bluuebunny/crossref_metadata_2025 huggingface dataset:
Dimensional and Locational Integrity in the Replication of Polymeric Microdevices
Authors: You Byoung Hee , Park Daniel S. , Chen Ping-Chuan , Caceres Wilfredo M. , Nikitopoulos Dimitris E. , Soper Steven A. , Murphy Michael C.
Published: January 2010

In molding, geometric variation of molded parts is inevitable since the parts have a thermal history, including expansion and shrinkage, during the molding process. Shrinkage induces variation between the designed dimensions and locations of features on molded parts while the parts are cooled. Characterization of the variation is necessary to ensure dimensional and location integrity. Hot embossing and injection molding were performed in order to assess variation. Measurements were made using a Measurescope (MM-22, Nikon Corp., Kawasaki, Japan). The measured locations and dimensions were compared to estimates obtained using a simple model based on the linear thermal expansion coefficients (CTE) of the molded materials. The measured and the estimated shrinkage from hot embossing were incorporated in the fabrication of microtiter plate-based polymer microfluidic platforms.
Thermal Challenges in the Present and Next Generation of PC Processors
Authors: Refai-Ahmed Gamal
Published: January 2010

The challenges on the present thermal management devices of the present and future generation will be identified. The expected power roadmap will be revealed for high end processors. The different types of thermal management techniques will be disclosed as a function of the heat flux from the processors. In addition, the anticipated thermal resistance for thermal management devices for CPU&GPU will be presented. Attention will be focused on the order of magnitude for the different thermal resistance elements will also be identified.
Reliability of Flip Chip Package Depending on Underfill Encapsulating Processes
Authors: Katsurayama Satoru , Saka Masumi
Published: January 2010

Recently, we found a guideline to grasp the relationship between generated stresses, strain at any interface in a flip chip (F/C) package and warpage. Additionally, we found a possibility that generated stress and strain at any interface could be controlled by assembly process up to encapsulating even if same package was used. In the present paper, in order to understand the further details of the mechanism of package deformation, we investigate difference in warpage dependent on the encapsulation processes of capillary underfill (CUF) and no flow underfill (NUF), using same material as underfill (UF) and same F/C package structure. And we discuss package warpage and reliability dependent on encapsulation processes.
Micro-Raman Thermometry of Laser Heated Surfaces
Authors: Serrano Justin R. , Phinney Leslie M.
Published: January 2010

Optically powered devices are typically irradiated by high intensity lasers and rely on the temperature excursion generated by the laser for operation. While numerical modeling can estimate the temperature profile of the irradiated devices, only direct measurements can determine the actual device temperatures. Available surface thermometry techniques, such as infrared imaging, scanning thermal microscopy and thermoreflectance are generally incompatible with an optical powering scheme, the micron-scale layer thicknesses of microsystem devices, or both. In this paper we discuss the use of micro-Raman thermometry to obtain the first spatially-resolved temperature measurements of various polycrystalline silicon (polysilicon) surfaces heated with an 808 nm continuous wave (CW) laser at a 60° angle of incidence. The micron-scale resolution of the micro-Raman technique permitted mapping of the surface temperature in the vicinity of the heating laser spot and throughout the device. In addition to discussing the requirements for accurate data collection, the implications of optical interference on the heated structures are also considered.
Evaluation of Interface Strength at the 3D-Corner in Si-Resin Joint Considering Residual Thermal Stresses
Authors: Koguchi Hideo , Taniguchi Takashi
Published: January 2010

A mismatch of different material properties in joints may cause stress singularities, which lead to the failure of the bonding part. It is very important to reveal a stress singularity field for evaluating the strength of interface in three-dimensional joints. Furthermore, thermal residual stresses occur in a cooling process after bonding the joints, and the stress singularity for thermal stress also occurs. In the present study, a boundary element method and an eigen value analysis based on finite element method are used for evaluating the intensity of stress singularity. Three-dimensional boundary element program based on the fundamental solution for two-phase isotropic body is used. The strength of interface in two kinds of Si-resin specimen with different bonding area is investigated analytically and experimentally. Stress singularity analysis applying an external force for debonding the joints is firstly carried out. After that, stress singularity field for the residual stresses varying material property in resin with temperature is determined. Combining the stress singularity fields for the mechanical force and the residual thermal stress yields a final stress distribution for evaluating the strength of interface. Finally, a relationship of force for delamination in joints with different bonding areas is derived.
Assessment of 20 Micrometer Diameter Wires for Wire Bond Interconnect Technology
Authors: Saiyed S. , Kudtarkar S. A. , Murcko R. , Srihari K.
Published: January 2010

