bluuebunny/crossref_metadata_2025 huggingface dataset:
Glacial thermohaline circulation states of the northern Atlantic: the compatibility of modelling and observations
Authors: BIGG G. R. , WADLEY M. R. , STEVENS D. P. , JOHNSON J. A.
Published: June 2010

Observational evidence from deep‐sea cores suggests that the ocean circulation during the last glacial cycle was highly variable, at times occupying states very different from those found today. Modelling can be used to dynamically constrain the possible circulation states compatible with observations, thus guiding both understanding of past climate but also the geographical and scientific thrust of future palaeoceanographic research. The Last Glacial Maximum has been extensively studied and here, using carbon isotopes, among other variables, the most likely thermohaline state consistent with palaeoclimatic data is constructed. Past and new modelling efforts for the Last Glacial Maximum are then examined, to contrast questions resolvable by the modelling/data comparison with those that remain unanswered. This shows modelling evidence to confirm the prevailing view of intermediate‐depth North Atlantic Deep Water being produced at the Last Glacial Maximum, in combination with deep water production around Antarctica. The potential sites for this deep and intermediate water production are defined by the basic state of the thermohaline circulation. However, their relative importance is a function of small perturbations in the surface temperature and salinity fields brought about by active coupling between the ocean and atmosphere. Regions where these water masses may have been produced at the Last Glacial Maximum are suggested.
40
Ar/
39
Ar, U–Pb, and Sm–Nd constraints on the timing of metamorphic events in the Maksyutov Complex, southern Ural Mountains
Authors: BEANE R. J. , CONNELLY J. N.
Published: June 2010

New
40
Ar/
39
Ar, U–Pb, and Sm–Nd data from 13 metamorphic samples constrain the formation and exhumation of the high-pressure Maksyutov Complex in the southern Uralide orogen. The Maksyutov Complex records the highest-pressure metamorphism in the southern Uralides, and is part of the thrust stack that composes the footwall beneath the Main Ural Fault. The new isotopic data from eclogite in the Lower Unit of the Maksyutov Complex include
40
Ar/
39
Ar data from phengite, U–Pb data from rutile and apatite and Sm–Nd data from garnet, clinopyroxene, rutile and apatite. These data indicate that eclogite–facies metamorphism occurred in the Mid-Devonian Epoch (
c
. 380 Ma), corresponding with eastward subduction of the East European craton beneath the Magnitogorsk island arc. After partial exhumation, the Lower unit was juxtaposed
c
. 360 Ma (based on
40
Ar/
39
Ar white mica data) with the Middle and Upper units at mid-crustal levels during the development of a D
3
shear zone within the subduction zone. By the Late Carboniferous Epoch, the Maksyutov Complex was exhumed to upper-crustal levels, compatible with sedimentologic evidence that at this time the foreland thrust and fold belt began to form, and material was shed off it into the foreland basin.
An Early Ordovician age for the Annascaul Formation of the SE Dingle Peninsula, SW Ireland
Authors: TODD SIMON P. , CONNERY CAROL , HIGGS KENNETH T. , MURPHY FINBARR C.
Published: June 2010

The phyllitic mudrocks, quartz wacke sandstones and mélange units of the Annascaul Formation in the SE Dingle Peninsula, SW Ireland have been previously assumed to be Silurian in age, similar to overlying fossiliferous Wenlock rocks of the Ballynane Member. The contact between the Ballynane Member and the underlying Annascaul beds is either faulted or unconformable , and the Annascaul mudrocks contain two or more cleavages not present in the Silurian Ballynane and younger strata. The Ballynane Member is therefore differentiated from the Annascaul Formation by upgrading the proven Wenlock Ballynane beds to formational status. Grey and black mudrocks in the Annascaul Formation have yielded diagnostic palynomorph assemblages indicative of an Early Ordovician age. The Annascaul Formation invites comparison with similar Early Ordovician rocks, south of the putative trace of the Iapetus Suture, in SE and eastern Ireland, in the English Lake District, and in central Newfoundland.
40
Ar/
39
Ar age of the Cabo de Gata volcanic series and displacements on the Carboneras fault zone, SE Spain
Authors: SCOTNEY P. , BURGESS R. , RUTTER E. H.
Published: June 2010

The SW–NE-trending Carboneras fault zone of SE Spain separates a terrain comprising uplifted massifs of the metamorphic basement of the Betic Cordilleras and intervening Neogene sedimentary basins, from the Cabo de Gata volcanic series. Along the southeastern boundary of the Carboneras fault, Burdigalian marls and tuffs, mark the beginning of the volcanic episode, rest unconformably on the basement, and were tilted to the vertical during the earliest stages of movement on the fault zone.
40
Ar/
39
Ar dating of hornblende grains and igneous clasts from the tuffs constrain the onset of the volcanic episode at 21 Ma, some 4 Ma earlier than previously reported. Volcanic rocks higher in the sequence that overstep unconformably onto the southern edge of the fault zone yielded an age of 11 Ma, thus constraining the earliest episode of motion on the fault zone between these age limits. The main phase of left-lateral strike-slip movement on the Carboneras fault may be later than this time. Movements on more northerly strands of the fault zone, including the uplift of the Sierra Cabrera basement block to the NW, continued at least through Pliocene times. The onset of volcanism is broadly coeval with the unroofing of the orogen by extensional collapse, and supports earlier inferences of very rapid rates of uplift and cooling of the basement rocks.
Contrasting modes of reactivation in the Outer Hebrides Fault Zone, northern Barra, Scotland
Authors: MACINNES E. A. , ALSOP G. I. , OLIVER G. J. H.
Published: June 2010

