volcanic rocks of the Tungurahua volcano and results from 5 units from the Rumipampa archeological site in Quito. Few l...

One of the main assumptions of the theory of plate tectonics is that all plates are rigid. However, in some plate reconstructions, the fits improve if the continents deform. Moreover, along parts of the North Atlantic continental margins, there is good evidence for post-rift deformation, in the form of inverted basins and compressional domes. Possi...

We report new paleomagnetic results from 55 out of 76 sites sampled at different localities along a transect from Nazca to Cuzco where the general structures of the Peruvian Andes are strongly offset across the Abancay deflection. Nine new 39Ar/40Ar ages better constrain the timing of volcanism along the western edge of the Western Cordillera at th...

One of the most prominent tectonic features of the Andes is the Central Andean Rotation Pattern (CARP), which is closely related to the Bolivian Orocline and characterized by paleomagnetically determined clockwise rotations in northern Chile and counterclockwise rotations in southern Peru (Arriagada et al., 2008). Along the Chilean margin, between...

In the Paleozoic, South America, South Africa and Antarctica were part of Gondwana. The Weddell Sea began to form at about 146 Ma, after rifting between the Antarctic Peninsula and southernmost South America. Much uncertainty still exists about the geometrical fit and subsequent drift history between Patagonia and Antarctica. Geophysical and geolog...

Magnetic fabrics recorded by continental sediments from the Central Andes were systematically measured for about 200 sites also studied for tectonic rotation. Most sediments of Cenozoic age are fine-grained red beds with a significant content of magnetite of volcanoclastic origine. 80 sites were collected in the Puna and Argentinan Andes, 40 sites...

During the last 15 years, we have extensively sampled continental deposits in the Central Andes (Altiplano-Puna) to study tectonic rotations and the magnetic fabric recorded by these sediments was also systematically measured. At almost all sites, a well-defined magnetic lineation is recorded. At most localities, the orientation of the magnetic lin...

The genetic relationship between mafic dike swarms and plutonic reservoirs in the mesozoic of central chile (30°–33°45' S): insights from AMS and geochemistry Abstract Five mafic dike swarms between 30° and 33°45' S were studied for their geochemical signature and kinematics of magma flow directions by means of AMS data. In the Coastal Range of cen...

During the early 60s, Norbert Bonhommet extensively sampled in the Chaîne des Puys, France (>150 sites, 50 volcanic units) for his Doctorat d'Etat at the Institut de Physique du Globe de Strasbourg. Much of the volcanism is Brunhes-age and as young as the Holocene. Bonhommet and Babkine (1967) discovered reversed paleomagnetic directions in the Olb...

Using available information on the magnitude and age of tectonic shortening, as well as paleomagnetically determined tectonic rotations, we have run a series of 2-D map view restorations of the central Andes. Neogene shortening in the foreland belt induced only slight orogenic curvature of the central Andes. The constraints on the ages of the large...

40Ar/39Ar ages and paleomagnetic correlations using characteristic remanent magnetizations (ChRM) show that two main ignimbrite sheets were deposited at 4.86 ± 0.07 Ma (La Joya Ignimbrite: LJI) and at 1.63 ± 0.07 Ma (Arequipa Airport Ignimbrite: AAI) in the Arequipa area, southern Peru. The AAI is a 20–100 m-thick ignimbrite that fills in the Arequ...

Chuquicamata, in northern Chile, is one of the largest porphyry copper deposits in the world; the western side of its orebody is bounded by a major longitudinal fault, the West fault. We report paleomagnetic results from surface sites and drill cores from different geological units at Chuquicamata, especially within the late Eocene Fiesta granodior...

In the Carolina de Michilla district, northern Chile, stratabound copper mineralization is hosted by Jurassic volcanic rocks along the trace of the Atacama fault system. In this study, we present the overall effects of hydrothermal alteration on the magnetic properties of rocks in this district. Two types of metasomatic alteration associations occu...