Search results for "Plate"

Cytotoxicity of a new hemostatic agent on human pulp fibroblasts in vitro

2011

Objective: The objective of this study was to evaluate the cytotoxicity of the plant extract ankaferd blood stopper (ABS) in vitro. Study Design: ABS was eluted with fresh Dulbecco's Modified Eagle's Medium (DMEM) without serum for 72 h, at 37°C. The cells treated with various dilutions of ABS were seeded into 96-well microplate at 10 4 /well in triplicates. Cells without treatment served as a control group. The number of viable cells after 48 h incubation was determined by a modified 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay. The relative viability of pulp cells was expressed as color intensity of the number in the experimental wells relative to that of t…

The Leiza palaeo-fault: Role and importance in the Upper Cretaceous sedimentation and palaeogeography of the Basque Pyrenees (Spain)

1999

Abstract New analysis of the Upper Cretaceous deposits of the Central Depression, a syncline within the Basque Pyrenees, shows that this structure was a deep marine basin analogous to the regional flysch troughs. It was bounded by active faults, including the Leiza palaeo-fault, which sustained erosion of the partly subaerially exposed margins. The Leiza palaeo-fault and its western counterpart, the Kalamua palaeo-fault, are thought to constitute the former plate boundary between Iberia and Europe, and a westward continuation of the North Pyrenean Palaeo-Fault.

The Foundation Seamount Chain: A first survey and sampling

1997

The Foundation Seamounts form a 1400 km-long chain on the Pacific plate from 32 °S, 127 °W to the Pacific-Antarctic spreading axis at 38 °S, 111 °W. Previously only known from sparse single-beam echosoundings and satellite altimetry, we present here the first multibeam bathymetric survey and geological sampling results. We confirm that the submarine topography correlates with the altimetry, and that the chain is volcanic rather than tectonic or microcontinental in origin. The chain can be divided up morphologically and geochemically into three section: (1) west of 125 °W large flat-topped volcanoes composed of incompatible-element depleted lavas ( ≈ 1) of a near-ridge origin with little or …

Positron Studies of Subsurface Zone in Titanium Created in Sliding Wear

2014

Positron annihilation studies of the subsurface zone constituted during dry sliding in pure titanium are reported. A new type of defect depth profile in this zone, which is not an exponential decay usually reported for other metals and alloys, is observed. Two layers in the subsurface zone are present in this metal. In the layer adjacent to the worn surface, the characteristic plateau of the mean positron lifetime that extends to a depth of 60–70 μm was observed. Small vacancy clusters and dislocations were recognized in this layer. At deeper zone, the mean positron lifetime decreased exponentially in the manner typical for the other metals. In this zone, vacancy clusters increase in size a…

Single zircon evaporation ages from Obudu Plateau: First evidence of archaean components in the schists of south-eastern Nigeria

1998

Palaeomagnetism of the central Cuban Cretaceous Arc sequences and geodynamic implications

2009

Abstract A detailed palaeomagnetic study of Cretaceous age volcanic and sedimentary arc rocks from central Cuba has been carried out. Samples from 32 sites (12 localities) were subjected to detailed demagnetisation experiments. Nineteen sites from the Los Paso, Matagua, Provincial and Cabaiguan Formations yielded high unblocking temperature, dual polarity directions of magnetisation which pass the fold tests with confidence levels of 95% or more and are considered to be primary in origin. The palaeomagnetic inclinations are equivalent to palaeolatitudes of 9°N for the Aptian, 18°N for the Albian. A synfolding remanence identified in 5 sites from the younger Hilario Formation indicates a lat…

Precipitation Pulses and Soil CO2 Emission in Desert Shrubland of Artemisia ordosica on the Ordos Plateau of Inner Mongolia, China

2009

National Natural Science Foundation of China [40730105, 40501072, 40673067]; National Key Basic Research Program (973 Program) of China [2002CB412503]; Chinese Academy of Sciences [KZCX2-YW-149]

Quantifying the P-T-t conditions of north-south Lhasa terrane accretion: new insight into the pre-Himalayan architecture of the Tibetan plateau

2014

An integrated field, petrological and geochronological study of the Basong Tso region of south-eastern Tibet has constrained the timing and P–T conditions of north–south Lhasa terrane accretion and provides new insight into the tectonothermal evolution of the Tibetan plateau. Two distinct high-grade metamorphic belts are recognized in the region: a southern belt (the Basong Tso complex) that consists of sheared schist and orthogneiss; and a northern belt (the Zhala complex) that comprises paragneiss and granite. Combined pseudosection modelling and U–Pb geochronology of monazite and zircon indicates that the Basong Tso complex records peak metamorphic conditions of 9 ± 0.5 kbar and 690 ± 25…

Development of topography in 3-D continental-collision models

2015

Understanding the formation and evolution of high mountain belts, such as the Himalayas and the adjacent Tibetan Plateau, has been the focus of many tectonic and numerical models. Here we employ 3-D numerical simulations to investigate the role that subduction, collision, and indentation play on lithosphere dynamics at convergent margins, and to analyze the conditions under which large topographic plateaus can form in an integrated lithospheric and upper mantle-scale model. Distinct dynamics are obtained for the oceanic subduction side (trench retreat, slab rollback) and the continental-collision side (trench advance, slab detachment, topographic uplift, lateral extrusion). We show that sla…

Subduction of the Nazca Ridge and the Inca Plateau: Insights into the formation of ore deposits in Peru

2005

A large number of ore deposits that formed in the Peruvian Andes during the Miocene (15-5 Ma) are related to the subduction of the Nazea plate beneath the South American plate. Here we show that the spatial and temporal distribution of these deposits correspond with the arrival of relatively buoyant topographic anomalies, namely the Nazca Ridge in central Peru and the now-consumed Inca Plateau in northern Peru, at the subduction zone. Plate reconstruction shows a rapid metallogenic response to the arrival of the topographic anomalies at the subduction trench. This is indicated by clusters of ore deposits situated within the proximity of the laterally migrating zones of ridge subduction. It …