The gently ESE-dipping Outer Hebrides Fault Zone may be traced for
c
. 170 km through the Lewisian gneisses of northwestern Scotland and defines broad, arcuate swings in strike from NE–SW to almost north–south. This study evaluates the kinematic evolution of the fault zone within the hinge region of such a strike swing exposed in the small isles north of Barra. New structural mapping of this area has concentrated on the geometry, kinematic significance and the relative age of different structural elements of the fault zone, and provides a comparison with the better known tectonics of the northern portions of the Outer Hebrides Fault Zone. Hitherto unrecognized top-to-the-NW ductile thrusting in this southern portion of the fault zone, coupled with abundant evidence of extensional reactivation and lack of sinistral strike-slip in phyllonites as reported further north, suggests that the present segmented and arcuate geometry is a primary feature of the fault system. The original thrust template governed the subsequent reactivation and relative importance of both late Caledonian strike-slip and extensional collapse components. Inherited structural architectures may thus provide geometric constraints on the nature and patterns of subsequent reactivation and tectonism.
U–Pb geochronology of Neoproterozoic and Caledonian tectonothermal events in the East Greenland Caledonides
Authors: WATT G. R. , KINNY P. D. , FRIDERICHSEN J. D.
Published: June 2010

The East Greenland Caledonides occupy a crucial position in plate-tectonic reconstructions of the Late Mesoproterozoic to Early Neoproterozoic Grenville–Sveconorwegian belt. We present new field and isotopic data from the northern Stauning Alper which indicate that the 1050–930 Ma history of the area was characterized by deposition of extensive clastic sequences. Sources of detritus were dominated by rocks of Mesoproterozoic age, with only limited contributions from Archaean sources, suggesting deposition at a distance from the present Caledonian foreland. A Neoproterozoic granite (938±13 Ma) provides evidence for thermal perturbation at a time of extensional collapse and uplift recorded in NW Scotland, the Grenville Belt of Canada, Labrador and the Sveconorwegian of SW Sweden and southern Norway. Widespread anatexis in the northern Stauning Alper at
c.
 430–425 Ma resulted from both collisional melting and decompression melting on uplift contemporaneous with the early part of orogenic collapse of the Caledonian Fold Belt. Caledonian deformation was focused at the zone of most extensive granite emplacement. Isotopic evidence suggests that Caledonian granites, previously thought to be entirely post-kinematic, actually predate late Caledonian extension.
Climatic evolution on the southeastern margin of the Tethys (Negev, Israel) from the Palaeocene to the early Eocene: focus on the late Palaeocene thermal maximum
Authors: BOLLE M. P. , PARDO A. , ADATTE T. , VON SALIS K. , BURNS S.
Published: June 2010

During the early Palaeocene (zones P1 to P2), the southeastern Tethyan margin experienced a warm and humid climate with high rainfall as indicated by the abundance of kaolinite within marine sedimentary rocks. Subsequently, in Zone P2, arid climatic conditions evolved in the coastal basins of the southern Tethys margin as indicated by the gradual disappearance of kaolinite and the increased abundance of palygorskite and sepiolite. Arid climatic conditions persisted during the Selandian and Thanetian (late Palaeocene) and reached a maximum in the Ypresian (early Eocene). During the late Palaeocene thermal maximum, warm climatic conditions were associated with increased aridity and led to sea surface warming, though not bottom water warming, as suggested by the planktic δ
18
O excursion observed at the Zomet Telalim basin (Negev, Israel). Strongly reduced surface productivity accompanied by unusually light δ
13
C are associated with the late Palaeocene thermal maximum in the Negev as well as globally.
Active normal fault evolution in Greece revealed by geomorphology and drainage patterns
Authors: GOLDSWORTHY MARY , JACKSON JAMES
Published: June 2010

Active normal fault systems in Greece are associated with characteristic geomorphology and drainage patterns that are recognizable in satellite images and digital topography. Some allowance must be made for the nature of the footwall rocks, which can exert an important influence on these patterns, and we examine the three main types in Greece: hard Mesozoic limestone, relatively soft schist, volcanic rocks or flysch, and very soft Neogene sediments. Drainage and geomorphology can be used to identify active faults that were previously unknown, but can also reveal information about Plio-Quaternary fault evolution and interaction that may be inaccessible by other means. We illustrate such processes with examples showing the migration of normal fault systems into their hanging walls, and the change in normal faulting activity from NW–SE faults to E–W faults, both of which are common in Greece.
Tectonics in the eastern central Patagonian Cordillera (45°30′–47°30′S)
Authors: SUÁREZ MANUEL , DE LA CRUZ RITA
Published: June 2010