In the domain of wire bonding technology, the size and pitch of bond pads and ball bonds are shrinking to accommodate the demand for higher I/Os and increased functionality per chip area. This trend serves as a catalyst for bonding wire manufacturers to continuously develop lower diameter bonding wires. One mil (25 μm) diameter bonding wire, used widely in this interconnection technique, is now being replaced by 0.8 mil (20 μm) diameter bonding wire. In keeping with the need for higher operating speeds and higher temperatures for today’s ICs, the reliability of ball bonds formed by small diameter wires is of concern and requires investigation. This study explores the effects of 0.8 mil (20 μm) diameter bonding wire on the wire bond ball joint reliability and compares these effects with 1.0 mil (25 μm) diameter bonding wire. The reliability of the ball bonds was assessed using mechanical tests (wire pull and ball shear) for units subjected to stress tests such as the unbiased highly accelerated stress test and high temperature storage tests. The results of this investigation reveal that both the wire diameters are able to sustain their integrity after moisture testing. But, the bond strength degrades after high temperature tests due to the Kirkendall voiding mechanism occurring between gold wire and the aluminum bond pad.
An Integrated Thermoelectric Nanofluid Heat Exchanger
Authors: Rutherford William , Elomar Wessam , Nnanna A. G. Agwu , Sankowski Brian
Published: January 2010

This paper presents an experimental investigation of thermoelectric, TE, cooling system using nanofluid-based heat exchanger. The presence of nanoparticles in buoyancy-driven flows affects the thermophysical properties of the fluid and consequently alters the rate of heat transfer. The TE module is sandwiched between a heat source and the heat exchanger, with the cold side of the TEM attached to the heat source. The focus of this paper is to assess the enhancement in coefficient of performance of TEM using with 27nm Al2O3 — H2O nanofluid-based heat exchanger. Experimental simulations were performed to measure the transient and steady-state thermal response of TE to imposed isothermal condition. The volume fraction is varied between 0 to 2%. Preliminary results obtained for volume fraction of 0% (without nanoparticle) is reported in this paper. Result show that the COP is a strong function of the effectiveness of the heat exchanger and thermal contact resistance. Additional experimental runs are being conducted to show if at all, COP can be augmented using nanofluid-based heat exchanger.
Quantitative Characterization of True Leak Rate of Micro to Nanoliter Packages Using a Helium Mass Spectrometer
Authors: Goswami A. , Han B. , Ham Suk-Jin , Jeong Byung-Gil
Published: January 2010

The helium mass spectrometer has been used extensively for qualitative analysis of fine leaks. However, qualitative analysis for the small volumes (typically < 10−3 cc) of MEMS packages can produce erroneous results. In addition, the qualitative use of the helium fine leak test does not allow comparison of two different packages. Nor can the results be correlated with data from accelerated tests such as 85°C/85%RH test. These limitations warrant the development of a method to assess hermeticity quantitatively. This paper proposes a procedure to quantitatively measure the true leak rate of micro to nanoliter packages using the helium mass spectrometer. The proposed method is based on the fact that the profile of the measured leak rate signal depends only on the true leak rate and the volume of the package. Prior knowledge of the volume of the package enables determination of the true leak rate by performing a weighted non-linear regression analysis of the data. The method was implemented to measure the true leak rate of a MEMS RF filter package. The package was tested under three different test conditions yielding three different signal profiles. The method yielded a consistent value for the true leak rate, which verified the robustness of the method. The proposed method provides a true leak rate as a quantitative measure of hermeticity. The accurate true leak rates will help evaluate new bonding materials/processes and package designs fast and effectively.
Thermoelectric Micro-Cooler of Bismuth Telluride Thin Films
Authors: Miyazaki Koji , Kurosaki Jun-Ichiro , Takashiri Masayuki , Lenoir Bertrand , Tsukamoto Hiroshi
Published: January 2010

In this study, we fabricated bismuth-telluride thin films and their in-plane thermoelectric micro-coolers (4mm×4mm) by using the flash evaporation method. We prepared fine powders of Bi2.0Te2.7Se0.3 (n-type) and Bi0.4Te3.0Sb1.6 (p-type). The thermoelectric properties of as-grown thin films are lower than those of bulk materials. Therefore the as-grown thin films were annealed in hydrogen at atmospheric pressure for 1 hour in a temperature range of 200 to 400°C. By optimizing the annealing temperature, thin films with high thermoelectric power factors of 8.8 μW/(cm·K2) in n-type and 13.8 μW/(cm·K2) in p-type are obtained. To evaluate the figure of merit of the thin film, the thermal conductivity of the n-type thin film is measured by the 3ω method. The thin film annealed at 200 °C exhibited a cross-plane thermal conductivity of 1.2 W/(m·K). Micro-coolers of flash-evaporated bismuth-telluride thin films are fabricated using three shadow masks. The shadow masks are prepared by standard micro-fabrication processes such as nitridation of Si, dry etching, and wet etching. Thermoelectric power of the as-grown thin film devices with 16 pairs of p-n legs are measured by YAG laser heating at the center of the devices. The thermoelectric power of thermoelectric legs is evaluated to be 180μV/K per one p-n leg pair. According to the Kelvin’s law, it corresponds to 54mV Peltier coefficient per p-n pair.
Design Optimization of Fixed-Valve Micropumps for Miniature Cooling Systems
Authors: Forster Fred K. , Walter Travis
Published: January 2010

