Structural Inheritance Research Articles

A Several-Kilometer-Long Archosaur Route in the Triassic of the Swiss Alps

The Mesozoic sedimentary cover of the Aiguilles Rouges Massif straddling the Swiss-French border has yielded several archosaur footprint sites dated to the Early or Middle Triassic and composed of mostly poorly preserved footprints lacking any orderly arrangement and resting on a megatracksite level. Here we describe two short archosaur trackways attributed to Isochirotherium herculis and located at ca. 2400 m asl in two distinct small valleys separated from each other by a linear distance of 6.4 km. Projection of both trackways onto the same plane showed that they were aligned with a deviation angle of only 3 degrees. These aligned trackways are interpreted as remnants of a straight and narrow walking route taken by a single trackmaker species. It is possible that both trackway segments were made by the same individual. In the present landscape, the Triassic outcrops are small and scattered along a roughly straight NE-SW line. The orientation of the trackways agrees with the general orientation of the outcrops, which is very unlikely to be caused by chance only. We explain this apparent coincidence as resulting from the structural inheritance of a general NE-SW Paleozoic shear zone that controlled the orientation of the Vindelician High on which the archosaurs walked, then that defined the axis of the much later Massif uplift, and eventually affected the general orientation of the erosion that uncovered the trackways.

Cenozoic tectonic patterns and their controls on growth strata in the northern Tianshan fold and thrust belt, northwest China

Field-based mapping and subsurface interpretations of high-resolution seismic images, as well as other geophysical data, have been integrated to investigate tectonic patterns and growth strata in the northern Tianshan fold and thrust belt (NTFTB). The NTFTB formed as a result of intense deformation and uplift of the northern Tianshan region that was triggered by the far field effects of the Indo-Eurasia plate collision. The structural styles of the NTFTB vary, and are primarily classified as thick-skinned thrust nappes that involve basement rocks and thin-skinned fault-related fold structures with multiple décollement layers in the sedimentary strata. The overall NTFTB can be divided into three segments based on its structural geometry. The western segment is characterized by an intense backthrust in the northern Tianshan piedmont, with little displacement transfer into the southern Junggar Basin. In the central segment, the emergence of three rows of anticlines reveals a progressive deformation sequence and displacement transfer into the foreland through multiple décollements. In the eastern segment, the tectonic pattern is characterized by steep faults that branch forward in a narrow zone to generate intense uplift. Evidences indicate that major basement faults, paleo-uplifts, and inheritance of former structures play key roles in driving the segmentation of the NTFTB, and that secondary fault assemblages may control regional tectonic styles within each tectonic unit. Cenozoic growth strata have been observed in the NTFTB, the geometry and deformation mechanism of which are subject to the structural style in a given structure. Growth strata can also provide constraints for time of deformation in the northern Tianshan, and the Dushanzi Formation has been shown to represent clear growth in the piedmont, which indicates rapid uplift of the northern Tianshan as well as intense tectonic activity in the NTFTB in the late Miocene. The growth strata become younger within structures to the north, towards the foreland. In general, the Cenozoic evolutional process has been relatively uniform in the northern Tianshan, generally showing a forward propagation of fault splays into the foreland, and the geometry and distribution of sedimentary strata have been controlled by tectonics.

Layering and structural inheritance controls on fault zone structure in three dimensions: a case study from the northern Molasse Basin, Switzerland

Mechanical heterogeneity of a sedimentary sequence exerts a primary control on the geometry of fault zones and the proportion of offset accommodated by folding. The Wildensbuch Fault Zone in the Swiss Molasse Basin, with a maximum throw of 40 m, intersects a Mesozoic section containing a thick (120 m) clay-dominated unit (Opalinus Clay) over- and underlain by more competent limestone units. Interpretation of a 3D seismic reflection survey indicates that the fault zone formed by upward propagation of an east–west-trending basement structure, through the Mesozoic section, in response to NE–SW Miocene extension. This configuration formed an array of left-stepping normal fault segments above and below the Opalinus Clay. In cross-section a broad monoclinal fold is observed in the Opalinus Clay. Folding, however, is not ubiquitous and occurs in the Opalinus Clay where fault segments above and below are oblique to one another; where they are parallel the fault passes through the Opalinus Clay with little folding. These observations demonstrate that, even in strongly heterogeneous sequences, here a four-fold difference in both Young's modulus and cohesion between layers, the occurrence of folding may depend on the local relationship between fault geometry and applied stress field rather than rheological properties alone.