A subhorizontal angular erosional unconformity that separates subhorizontal Upper Palaeocene–Lower Eocene fluvial deposits of the Ligorio Márquez Formation from folded and faulted Lower Cretaceous tuffs and sedimentary rocks in the area south of Chile Chico, in the northern Patagonian fold-and-thrust belt of southern Chile (46°45′S), indicates tectonism prior to the previously recognized post-Early Miocene contractional event. Similar observations between latitudes 45°30′ and 47°30′S in Argentina support the existence of a pre-Palaeocene–Eocene contractional tectonic phase and, locally, of a late Early Cretaceous event. This indicates that the northern Patagonian fold-and-thrust belt includes structures earlier than previously thought, probably masked by the later Neogene ones. The timing of this earlier tectonism is not precisely known, beyond being pre-Upper Palaeocene–Lower Eocene and post-Barremian. One possibility is that it may be the earlier stages of a progressive deformation that in its later stages is represented by the post-Lower Miocene tectonism previously documented in the region. In this case it may represent the latest Cretaceous?–Palaeocene major contractional tectonism and uplift well documented along the southernmost Patagonian Cordillera, south of latitude 51°S. The Upper Palaeocene–Lower Eocene Ligorio Márquez Formation may represent the first accumulation in a foreland (wedge top) basin developed east of the orogenic front. Subsequently, and probably during the Middle Miocene, these beds were folded and faulted during the tectonism that generated the foreland basin where the fluvial deposits of the Galera Formation accumulated. Different speculative scenarios for the origin of this compression can be invoked depending on its age.
Ludlow (late Silurian) oceanic episodes and events
Authors: JEPPSSON LENNART , ALDRIDGE RICHARD J.
Published: June 2010

Biotic and sedimentological cycles in the late Silurian are closely similar to those recognized in the early Silurian. They are explained here by alternations between primo and secundo conditions, the former being characterized by cold dense oceanic bottom waters and high nutrient supply, and the latter by salinity-dense bottom waters and diminished nutrient supply. The lithological pattern, together with the turnover of conodont faunas and of other fossil groups, permits the identification of a sequence of episodes and events in the Ludlow following the Klinte Secundo Episode, which developed in the latest Wenlock: The Sproge Primo Episode, the Linde Event, the Etelhem Secundo Episode, the Havdhem Primo Episode, the Lau Event, the Hoburgen Secundo Episode and the Klev Secundo–Primo Event, continuing into the earliest Přídolí. Testing of this model against others that invoke a primary sea-level control is marred by the current imprecisions of biostratigraphical correlation.
The influence of basement structure on the evolution of the Taranaki Basin, New Zealand
Authors: MUIR R. J. , BRADSHAW J. D. , WEAVER S. D. , LAIRD M. G.
Published: June 2010

The Taranaki Basin, situated offshore western New Zealand, is one of several large sedimentary basins formed during the Late Cretaceous in response to break-up of the palaeo-Pacific margin of Gondwana. A review of published structural, stratigraphic and geochronological data indicates that NE to NNE striking basement faults, generated during Palaeozoic to Mesozoic terrane accretion along the Gondwana margin, have strongly influenced the development of the basin. The main basin-bounding faults, the Cape Egmont Fault Zone and the Taranaki Fault, correspond to the boundaries of a narrow belt of plutonic rocks known as the Median Tectonic Zone. Geological data from onshore South Island suggests that right-lateral movement occurred along the boundaries of the Median Tectonic Zone during the Early Cretaceous. From the Late Cretaceous to Early Tertiary, NE to NNE striking normal faults within the Taranaki Basin controlled deposition in a series of en-echelon half-grabens and sub-basins. Many of the normal faults were later reactivated during a phase of compressional deformation associated with the development of the Australian-Pacific plate boundary through New Zealand. Reverse movement on the Taranaki Fault began in the early Miocene and deformation propagated westward reaching the Cape Egmont Fault Zone in the late Miocene to early Pliocene.
The eastern Palmer Land shear zone: a new terrane accretion model for the Mesozoic development of the Antarctic Peninsula
Authors: VAUGHAN ALAN P. M. , STOREY BRYAN C.
Published: June 2010

A major ductile fault zone, the eastern Palmer Land shear zone, has been identified east of the spine of the southern Antarctic Peninsula. This shear zone separates newly identified geological domains, and indicates that during Late Jurassic terrane accretion and collision, two and possibly three separate terranes collided, resulting in the Palmer Land orogeny. The orogeny is best developed in eastern Palmer Land and eastern Ellsworth Land. There, shallow-marine sedimentary rocks of the Latady Formation, and a metamorphic and igneous basement complex of possible Lower Palaeozoic to pre-Early Jurassic age, are thrust and folded. This forms an arcuate, east-directed, foreland, fold and thrust belt up to 100 km wide and 750 km long, parallel to the axis of the Antarctic Peninsula. The newly identified Antarctic Peninsula domains include: (1) a parautochthonous Eastern Domain that represents part of the margin of the Gondwana continent, comparable to the Western Province of New Zealand, the Ross Province superterrane of Marie Byrd Land, the Eastern Series of south-central Chile, the Pampa de Agnía and Tepuel rocks of north Patagonia, and the Cordillera Darwin rocks of Tierra del Fuego, (2) a suspect Central Domain that represents an allochthonous, microcontinental, magmatic arc terrane, comparable to the Median Tectonic Zone of New Zealand, the Amundsen Province superterrane of Marie Byrd Land, and Coastal Cordillera of north Chile and (3) a suspect Western Domain, with strong similarities to the Eastern Province of New Zealand, Western Series of south-central Chile, and Chonos metamorphic complex of north Patagonia, that represents either a subduction–accretion complex to the Central Domain, or another separate crustal fragment. Although an allochthonous terrane hypothesis for the Antarctic Peninsula remains to be fully tested, this has much in common with models for the New Zealand and South American parts of the Pacific margin of Gondwana. The identification of a potential allochthonous terrane–continent collision zone allows us to define the edge of the Gondwana continent in the Antarctic Peninsula sector of the supercontinent margin, which has implications for Mesozoic reconstructions of Gondwana.
Detrital zircon geochronology and provenance of the Torridonian, NW Scotland
Authors: RAINBIRD ROBERT H. , HAMILTON MICHAEL A. , YOUNG GRANT M.
Published: June 2010

