bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Robiniapseudoacacia on leaf litter decomposition and nitrogen mineralization in a northern hardwood stand
Authors: Hirschfeld John Robert , Finn John Thomas , Patterson III William Albert
Published: December 2007

We studied the effects of the presence ofRobiniapseudoacacia L. on decomposition rates and nitrogen mineralization in the forest floor of two northern hardwood stands in western Massachusetts, one with and one without Robinia. Leaves from two hardwood species on the two sites and Robinia leaves were set out in mesh bags on the two sites for a total of 10 treatments. Increased nitrogen concentrations and lower carbon/nitrogen ratios were evident in leaves from the stand with Robinia, but this did not significantly affect rates of decomposition, which were the same for all 10 combinations of species, source, and site. Mineralization was observed only in leaves of Robinia placed on the Robinia stand and in leaves of Acersaccharum Marsh. placed on the stand without Robinia. Carbon/nitrogen ratios of Robinia litter were significantly lower than carbon/nitrogen ratios of Fraxinusamericana L. or Acer litter throughout the experiment. Site of decomposition did not appear to affect carbon/nitrogen ratios as decomposition proceeded.
Changes in needle morphology, anatomy, and mineral content during the recovery of protected balsam fir trees initially defoliated by the spruce budworm
Authors: Piene H. , Percy Kevin E.
Published: December 2007

Morphological, anatomical, and chemical changes in foliage of 25- to 30-year-old balsam fir trees (Abiesbalsamea (L.) Mill.) that had been completely defoliated in 1977 by the spruce budworm (Choristoneurafumiferana (Clem.)) and then protected for 5 years by insecticide, were compared with foliage from adjacent undefoliated trees. The comparison showed that in 1978, the 1st year of refoliation, needle length, weight, and width were greater in the defoliated trees, while in 1979 they were less. In 1980, needle length was again less, but no difference was observed in needle weight and width. Needle length, weight, and width were similar in the defoliated and undefoliated trees in 1981 and 1982. Needle density in the defoliated trees was lower in 1978, but greater in 1979, while no difference occurred in 1980–1982. Foliar nitrogen content was higher in the defoliated trees in 1978–1980. Foliar phosphorus and potassium content were higher in the defoliated trees only in 1978. Needle and mesophyll cross-sectional areas in the defoliated trees were larger in 1978, but were smaller in 1979. There were no differences during 1980–1982. Mesophyll and needle cross-sectional areas were positively correlated throughout 1978–1982. Relative amounts of total protein were higher, whereas those of total insoluble carbohydrates were lower in 1978–1980 needles from undefoliated trees.
Bids for silvicultural services: estimating reasonable costs and identifying bidding errors
Authors: Guldin Richard W.
Published: December 2007

Econometric procedures were developed for (i) estimating the reasonable cost of a contract before advertising for bids and (ii) identifying abnormally low bids immediately after the bids tendered are opened. Two-order statistics were used in this initial study of low bidding in forestry. The ratio G (low bid minus mean of all bids divided by the standard deviation of all bids) follows Gumbel's type I extreme value distribution. The natural logarithm of the ratio M (the margin between the two lowest bids divided by the range in bids) has the same form. The "reasonable cost" of a contract not yet awarded can be estimated as a function of the distributions of G and M and the mean low bid and range of bids from prior contracts for the same service. Statistical tests for outliers from exponential distributions of order statistics can help identify abnormally low bids that may contain bidding errors. The moments of the G and M distributions reveal that half the silvicultural contractors are foregoing profits greater than 15% of the total contract cost, more than $6.79 per acre. The principal reasons are incomplete market information for preparing bids, heterogeneous cost structures among bidders, and cost advantages arising from work site location compared with the base of operations.
Taproots of jack pine (Pinusbanksiana Lamb.) and soil tongues in Saskatchewan
Authors: Rowe J. Stan , Acton Don F.
Published: December 2007