Templeton's Academy

Templeton's Academy Justin Thomas Nevin (bio) The academy was a highly popular educational model in the early national era, appealing particularly to young rural males who desired more than an elementary education. To lure a wide, paying clientele, rural academies offered both basic English and more demanding Latin tracks using what educators called the amalgamation model. In the early national period, key contributing factors to academies' increasing popularity were rapidly shifting economic forces, the advent of childhood as a discrete life stage, and the entrepreneurial spirit that accompanied industrial capitalism. Relatedly, the waning of English-style craft apprenticeship necessitated new institutions for young males to transition into adulthood and economic self-sufficiency. Without the assurance of this indentured craft apprenticeship to help them transition, young white middle-class males often entered the academy to undertake a metamorphosis that was no longer so easily defined.1 For many such boys, that transformation was delivered by new and constantly changing means of remaking oneself in the image of the new republic. At the same time, burgeoning republican educational ideals loosely coincided with an "emerging normative view of childhood" [End Page 291] that encountered "an imagined child, akin but not identical to the middle-class child."2 Such early national developments structured and were partially structured by academies, which existed at the very centers of many frontier villages. A village's deliberate planning constituted a commercial strategy to integrate dispersed farms into the geographic syntax of republican life (BF, 67). Childhood studies scholar Steven Mintz writes, "Convinced that the stability of the new republic depended on a virtuous citizenry, the postrevolutionary generation called for more intensive styles of childrearing and more prolonged and systematic forms of education."3 For "republican essayists" of that time, virtue "meant discipline, sacrifice, simplicity, and intelligence, and they called upon teachers, ministers, and parents to aid in the creation and ministry of a virtuous citizenry."4 Detractors alleged that, despite these institutions' inconsistent curricula and rudimentary studies, academies' proponents overpromised scholastic achievement, social mobility, and economic opportunity. Though some academies served as nothing more than "glorified elementary schools,"5 the academy nonetheless offered a influential model that addressed local needs while aiming to integrate locally rooted youth into the national fold. In contrast to lesser school structures, academies used durable building materials that entailed a major communal investment. parallel composites: cooper's architectural, literary, and educational orders Because an academy is both an ideologically imbued educational model and a specific material structure, James Fenimore Cooper's close attention to Templeton's academy in The Pioneers (1823) allows the author to engage with contemporary educational debates—those surrounding [End Page 292] formal schooling—that parallel emerging republican ideals. Cooper's detailed consideration of the academy's architecture and curricula also puts the institution in dialogue with the aesthetics of his frontier romance. Scholars have noted the continuity between Cooper's descriptions of the architectural style called the Composite order, which fused Ionic and Corinthian features, and the grand American project of integrating a diverse population.6 Instead of employing the European style of joinery called scribe rule in Templeton's construction, Cooper fuses the Composite order to the American style of joinery called the square rule.7 Although The Pioneers is partially derisive toward the Composite order, the author nonetheless celebrates it "as uniquely suited to allow the future to dialog with the past without having to dismantle its structural inheritances."8 Cooper's specification of the square rule is particularly relevant in this light. Philip Fisher writes that "the historical novel is a device for practicing how to meet a certain but postponed future."9 Because the academy model is concerned with both preservation and futurity, nationalism and localism, it is thematically and narratively significant to Cooper's romance. Foregrounding Templeton's academy enriches our understanding of the social complexities in The Pioneers. The academy both addressed demand for and facilitated standardized, formal educational approaches. Since the nation's founding, republican-minded schooling has been crucial to developing American cohesion. Expressing a Revolutionary ideal that attempted to straddle individual liberties and social order, luminaries such as Noah Webster, Benjamin Rush, and Thomas Jefferson regarded education as central...