Between 30 and 50 single detrital zircons from each of four specimens of the Stoer Group and two specimens from the unconformably overlying Torridon Group were analysed on the GSC SHRIMP II ion probe.
207
Pb/
206
Pb ages of zircons from the Stoer Group range between 3.00 and 1.74 Ga with 95% concentrated between 2.93 and 2.48 Ga. The Bay of Stoer Formation has a small mode
c.
 2.55 Ga, matching overgrowth ages on some older grains. A few grains between 1.92 and 1.74 Ga occur in each of the Stoer Group specimens. These data are consistent with conventional provenance information and sedimentology, which indicate that the bulk of the Stoer Group probably was derived from local basement of the Lewisian Gneiss Complex and that deposition occurred adjacent to basin-margin growth faults. The two Torridon Group samples have similar detrital zircon age profiles with distinctive modes at 1.80 Ga, 1.66 Ga and 1.10 Ga, interpreted to represent sources of Ketilidian, Labradorian and Grenvillian affinity, respectively. A less well defined cluster
c.
 2.85–2.55 Ga reflects reworking of the underlying Stoer Group and possibly direct contribution from the Lewisian Gneiss Complex. The youngest concordant detrital zircon yields a maximum age of 1060±18 Ma for the Torridon Group (Applecross Formation). Our data, together with palaeocurrents from the Applecross Formation, suggest that the Torridon Group could have been deposited by a late to post-Grenvillian intermontane or foreland trunk river system flowing northeasterly, parallel to the Grenvillian orogenic belt.
A mineralogical and fluid inclusion study of the Harberton Bridge Fe–Zn–Pb deposit, County Kildare, Ireland
Authors: TRUDE K. J. , WILKINSON J. J.
Published: June 2010

The Harberton Bridge deposit is located 2 km NW of the Lower Palaeozoic Kildare inlier in east central Ireland and represents one of a number of small, breccia-hosted Fe–Zn–Pb deposits that occur in the Kildare district. Widely regarded as an example of Mississippi Valley-type mineralization, the Harberton Bridge deposit provides important clues regarding the origin of the carbonate-hosted Zn–Pb deposits of the Irish orefield as a whole. Mineralization was studied in core using cathodoluminescence, transmitted and reflected light microscopy and fluid inclusion microthermometry. Fluid inclusions from calcite associated with sphalerite–galena–marcasite mineralization have homogenization temperatures in the range 45–69°C and salinities mainly between 12 and 17wt% NaCl equivalent. The data obtained suggest that the Harberton Bridge deposit formed from a single, low temperature (<80°C), moderate salinity fluid, considered to be a cooler version of the higher temperature fluids involved in mineralization at all of the economic Irish deposits. The inferred common fluid origin with the major deposits confirms the position of the Kildare district as representative of an end-member of mineralization styles in the Irish orefield. The differences in style are attributed to a late timing of mineralization, absence of abundant biogenic H
2
S and the involvement of a relatively shallowly basement-circulated, low temperature orefluid.
U–Pb geochronology of the Fort Augustus granite gneiss: constraints on the timing of Neoproterozoic and Palaeozoic tectonothermal events in the NW Highlands of Scotland
Authors: ROGERS G. , KINNY P. D. , STRACHAN R. A. , FRIEND C. R. L. , PATERSON B. A.
Published: June 2010

The West Highland granite gneiss suite in Inverness-shire, Scotland, represents a series of S-type, anatectic granites formed by partial melting of host Neoproterozoic metasediments of the Moine Supergroup. U–Pb (SHRIMP) dating of zircons from a member of the suite, the Fort Augustus granite gneiss, indicates that the granitic protolith to the gneiss was intruded at 870±30 Ma. This is indistinguishable from the published age determined by the same method for the Ardgour granite gneiss at Glenfinnan, thus supporting the assumption that the various members of the West Highland granite gneiss are part of a single intrusive suite. The spread of ages from the zircon cores (1626–947 Ma) is interpreted to indicate a Proterozoic source terrain for the Moine sediments that were later melted to form the granitic protolith. A U–Pb age of 470±2 Ma obtained for titanite in the Fort Augustus granite gneiss is interpreted to date amphibolite-facies metamorphism during the early to mid-Ordovician Grampian Orogeny. The emerging similarity in the timing of this event either side of the Great Glen Fault implies that this structure does not juxtapose crustal blocks with significantly different histories with respect to the Grampian Orogeny.
Late Oligocene volcanism and extension in the southern Red Sea Hills, Sudan
Authors: KENEA N. H. , EBINGER C. J. , REX D. C.
Published: June 2010