The piezoelectrically driven fixed-valve micropump may be an attractive choice for miniature liquid cooling systems due to its low-cost potential and simple fabrication. The thin, stackable design can be fabricated in many materials, including silicon, metal and plastic. Previous linear system modeling has been used to predict resonant behavior in terms of valve Reynolds number and used as a guideline for design, but can not yield predictions of pressure and flow, which depend on nonlinear fluid dynamic phenomena. In this study we report an extended model that incorporates the calculation of block-load pressure and no-load flow in a manner such that thousands of designs can be analyzed quickly. The results indicate that by calculating these two pump performance parameters over a design space of valve size and actuator stiffness, pump design is better able to match pump performance to system requirements. Experimental verification was performed using prototype pumps with interchangeable plastic and metal parts to demonstrate the approach for these two low cost materials.
An Improved Method of Thermal Resistance Measurement for Variable Thermal Resistors
Authors: Kim Hyeun-Su , Song Hyun Oh , Kenny Thomas W.
Published: January 2010

As part of the study and development of a variable thermal resistor (VTR), we present an improved thermal resistance measurement method for the VTR in the presence of unwanted signal drifting. To measure the change of thermal resistance, instead of waiting for the steady state value of the temperature signal, we repeatedly measure only the early transient part of the thermal response signal and then fit to get thermal resistance estimation. The required lengths of measurement were studied for the tests with various thermal time constants. Using this method, we performed thermal switching tests with various material pairs in contact in order to find the material pair that minimizes thermal contact resistance.
Comparison of Experimental Temperature Results With Numerical Modeling Predictions of a Real-World Compact Data Center Facility
Authors: Amemiya Yasuo , Iyengar Madhusudan , Hamann Hendrik , O’Boyle Martin , Schappert Michael , Shen Jing , van Kessel Theodore
Published: January 2010

In this paper we address the high level of validation of commercially available numerical predictive tools, namely CFD models, for data center applications. Experimental data at a real world facility is compared with computational results. Specifically, a recently developed temperature measurement tool is used to capture three dimensional temperature profiles of the facility with very fine spatial granularity. These detailed contours based on actual measurements reveal hot air recirculation patterns in the room as well as variable utilization levels of the room air-conditioning units. We compare these experimental temperature distributions measured using a novel 3D mapping tool with CFD thermal modeling results. An algorithm for generating CFD models for real world systems is proposed and demonstrated. It is found that due to the extensive inaccuracies in rapidly gathered input data as well as inherent limitations of the model, there can be significant discrepancies between predicted and actual temperatures. In addition to steady state measurements, transient data was also collected and are presented. Knowledge of the transient temperature profiles at different parts of the room allows an estimation of the temporal behavior of the data center. Transient temperature fluctuations are presented which capture the real variations in the system boundary conditions, for example the temperature of the chilled water to the air conditioning units, or the power dissipation of the servers over time.
Intermetallic Effects of Electroplated Lead-Free Solder Bumps Using a Novel Single Chamber Electroplating Process for Large Diameter Wafers
Authors: Brown J. Teye , Popat Ajay M. , O’Neal Chad B. , Xie Yixiang
Published: January 2010

In this study solder bumps of various alloys and less than 100 microns in diameter were electroplated using a novel single chamber electroplating process in which the plating baths are exchanged between the different metal plating layers. This equipment is new to the manufacturing arena. The reflow profile and process was then optimized for the various alloys such as SnAg, and electroplated layered SnPb, and PbSn 95/5%, with PbSn 95/5% being the control leaded solder for comparison. Various fluxes were also used during the reflow of these bumps. The solder bumps were reflowed on a conduction reflow oven in a nitrogen environment such that the temperature profile could be carefully controlled. The bumps were analyzed by examining the bump diameter and height uniformity, surface quality, and elemental composition and distribution inside the bumps. These analyses were done by visual inspection by optical microscopy, scanning electron microscopy, and electron dispersive spectroscopy (EDS). The wafers were diced near a row of solder bumps, then podded and polished using a metallographic polishing system to the center of solder bumps. These bump cross-sections were then examined by EDS to perform elemental mapping of the alloy constituents.
Analytical Modeling of Energy Consumption and Thermal Performance of Data Center Cooling Systems: From the Chip to the Environment
Authors: Iyengar Madhusudan , Schmidt Roger R.
Published: January 2010

The increasingly ubiquitous nature of computer and internet usage in our society, has driven advances in semiconductor technology, server packaging, and cluster level optimizations, in the IT industry. Not surprisingly this has an impact on our societal infrastructure with respect to providing the requisite energy to fuel these power hungry machines. Cooling has been found to contribute to about a third of the total data center energy consumption, and is the focus of this study. In this paper we develop and present physics based models to allow the prediction of the energy consumption and heat transfer phenomenon in a data center. These models allow the estimation of the microprocessor junction and server inlet air temperatures for different flow and temperature conditions at various parts of the data center cooling infrastructure. For a case study example considered, the chiller energy use was the biggest fraction of about 41% and also the most inefficient. The room air conditioning was the second largest energy component and also the second most inefficient. A sensitivity analysis of plant and chiller energy efficiency with chiller set point temperature and outdoor air conditions is also presented.
Thermofluid Characteristics of Two-Phase Microgap Coolers
Authors: Kim Dae W. , Rahim Emil , Bar-Cohen Avram , Han Bongtae
Published: January 2010