The examination of tree roots and profiles of sandy soils in northern Saskatchewan suggests that the common tonguing of grey eluviated A horizon materials into the brown subsoil is caused by the taproots of jack pine (Pinusbanksiana Lamb.). The tongues are apparently initiated in root casts formed either by windthrow, when the vertical roots of living or fire-killed trees are pulled out of the ground, or by insitu decay of undisturbed taproots. Narrow semiindurated sheaths around many of the tongues and faint bleaching of undisturbed bedded materials beneath them suggest that once formed, they continue to be conduits for percolating water and foci for pedogenesis. Sectioning soils through the B horizon in the horizontal plane reveals the sizes and densities of the tongues better than conventional profiles in the vertical plane. Although the persistence and permanency of the tongues is not known, their presence or absence on particular sites may prove useful in studying the ecology and history of the pine, as well as of other similarly rooted tree species.
Long-term increase of nitrogen availability from fertilization of Douglas-fir
Authors: Binkley Dan , Reid Paula
Published: December 2007

Most Douglas-fir stands respond to nitrogen fertilization by increasing stem growth for less than 8 years, but one plantation at the United States Forest Service Wind River Experimental Forest has responded for over 15 years. The nitrogen concentration of foliage and fresh litter were higher in the fertilized (applied at 470 kg N/ha) plots 18 years after fertilization. Retranslocation of N from senescent needles was not affected and stem growth per unit N in the canopy was similar between unfertilized and fertilized plots. An index of soil N availability in the fertilized plots was twice that of unfertilized plots. The higher stem growth, leaf area, and stem growth per unit leaf area appeared related to a sustained increase in soil N availability rather than increased N-use efficiency. Soil N transformation processes need to be examined to complete the explanation of the unusually prolonged fertilizer response in these plots.
Delayed emergence of four conifer species on postfire seedbeds in eastern Canada
Authors: Thomas P. A. , Wein Ross W.
Published: December 2007

This study compares the emergence of jack pine (Pinusbanksiana Lamb.), eastern white pine (Pinusstrobus L.), black spruce (Piceamariana (Mill.) B.S.P.) and balsam fir (Abiesbalsamea (L.). Mill.) for three seasons after sowing on two postfire seedbeds to test the hypothesis that conifer species differ in their ability to store viable seeds in the soil. Less than 20% of all viable seeds produced emergent seedlings in the first growing season. Emergence continued in the second growing season but not in the third. No viable seeds of any species were found at the end of the experiment. During the second growing season (July 1), the emergence of jack pine was greatest at the warmer and drier site but at the cooler and moister site, large numbers of black spruce emerged; by the end of the second season jack pine seedlings predominated at both sites. Although this delayed emergence accounted for <3% of the viable jack pine seeds sown, this percentage would be sufficient to produce a dense stand given normal postfire seedfall rates. It is suggested that delayed emergence from the soil along with partial seed retention in tree crowns are strategies of jack pine and black spruce which increase the probability of establishment even if the immediate postfire conditions are particularly inhospitable.
The influence of cutting treatments with indole-3-butyric acid and boron, stock plant moisture stress, and shading on rooting in Sitka spruce
Authors: Driessche R. Van Den
Published: December 2007

Methods of improving rooting of Sitka spruce (Piceasitchensis (Bong.) Carr) cuttings were studied. In experiment 1, cuttings from twenty-five 8- to 11-year-old trees were treated with five levels of indole-3-butyric acid (IBA) (0, 25, 50, 100, and 3000 mg L−1) and five levels of boron (B) (0, 0.5, 1.0, 5.0, and 10.0 mg L−1) in a factorial experiment. IBA was applied in a 24-h soak, except at 3000 mg L−1, when a 5-s dip was used. Greatest rooting was achieved with 25 mg IBA L−1 (55 vs. 38% for 0 mg IBA L−1), but rooting achieved with 3000 mg IBA L−1 (49%) was not significantly less. B had no effect on rooting. In a second experiment, 2-year-old stock plants, rerooted from hedges and 17 years from seed, were subjected to two watering treatments and three shading treatments applied factorially. Watering treatments were (i) normal watering to maintain moist soil in pots and ((i) low watering achieved by withholding water for 8 weeks in July and August. Shading treatments were (i) unshaded, (ii) shading from 1 July, and (iii) shading from 1 September until cuttings were removed in January. Shading reduced light intensity to 38% of full daylight. The low-watering treatment caused severe moisture stress and some mortality of stock plants. It also reduced rooting 16–24%, depending on the clone. Shading increased rooting 10–25%, depending on the clone, but there was little difference between times of shading.
Floral response of Piceaglauca to gibberellin A4/7, napthaleneacetic acid, root-pruning, and biennial treatment
Authors: Marquard Robert D. , Hanover James W.
Published: December 2007