The temporal and spatial relationships between Cenozoic extension in the Red Sea and flood basalt volcanism in the Ethiopian plateau region were poorly understood along the Red Sea Hills region of Sudan. Rift basins in the Red Sea area developed in terranes accreted in Pan-African time, and it is believed that some of these ancient sutures controlled later Red Sea rifting. The objectives of field, remote sensing and geochronological studies of the southern Red Sea Hills near the Sudan–Eritrea border were to constrain the geometry and kinematics of extension, the timing of volcanism, and the structural relationship between Cenozoic and Pan-African faults. Basaltic volcanism began at about 31 Ma in the Derudeb region, coincident with the widespread flood basaltic volcanism in Ethiopia and Yemen associated with the Afar plume, suggesting a causal link. Felsic lavas erupted onto a faulted erosional surface at about 29 Ma, based on
40
Ar/
39
Ar step heating results on feldspar separates. The original form of these basins has been modified by subsequent faulting, Red Sea rift flank uplift, and erosion. Structural patterns indicate that extension increases eastward toward the Red Sea, with stratal dips of up to 35° in the Adar Ribad region, but most of this fault block rotation post-dates the rhyolite eruptions. The location of the Odi and Adar Ribad basins, and the reactivation of segments of Pan-African shear zones of the Baraka suture suggest that the development of these basins was influenced by pre-existing crustal shear zones, although some faults and dykes cross-cut other basement structures.
Cambrian palaeomagnetic data from Baltica: implications for true polar wander and Cambrian palaeogeography
Authors: TORSVIK TROND H. , REHNSTRÖM EMMA F.
Published: June 2010

A reliable Early Cambrian (
c.
 535 Ma) and a preliminary Late Cambrian (
c.
 500 Ma) palaeomagnetic pole from Baltica (Sweden) overlap within uncertainty, and they are also broadly compatible with Vendian (
c.
 583 Ma) palaeomagnetic data. Apparent polar wander for Baltica amounts to less than 25° between 583 and 500 Ma and, therefore, negates recent speculations that the Earth tipped 90° during the Early Cambrian (true polar wander).

Throughout Vendian and Cambrian times, Baltica lay at southerly latitudes (
c.
 30–60°S). Baltica was geographically inverted, and present-day northern Baltica faced the NW margin of Gondwana which covered the south pole. Laurentia-Eastern Baltica and Laurentia–West Gondwana were separated by the Iapetus Ocean, while the Ægir Sea separated Western Baltica from the Taimyr region of Siberia. During the Cambrian Baltica probably moved eastward along the Gondwana margin, and by
c.
 515–520 Ma subduction in the Ægir Sea was initiated. A major event is recognized in Late Cambrian or Early Ordovician times (
c.
 500–478 Ma) when Baltica must have undergone a 55° counter-clockwise rotation in
c.
 22 million years (3°/Ma). We relate this to the early Caledonian Finnmarkian Orogeny which involved arc–continent collision following subduction.
Large-scale slumping deduced from structural and sedimentary features in the Lower Palaeozoic Anglo-Brabant fold belt, Belgium
Authors: DEBACKER T. N. , SINTUBIN M. , VERNIERS J.
Published: June 2010

Distinguishing slump folds from tectonic folds in poorly exposed areas can be difficult, especially when the scale of the slump folds exceeds outcrop scale. In the southeastern part of the single-phase deformed, Lower Palaeozoic Anglo-Brabant fold belt a comparison of cleavage/fold relationships and stratigraphic polarity shows that a 200 m thick interval of middle Caradoc fine-grained turbidites in the core of a large synform was overturned prior to tectonic deformation. This overturning is attributed to large-scale slumping, which was most likely a result of middle Caradoc seismic activity.

The exposed portion of the large slump sheet contains only a few small slump folds and intraformational breccias, making up less than 5% of the exposed thickness. If the beds were not overturned, large-scale slumping would never be suspected and the small slump folds would probably be interpreted as localized features in an overall ‘stable’ sedimentary pile. This may explain why so few ancient large-scale slides and slumps have been reported: the small amount of internal deformation makes them very difficult to recognize, especially when dealing with poorly exposed areas. As such, large ancient slides and slumps may be more common than suggested by the geological literature.
Stacking pattern of cyclic carbonate platform strata: Lower Cretaceous of southern Apennines, Italy
Authors: RASPINI ARTURO
Published: June 2010

Detailed sedimentological analysis of Aptian/Albian shallow-water carbonate platform strata from Monte Faito, southern Italy, reveal composite sea-level change. The organization of the lithofacies and their related diagenetic overprint have allowed the identification of 50 elementary cycles. They often show exposure-related diagenetic features superimposed on subtidal deposits, suggesting drops of relative sea level.

Elementary cycles are grouped into 16 bundles forming six superbundles. The hierarchical organization of the cycles are interpreted to be related to composite eustatic sea-level fluctuations driven by the Earth’s orbital perturbation in the Milankovitch frequency band. Moreover, the systematic variation of superbundle thickness and the general evolution of the lithofacies reflects variations of accommodation potential defining longer-term environmental changes.

Different lithofacies forming elementary cycles are frequently separated by bedding planes that, when viewed in a sequence stratigraphic context, are interpreted as transgressive surfaces, maximum flooding surfaces or sequence boundaries. This allows the recognition of lowstand, transgressive and highstand deposits in the cyclic units.