The thermofluid characteristics of a chip-scale microgap cooler, including single-phase flow of water and FC-72 and flow boiling of FC-72, are explored. Heat transfer and pressure drop results for single phase water are used to validate a detailed numerical model and, together with the convective FC-72 data, establish a baseline for microgap cooler performance. Experimental results for single phase water and FC-72 flowing in 120 μm, 260 μm and 600 μm microgap coolers, 31mm wide by 34mm long, at velocities of 0.1 – 2 m/s are reported. “Pseudo-boiling” driven by dissolved gas and flow boiling of FC-72 are found to provide significant enhancement in heat transfer relative to theoretical single phase values.
Simplified Thermal Model of Silicon Thermoelectric Microcooler for On-Chip Hot Spot Remediation
Authors: Wang Peng , Bar-Cohen Avram
Published: January 2010

Thermal management of on-chip hot spots has become an increasing challenge in recent years because such localized high flux hot spots can not be effectively removed by conventional cooling techniques. The authors have recently explored the novel use of the silicon chip itself as a solid state thermoelectric micrcooler (μTEC) for hot spot thermal management. This paper describes the development and application of a thermo-electric design tool based on closed-form equations for the primary variables. This tool can be used to effectively reduce the complexity and required time for the design and optimization of the silicon microcooler geometry and material properties for on-chip hot spot remediation.
Effect of Forward and Backward Compatibility of Solder Paste and Component Finish on Fine-Pitch Component Assemblies Using ENIG and IMAG PWB Finishes
Authors: Kannabiran Anand , Penmatsa Sreekanth Varma , Ramkumar S. Manian , Ghaffarian Reza
Published: January 2010

The primary objective of this experimental research is to understand the common issues faced in a manufacturing environment that assembles products containing a variety of fine-pitch devices. The testing phase of the research, relates to characterizing the thermo-mechanical integrity of surface mount mixed (Sn-Pb & lead-free) assembly solder joints. The investigation involves both forward and backward compatibility in electronics assemblies on Pb-free PWB surface finishes. A full factorial design is used in the investigation, with 3 factors — solder paste, component finish and PWB surface finish. Eutectic Sn-Pb paste (63–37% wt) and SAC305 (Sn 3.0%Ag0.5%Cu) paste are used as Pb-containing and Pb-free levels respectively. For component finish metallization, Sn-Pb termination finish/bump composition is used for Pb-containing level while Sn termination/SAC 405 bump composition represents the Pb-free level. Immersion Silver (ImAg) and Electroless Nickel Immersion Gold (ENIG) surface finish on printed wiring board (PWB) is used for testing and analysis. The testing was aimed at providing results for a wide variety of fine-pitch components commonly used in surface mount solder assemblies. Hence, a PWB containing flip chip (0.4mm pitch), Ultra chip scale package (UCSP), micro-lead frame (MLF) or quad flat pack no-lead (QFN), thin small outline package (TSOP −0.5 mm pitch) and plastic ball grid array (PBGA −1156 I/O and 256 I/O −1 mm pitch) devices was designed and used for testing. The test vehicle also includes resistors (0201, 0402 & 0603). The stencil thickness and openings were selected to accommodate both the large PBGA (1156 I/O) and finer pitch components. The reflow profile was designed taking into account the component maximum temperature exposure limitations, due to non-uniformity in heating, determined from thermocouples during initial assembly. Lessons learned from the design, reflow process optimization and manufacturing are presented in this paper. The solder joints were subjected to isothermal aging followed by mechanical shock test, attempting to establish a relationship between the intermetallic growth at the solder/PWB interface and the mechanical integrity of the solder joint. The compounding of test, unlike singular test methods, provides a more realistic estimate of the reliability and life of the joint in the field. The assemblies were cross-sectioned after the tests and the microstructure of the solder joints will be analyzed to study the intermetallic growth upon isothermal aging.
A Study on Polymer Pin Fin Based Heat Sinks
Authors: Ansari Ajmal
Published: January 2010

Recent developments in polymer additives and formulations have made available resins that have thermal conductivity that is one to two orders of magnitude higher than that of typical engineering polymers. Such polymers can be potentially used for designing heat sinks. There are two primary advantages of polymer heat sinks: ability to form shapes that may not be feasible with metal and flexibility that allows the heat sink to be bent in various shapes. This paper presents results from a study that was conducted to determine the suitability of commercially available Flexible Heat Sink Material for use in cooling high power LED’s.
Loop Thermosyphon Design for Cooling of Large Area, High Heat Flux Sources
Authors: Hartenstine John R. , Bonner Richard W. , Montgomery Jared R. , Semenic Tadej
Published: January 2010

