Синтез моделей діалогового інтерфейсу управління процесами навчання в інтелектуальних тренажерах

Розглянуто підстави синтезу мультимедійних діалогових комплексів в АІС призначених для відображення динамічних ситуацій з використанням СППР для управління інтелектуальними тренажерами

Late Cretaceous to Paleocene oroclinal bending in the central Pontides (Turkey)

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Does pulsed Tibetan deformation correlate with Indian plate motion changes?

Models that aim to explain the causes of the significant Indian plate motion acceleration around 70 Ma, and the subsequent deceleration around 52 Ma predict different scenarios regarding crustal shortening of the Tibetan Plateau, which can be tested by precisely determining the timing of regional shortening events in Tibet. Here we attempt to determine this timing by presenting a high-resolution magnetostratigraphy of a ∼3.5 km thick sedimentary sequence in the syn-contractional Gonjo Basin, east-central Tibet. We successfully isolated the primary remanence as confirmed by positive fold and reversal tests. Correlation to the geomagnetic polarity time scale reveals a 69–41.5 Ma age for the Gonjo Basin sedimentary succession. Average sedimentation rates indicate two episodes of enhanced sediment accumulation rate at 69–64 Ma and 52–48 Ma, which coincide with periods of vertical axis rotation recorded in the basin fill. This coincidence suggests a tectonic cause, which given regional structures we interpret as shortening pulses. Our results are similar to those from basins elsewhere in southern, central and northern Tibet, suggesting plateau-wide, synchronous shortening pulses at ∼69–64 Ma and ∼52–48 Ma. These pulses are synchronous with major acceleration and deceleration of India-Asia convergence rate, suggesting that both the acceleration and deceleration of India-Asia convergence may be associated with enhanced crustal deformation in Tibet, which we use to evaluate previous dynamic models explaining the Indian plate motion changes and India-Asia collision processes

Subduction initiation in the Scotia Sea region and opening of the Drake Passage: When and why?

During evolution of the South Sandwich subduction zone, which has consumed South American Plate oceanic lithosphere, somehow continental crust of both the South American and Antarctic plates have become incorporated into its upper plate. Continental fragments of both plates are currently separated by small oceanic basins in the upper plate above the South Sandwich subduction zone, in the Scotia Sea region, but how fragments of both continents became incorporated in the same upper plate remains enigmatic. Here we present an updated kinematic reconstruction of the Scotia Sea region using the latest published marine magnetic anomaly constraints, and place this in a South America-Africa-Antarctica plate circuit in which we take intracontinental deformation into account. We show that a change in marine magnetic anomaly orientation in the Weddell Sea requires that previously inferred initiation of subduction of South American oceanic crust of the northern Weddell Sea below the eastern margin of South Orkney Islands continental crust, then still attached to the Antarctic Peninsula, already occurred around 80 Ma. Subsequently, between ~71–50 Ma, we propose that the trench propagated northwards into South America by delamination of South American lithosphere: this resulted in the transfer of delaminated South American continental crust to the overriding plate of the South Sandwich subduction zone. We show that continental delamination may have been facilitated by absolute southward motion of South America that was resisted by South Sandwich slab dragging. Pre-drift extension preceding the oceanic Scotia Sea basins led around 50 Ma to opening of the Drake Passage, preconditioning the southern ocean for the Antarctic Circumpolar Current. This 50 Ma extension was concurrent with a strong change in absolute plate motion of the South American Plate that changed from S to WNW, leading to upper plate retreat relative to the more or less mantle stationary South Sandwich Trench that did not partake in the absolute plate motion change. While subduction continued, this mantle-stationary trench setting lasted until ~30 Ma, after which rollback started to contribute to back-arc extension. We find that roll-back and upper plate retreat have contributed more or less equally to the total amount of ~2000 km of extension accommodated in the Scotia Sea basins. We highlight that viewing tectonic motions in a context of absolute plate motion is key for identifying slab motion (e.g., rollback, trench-parallel slab dragging) and consequently mantle-forcing of geological processes

The Gediz River fluvial archive: A benchmark for Quaternary research in Western Anatolia