Processes and deformation rates generating seismicity in metropolitan France and conterminous Western Europe

Most of metropolitan France and conterminous Western Europe is currently located within the Eurasia intraplate domain, far from major plate boundaries (the Atlantic ridge and Nubia – Eurasia convergence zone). As in other intraplate regions, present-day deformation and seismicity rates are very slow, resulting in limited data and strong uncertainties on the ongoing seismotectonics and seismic hazards. In the last two decades, new geological, seismological and geodetic data and research have brought to light unexpected deformation patterns in metropolitan France, such as orogen-normal extensionca.0.5 mm yr−1in the Pyrenees and Western Alps that cannot be associated with their mountain-building history. Elsewhere, present-day deformation and seismicity data provide a partial picture that points to mostly extensive to strike-slip deformation regimes (except in the Western Alps foreland). A review of the numerous studies and observations shows that plate tectonics (plate motion, mantle convection) are not the sole, nor likely the primary driver of present-day deformation and seismicity and that additional processes must be considered, such as topography potential energy, erosion or glacial isostatic adjustment since the last glaciation. The exact role of each process probably varies from one region to another and remains to be characterized. In addition, structural inheritance (crust or mantle weakening from past tectonic events) can play a strong role in deformation localization and amplification up to factors of 5–20, which could explain some of the spatial variability in seismicity. On the basis of this review, we identify three research directions that should be developed to better characterize the seismicity, deformation rates and related processes in metropolitan France: macroseismic and historical seismicity, especially regarding moment magnitude estimations; geodetic deformation, including in regions of low seismicity where the ratio of seismic to aseismic deformation remains a key unknown; an integrated and consistent seismotectonic framework comprising numerical models, geological, seismological and geodetic data. The latter has the potential for significant improvements in the characterization of seismicity and seismic hazard in metropolitan France but also Western Europe.

The Formation of Continental Fragments in Subduction Settings: The Importance of Structural Inheritance and Subduction System Dynamics

AbstractMicrocontinents and continental fragments are pieces of continental lithosphere, formed by extension and breakup, followed by plate boundary relocations. Microcontinents or continental fragments affiliated with passive margins are well documented, but those close to active margins are less studied. We use dynamic two‐ and three‐dimensional numerical experiments to investigate how preexisting weaknesses within a continental upper plate affect extension and the possible formation of continental fragments. Our parametric study of the configuration (width and viscosity) of this imposed weakness indicates that stress localization and breakup of the upper plate are most efficient for narrow weak zones and a viscosity contrast between the weak zone and the surrounding crust of at least 1 order of magnitude. Moreover, upper plate extension and breakup occurs only if extension has a rotational component, here caused by the presence of a continental indenter on the downgoing plate. The width of the indenter relative to oceanic part of the downgoing plate controls differential slab pull that triggers trench retreat and upper plate deformation. A downgoing plate with a relatively large continental indenter yields large enough slab rotation to detach a continental block from the overriding plate and form wide back‐arc basins. Variations in the weak zone angle with respect to the trench result in different basin geometries. We successfully modeled the first step in breakup of active continental margins and determined the settings that may facilitate microcontinent formation in a subduction framework.

Grafting Methyl Groups on the Si(111) Surface as a Buffer Layer for van der Waals Epitaxial Growth of ZnO Nanorods in Chemical Bath Deposition

The absence of an epitaxial relation of material growth with silicon substrates usually results from the formation of native oxide on the substrate surface, especially in the lengthy solution process at elevated temperature. An effective method to impede surface oxidation and the consequent inheritance of the lattice structure of the substrate are beneficial for the epitaxial growth. In this study, we use the two-step halogenation/methylation process to create a methylated Si(111) surface for the growth of ZnO nanorods in a chemical bath deposition (CBD) process. The grafted methyl groups effectively passivate the Si(111) surface, and the deposited ZnO nanorods exhibit an epitaxial relation with the silicon substrate—ZnO[0001]//Si[111]; ZnO{11̅00}//Si{22̅0}. Because no chemical bonding is formed between the ZnO nanorods and the Si(111) substrate, this solution process exhibits the characteristics of the van der Waals epitaxial (vdWE) growth. The approach developed in this study paves a way for vdWE growth of nanostructures on Si substrates by the CBD process.