Two-phase flow loop technologies capable of acquiring high heat fluxes (>1kW/cm2) from large area heat sources (10cm2) are being considered for the next generation naval thermal requirements. A loop thermosyphon device (∼1 meter tall) was fabricated and tested that included several copper porous wick structures in cylindrical evaporators. The first two were standard annular monoporous and biporous wick designs. The third wick consists of an annular evaporator wick and an integral secondary slab wick for improved liquid transport. In this configuration a circular array of cylindrical vapor vents are formed integral to the primary and secondary transport wick composite. Critical heat fluxes using these wick structures were measured between 240W/cm2 and 465W/cm2 over a 10cm2 area with water as the working fluid at 70°C saturation temperature. A thermosyphon model capable of predicting flow rate at various operating conditions based on a separated flow model is presented.
Atomic structure calculations and beam-foil observations of La IV
Authors: Biémont Émile , Clar Mathieu , Enzonga Saturnin Yoca , Fivet Vanessa , Quinet Pascal , Träbert Elmar , Garnir Henri-Pierre
Published: January 2010

Relativistic Hartree–Fock and multiconfigurational Dirac–Fock calculations of atomic structure and transition rates have been carried out in trebly ionized lanthanum (La3+, Z = 57). The calculations have to cope with configuration interaction effects but also with the very complex situation of the collapse of the 4f wave function. The calculations are compared to experimental data obtained with beam-foil spectroscopy in the extreme ultraviolet, at ion energies that favour the production of the spectrum La IV. Besides lines known from sliding spark discharges, many more lines are observed that have not yet been identified. Time-resolved measurements yield three level lifetimes in La IV that agree roughly with the results of our own calculations.
Robert Kidston (1852–1924): biography of a Scottish palaeobotanist
Authors: Thomson Christine A. , Wilkinson Ian P.
Published: January 2010

Synopsis

This brief biography summarizes the life of Scots-born Robert Kidston (1852–1924), who was arguably the best and most influential palaeobotanist of his day. In over 180 scientific papers he laid the foundations for a modern understanding of the taxonomy and palaeobiology of Devonian and Carboniferous plants. His expertise was critical to the research and curation of the Geological Survey and British Museum (Natural History) and excavations of Glasgow's Fossil Grove introduced the great Carboniferous forests into the public imagination. Despite their age, his meticulously documented collections of slides (deposited in the Botany collection University of Glasgow) and hand specimens and notebooks (deposited in the collections of the British Geological Survey, Nottingham) provide a wealth of important scientific data with modern applications in plant taxonomy, biostratigraphy and palaeoclimatic reconstruction.
The palaeoecology of two Scottish encrinites: Jurassic crinoid assemblages from the Trotternish Peninsula, Isle of Skye, Scotland
Authors: Hunter Aaron W. , Clark Neil D. L.
Published: January 2010

Synopsis

Despite a long history of investigation, articulate crinoids from the Jurassic of Scotland have not received great attention compared to their counterparts in Southern England or continental Europe; this is thought to be largely due to poor preservation. Two examples of ‘local’ encrinites (rocks almost entirely composed of crinoids debris), one from the Pliensbachian and the other from the Aalenian/Bajocian from the Isle of Skye, are shown to consist of columnals of
Hispidocrinus
cf.
schlumbergeri
and
Balanocrinus donovani
respectively. They represent local encrinites that have been deposited parautochthonously; one in a proximal, and the other in a more offshore low energy environment. This demonstrates that even limited encrinite material can not only be assigned systematically, but can also be used to reconstruct the original palaeoenvironments that the crinoids inhabited.
A new high-resolution aeromagnetic dataset over central Ayrshire: insights into the concealed geology
Authors: Busby J. P. , Akhurst M. C. , Walker A. S. D.
Published: January 2010

Synopsis

High-resolution aeromagnetic data have been acquired over central Ayrshire as part of a multi-component environmental and resource survey. The data were recorded along easterly orientated flight lines at 200 m separation and show a very marked improvement in resolution over the pre-existing aeromagnetic data for the region. The distribution of the extensive volcanic and intrusive igneous rocks in the near sub-surface is defined more accurately, many new features are recognized and features distinguished in the pre-existing aeromagnetic data are now seen to be laterally continuous. Northwesterly trending lineaments are clearly defined and most can be attributed to Palaeogene dykes, the majority of which are reversely magnetized. Depth to source solutions and modelling suggest that even though the dykes have a limited width at outcrop, their widths increase with depth. Permo-Carboniferous easterly trending dykes are not well resolved in the new aeromagnetic data. This is most likely due to a low amplitude resultant magnetic vector that, combined with the easterly-orientated flight lines, results in few large anomalies. One significant northwesterly trending lineament is interpreted as the trace of the Cleveland Dyke across the Midland Valley. These new data should be of value to the extractive and water industries and assist in the planning and sustainable management of these resources.
The Cluanie granodiorite, NW Highlands of Scotland: a late Caledonian pluton of trondhjemitic affinity
Authors: Neill I. , Stephens W. E.
Published: January 2010