The Gediz River, one of the principal rivers of Western Anatolia, has an extensive Pleistocene fluvial archive that potentially offers a unique window into fluvial system behaviour on the western margins of Asia during the Quaternary. In this paper we review our work on the Quaternary Gediz River Project (2001–2010) and present new data which leads to a revised stratigraphical model for the Early Pleistocene development of this fluvial system. In previous work we confirmed the preservation of eleven buried Early Pleistocene fluvial terraces of the Gediz River (designated GT11, the oldest and highest, to GT1, the youngest and lowest) which lie beneath the basalt-covered plateaux of the Kula Volcanic Province. Deciphering the information locked in this fluvial archive requires the construction of a robust geochronology. Fortunately, the Gediz archive provides ample opportunity for age-constraint based upon age estimates derived from basaltic lava flows that repeatedly entered the palaeo-Gediz valley floors. In this paper we present, for the first time, our complete dataset of 40Ar/39Ar age estimates and associated palaeomagnetic measurements. These data, which can be directly related to the underlying fluvial deposits, provide age constraints critical to our understanding of this sequence. The new chronology establishes the onset of Quaternary volcanism at ∼1320ka (MIS42). This volcanism, which is associated with GT6, confirms a pre-MIS42 age for terraces GT11-GT7. Evidence from the colluvial sequences directly overlying these early terraces suggests that they formed in response to hydrological and sediment budget changes forced by climate-driven vegetation change. The cyclic formation of terraces and their timing suggests they represent the obliquity-driven climate changes of the Early Pleistocene. By way of contrast the GT5-GT1 terrace sequence, constrained by a lava flow with an age estimate of ∼1247ka, span the time-interval MIS42 – MIS38 and therefore do not match the frequency of climate change as previously suggested. The onset of volcanism breaks the simple linkage of terracing to climate-driven change. These younger terraces more likely reflect a localized terracing process triggered by base level changes forced by volcanic eruptions and associated reactivation of pre-existing faults, lava dam construction, landsliding and subsequent lava-dammed lake drainage. Establishing a firm stratigraphy and geochronology for the Early Pleistocene archive provides a secure framework for future exploitation of this part of the archive and sets the standard as we begin our work on the Middle-Late Pleistocene sequence. We believe this work forms a benchmark study for detailed Quaternary research in Turkey

Geomagnetism, Paleomagnetism and Electromagnetism Perspectives on Integrated, Coordinated, Open, Networked (ICON) Science

This article is composed of three independent commentaries about the state of Integrated, Coordinated, Open, Networked (ICON) principles (Goldman et al., 2021, https://doi.org/10.1002/essoar.10508554.1) in the Geomagnetism, Paleomagnetism, and Electromagnetism (GPE) section and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: Global collaboration, reproducibility, data sharing and infrastructure; Inclusive equitable, and accessible science: Involvement, challenges, and support of early career, BIPOC, women, LGBTQIA+, and/or disabled researchers; Community engagement, citizen science, education, and stakeholder involvement. Data sharing practices and open repository use still varies strongly between GPE communities. Some have a long tradition of data sharing; others are only starting it. Globally, GPE leadership is strongly dominated by white males and diversity may increase through the creation of Science Equality Commissions. Improved global stakeholder involvement can increase research impacts and help fight inequalities. In all investigated topics we see promising beginnings but also recognize obstacles that include a lack of funding, a lack of understanding of diversity, and prioritizing short-term gain over long-term benefit. Nonetheless, we are hopeful that our community will embrace ICON science