A Complex Hierarchy of Avoidance Behaviors in a Single-Cell Eukaryote.

Complex behavior is associated with animals withnervous systems, but decision-making and learning also occur in non-neural organisms [1], including singly nucleated cells [2-5] and multi-nucleate synctia [6-8]. Ciliates are single-cell eukaryotes, widely dispersed in aquatic habitats [9], with an extensive behavioral repertoire [10-13]. In 1906, Herbert Spencer Jennings [14, 15] described in the sessile ciliate Stentor roeseli a hierarchy of responses to repeated stimulation, which are among the most complex behaviors reported for a singly nucleated cell [16, 17]. These results attracted widespread interest [18, 19] and exert continuing fascination [7, 20-22] but were discredited during the behaviorist orthodoxy by claims of non-reproducibility [23]. These claims were based on experiments with the motile ciliate Stentor coeruleus. We acquired and maintained the correct organism in laboratory culture and used micromanipulation and video microscopy to confirm Jennings' observations. Despite significant individual variation, not addressed by Jennings, S.roeseli exhibits avoidance behaviors in a characteristic hierarchy of bending, ciliary alteration, contractions, and detachment, which is distinct from habituation or conditioning. Remarkably, the choice of contraction versus detachment is consistent with a fair coin toss. Such behavioral complexity may have had an evolutionary advantage in protist ecosystems, and the ciliate cortex may have provided mechanisms for implementing such behavior prior to the emergence of multicellularity. Our work resurrects Jennings' pioneering insights and adds to the list of exceptional features, including regeneration [24], genome rearrangement [25], codon reassignment [26], and cortical inheritance [27], for which the ciliate clade is renowned.

Deep Origin of the Dome‐Shaped Hyblean Plateau, Southeastern Sicily: A New Tectono‐Magmatic Model

AbstractSoutheastern Sicily is characterized by a prominent topography known as the Hyblean Plateau. It is commonly considered as a flexural bulge formed by the northwest plunging of the Hyblean‐Malta platform beneath the Sicilian Fold and Thrust Belt. However its noncylindrical shape and multiphase uplift history correlated to the Late Miocene and Plio‐Pleistocene volcanism outline a possible magmatic control on the Hyblean Plateau topographic expression. We argue, using 2‐D flexural models, that the flexural bending alone is unlikely to explain the high anomalous elevation of the Hyblean Plateau. Moreover, topographic analysis show that the Hyblean Plateau has a dome shape composed of radially tilted preserved surfaces defining individual blocks. The block edges seem to be related to deep‐seated inherited faults. Using an analogue modeling approach, we show that magmatic intrusions beneath the thick Meso‐Cenozoic sedimentary cover can reproduce the first‐order morphology of the Hyblean Plateau when a structural inheritance is imposed. Accordingly, we propose a tectono‐magmatic model that favors mafic sill intrusions as the major uplift source for the topographic anomaly. However, to explain the strong positive Bouguer anomaly, a deeper high‐density intracrustal body is needed. Moho uprising related to Mesozoic rifting or mafic lower crust underplating/intraplating since the Late Cretaceous can be evoked. The small wavelength of the topography and the deep intracrustal mass anomaly makes the lithospheric elastic stresses sufficiently high to maintain a nonisostatic state over the geological time scales.

The Influence of Structural Inheritance and Multiphase Extension on Rift Development, the NorthernNorth Sea

AbstractThe northern North Sea rift evolved through multiple rift phases within a highly heterogeneous crystalline basement. The geometry and evolution of syn‐rift depocenters during this multiphase evolution and the mechanisms and extent to which they were influenced by preexisting structural heterogeneities remain elusive, particularly at the regional scale. Using an extensive database of borehole‐constrained 2D seismic reflection data, we examine how the physiography of the northern North Sea rift evolved throughout late Permian‐Early Triassic (RP1) and Late Jurassic‐Early Cretaceous (RP2) rift phases, and assess the influence of basement structures related to the Caledonian orogeny and subsequent Devonian extension. During RP1, the location of major depocenters, the Stord and East Shetland basins, was controlled by favorably oriented Devonian shear zones. RP2 shows a diminished influence from structural heterogeneities, activity localizes along the Viking‐Sogn graben system and the East Shetland Basin, with negligible activity in the Stord Basin and Horda Platform. The Utsira High and the Devonian Lomre Shear Zone form the eastern barrier to rift activity during RP2. Toward the end of RP2, rift activity migrated northward as extension related to opening of the proto‐North Atlantic becomes the dominant regional stress as rift activity in the northern North Sea decreases. Through documenting the evolving syn‐rift depocenters of the northern North Sea rift, we show how structural heterogeneities and prior rift phases influence regional rift physiography and kinematics, controlling the segmentation of depocenters, as well as the locations, styles, and magnitude of fault activity and reactivation during subsequent events.