Considering both the bundle/superbundle ratio and the sequence stratigraphic interpretation of the superbundles, a chronostratigraphic diagram illustrating both gaps at bundle level and their expected location along the section was created. It establishes that the section developed over about 2.4 Ma.
New sedimentological and structural data from the Ecemiş Fault Zone, southern Turkey: implications for its timing and offset and the Cenozoic tectonic escape of Anatolia
Authors: JAFFEY N. , ROBERTSON A. H. F.
Published: June 2010

The left-lateral Ecemiş Fault Zone, with a newly estimated displacement
c.
 60 km, records important strike-slip deformation within Anatolia, prior to and during the Plio-Quaternary tectonic escape of the Anatolian ‘microplate’ along the well recognized right-lateral North Anatolian and the left-lateral East Anatolian Fault Zones. Mesozoic shallow-water carbonate deposition on the northern passive margin of a Tauride microcontinent was followed by southward ophiolite emplacement in latest Cretaceous time. Late Eocene final closure of one, or several, ocean basins within Central Anatolia further north caused further deformation, including large-scale north-vergent thrusting. Regional orogenic exhumation in the Oligocene to Mid-Miocene was accompanied by deposition of non-marine red-beds adjacent to the future Ecemiş Fault Zone and adjacent basins. Through-going left-lateral strike slip was initiated by the Mid-Miocene (or slightly earlier) and became become more transtensional/extensional during Pliocene–Quaternary time. Minor continuing left-lateral strike-slip is documented by stream offsets on major Plio-Quaternary alluvial fans shed from master fault scarps. The Ecemiş Fault Zone is, thus, identified as a regionally important strike-slip fault zone that was initially (Mid–Late Miocene) dominated by strike-slip and later (Pliocene–Quaternary) by extension.
Construction of a Palaeogene tide-dominated shelf: influence of Top Chalk topography and sediment supply (Wessex Basin, UK)
Authors: NEWELL ANDREW J.
Published: June 2010

Palaeogene siliciclastic sediments (Reading and London Clay Formations) in the Wessex Basin record an upward change through four tidally influenced deposition systems. The lowest (Reading Formation) was deposited in estuarine and coastal plain environments. The overlying London Clay records discrete upward changes from deltaic, to mixed tidal flat, to tidal sandsheet (‘Bagshot Sands’). Erosional topography on the Top Chalk surface had an important control on deposition: (1) topographic lows controlled the initial sites of marine flooding and sedimentation; (2) lows would have acted as conduits for sediment delivery; (3) lows created additional accommodation by the compaction of thick mud fills; (4) lows may have formed preferential sites for delta growth. As topography was reduced by sediment infill, depositional units tended toward more sheet-like geometries. Heavy minerals reveal that an upward progradational/aggradational trend and the development of more sand-rich facies are related to a change in provenance toward sand-rich Cornubian sources.
Generic relationships in the mineral-chemical stratigraphy of turbidite sandstones
Authors: HURST ANDREW , MORTON ANDREW C.
Published: June 2010

Ratios of abundance of hydraulically and diagenetically equivalent heavy minerals (apatite:tourmaline, garnet:zircon) from deep-water sandstones, of similar age and derived from the same overall source terrain, have contrasting trends. The differences are explained by contrasting sediment transport paths. Deep-water sandstones with fluctuating heavy mineral ratios are inferred to be derived directly from alluvial basins, bypassing any contemporaneous shallow marine shelf. Deep-water sandstones with homogeneous heavy mineralogy are inferred to be fed by sediment that originally accumulated on shallow marine shelves but was subsequently mixed.
The structure of the Faeroe–Shetland Trough from integrated deep seismic and potential field modelling
Authors: SMALLWOOD J. R. , TOWNS M. J. , WHITE R. S.
Published: June 2010

In the Faeroe–Shetland Trough, thick basaltic lava units make it difficult to image underlying structure with conventional seismic profiles. We have therefore used potential field modelling to estimate crustal structure along the FAST deep seismic line and other regional transects. We introduce the additional constraints of crustal isostasy to gravity models and the observations of the polarity of magnetic remanence within the lava pile to magnetic models. The crustal stretching factor ranges up to 3 along the FAST traverse, and our model also suggests that a sedimentary section with a thickness of up to 3–4 km is present beneath a
c.
 2 km basalt layer on the Faeroese shelf.
Combined escape tectonics and subduction rollback–back arc extension: a model for the evolution of Tertiary rift basins in Thailand, Malaysia and Laos
Authors: MORLEY C. K.
Published: June 2010

The Tertiary rift basins of Thailand and adjacent countries show considerable variability in the timing of rift initiation, termination, the timing and magnitude of thermal subsidence, and the timing and intensity of inversion episodes. The rift basins developed on continental blocks that were extruded southeastwards. Hence their development must be tied into Himalayan extrusion tectonics. Current tectonic models propose that the Tertiary basins opened up as pull-apart basins associated with strike-slip faults. Published geochronology of strike-slip fault zone rocks, mapping of fault patterns in the Tertiary basins and mapped releasing-restraining bend geometries all indicate that in Thailand major sinistral strike-slip motion ceased at about 30 Ma, prior to the formation of most rift basins the Thailand. The effects of later dextral slip were minor and probably a result of reactivation during episodes of inversion during NW–SE to NE–SW (Himalayan) compression. Dextral slip was not responsible for opening most of the rift basins in Thailand. An alternative mechanism to open the rift basins is subduction rollback of the Indian plate to the west of Thailand. It is proposed that subuction rollback can help explain some of the characteristics of the rift basins such as non-uniform lithospheric extension, deep sag basins, and the diachronous onset and termination of rifting.
Structure of the Main Central Thrust zone and extrusion of the High Himalayan deep crustal wedge, Kishtwar–Zanskar Himalaya
Authors: STEPHENSON B. J. , SEARLE M. P. , WATERS D. J. , REX D. C.
Published: June 2010