The floral response of 6-year-old seedling white spruce (Piceaglauca (Moench) Voss.) was evaluated after treatment in 1981 with the gibberellin mixture of A4 and A7 (GA4/7), napthaleneacetic acid (NAA), and root-pruning. To evaluate the effectiveness of biennial treatment, trees treated in 1981 were again treated in 1983 and compared with a second group of trees treated only in 1983. Trees treated in 1981 with 500 mg•L−1 GA4/7 plus 25 mg•L−1 NAA and root-pruning averaged 42 female strobili per tree and control trees remained vegetative. Root-pruning significantly reduced terminal shoot growth and shoot water potential. No male strobili were produced on study trees. Trees treated in 1981 and again in 1983 were as productive (based on female counts) as trees treated only in 1983. Two treatments in 1983 significantly enhanced female strobilus production over the control: (i) 500 mg•L−1 GA4/7 alone and (ii) 250 mg•L−1 GA4/7 plus root-pruning. These treatments averaged 150 and 192 female strobili per tree, respectively; control trees averaged 30. Biennial treatment with GA4/7 and root-pruning can effectively continue to increase female cone production of white spruce.
Influence of soil water potential and mycorrhizal colonization on root growth of yellow-poplar and sweet gum seedlings grown in compacted soil
Authors: Simmons G. L. , Pope P. E.
Published: December 2007

A greenhouse study was conducted to determine the influence of soil water potential and endomycorrhizal fungi on root growth of yellow-poplar (Liriodendrontulipifera L.) and sweet gum (Liquidambarstyraciflua L.) seedlings grown at three soil bulk densities. Silt loam soil was compacted in PVC pots to bulk densities of 1.25 (low), 1.40 (medium), or 1.55 (high) Mg • m−3, and equilibrated at −10 kPa soil water potential. Newly germinated seedlings were transplanted into the pots, inoculated with fungal chlamydospores of Glomusmacrocarpum or Glomusfasciculaturn, or distilled water (control), and grown for 3 months at −10 or −300 kPa soil water potential. Total porosity, air-filled porosity, water content, and mechanical resistance of the soil were determined for samples compacted to the same bulk densities and equilibrated at the same soil water potentials as were used in the greenhouse study. Root growth was reduced by the high mechanical resistance caused by bulk densities of 1.40 and 1.55 Mg • m−3 at −300 kPa water potential. At both water potentials, total length of lateral roots and fibrosity of the root system of both tree species decreased significantly when bulk density increased from 1.40 to 1.55 Mg • m−3. Air-filled porosity less than 0.12 m3 • m−3 limited root growth when water potential was −10 kPa, and mechanical resistance greater than 3438 kPa restricted growth at −300 kPa. At −10 kPa, root length and fibrosity were greatest for inoculated sweet gum seedlings at each bulk density. At −300 kPa, sweet gum seedlings inoculated with G. fasciculatum had the greatest root length and fibrosity at the low and medium bulk densities. Mycorrhizal effects on root length of yellow-poplar were variable, and fibrosity was not significantly affected by mycorrhizal treatment.
Estimation of seed orchard efficiencies by means of multistage variable probability sampling
Authors: Bartram C. , Miller G.
Published: December 2007

This paper describes two frameworks for developing effective multistage variable probability sampling methods to estimate seed orchard efficiencies. In both cases a standard multistage approach is implemented initially in multiple orchards and years. The effectiveness of this approach is then evaluated against several alternative methods, using the initial efficiency data collected, and subsequent survey procedures are prescribed on the basis of this analysis. An example illustrating the application of this methodology in coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seed orchards in British Columbia is presented.
Western gall rust dynamics and impact in young lodgepole pine stands in west-central Alberta
Authors: Bella I. E. , Navratil S.
Published: December 2007