THE PROCESSES` CYCLICITY OF COMPOSITIONAL TRANSFORMATIONS OF THE URBAN EN

The article substantiates the cyclicality of the processes of urban development of historical planning of Ukrainian cities and illustrates by the examples of four cities with initially diverse composition - Lviv with a circular, Kharkiv with a radial, Vinnytsia with linear and Dnipro with a grid planning system. It is determined that one of the most important directions of systematization of previously revealed patterns of spatial and spatial growth of urban planning is the classification of development types of the compositional structure, which are determined by the basic parameters and properties of dynamic spatial modifications of the urban planning composition. These are the categories of resistance, mutation, transformation and synthesis. Resistance is characterized by the processes of inheritance and maintenance of the initial planning structures, as well as their systematic spatial growth. The mutation is described by the processes of peripheral modifications of initially prominent shaping patterns with their subsequent development while preserving the primary features of the spatial structure. Transformation is realized by the processes of significant modification of the vectors of development of the planning structure, which leads to a total change in the type of composite model. For synthesis, the main feature is the formation of subcenters of the composition based on previously identified patterns of development of a certain planning structure with the change of spatial scale. The transition process from resistance phase of the spatial development to mutation phase occurs through the development of new centrifugal axes and structures in the periphery; transformation phase is determined by more radical compositional changes to the structure based on pre-formed directions; the last phase of a certain cyclical development -- synthesis -- characterized by the formation of subcenters on the basis of all the previous regularities of the composite elements. For Ukrainian cities, the main common feature is the stage of transformation, at which significant territorial growth occurs with the formation of a centrifugal radial system of axes, which are closed by circles at the periphery, that is, any previous scheme is transformed into a radial-annular compositional structure.

Clan Networks and Enterprise Innovation：Synergy and Balance of Prior Experience of Rural Entrepreneurs

Over the past 40 years of reform and opening up, China’s sustained rapid economic growth is closely related to the effective solution of the three rural issues. Compared with cities, China’s rural areas have relatively low level of economic development, relatively closed information, narrow financing channels, weak infrastructure conditions, and a lack of human capital and professional knowledge. At the same time, the relatively stable population structure, genetic relationship and intergenerational inheritance make the rural areas have closer clan relations. In this situation, how rural entrepreneurs seek advantages and avoid disadvantages, and obtain resources needed for enterprise development is not only related to the quality of their innovation and entrepreneurship, but also of great significance to the revitalization of rural economy.Existing research has recognized the important role of clan networks and other social capital, but it has not explained clearly what factors in clan networks are the key factors affecting the innovation of rural enterprises, and it has not recognized the moderating effect and inter-regional differences of prior experience of rural entrepreneurs.This paper empirically tests the influence of clan networks on enterprise innovation based on the micro data of the survey on thousand villages”, including the coordination and balance of prior experience of entrepreneurs. This paper finds that clan intensity reflects the relationship and cognitive characteristics of social capital, and the supply of resource capital and normative capital can promote the innovation level of rural entrepreneurial enterprises. In regions with high level of economic development or strong clan culture, clan scale has a more significant negative impact on the enterprise innovation level. That is to say, clan scale reflects more network characteristics of social capital and inhibits enterprise innovation by excluding outsiders and restricting the flow of personnel and knowledge. At the same time, the competence view based on the social capital theory finds that the accumulation of prior experience can improve the knowledge, resource, cognitive level or personal ability of entrepreneurs, making rural entrepreneurs better play the positive role of clan strength in innovation and reduce the potential negative impact of the clan scale on innovation. That is to say, the prior experience of entrepreneurs plays a balance and synergy role between clan networks and enterprise innovation.This paper contributes to the following four aspects: Firstly, it enriches the existing literature’s understanding of the influencing factors of enterprise innovation, focuses on the unique social situation in China, and studies the internal mechanism of clan networks and enterprise innovation. Secondly, we divide clan networks into two levels: scale and intensity, to conduct a more comprehensive and detailed study, and find that the clan strength reflecting clan cohesion has a more positive impact on the level of enterprise innovation. Thirdly, we analyze how the prior experience of entrepreneurs moderates the impact of clan networks. Fourthly, we take 3311 Chinese rural entrepreneurs as samples to reveal the impact mechanism of regional clan networks on the enterprise innovation level in rural areas of China.

