bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of fine-grained sediment transport processes and products in the California Continental Borderland
Authors: Gorsline D. S. , Kolpack R. L. , Karl H. A. , Drake D. E. , Thornton S. E. , Schwalbach J. R. , Savrda C. E. , Fleischer P. 
Published: April 2008

Summary
The California Continental Borderland contains a series of margin basins which are sediment traps at increasing distance from the principal terrigenous and biological sediment sources located in the northern coastal areas. Terrigenous sediments are contributed during a short winter season from small steep coastal drainages. Sand content can be as much as 30–40% of the total contributed load. Silts and clays are sorted out of the river input by coastal wave action and distributed offshore by the seasonal ocean circulation systems. Suspended sediment moves to the basin floors via nepheloid plumes that are generated in the well mixed coastal waters and move offshore with the currents as surface, mid-depth and bottom turbid plumes. During times of low suspensate content in the dry season, lateral transport is dominant. At times of high sediment input and higher concentrations of fine suspensates in the coastal waters, cascading to successively deeper pycnoclines becomes an important process. Resuspension of fine sediments from the outer shelf substrate and the axes of submarine canyons by internal waves and tidally generated currents also contributes to the load of the bottom nepheloid plumes.
Large semi-fixed seasonal eddies in the Borderland surface circulation hold the suspended load in the northern sector of the borderland for several days to weeks. Zooplankters have ample opportunity to filter out this material and aggregate it into faecal pellets which rapidly fall to the local basin floors. The removal is sufficiently effective so as to deposit a minimum of 60% of the continental contribution within the northern inner zone of the borderland. High sedimentation rates in these basins promote mass-movement and also decrease the already low oxygen contents of basin floor water as a result of oxidation of the organic fraction of the suspended load. Primary sedimentation structures are preserved in these anaerobic basin floor environments. Mass-movements initiate mud turbidity currents that move to the central basin floors. Mass-movements include creep and sliding of thin sheets from low angle slopes. These effects are amplified following exceptional floods at intervals of around 30 years.
Fine-grained sediments associated with fan lobes: Santa Paula Creek, California
Authors: Bourrouilh R. , Gorsline D. S. 
Published: April 2008

Summary
Plio-Pleistocene slumps, debris-flow deposits, turbidites and hemipelagic sediments accumulated in the Ventura Basin to thicknesses of almost 2 km. The section exposed along Santa Paula Creek, California, contains at least six units of thick sandstones and conglomerates that represent fan lobes deposited at times of either tectonic pulses or minor climatic changes. Sections exposed in Adams Creek about 5 km west of the Santa Paula section suggest that the Santa Paula section was located on the fringes of these lobes. Gross sedimentation rates for the entire section are of the order of 1 m/1000 yrs. This is similar to the accumulation rates in the contemporary Santa Barbara Basin. The bulk of the intervening mudstones, siltstones and fine sandstones are thin-bedded (less than 10 cm thick) and represent interdistributary and basin plain facies. Mudstones are often laminated and the relatively sparse evidence of bioturbation suggests that the basin bottom waters were anoxic. Open connection over sills is evidenced by the discovery of the skeletal parts of a whale. The section illustrates the structures and associations of fine-grained sediments in a deep-water turbidite basin of high accumulation rate.
Hemipelagic chalks in a clastic submarine fan sequence: Miocene SW Turkey
Authors: Hayward A. B. 
Published: April 2008

Summary
The Miocene Salir Formation in SW Turkey is a 500 m thick dominantly terrigenous clastic succession deposited by turbidity currents and other mass-flow mechanisms on a series of small submarine fans. During intervals of non-clastic deposition hemipelagic chalk horizons up to 60 mm thick accumulated.
The chalks comprise disseminated planktonic and small benthonic foraminifera dispersed in a micrite matrix with abundant poorly preserved coccolith plates and other nannoplankton fragments. Biogenic sand and silt-sized particles form up to 20% of the rock. Carbonate content ranges from 55% to 95%. The non-carbonate component comprises dispersed clay platelets and in some beds silt-sized particles. The chalks range from structureless homogeneous units, to beds which show a wide range of sedimentary structures which suggest reworking of the slowly deposited hemipelagic ooze by bottom currents of fluctuating velocity.
The lateral and vertical distribution of the hemipelagic chalks reflects the area on the submarine fan on which they were deposited. Areas away from the main locus of deposition, for example interchannel areas in proximal sequences, and inactive mid-fan areas are characterized by frequent and often thick chalk beds. In active mid-fan and inner-fan channel areas hemipelagic chalks are scarce or absent.
Source rock potential of Bahamian Trough carbonates
Authors: Crevello P. D. , Patton J. W. , Oesleby T. W. , Schlager W. , Droxler A. 
Published: April 2008