A sample of 29 405 lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) trees was assessed from 1982 to 1985, and stem analysis data of 75 trees from five heavily infested second-growth stands in the foothills of the Rockies were analyzed to determine the incidence, development, and impact of western gall rust Endocronartiumharknessii (J.P. Moore) Y. Hiratsuka, in relation to age of trees and stand and site factors. The incidence of western gall rust increased with stand age and time. In stands up to 12 years old, the incidence averaged about 5% and increased rapidly to about 20% at age 20. A rapid increase in incidence over time occurred in younger age-classes. In stands 20 years or older, the incidence of new infection was low. Mortality associated with western gall rust among crop trees was low. There was, however, 30% mortality in an unthinned 22-year-old stand over its life. Impact on growth was highly significant (p < 0.01). In the periods 11–15 years and 16–20 years after the wave of heavy infection, reductions in volume growth of infected crop trees were 15 and 25%, respectively. This loss amounts to 15% of the total volume over the 20-year period during which the stands are affected. Western gall rust incidence was higher (p < 0.01) in stands on east-facing slopes than on south- and north-facing slopes. Stands at elevations between 1200 and 1400 m had the highest incidence. Forest management strategies to reduce the impact of western gall rust are discussed, with emphasis on spacing that includes sanitary removal of infected trees.
Cross-sectional estimation of empirical southern United States pulpwood harvesting cost functions
Authors: Cubbage Frederick W. , Wojtkowski Paul A. , Bullard Steven H.
Published: December 2007

This paper develops and explains an empirical method of using cross-sectional data to determine cost functions for forestry operations. Primary logging firm data, basic production economics theory, and regression analysis were used to estimate aggregate cost functions by harvest system for southern United States pulpwood harvesting operations. Estimation of aggregate total costs first, followed by mathematical derivation of average costs, proved superior to direct estimation of average costs. Exponential functions were best at estimating the cost relationships observed in the empirical pulpwood harvesting data.
Shoot production in Douglas-fir branches
Authors: Wilson Brayton F.
Published: December 2007

Of the 3981 shoots present in 1986 on 16 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) branches, 6–12 years old, only 1933 produced new shoots in 1987, and of these only 311 produced more than one shoot. Length of new terminal shoots was determined primarily by the length of the parent shoot (R2 = 0.57). Shoots that did not elongate had blunt buds, < 1 mm long, with no leaf primordia; shoots that elongated had pointed buds, > 2 mm long, with many leaf primordia. Buds < 1 mm long survived up to 3 years without elongating; needles on these shoots survived an additional 2 years. Parent shoots longer than 13 cm all elongated. The percentage of parent shoots < 14 cm long that did not elongate, and would have subsequently died, increased with (i) decreasing parent shoot length; (ii) increasing whorl number along the main axis of the branch (toward the branch base); (iii) decreasing total elongation of all shoots on the branch, a measure of branch vigor.
Foliar analysis and response of fertilized chlorotic Sitka spruce plantations on salal-dominated cedar–hemlock cutovers on Vancouver Island
Authors: Weetman G. F. , Fournier R. , Barker J. , Schnorbus-Panozzo E. , Germain A.
Published: December 2007

A series of microplot and conventional plot trials were used to determine the nutritional status and required nutrient additions to bring young chlorotic Sitka spruce (Piceasitchensis (Bong.) Carr) plantations out of "check." Check occurs on clear-cut and burned old-growth western red cedar (Thujaplicata Donn ex D. Don) and western hemlock (Tsugaheterophylla (Raf.) Sarg.) stands in the Coastal Western Hemlock biogeoclimatic zone growing on deep morhumus Podzols invaded by dense salal (Gaultheriashallon). Microplot trials identified the requirement for N and P. Checked trees responded to fertilization immediately with a 4- to 8-year temporary increase in leader length. Grubbing out of aboveground salal did not improve tree nutrition. There is a close parallel to "heather check" noted with Sitka spruce in British and Irish moorlands; a possible allelopathic effect of salal is suspected. It is concluded that one or more N and P additions are required to establish crown closure. Fertilized Sitka spruce show a high incidence of spruce weevil attack. The deficient and optimum foliar nutrient concentrations developed in Britain for the diagnosis of Sitka spruce appear to be applicable.
Annual variation in fusiform rust infection of slash and loblolly pine seed lots in time-replicated plantings
Authors: Froelich R. C.
Published: December 2007