Terrane Boundary Reactivation, Barriers to Lateral Fault Propagation and Reactivated Fabrics: Rifting Across the Median Batholith Zone, Great South Basin, New Zealand

AbstractProminent preexisting structural heterogeneities within the lithosphere may localize or partition deformation during tectonic events. The NE‐trending Great South Basin, offshore New Zealand, formed perpendicular to a series of underlying crustal terranes, including the dominantly granitic Median Batholith Zone, which along with the boundaries between individual terranes exert a strong control on rift physiography and kinematics. We find that the crustal‐to‐lithospheric scale southern terrane boundary of the Median Batholith Zone is associated with a crustal‐scale shear zone that was reactivated during Late Cretaceous extension between Zealandia and Australia. This reactivated terrane boundary is oriented at a high angle to the faults defining the Great South Basin. We identify a large granitic laccolith along the southern margin of the Median Batholith, expressed as subhorizontal packages of reflectivity and acoustically transparent areas on seismic reflection data. The presence of this strong granitic body inhibits the lateral southwestward propagation of NE‐trending faults, which segment into a series of splays that rotate to align along the margin as they approach. Further, we also identify two E‐W‐ and NE‐SW‐oriented basement fabrics, likely corresponding to prominent foliations, which are exploited by small‐scale faults across the basin. We show that different mechanisms of structural inheritance are able to operate simultaneously, and somewhat independently, within rift systems at different scales of observation. The presence of structural heterogeneities across all scales needs to be incorporated into our understanding of the structural evolution of complex rift systems.

A novel metallic silicon hexaboride, Cmca-B6Si

Using first-principles calculations, we propose a novel metallic silicon hexaboride, Cmca-B6Si. This structure is dynamically and mechanically stable at ambient pressure. Furthermore, the formation energy of Cmca-B6Si is lower than those of synthesized Pnnm-SiB6 and SiB4, indicating that Cmca-B6Si is thermodynamically stable. The calculations of thermodynamic stability and structural inheritance indicate that Cmca-B6Si may be obtained by removing Li from the synthesized LiB6Si, that is, by imitating the preparation of Si24 and T-Graphene C4. The structure of Cmca-B6Si is a covalent three dimensional framework linked by B12 icosahedrons and Si atoms. The analysis of band structure and density of states reveals that Cmca-B6Si is metallic because of the partially occupied 2p and 3p electrons of B and Si atoms, respectively. The electron orbitals reveal that Cmca-B6Si has a novel two-dimensional metallicity. This study gives a fundamental investigation on the structural, phonon, and electronic properties of Cmca-B6Si.

Scale matters: The influence of structural inheritance on fracture patterns

Fracture systems are often geometrically invariant across a range of scales, but the impact of structural inheritance on this relationship is poorly understood. This paper shows how fracture orientations in sedimentary rocks vary at different scales when influenced by pre-rift basement structures. We use high-resolution unmanned aerial vehicle (UAV) orthophotos to map folds and fractures in the basement and cover rocks of the Gippsland Basin, southeast Australia. Outcrop-scale observations are compared with >1 km long faults previously interpreted from potential field data. We use length-coloured rose diagrams of fracture traces to compare trends in fracture orientations. Early Cretaceous syn-rift normal faults exhibit the same ENE-WSW trend at basin (>1 km) and outcrop (meters) scales. Pervasive outcrop-scale, subvertical, NNW-SSE striking joints record a subsequent regional shortening event, but at the basin scale this is only expressed as reverse reactivated ENE-WSW striking faults. Thus, fabrics and/or faults in the underlying basement exert significant control on the orientation of basin-scale fractures in the cover but appear to have limited influence on outcrop-scale fracture orientations. Our observations show that fracture systems influenced by structural inheritance are not scale-invariant, and that a proper understanding of structural architecture can only be achieved by analysing data that span multiple scales.