Summary
The organic content of fine-grained carbonate muds deposited in the intraplatform basins and canyons of the Bahamas range between 0.1 and 2.6% total organic carbon (TOC). Geochemical analyses suggest some of these muds are a potential source for hydrocarbon. Interbedded with the carbonate muds are porous carbonate sands and gravels which can serve as local reservoirs or serve as conduits for hydrocarbons to migrate into carbonate slope and platform reservoir facies.
Ingeneral, periplatform oozes are lean (generally less than 0.5 to 1% TOC) whereas green muds, very likely the products of turbidity currents, have higher organic contents (0.5 to more than 2.5% TOC), but values of TOC vary considerably both within and between study areas. Tongue of the Ocean and Exuma Sound are less than 80 km apart but their average TOC values differ markedly, 1% and 0.33% respectively. Higher sedimentation rates in the Tongue of the Ocean are thought, in part, to be responsible for better preservation of organic matter.

In Tongue of the Ocean, cyclic variations in TOC are correlated with fluctuations of sea-level. High stands of sea-level are recorded by aragonite-rich muds with TOC on the average 0.5% higher than the calcitic periplatform oozes deposited during low stands of sea-level. Organic fractions of green muds have δ
13
C values (−16.4‰ to −13.9‰ vs PDB) which are similar to platform carbonates, whereas lighter δ
13
C values of periplatform oozes reflect mixing of organic material derived from platform and pelagic sources.

Rock-Eval analysis shows that the periplatform oozes are relatively rich in oxygen; this, along with their low organic contents, results in a poor source rock potential. The green muds range between type II (mixed gas and oil potential) and III (gas potential) source rocks, which, through favourable maturation, should generate hydrocarbons. Gas chromatographic analysis of organic matter evolved at relatively low temperatures (300°C) demonstrated that these immature sediments underwent vapourization and thermal cracking of relatively heat-sensitive or thermally labile material.
Sapropels and organic-rich variants in the Mediterranean: sequence development and classification
Authors: Anastasakis George C. , Stanley Daniel Jean 
Published: April 2008

Summary
Sapropel is the term often applied in a general manner to dark, organic-rich layers of late Quaternary age in the eastern Mediterranean. The DSDP Leg 42A studies have more precisely defined sapropel layers as those containing more than 2.0% organic carbon by weight, and sapropelic layers as those that contain between 0.5 and 2.0% organic carbon. The present study further focuses on extensive vertical and lateral petrological variations of these and associated organic-rich layers. Herein the different sediment lithofacies that form both sapropel and sapropelic sequences in radiocarbon-dated cores distributed throughout the basin are defined. Organic carbon and carbonate carbon content and their ratio are useful criteria; some sedimentary structures and textures also help define sediment types.
The recognition of the dominant vertical successions of lithofacies that form typical sapropel and sapropelic sequences is important; these provide further evidence that favour marked episodic water mass stratification and associated stagnation. The lithofacies succession typically includes the following, from base up: greyish mud becoming darker upward and passing into a grey ooze which is separated from the overlying dark grey to black sapropel (or sapropelic) layer by a sharp contact; the latter layer, in turn, is topped by a thin grey ooze and an orange-brown oxidized layer. These sediments, poor in benthonic faunas, are interbedded within lighter, well-oxygenated open marine lithofacies.
Sapropel and sapropelic sequences comprise sediment types which are largely hemipelagic in origin (suspension settling through the water column); variations within such vertical successions may be directly related to palaeoceanographic events. Regional study, however, reveals numerous variations displayed by these two sequences, and thus further classification of the different organic-rich layers is needed. Lithofacies members are sometimes absent, or poorly developed, or repeated as a result of transport processes (mostly gravity-flow mechanisms) and/or specific oceanographic conditions affecting a depositional site. On the basis of the above, we identify episapropel and episapropelic sequences. These are defined as highly irregular sequences which include sediment types that are locally introduced by sediment gravity-flows, commonly mud-carrying turbidity currents. A more accurate assessment of the diverse organic-rich sequences in cores across the basin helps us to better understand the nature of short-term stagnation-oxygenation cycles that affected the eastern Mediterranean, and may also shed light on some black shales of open marine origin preserved in the rock record.
Bioturbation in deep-sea fine-grained sediments: influence of sediment texture, turbidite frequency and rates of environmental change
Authors: Wetzel A. 
Published: April 2008