Synopsis

The Cluanie Pluton is a late Caledonian granitoid emplaced into the Glenfinnan Division of the Moine Supergroup in the NW Scottish Highlands. A field investigation of the pluton and its internal facies is presented along with new major- and trace-element whole-rock XRF analyses, and geobarometric and geothermometric studies. Cluanie is predominantly composed of hornblende granodiorite characterized by varying concentrations of distinctive alkali feldspar megacrysts, with minor amounts of biotite granodiorite and rare mingled porphyritic microgranodiorite. The alkali feldspar megacrysts appear to be magmatic in origin. Rare spectacular pegmatitic concentrations most likely represent physical accumulation of the megacrysts. The pluton is geochemically a high Na/K trondhjemite, the only such pluton known among the Newer Granites of Scotland. On the basis of geochemical evidence and a comparison with partial melting experiments, we propose that the magmas were derived by fluid-rich melting of an amphibolitic source leading to relatively low temperature magmas which were significantly contaminated by Moine metasediments. The pluton was emplaced in the mid crust at about 4.3 kbar during an episode of dextral shear on the Glen Glass Fault related to regional strike-slip faulting on the Great Glen Fault system atc. 425 Ma.
Charles Darwin and Andrew Smith – an overseas exchange
Authors: Anderson Lyall I.
Published: January 2010

Synopsis

Charles Darwin met Andrew Smith in Cape Town, southern Africa on the last leg of his voyage aboard HMS
Beagle
(1831–1836). Both men shared a common background of having attended medical school at the University of Edinburgh although there was no apparent overlap of their times there; the latter became a career medic whereas the former did not. Evidence from the
Beagle
Collection of geological samples held at the Sedgwick Museum of Earth Sciences reveals that as well as accompanying Darwin on geological fieldwork around Cape Town, Smith supplied him with rocks which he had collected personally during his expedition to central southern Africa the previous year (1835). The two men remained firm correspondents until the year before Smith’s death in 1872.
The Highland Border Ophiolite of Scotland: observations from the Highland Workshop field excursion of April 2008
Authors: Henderson W. G. , Tanner P. W. G. , Strachan R. A.
Published: January 2010

Synopsis

In April 2008, 23 attendees of the Highland Workshop visited critical localities of the Scottish Highland Border Complex between Aberfoyle and the Isle of Bute. Widespread existence of fragmental ophicarbonates was confirmed, with the possibility that at least some may have formed as fault gouges in an ocean–continent transition environment similar to those reported from serpentinites in Ligurian-type extensional continent–ocean margins. The consensus view was that amphibolites at Loch Ard and on Bute appear to have been at no higher metamorphic grade than epidote-amphibolite facies. Also that, narrow zones of ‘granitoid rocks’ and spotting in Dalradian rocks in contact with ophicarbonate rocks could represent relatively low Barrovian regional metamorphic temperature effects rather than evidence for contact metamorphism in the sole of an obducted ophiolite. Finally, the Highland Border Ophiolite appears to have originally overlain the Southern Highland and Trossachs groups and was rotated with them by the D4 Downbend Antiform. No evidence was seen at these localities to support the hypothesis that the Highland Border Complex youngs to the NW or did not undergo Grampian deformational events.
Neotectonic deformation in a Scottish fjord, Loch Broom, NW Scotland
Authors: Stoker M. , Bradwell T.
Published: January 2010

Synopsis

Multibeam bathymetry, boomer seismic profiles and sediment core data from outer Loch Broom reveal slumping of the basin-floor fjord deposits of the Assynt Glacigenic Formation. On the swath image, the expression of slumping is manifest as two distinct sea bed depressions, at least 10 m deep and several hundred metres wide. Although the extent of displacement is constrained within the fjord, the seismic profiles reveal extensional and compressional faulting, and associated folding, within the fjord infill. The possibility that collapse of the sea bed has been partly facilitated by some kind of associated fluid release along the fault planes cannot be discounted. Local (core data) and regional stratigraphical information indicate that slumping occurred shortly after deposition of the Assynt Glacigenic Formation, between about 14 and 13 ka
bp
, during the deglaciation of the fjord region. It is inferred that these slumps broadly correlate with two areas of major sliding in adjacent fjord basins, and are linked to a regional phase of Lateglacial instability throughout the Summer Isles region. It is suggested that earthquake activity related to ice unloading is the most probable cause of this deformation. Holocene bottom-current activity has partially modified the shape of the depressions, and influenced the nature of the sediment infill.
Digital surface models and the landscape: interaction between bedrock and glacial geology in the Ullapool area
Authors: Goodenough K. M. , Krabbendam M. , Bradwell T. , Finlayson A. , Leslie A. G.
Published: January 2010

Synopsis

The front cover image for this volume is a hill-shaded digital surface model (DSM) of the Ullapool area, created using NEXTMap Britain elevation data from Intermap Technologies. This is a classic area for bedrock geology, transected by the Moine Thrust Zone, and in recent years it has also been studied in detail for its glacial history. Perhaps equally important, this is one of Scotland's most iconic landscapes. The geology of the area comprises a number of distinct sequences, each of which has a characteristic landscape expression as illustrated by the DSM. This paper considers the influence of the bedrock geology on the glacial geomorphology, and shows that the interplay of the two has led to the development of the different landscape elements of this spectacular area. Surprisingly, it is not always the major geological features – such as the Moine Thrust – that have the strongest topographic expression.
The layered ultrabasic rocks of Sgurr Dubh, Isle of Skye
Authors: Weedon Douglas S.
Published: January 2010

Synopsis

The Sgurr Dubh ultrabasic rocks show many features indicative of bottom accumulation of cumulus crystals from a basaltic or picritic magma.