Trees from two putatively fusiform rust resistant and two susceptible seed lots of slash pine (Pinuselliottii Engelm. var. elliottii) and loblolly pine (P. taeda L.) were planted in 4 or 5 consecutive years at three locations in south Mississippi and examined annually for rust galls that originated the previous year. Disease incidence was usually less than 20% in the first growing season. Resistant and susceptible slash pine had light incidence of rust after about age 5. The susceptible lobloly pine often developed considerable numbers of branch galls after the fifth season, but most were several metres from the main stem of the trees. The resistant loblolly pine of Livingston Parish, Louisiana, never developed more than 23% infection in any 1 year in thirty 80-tree plots. The three remaining seed lots often exceeded 50% infection in some years, but differences among seed lots were usually small. Rankings of the four species seed lots or the six families that made up the resistant slash seed lot varied by trial (year planted and year infected). Replicating experiments in time on high-hazard sites for rust should better define occurrence and importance of location × family interactions.
Major and trace element concentrations in surface organic layers, mineral soil, and white oak xylem downwind from a coal-fired power plant
Authors: Long R. P. , Davis D. D.
Published: December 2007

White oak (Quercusalba L.) xylem tissues, associated mineral soils (0 to 25 cm), and surface organic layers (O2 horizon) were sampled downwind from a 623 MW coal-fired power plant to determine whether major or trace element concentration patterns were affected by changes in emission stack heights during a 32-year operating period. Four sites with Hazleton (Typic Dystrochrept) soils located at 0.25, 1.2, 2.0, and 10.3 km downwind from the power plant were sampled. In surface O2 layers, Fe and Co concentrations varied inversely with distance from the power plant. Inductively coupled plasma–atomic emission spectroscopy was used to determine concentrations (ppm) of P, K, Ca, Mg, Fe, Mn, B, Na, Sr, Ba, Cu, Al, Si, Cr, Ni, Co, Pb, and Cd in xylem tissues during four separate time periods: one preoperation and three periods concurrent with power plant operation. Only Sr concentrations showed a consistent pattern of greatest accumulation in the xylem during periods when emission stacks were lowest, and at sites closest to the power plant. Potentially toxic elements were not detected at elevated levels in xylem tissues; however, xylem Sr may be a sensitive bioindicator of historical fly-ash deposition.
Genetic architecture and adaptive landscape of interior lodgepole pine (Pinuscontorta ssp. latifolia) in Canada
Authors: Xie Chang-Yi , Ying Cheng C.
Published: December 2007

The genetic architecture and adaptive landscape of interior lodgepole pine (Pinuscontorta ssp. latifolia Engelm. ex S. Wats.) in Canada were investigated in a provenance–family plantation located in central British Columbia. Fifty-three natural populations were sampled from three geographic regions covering the entire Canadian range, and their performance in growth and survival was recorded periodically over 20 years. Test results indicate that genetic variation among regions and among populations within regions was highly significant in all the traits investigated and accounted for, respectively, 53% and 41% of the total genetic variation in growth and 41% and 54% in survival. Within-population variation was also significant in growth but not in survival. Interior lodgepole pine in the central region demonstrated less genetic variation than in the northern and southern regions at both the population and family levels. In addition, the proportion of genetic variation associated with population was lower in the central region than in the other regions. Population differentiation in both growth and survival showed discernible elevational and geographic patterns. Regression models describing these adaptive patterns accounted for more than 80% of the among-population variation, and their veracity was verified with independent data. Populations of northern, coastal–interior transition, and high-elevation origin tended to have smaller trees with higher mortality. However, the patterns were not linear but differed in slope and (or) direction among regions. The adaptedness of populations tended to decrease as they were farther away from their origin, with a few exceptions displaying broad adaptation across more than 3° of latitude. As the test proceeded, population differentiation became more evident and adaptive clines became steeper. Some practical implications of these findings have been discussed.
TOPOLOGICAL GRAVITY LOCALIZATION ON A δ-FUNCTION LIKE BRANE
Authors: TAHIM M. O. , ALMEIDA C. A. S.
Published: December 2007