Summary

In the deep sea, burrowing infauna can adapt to variation in sediment texture within < 100–300 years. When there is continuous sedimentation, a continuous bioturbation process also takes place and the biogenic trace association found in the fossil record may be dominated by deeply penetrating burrows. A low-diversity trace fossil association (
Zoophycos
ichnofacies) is typical. On the other hand, when turbidites interrupt the continuous bioturbation process, a highly diverse trace fossil association is often found in the fossil state that also contains highly organized near-surface traces (
Nereites
ichnofacies). This biotope is usually controlled by the non-turbiditic sedimentation rate and the recurrence time of turbidites. Biogenic trace assemblages are mainly controlled by the nature of sedimentation and other environmental conditions rather than by water depth. Therefore, the widely accepted use of trace fossils as palaeobathymetric indicators in the deep sea may be restricted.
Submarine volcaniclastic rocks
Authors: Fisher Richard V. 
Published: April 2008

Summary
The type, relative abundance and stratigraphical relationships of volcanic rocks that comprise island volcanoes are a function of (i) depth of extrusion beneath water, (ii) magma composition, and (iii) lava-water interactions. The water depth at which explosions can occur is called the pressure compensation level (PCL) and is variable. Explosive eruptions that occur above the PCL and below sealevel can give rise to abundant hydroclastic and pyroclastic debris. Below the PCL, clastic material cannot form explosively; it forms from lava by thermal shock. The volcaniclastic products are widely dispersed in basins adjacent to extrusion sources by three principal kinds of marine transport processes. These are slides, sediment gravity flows and suspension fallout. Volcaniclastic debris can be derived in subaqueous and subaerial-to-subaqueous environments (i) directly from eruptions, (ii) from remobilization of juvenile volcaniclastics, or (iii) from epiclastic material which initially develops above sealevel.

Sediment gravity flows (fluids driven by sediment motion) exhibit the phenomenon of
flow transformation
. This term is used here for the process by which (i) sediment gravity flow behaviour changes from turbulent to laminar, or vice versa, within the body of a flow, (ii) flows separate into laminar and turbulent parts by gravity, and (iii) flows separate by turbulent mixing with ambient fluid into turbulent and laminar parts. Dominant kinds of subaqueous volcaniclastic sediment gravity flows are debris flows, hot or cold pyroclastic flows and turbidites. Fine grained material can be thrown into suspension locally during flow transformations or underwater eruptions, but thin, regionally distributed subaqueous fallout tephra is mostly derived from siliceous Plinian eruptions.
Intersection of a marginal basin with a continent: structure and sediments of the Bay of Plenty, New Zealand
Authors: Lewis K. B. , Pantin H. M. 
Published: April 2008

Summary
West of the Kermadec Trench and Arc, the Havre Trough is an actively spreading, oceanic marginal basin. Bathymetric, magnetic and seismic data indicate that it terminates against the lower slope off the Bay of Plenty, North Island, New Zealand. It is replaced on the adjacent upper slope, and on land, by the ensialic marginal basin known as the Taupo Volcanic Zone, which is part of the Hikurangi Plate Boundary System. The Taupo Volcanic Zone is offset about 50 km eastwards from the Havre Trough, by transform faults on the middle and lower slope. It is intersected on the upper slope, and its bounding faults are offset, by the northern end of the North Island Shear Belt.
The central part of the Bay of Plenty, which is crossed by the marginal basins, is characterized by a network of active faults, and by arc and back-arc volcanism. Sedimentation here is highly variable and the result of local balances between a continuous, rapid, terrigenous supply from rising, frontal ridge mountains to the E, and an intermittent supply of mainly rhyolitic, pyroclastic debris from the Taupo Volcanic Zone. This contrasts with the smooth, non-volcanic, eastern side of the bay where there is a sigmoidal, prograding shelf and slope of terrigenous silt on the northward plunging frontal ridge. It also contrasts with the western side of the bay where an extinct, Upper Miocene to Lower Pleistocene, arc-back-arc system has been eroded and is covered by a veneer of relict gravel and volcanogenic sand on the shelf, and buried by sandy mud on the slope.
The Hercynian Geanticline of Helez and the Late Palaeozoic history of the Levant
Authors: Gvirtzman Gdaliahu , Weissbrod Tuvia 
Published: April 2008