Dunites are common towards the base of the layered sequence, intercumulus feldspar and clinopyroxene becoming more plentiful as the sequence is ascended. Chromite bands are common within the dunitic rocks. In the higher structural levels, cumulus feldspar crystals appear with the olivines, and layered structures, comprising alternating feldspar-rich and olivine-rich bands, here become common.

Optical studies of the component minerals, together with four analyses of selected rocks, indicate a small, albeit significant, cryptic variation throughout the mass—olivine from Fa
13
to Fa
16.5
, feldspar from An
85
to An
80.

Diffusion within intercumulus material is considered the most probable explanation for the local formation of dunites. Comparison with the layered ultrabasic rocks of Rhum indicates that the Skye ultrabasic rocks crystallized at somewhat higher temperature, and that a longer temperature interval ensued between the crystallization of the olivines and the feldspars, a factor considered important in explaining the formation of dunites within the Skye rocks.

Auto-brecciation and segregation-veins are common in parts of the mass, and there is evidence that marginal movements have occurred. The ultrabasic rocks are considered to have formed by crystal accumulation affected by various physical processes; they appear also to represent a magmatic disconformity within the sequence of basic igneous intrusions of the Cuillin.
Shoreward facies changes and their relation to cyclical sedimentation in part of the Namurian east of Stirling, Scotland
Authors: Read W. A.
Published: January 2010

Synopsis

A thick, persistent bed of shale known as the Black Metals, which lies near the middle of the Limestone Coal Group (Namurian, E
1
Zone), was deposited partly under marine conditions. It may be traced with little change over the Central Coalfield, but in the Kincardine Basin east of Stirling it becomes split by sandy beds which increase progressively in number and thickness eastwards so that within only 10 to 15 miles the whole succession is dominantly sandy. Seatearths and coals also appear. Variations in thickness and lithology are traced by means of 80 sections and illustrated by a series of maps.

The undivided Black Metals may be considered as part of an unusually thick and persistent cycle, formed during a general, possibly eustatic, rise of sea-level. The complex lithological variations east of Alloa and Grangemouth are thought to be due to the interplay of this major marine transgression and local processes of subsidence and sedimentation, probably including the progressive building out and abandonment of local deltas topped by vegetation, which gave rise to a series of thin, impersistent, coal-bearing cycles within the Black Metals. Faunal alternations in the all-shale successions of the west may reflect the formation of coal-bearing cycles further east.
Potassium-argon ages of some Dalradian, Moine and related Scottish rocks
Authors: Brown P. E. , York D. , Soper N. J. , Miller J. A. , MacIntyre R. M. , Farrar E.
Published: January 2010

Synopsis

New potassium-argon ages on Moine schists from north and central Sutherland are in general agreement with the age of 415–420 million years already found to be characteristic of the Moine outcrop. A similar age has been obtained on an F
3
pegmatite from the Loch Monar area and a Lewisian pelite, with F
3
crumples, from Loch Hourn. Dalradian specimens from Perthshire and Banff-shire show a spread of ages from 471 to 420 million years and are interpreted as overprints of a pre-Arenig metamorphism.
Some structural features of the Caledonian granitic complex at Strontian, Argyllshire
Authors: Munro M.
Published: January 2010

Synopsis

This complex consists of two main units—a mass of granodioritic rock, which has a non-porphyritic, tonalitic margin grading into a porphyritic core, and contains planar, and locally linear, flow structures, and a mass of virtually structureless biotite granite, which is bordered by a zone of vein-like apophyses. It is surrounded by a zone approximately three-quarters of a mile wide within which the country rock structures have been deflected and deformed. Fractures exploited by the biotite granite, and at various times by aplites and pegmatites, show similarities in orientation. Joints show a different orientation pattern and appear to be largely unrelated in origin to the complex. It is suggested that, firstly the granodioritic, and then the biotite granite magmas ascended within the crust to form stock-like bodies, and that in the former case a tongue-like extension to the north occurred, possibly under tectonic control.
White trap in some Ayrshire Coals
Authors: Mykura W.
Published: January 2010

Synopsis

Small intrusions of basic igneous rock in certain coals in the West Ayrshire coalfield occur as discrete bodies of white trap. In the Sillyhole Coal near Dalmellington these bodies are either horizontally elongated varying in shape from lenticular to nearly spherical, or small, vertically elongated and of more irregular shape.

The coal is altered to vesicular natural coke with polygonal jointing, the axes of the coke polygons being curved so as to be normal both to the margins of the seam and to the junction with the white trap. The combined thickness of the seam of coal and white trap is always greater than the thickness of the same seam in an unaltered state, the total thickness being directly proportional to the amount of white trap present in the seam.

Coals containing white trap bodies of this type passed through a plastic phase when magma was being intruded. During this period the horizontally elongated white trap bodies were formed, their mode of formation being analogous to that of pillow lavas. With rising temperature the coal re-solidified and shrank to form coke polygons, the magma filling joints between polygons and locally expanding to form the vertically elongated white trap bodies.
The Bearreraig Sandstone Series (Middle Jurassic) of Skye and Raasay
Authors: Morton Nicol
Published: January 2010

Synopsis

The Bearreraig Sandstone Series crops out in north-east Skye, Raasay and Strathaird. In Strathaird the extremely rapid variations in thickness and lithology suggest near-shore deposition. In Raasay the northward increase in the proportion of bioclastic material suggests derivation of terrigenous material from a main source to the south. In north-east Skye, however, the dominant features of sedimentation can be traced over a wider area, suggesting that the area was less influenced by strictly local factors.