The Main Central Thrust is a crustal-scale ductile shear zone between 1.5 and 3 km wide which places the Oligocene–Miocene metamorphic rocks of the High Himalayan zone south or SW over the unmetamorphosed or weakly metamorphosed rocks of the Lesser Himalaya. The high strain zone of the Main Central Thrust is coincident with an inverted metamorphic field gradient from biotite to kyanite grade over a structural thickness of 1500 m. Kyanite-grade rocks metamorphosed at 9.5–10 kbar were exhumed from depths of 33–37 km along the Main Central Thrust hanging wall and emplaced over Lesser Himalayan rocks never buried deeper than 10–12 km. Exhumation of the deepest buried kyanite-grade rocks occurred along the zone. Above the Main Central Thrust zone approximately 45 km width (28 km structural thickness) of the High Himalaya exposes sillimanite-grade gneisses, migmatites and 19.5–21.5 Ma old leucogranites formed at pressures between 4.5 and 7 kbar and depths of 16–25 km. A NE-dipping normal fault ductile shear zone at the top of the slab (Zanskar Shear Zone) shows condensed but right way-up isograds from sillimanite to chlorite grade over 2–400 metres structural thickness.
40
Ar/
39
Ar geochronology shows that most of the High Himalayan slab had cooled below 350°C by 16 Ma supporting models linking the two bounding faults of the High Himalaya both kinematically and temporally. There is no evidence of melting along the Main Central Thrust zone and the Himalayan leucogranites were generated 10–30 km structurally above the Main Central Thrust. Frictional heating along the Main Central Thrust could not therefore have played any role in generating the leucogranites. Thus far, there is little evidence for late Miocene reactivation along the Main Central Thrust, as seen elsewhere along the Main Central Thrust in Nepal.
Structure and tectonic development of the Ghab basin and the Dead Sea fault system, Syria
Authors: BREW GRAHAM , LUPA JACEK , BARAZANGI MUAWIA , SAWAF TARIF , AL-IMAM ANWAR , ZAZA TAREK
Published: June 2010

We examine the structure and evolution of the Ghab basin that formed on the active, yet poorly understood, northern segment of the Dead Sea transform fault system. The basin formed in Plio-Quaternary time at a complex step-over zone on the fault. Subsidence occurred along cross-basin and transform-parallel faults in two asymmetric depocentres. The larger depocentre in the south of the basin is asymmetric towards the east, the margin along which most active transform displacement apparently occurs. The Syrian Coastal Ranges, located directly west of the Ghab basin, are a consequence of Late Cretaceous and Cenozoic regional compression, heavily modified by the Dead Sea fault system and Ghab basin formation. We prefer a model whereby the Dead Sea fault system in northwest Syria developed in Plio-Quaternary time, consistent with previously proposed models of two-phase Dead Sea fault system movement and Red Sea spreading.
Sequence stratigraphy and orbital forcing in Permian (Rotliegend) desert deposits: a discussion
Authors: BAILEY R. J.
Published: June 2010

Rotliegend sequence stratigraphy in the Southern Permian Basin suggests climatically forced fluctuations in the level of an expanding playa lake system. The associated facies changes are abrupt and define essentially isochronous sequence boundaries. Spectral analyses of gamma ray logs have indicated that individual sequences display internal cyclicity consistent with orbital (Milankovitch) forcing. Confirmatory results have been reported from the spectral analysis of field logs from the continental Permian Brodick Beds of the Isle of Arran. These studies claim that, since the cycles are orbitally forced, they have chronostratigraphic significance. However, they are based on dubious assumptions concerning the unvarying rate and continuity of deposition of the sequences in question. In the case of the Southern Permian Basin, the assumption is applied to c. 50 m units, but the result is an implausible chronostratigraphic model. For the Brodick Beds, the assumption is applied to a 675 m succession and there is a crucial ambiguity in the relationship between the lithostratigraphic cycles and the Permian orbital cycles. The studies do not provide persuasive evidence of the consistent encoding of Milankovitch orbital cycles in Permian desert deposits.
Relationships between hornblende K–Ar ages, chemical composition and hydrogen isotopes, Connemara, western Ireland: evidence for a massive extinct hydrothermal system
Authors: JAPPY T. G. , LEAKE B. E. , FALLICK A. E.
Published: June 2010

Major element compositional analyses, K–Ar ages, δD‰ and δ
18
O‰ values for 30 zoned and unzoned hornblendes from Dalradian amphibolites and metagabbros, mostly in north Connemara are reported. Although the cooling ages are expected from previous U–Pb zircon studies to be
c.
 475–450 Ma, the results obtained are from 556±6 to 410±9 Ma with an average of 470 Ma. Fluid movements, probably at 275±15°C, i.e. much below Ar closure temperature for hornblende, erratically reset the ages, as is shown by a negative correlation of hornblende δD and age and a wide scatter of ages even within 2 m. The changes were implemented by H–D exchange between fluid and hornblendes in which ionic porosity,
Z
, influenced the loss of Ar and possibly its gain from the fluid to give the excess Ar found in some samples.
Z
is controlled by hornblende chemical composition. High Mg, Si and Mg/Fe and low Fe, Al, Ti, Na and particularly low K, amphiboles giving low
Z
values retained Ar more firmly and gained Ar more readily than compositions which had higher
Z
values, which gave younger ages. These range down to
c.
 400 Ma, being the age of the intrusion of the Galway Granite suite that initiated the fluid circulation. The scatter of ages is a consequence of incomplete equilibration, mainly because of the slow H–D exchange rate below 350°C and partly because the fluid permeated erratically in different areas and down cracks of all kinds, promoting irregular Ar movement. The meteoric fluid circulated through Connemara, the Galway Granite and at least some of the contiguous Silurian sediments of the South Mayo trough. These overlying sediments may have contributed to the water circulated in north Connemara which was slightly less negative δD than in central Connemara. For hornblende K–Ar ages to be a reliable measure of times of uplift and cooling, they need to be demonstrated to be free from the influence of hot fluids by showing no correlation of age with δD.
Intravenous cell therapy for acute renal failure with serum amyloid A protein-reprogrammed cells
Authors: Kelly Katherine J. , Kluve-Beckerman Barbara , Zhang Jizhong , Dominguez Jesus H.
Published: June 2010