Summary
The presence of a large structure of Late Palaeozoic age has been deduced from analysis of Palaeozoic columnar sections from the Levant countries, Israel, Jordan, Egypt, Saudi Arabia and Syria. This structure, which was uplifted and truncated in two phases, pre-Carboniferous and pre-Permian, is here termed the Geanticline of Helez and is related to Hercynian movements. Permian to Triassic sediments overlie the Precambrian basement at its crest, whereas on the flanks of the structure, Palaeozoic sediments from Cambrian to Carboniferous in age wedge out gradually towards the culmination. Similar Hercynian geanticlines are known from the Hazro-Singar area near the Syrian-Turkish border, from Ennedi- Al Awaynat near the Libyan-Egyptian-Sudanese border, as well as elsewhere in North Africa. The culmination of the structure, some 500 km in diameter, extends over a large area of Israel, Sinai and Jordan. The flanks of the geanticline, originally dome-shaped, could be identified only in three directions. The missing northwestern flank, dipping towards the southeastern corner of the Mediterranean Sea, was probably removed during rifting and spreading from Late Triassic to Late Cretaceous times and may be located today in the Antalya area or elsewhere in Turkey. Its original location is today occupied by the Mesozoic basaltic ocean-floor of the Neo-Tethys, which is assumed to underlie the Levantine Basin of the Mediterranean.
Structural history of the Antalya Complex in the ‘Isparta angle’, Southwest Turkey
Authors: Waldron J. W. F. 
Published: April 2008

Summary
The Isparta angle is the north-pointing cusp where the arc of the Hellenides meets that of the Taurides in southwestern Turkey. The Antalya Complex is an assemblage of allochthonous deep- to shallow-water Mesozoic sedimentary rocks and ophiolite fragments present at the centre of the angle, surrounded by massive platform carbonate units, also of Mesozoic age.
Structural mapping of the folded and faulted Antalya Complex in the Eǧridir region at the centre of the Isparta angle indicates at least two major episodes of deformation. An earlier phase, probably latest Cretaceous in age, resulted in the thrusting of deep-water sediments over shelf-edge units which originally lay to the northeast. Subsequent southwest-vergent folding and thrusting in the Tertiary era locally reversed the earlier stacking order. Regularly imbricated thrust complexes were converted into chaotic mélange-like terrains.
The sedimentary cover was shortened by at least 72% as a cumulative result of these events. Palinspastic reconstruction of the Antalya Complex sedimentary basin indicates a wide original separation of the carbonate platform units on the east and west limbs of the Isparta angle, with at least one smaller platform between. These units were therefore probably separate carbonate banks, analogous to the present-day Bahama Banks.
Fossil and K-Ar data for the age of the Antalya complex, S W Turkey
Authors: Yılmaz Pınar O. 
Published: April 2008

Summary
The Antalya Complex of southwestern Turkey contains, from west to east, the autochthonous Mesozoic-Cenozoic platform carbonates of the Bey Daǧları massif and three allochthonous units: the Kumluca complex of imbricated Mesozoic continentalmargin sedimentary rocks; units of the Late Cretaceous Alakır Çay ophiolite sequence and the Late Cretaceous Tekirova partial ophiolite sequence; and the Teke-Tahtalı Daǧ unit of Palaeozoic-Mesozoic sedimentary rocks originating on continental crust. The allochthonous units are overlain by conglomerates containing Maastrichtian clasts, ophiolitic olistostromes and locally by pelagic marls bearing Lower Miocene foraminifera. Samples from the Alakır Çay and Tekirova ophiolites have been isotopically dated. These ages cluster in the latest Cretaceous.
Fossils from pelagic sediments interbedded with pillowed basalt flows yielded ages of Late Triassic-Jurassic and Late Jurassic-Early Cretaceous, indicating intermittent volcanic activity through Mesozoic time. It is believed that the ophiolites of the Alakır Çay and Tekirova unit were formed in the same basin but were emplaced during separate events.
HP/LT metamorphism and the structure of the Alanya Massif, Southern Turkey: an allochthonous composite tectonic sheet
Authors: Okay A. I. , Özgül N. 
Published: April 2008