There were two main basins, one in north Skye, and the other in Raasay and Strathaird, separated by an area of relatively slow subsidence in the area between Raasay and north-east Skye.

In north-east Skye most of the ammonite zones have been located, but in Raasay and Strathaird, where much of the series is cross-bedded, only some zones can be identified. The base of the cross-bedded rocks is diachronous.

There are three sedimentary cycles, with a sharp change to shale at the base, followed by a gradation to sandstone. The bases of the cycles coincide with changes in the ammonite faunas, and can be correlated with transgressions in other areas.
Note on a temporary exposure in central Glasgow of Quaternary sediments with slump and load structures
Authors: Jardine W. G.
Published: January 2010

Synopsis

Small-scale structures in a Quaternary fine sand-clay series are attributed to loading followed by thrusting and injection during temporary liquefaction.
The sedimentology and diagenesis of Silurian turbidites in South-east Wigtownshire, Scotland
Authors: Rust B. R.
Published: January 2010

Synopsis

Sedimentary features of a marine Silurian sequence in south-west Scotland indicate transport and deposition by turbidity currents. Directional sedimentary structures at the base and top of graded greywackes show respectively that early erosive phases of the currents travelled from the north-east, whereas later depositional phases came from the north-west. Structures discussed in relation to their possible origin include sand volcanoes and current crescents.

The effects of widespread carbonate replacement and local hematite enrichment are described. There is little evidence in the greywackes for a diagenetic matrix, which is concluded to be largely detrital in origin.
Peat bogs in a Post-glacial sea and a buried raised beach in the western part of the Carse of Stirling
Authors: Sissons J. B. , Smith D. E.
Published: January 2010

Synopsis

Borehole evidence shows that in the western part of the Carse of Stirling there occurs a buried raised beach whose surface is between about 30 and 36 ft O.D. The beach appears to have been formed after about 10 300 B.P. and before about 9500 B.P., more probably around the latter date. The buried raised beach is normally overlain by peat and this in turn by carse clay. Over part of the area the carse clay is covered by surface peat. In two areas the carse clay is absent and thick peat occurs instead. Part of this thick peat accumulated as the carse clay was being deposited around it.
The structural evolution of the Tarskavaig and Moine nappes in Skye
Authors: Cheeney R. F. , Matthews D. W.
Published: January 2010

Synopsis

The structural complex comprising the Tarskavaig and Moine nappes of Skye has been re-mapped and analysed in detail. Large scale folds belong to only two generations and these can be correlated with generations of large folds in adjacent mainland areas. Small folds belong to at least four more generations in addition to the two generations already mentioned. Some of these small folds are, however, of little regional importance and are found only in zones of highly deformed rocks. These zones have developed at two separate times in the structural evolution; and, like thrust planes, belong to two other separate periods. General considerations indicate that the displacements on the thrust planes could be very much less than assumed, and there is the possibility that the Loch Alsh fold may well be a late stage structure, in contrast to earlier views.
New Lower Cambrian fossil localities in North-west Scotland
Authors: Brand P. J.
Published: January 2010

Synopsis

During a recent examination of new and temporary exposures of Lower Cambrian strata in the Assynt area between Skiag Bridge and Ullapool, several new localities were discovered where trilobite remains are present in the Fucoid Beds and
Salterella
Grit.
A note on the age relationships between the Sgurr Dubh Ultrabasic Laccolite and the Cuillin Gabbros
Authors: Gibb Fergus G. F.
Published: January 2010

Synopsis

The age relationship between the Sgurr Dubh ultrabasic laccolite and part of the surrounding gabbro that was established by Harker has recently been re-examined by Weedon. Weedon does not take into account, however, part of the evidence on which Harker’s original interpretation of the intrusive sequence was based, namely, that sizeable veins of gabbro extend into the peridotite. One such vein is described and Harker’s interpretation of its relationship with the peridotite shown to be wrong.
The limits of the Late-glacial Highland, or Loch Lomond, Readvance along the West Highland seaboard from Oban to Mallaig
Authors: McCann S. B.
Published: January 2010

Synopsis

The major Late-glacial gravel deposits of Loch Linnhe and the mainland coast of the Firth of Lome, and at the western ends of Loch Morar and Loch Shiel, are described; and it is suggested that they represent the contemporaneous outwash material of the last major Late-glacial readvance of the area. This suggestion of a similar mode of origin for all the deposits involves a modification of earlier views that much of the material is raised beach gravel, and reinforces criticisms, already made, of the methods of correlation used by J. K. Charlesworth to define important Late-glacial stages throughout the Highlands. Nonetheless, the limits suggested by Charlesworth for Stage M (the Loch Lomond or Highland Readvance) which is the major Late-glacial readvance of this part of the western Highlands, is substantiated with only minor modifications.