Alluvial sedimentation and tectono-stratigraphic evolution in a narrow extensional zigzag basin margin (northern Teruel Basin, Spain)

The northern part of the eastern margin of the extensional Neogene Teruel Basin (central-eastern Spain) consists of a non-linear, zigzag fault zone made of alternating ca. 2 km long, NNW-SSE trending segments and shorter NNE-SSW ones. Good outcrop conditions made possible a comprehensive integrated stratigraphic and structural study, especially focused on coarse clastic sediments deposited along the basin margin. Well-exposed stratal relationships with boundary faults, allowed the analysis of tectonic influence on sedimentation. Synsedimentary deformation includes growth faulting, rollover anticlines, and monoclines and associated onlap stratal terminations, angular unconformities, and other complex growth strata geometries. One of them is the onlap-over-rollover bed arrangement described here for the first time, which reveals the competition between tectonic subsidence and sedimentary supply. Both, the structural inheritance (dense Mesozoic fracture grid) and the dominant, nearly ‘multidirectional’ (σ1 vertical, σ2 ≈ σ3), Pliocene extensional regime with σ3 close to E-W, are considered to have controlled the margin structure and evolution. Tectono-stratigraphic evolution includes: (i) reactivation of inherited NNW-SSE faults and development of W-SW-directed small alluvial fans (SAF) while NNE-SSW segments acted as gentle relay ramp zones; (ii) progressive activation of NNE-SSW faults and development of NW-directed very small alluvial fans (VSAF); during stages i and ii sediments were trapped close to the margin, avoiding widespread progradation; (iii) linking of NNW-SSE and NNE-SSW structural segments, overall basin sinking and widespread alluvial progradation; (iv) fault activity attenuation and alluvial retrogradation. The particular structure and kinematic evolution of this margin controlled alluvial system patterns. Size of alluvial fans, directly set up at the border faults, was conditioned by the narrowness of the margin, small catchment areas, and proximity between faults, which prevented the development of large alluvial fans. The size of the relay zones, only a few hundred meters wide, acted in the same way, avoiding them to act as large sediment transfer areas and large alluvial fans to be established. These features make the Teruel Basin margin different to widely described extensional margins models.

Basement‐Cover Relationships and Their Along‐Strike Changes in the Linking Zone (Iberian Range, Spain): A Combined Structural and Gravimetric Study

AbstractContractional deformation in the transition between the Iberian and Catalan Coastal Ranges (Linking Zone) generated both thin‐skinned structures detached in low‐strength Triassic units and basement‐involved structures. To evaluate their extent and relative contribution to the overall structure, we carried out a study combining structural geology and gravimetry. New gravity data (938 stations) and density determinations (827 samples) were acquired and combined with previous existing databases to obtain Bouguer anomaly and residual Bouguer anomaly maps of the study area. Seven serial and balanced cross sections were built, their depth geometries being constrained through the 2.5‐D gravity modeling and the 3‐D gravity inversion that we accomplished. The residual Bouguer anomaly map shows a good correlation between basement antiforms and gravity highs whereas negative anomalies mostly correspond to (i) Meso‐Cenozoic synclines and (ii) Neogene‐Quaternary basins. Cross sections depict a southern, thick‐skinned domain where extensional, basement faults inherited from Late Jurassic‐Early Cretaceous times were inverted during the Cenozoic. To the north, we interpret the existence of both Triassic‐detached and basement‐involved deformation domains. The two deformation styles are vertically overlapped in the southernmost part of the Catalan Coastal Ranges but relay both across and along strike in the Eastern Iberian Range. These basement and cover relationships and their along‐strike variations are analyzed in terms of the interplay between structural inheritance, its obliquity to the shortening direction, and the continuity and effectiveness of Triassic décollements in the study area.