Summary
The southern part of the Alanya Massif is made up of three superposed, relatively flat-lying, crystalline nappes (Alanya Nappes), which tectonically overlie the largely sedimentary lithologies of the Antalya Unit (= Antalya Complex). The predominantly Mesozoic continental margin type lithologies of the Antalya Unit outcrop beneath the Alanya Nappes in a large tectonic window.
The structurally lowest of the Alanya Nappes (Mahmutlar Nappe) consists of a heterogeneous series of shales, sandstones, dolomites, limestones and quartzites all metamorphosed under greenschist facies conditions. At least part of the sequence is Permian in age. The intermediate Nappe (Sugözü Nappe) is made up of garnet-micaschists which contain bands and lenses of eclogites and blueschist metabasites. Petrographic study has shown that rocks of the Sugözü Nappe have undergone initial HP/LT metamorphism followed by greenschist facies metamorphism. The greenschist overprint has destroyed most of the primary HP/LT mineral assemblages. The structurally highest of the Alanya Nappes (Yumrudaǧ Nappe) consists of a thick Permian carbonate sequence underlain by a relatively thin schist unit metamorphosed under lower greenschist facies conditions.
The absence of HP/LT metamorphism in the structurally lowest and highest of the Alanya Nappes, and the greenschist facies metamorphism which has affected all three nappes indicate that the initial HP/LT metamorphism of the Sugözü Nappe was succeeded by the tectonic stacking of the Alanya Nappes, greenschist facies metamorphism and deformation. In post-Maastrichtian times the Alanya Nappes, which were by then welded into one unit, were thrust over the sedimentary rocks of the Antalya Unit. The final thrusting of the Alanya Nappes and the underlying Antalya Unit over the Tauride carbonate platform occurred before the Middle Eocene.
The significance of Crete for the evolution of the Eastern Mediterranean
Authors: Hall Robert , Audley-Charles M. G. , Carter D. J. 
Published: April 2008

Summary
The Hellenic Arc is a convergent zone extending between Greece and Turkey associated with northward subduction of the African plate under the Aegean. The isopic zones of Greece are usually shown to extend parallel to the arc through Crete, implying that the present convergent pattern is long established. However, although Crete is situated in the centre of the Hellenic fore-arc the elongation of the island parallel to the arc is not due to convergence but to late Cenozoic regional extension. Our work in Crete indicates that Tertiary facies belts were orientated approximately N-S and that initial convergence in the region was oblique to the present arc. The Upper Nappes of Crete record two major deformational phases: D1 produced N-S folds and D2 produced E-W folds, whereas the lowest unit on Crete, the Plattenkalk Series, records only the D2 phase.
We suggest that Crete records the Mesozoic extensional, and Tertiary compressional, history of the Apulian continental margin. Eocene E-W compression (D1) caused stacking of the Upper Nappes and HP/LT metamorphism. Oligocene N-S compression (D2) caused thrusting of the Upper Nappes onto the Plattenalk Series, and initiated the present convergent pattern which is unrelated to the earlier history of the region.
The significance of deformation associated with blueschist facies metamorphism on the Aegean island of Syros
Authors: Ridley John 
Published: April 2008

Summary
A thorough examination of the syn-metamorphic minor structures in the blueschists of the Aegean island of Syros allows a determination of the kinetics and nature of the deformation. The deformation is essentially related to ductile thrusting at up to 45 km depth.
The change in fold geometry with orientation, and the presence of a locally developed mineral lineation at a high-angle to the fold axes give two independent determinations of the direction of thrusting. The direction, 130 ± 10°, suggests a link between the tectonism here and that in the Izmir-Ankara zone of mainland Turkey.
The nature of the small-scale asymmetrical folding indicates shortening of the pile parallel to this thrust displacement. This, together with the suggestion from the metamorphic textures of increasing pressure and temperature during deformation suggest that the deformation is related to burial and is compressional, and hence is presumably related to a major collision event.