The evolving anatomy of a collapsing orogen

The Tethys Oceans separated Africa and Arabia from Eurasia, and India from Asia. Closure of the Tethys started in the Jurassic and led to the Alpine-Himalayan mountain chain. This thesis will focus on the Aegean segment of this mountain belt. The Aegean region is occupied by a stack of nappes that were emplaced during the closure of the Tethys. In the late Eocene, the oldest and most internal nappes of the nappe stack started to fall apart, or collapse: late-orogenic extension fragmented the nappe stack, leading to the formation of metamorphic core complexes and associated sedimentary basins, while stacking of new nappes continued at the active margin. This thesis focuses on the question whether it is possible to identify the large-scale geodynamic processes that led to the collapse – or fragmentation – of the Aegean segment of the Alpine orogen. To best identify these, the timing, magnitude and direction of vertical and horizontal motions in the entire Aegean region were reconstructed by paleontologic and paleomagnetic measurements and structural and sedimentologic analysis, since the possible large-scale processes are likely to lead to a specific spatial contemporaneous and evolving distribution of these motions. Thus, we reconstructed the evolving anatomy of the Aegean region since the onset of nappe stacking in the Jurassic. We investigated whether the fragmentation can be subdivided into different phases, and if so, we constrained the timing of onset and duration of these phases. Therefore, we reconstructed the palinspastic evolution of the Aegean region since the Eocene and compared it with the structural, metamorphic and magmatic history of the region. This led to the identification of a number of phases: 35-23 Ma, 23-15 Ma, 15-8 Ma, 8-3.5 Ma and 3.5-0 Ma. The first two phases are characterised by – probably roll-back induced – N-S extension, the formation of metamorphic core complexes and the onset of volcanism. Around 23 Ma, two nappes decoupled from the subducting slab. Afterwards, they were extended and exhumed between 23 and 15 Ma in two metamorphic core complexes, the tectonostratigraphically higher one of which experienced a high-temperature overprint as a result of exhumation of hot material along the lower one. Around 15 Ma, the onset of lateral extrusion of Anatolia led to clockwise rotation and reestablishment of compression in western Greece. From 8 Ma onward, the overriding Aegean lithosphere started to spread out over the underthrusting lithosphere, leading in the northwest to collision with Apulia. This collision was established around 3.5 Ma, after which the ongoing spreading of the Aegean region led to interfering curved extensional basins such as the Gulf of Corinth-Saronic Gulf composite basin system. The timing of these phases correlates well with Mediterranean wide, large-scale palinspastic and tectono-stratigraphic phase

Origin and consequences of western Mediterranean subduction, rollback, and slab segmentation

The western Mediterranean recorded subduction rollback, slab segmentation and separation. Here we address the questions of what caused Oligocene rollback initiation, and how its subsequent evolution split up an originally coherent fore arc into circum-southwest Mediterranean segments. We kinematically reconstruct western Mediterranean geology from subduction initiation to present, using Atlantic plate reconstructions as boundary condition. We test possible reconstructions against remnants of subducted lithosphere imaged by seismic tomography. Transform motion between Africa and Iberia (including the Baleares) between ~120 and 85 Ma was followed by up to 150 km convergence until 30 Ma. Subduction likely initiated along the transform fault that accommodated pre-85 Ma translation. By the ~30 Ma inception of rollback, up to 150 km of convergence had formed a small slab below the Baleares. Iberia was disconnected from Sardinia/Calabria through the North Balearic Transform Zone (NBTZ). Subduction below Sardinia/Calabria was slightly faster than below the Baleares, the difference being accommodated in the Pyrenees. A moving triple junction at the trench-NBTZ intersection formed a subduction transform edge propagator fault between the Baleares and Calabria slab segments. Calabria rolled back eastward, whereas the Baleares slab underwent radial (SW-S-SE) rollback. After Kabylides-Africa collision, the western slab segment retreated toward Gibraltar, here reconstructed as the maximum rollback end-member model, and a Kabylides slab detached from Africa. Opening of a slab window below the NBTZ allowed asthenospheric rise to the base of the fore arc creating high-temperature metamorphism. Western Mediterranean rollback commenced only after sufficient slab-pull was created from 100 to 150 km of slow, forced subduction before ~30 Ma

Mass wasting and uplift on Crete and Karpathos (Greece) during the early Pliocene related to beginning of south Aegean left-lateral strike slip tectonics