Centrin2 from the human parasite Toxoplasma gondii is required for its invasion and intracellular replication.

Centrins are EF-hand containing proteins ubiquitously found in eukaryotes and are key components of centrioles/basal bodies as well as certain contractile fibers. We previously identified three centrins in the human parasite Toxoplasma gondii, all of which localized to the centrioles. However, one of them, T. gondii (Tg) Centrin2 (CEN2), is also targeted to structures at the apical and basal ends of the parasite, as well as to annuli at the base of the apical cap of the membrane cortex. The role(s) that CEN2 play in these locations were unknown. Here, we report the functional characterization of CEN2 using a conditional knockdown method that combines transcriptional and protein stability control. The knockdown resulted in an ordered loss of CEN2 from its four compartments, due to differences in incorporation kinetics and structural inheritance over successive generations. This was correlated with a major invasion deficiency at early stages of CEN2 knockdown, and replication defects at later stages. These results indicate that CEN2 is incorporated into multiple cytoskeletal structures to serve distinct functions that are required for parasite survival.

Segmentation of Rifts Through Structural Inheritance: Creation of the Davis Strait

AbstractMesozoic‐Cenozoic rifting between Greenland and North America created the Labrador Sea and Baffin Bay, while leaving preserved continental lithosphere in the Davis Strait, which lies between them. Inherited crustal structures from a Palaeoproterozoic collision have been hypothesized to account for the tectonic features of this rift system. However, the role of mantle lithosphere heterogeneities in continental suturing has not been fully explored. Our study uses 3‐D numerical models to analyze the role of crustal and subcrustal heterogeneities in controlling deformation. We implement continental extension in the presence of mantle lithosphere suture zones and deformed crustal structures and present a suite of models analyzing the role of local inheritance related to the region. In particular, we investigate the respective roles of crust and mantle lithospheric scarring during an evolving stress regime in keeping with plate tectonic reconstructions of the Davis Strait. Numerical simulations, for the first time, can reproduce first‐order features that resemble the Labrador Sea, Davis Strait, Baffin Bay continental margins, and ocean basins. The positioning of a mantle lithosphere suture, hypothesized to exist from ancient orogenic activity, produces a more appropriate tectonic evolution of the region than the previously proposed crustal inheritance. Indeed, the obliquity of the continental mantle suture with respect to extension direction is shown here to be important in the preservation of the Davis Strait. Mantle lithosphere heterogeneities are often overlooked as a control of crustal‐scale deformation. Here, we highlight the subcrust as an avenue of exploration in the understanding of rift system evolution.

Role of rift structural inheritance in orogeny highlighted by the Western Pyrenees case-study

It is commonly accepted that many orogens form by contractional reactivation of earlier continental rifts or rifted margins. Therefore, to better understand orogenesis, it is important to also understand how rift domains and their associated structures are incorporated into orogens.We investigate the role of rift structural inheritance during orogeny using the Western Pyrenees as a case-study. To achieve our aim, we use a kinematic forward lithosphere deformation model (RIFTER) to produce flexural isostatically compensated as well as balanced cross-sections showing the structural and stratigraphic development of both the rift and orogenic stages of the Western Pyrenees. The cross-section produced extends from the Northern to the Southern Foreland Basins and crosses the Mauléon-Arzacq Basin.Our modelling results show how rift-domains and their faults are sequentially reactivated and incorporated into the present-day Western Pyrenees architecture. Based on the results from our case-study, we identify a sequence of tectonic stages separated by critical events that record the transition between different tectonic styles by which lithosphere is deformed. The pre-orogenic extensional stage is characterized by a hyper-extended rift system that eventually led to exhumed mantle. This constitutes the pre-orogenic template. The subsequent contractional tectonics consists of two stages: (i) the inversion of the hyper-extended rift system reactivating extensional structures and (ii) the crustal shortening of the southern proximal rift domain.Results of the Western Pyrenees case-study may be used to understand the development of other Alpine-type collisional systems involving the sequential reactivation and inversion of former hyper-extended rift systems.