Serum amyloid A protein (SAA), a prominent component of the acute-phase response, is strongly expressed in developing and repairing kidneys and promotes tubulogenesis. Accordingly, we reprogrammed relatively undifferentiated NRK52E cells with the mouse SAA1.1 gene and transplanted SAA-positive and -negative cells into rats with acute renal failure. We found that SAA-positive cells accelerated renal recovery in three models of acute renal failure: gentamicin nephrotoxicity, cisplatin-mediated renal injury, and ischemia-reperfusion renal injury. The dramatic improvement of renal failure was demonstrable within 2 days, consistent with an early paracrine effect. However, abundant donor cells were also found integrated in the healing tubular architecture after 7 days. We conclude that infusions of SAA-positive cells promote renal recovery after acute renal failure and offer a potentially powerful and novel therapy of renal failure.
Involvement of urinary proteins in the rat strain difference in sensitivity to ethylene glycol-induced renal toxicity
Authors: Li Yan , McLaren Marie C. , McMartin Kenneth E.
Published: June 2010

Ethylene glycol (EG) exposure is a common model for kidney stones, because animals accumulate calcium oxalate monohydrate (COM) in kidneys. Wistar rats are more sensitive to EG than Fischer 344 (F344) rats, with greater COM deposition in kidneys. The mechanisms by which COM accumulates differently among strains are poorly understood. Urinary proteins inhibit COM adhesion to renal cells, which could alter COM deposition in kidneys. We hypothesize that COM accumulates more in Wistar rat kidneys because of lower levels of inhibitory proteins in urine. Wistar and F344 rats were treated with 0.75% EG in drinking water for 8 wk. Twenty-four-hour urine was collected every 2 wk for analysis of urinary proteins. Similar studies were conducted for 2 wk using 2% hydroxyproline (HP) as an alternative oxalate source. Total urinary protein was higher in F344 than Wistar rats at all times. Tamm-Horsfall protein was not different between strains. Osteopontin (OPN) levels in Wistar urine and kidney tissue were higher and were further increased by EG treatment. This increase in OPN occurred before renal COM accumulation. Untreated F344 rats showed greater CD45 and ED-1 staining in kidneys than untreated Wistars; in contrast, EG treatment increased CD45 and ED-1 staining in Wistars more than in F344 rats, indicating macrophage infiltration. This increase occurred in parallel with the increase in OPN and before COM accumulation. Like EG, HP induced markedly greater oxalate concentrations in the plasma and urine of Wistar rats compared with F344 rats. These results suggest that OPN upregulation and macrophage infiltration do not completely protect against COM accumulation and may be a response to crystal retention. Because the two oxalate precursors, EG and HP, produced similar elevations of oxalate, the strain difference in COM accumulation may result more so from metabolic differences between strains than from differences in urinary proteins or inflammatory responses.
Planar cell polarity pathway regulates actin rearrangement, cell shape, motility, and nephrin distribution in podocytes
Authors: Babayeva Sima , Zilber Yulia , Torban Elena
Published: June 2010

Glomerular podocytes are highly polarized cells characterized by dynamic actin-based foot processes (FPs). Neighboring FPs form specialized junctions, slit diaphragms (SDs), which prevent passage of proteins into the ultrafiltrate. The SD protein complex is linked to cytoskeletal actin filaments and mutations in SD proteins lead to a dramatic change in cell morphology; proteinuria is accompanied by FP retraction and loss of SD structure. Thus, organization of the podocyte cytoskeleton is tightly linked to filtration barrier function. In a variety of cell systems, cytoskeleton arrangement is regulated by the planar cell polarity (PCP) pathway. PCP signals lead to the appearance of highly organized cellular structures that support directional cell movement and oriented cell division. Derangement of the PCP pathway causes neural tube defects and cystic kidney disease in mice. Here, we establish that the PCP pathway regulates the cytoskeleton of podocytes. We identify expression of core PCP proteins in mouse kidney sections and of PCP transcripts in murine and human cultured podocytes. The pathway is functional since Wnt5a causes redistribution of PCP proteins Dishevelled and Daam1. We also show that Wnt5a treatment changes podocyte morphology, alters nephrin distribution, increases the number of stress fibers, and increases cell motility. In reciprocal experiments, siRNA depletion of the core PCP gene Vangl2 reduced the number of cell projections and decreased stress fibers and cell motility. Finally, we demonstrate direct interactions between Vangl2 and the SD protein, MAGI-2. This suggests that the PCP pathway may be directly linked to organization of the SD as well as to regulation of podocyte cytoskeleton. Our observations indicate that PCP signaling may play an important role both in podocyte development and FP cytoskeleton dynamics.