Reconstruction of the vertical motion history of Crete and Karpathos (southeastern Aegean region, Greece) from the Messinian to Recent revealed a previously poorly documented late Messinian phase of strong subsidence with rates of 50–100 cm/k.y. followed by stasis during the first 250 k.y. of the Pliocene and then by uplift of 500–700 m during the late early to early middle Pliocene. Uplift continued up to Recent albeit at a slower pace and at different rates in different areas. The lower Pliocene in Crete and Karpathos is characterized by widespread occurrences of mass-wasting deposits, which were emplaced over a period of time spanning the first 1.35 m.y. of the Pliocene. The origin of these mass-wasting deposits has long been enigmatic but is here related to uplift which started in Crete as early as ca 5 Ma. It is suggested that the beginning uplift following strong subsidence of various fault blocks until late in the Messinian is related to the onset of south Aegean strike-slip faulting. We postulate that small-scale tilting of fault blocks by trans-tensional strike-slip faulting and increased seismic activity generated slope failures and subsequent sliding of poorly cemented lower Pliocene and uppermost Messinian Lago Mare sediments overlying the terminal Miocene erosional unconformity. The absence of mass-wasting deposits after 3.98 Ma, while uplift continued, is most likely the result of progressive compaction and cementation of the increasingly deeper buried Lago Mare and lower Pliocene sediments, thereby preventing slope failure to a depth of the terminal Miocene unconformity. Hiatuses in some places in Crete and on Karpathos, however, indicate that slope failures continued to occur although on a smaller scale and less frequent than before. Connecting the change from subsidence to uplift in the earliest Pliocene with the onset of left-lateral, strike-slip tectonics in the southeastern Aegean arc would make this major strike-slip system much older (by ~2 m.y.) than the generally accepted age of middle to late Pliocene. A recently postulated scenario of “Subduction Transform Edge Propagator” (STEP) faulting to explain the south Aegean strike-slip system predicts rates, distribution, and amount of uplift as rebound to south-westward retreat of the subducted slab along a transform fault zone that is in line with our findings on Crete and Karpathos and explains the absence of compressional structures associated with the uplift, as well as the ongoing southwestward motion of Crete

Mass wasting and uplift on Crete and Karpathos during the early Pliocene related to initiation of south Aegean left-lateral strike slip tectonics

Reconstruction of the vertical motion history of Crete and Karpathos (southeastern Aegean region, Greece) from the Messinian to Recent revealed a previously poorly documented late Messinian phase of strong subsidence with rates of 50-100 cm/k.y. followed by stasis during the first 250 k.y. of the Pliocene and then by uplift of 500-700 m during the late early to early middle Pliocene. Uplift continued up to Recent albeit at a slower pace and at different rates in different areas. The lower Pliocene in Crete and Karpathos is characterized by widespread occurrences of mass-wasting deposits, which were emplaced over a period of time spanning the first 1.35 m.y. of the Pliocene. The origin of these mass-wasting deposits has long been enigmatic but is here related to uplift which started in Crete as early as ca 5 Ma. It is suggested that the beginning uplift following strong subsidence of various fault blocks until late in the Messinian is related to the onset of south Aegean strike-slip faulting. We postulate that small-scale tilting of fault blocks by transtensional strike-slip faulting and increased seismic activity generated slope failures and subsequent sliding of poorly cemented lower Pliocene and uppermost Messinian Lago Mare sediments overlying the terminal Miocene erosional unconformity. The absence of mass-wasting deposits after 3.98 Ma, while uplift continued, is most likely the result of progressive compaction and cementation of the increasingly deeper buried Lago Mare and lower Pliocene sediments, thereby preventing slope failure to a depth of the terminal Mocene unconformity. Matuses in some places in Crete and on Karpathos, however, indicate that slope failures continued to occur although on a smaller scale and less frequent than before. Connecting the change from subsidence to uplift in the earliest Pliocene with the onset of left-lateral, strike-slip tectonics in the southeastern Aegean arc would make this major strike-slip system much older (by ∼2 m.y.) than the generally accepted age of middle to late Pliocene. A recently postulated scenario of "Subduction Transform Edge Propagator" (STEP) faulting to explain the south Aegean strike-slip system predicts rates, distribution, and amount of uplift as rebound to south-westward retreat of the subducted slab along a transform fault zone that is in line with our findings on Crete and Karpathos and explains the absence of compressional structures associated with the uplift, as well as the ongoing southwestward motion of Crete. © 2008 Geological Society of America