In the celebrated Plebanski formalism of topological gravity, the constraints connecting topological field theories and gravity are imposed in spacetimes with trivial topology. In the braneworld context there are two distinct regions of the spacetime, namely, the bulk and the braneworld volume. In this work we show how to construct topological classical gravity in a scenario containing one extra dimension and a δ-function like three-brane which naturally emerges from a spontaneously broken discrete symmetry. Starting from a D = 5 theory we obtain the action for General Relativity in the Palatini form in the bulk as well as in the braneworld volume. This result is important for future insights about quantum gravity on brane scenarios.
A COMPARISON OF NEURAL NETWORK MODEL SELECTION STRATEGIES FOR THE PRICING OF S&P 500 STOCK INDEX OPTIONS
Authors: THOMAIDIS N. S. , TZASTOUDIS V. S. , DOUNIAS G. D.
Published: December 2007

This paper compares a number of neural network model selection approaches on the basis of pricing S&P 500 stock index options. For the choice of the optimal architecture of the neural network, we experiment with a “top-down” pruning technique as well as two “bottom-up” strategies that start with simple models and gradually complicate the architecture if data indicate so. We adopt methods that base model selection on statistical hypothesis testing and information criteria and we compare their performance to a simple heuristic pruning technique. In the first set of experiments, neural network models are employed to fit the entire options surface and in the second they are used as parts of a hybrid intelligence scheme that combines a neural network model with theoretical option-pricing hints.
CLIMBER'S FINGER
Authors: Yamaguchi Toshihito , Ikuta Yoshikazu
Published: December 2007

Introduction: Climbers sometimes support their body with one finger hooked on a rocky ledge. This peculiar manoeuvre may cause a characteristic injury of the flexor tendon sheath, named "climber's finger".

Symptoms: (1) A sharp pain when grasping, and a sudden "snap" sound and snapping phenomenon in the concerned fingers and (2) a tender palpable mass proximal to the PIP joint.

Mechanism of occurrence: When a finger forms a hook, the highest stress point of the flexor tendon sheath is between the first cruciform pulley and the second annular pulley. When the full body weight is held mainly with the weak first cruciform pulley, it sometimes ruptures.

Therapy: Conservative therapy to prevent bowstringing was applied for eight cases. Six patients recovered after three months; the other two cases underwent operations.

Conclusion: If conservative therapy is found to be ineffective after three months, suturing of the tendon sheath should be indicated for climber's finger.
MEDIAN NERVE COMPRESSION SECONDARY TO LIPOMA ARISING FROM FLEXOR TENOSYNOVIUM: A CASE REPORT
Authors: Vekris Marios D. , Lykissas Marios G. , Beris Alexandros E.
Published: December 2007

Lipomas are space-occupying lesions that may rarely be responsible for compression neuropathies. Here we report a case of a lipoma arising from flexor tenosynovium that was responsible for a sensory disturbance resulting from the compression of the median nerve in the carpal tunnel. The patient had complete relief from the neurologic symptoms six months after lipoma excision.
The preservation of the Neogene Brassington Formation of the southern Pennines and its bearing on the evolution of Upland Britain
Authors: WALSH PETER THOMAS , BOULTER MICHAEL CHARLES , IJTABA MOHAMMED , URBANI DAVID MARTIN
Published: December 2007

The Brassington Formation of the southern Pennines comprises a succession of sands, gravels and clays, the youngest beds of which contain Lower Pliocene fossil plants. These strata are generally considered to have foundered into the Carboniferous Limestone through solution subsidence mechanisms. The subsidencc cavities also contain detached marginal blocks of shale, which locally contain Namurian goniatites.

Examination of the shale blocks from a number of widely separated localities has revealed that all contain Namurian spore assemblages, datable in some cases as
E
2
(Arnsbergian) age. The contact between the shale blocks and oldest sands of the Brassington Formation is unconformable and, characteristically, the latter are seen to rest on zones of lilac-stained weathered shale, representing a pre-subsidence land surface.

Evidence is presented which indicates that the Brassington Formation strata are conformable and that the succession represents a single cycle of sedimentation. Because of this conformable relationship it is inferred that this land surface is also of Lower Pliocenc (or Upper Miocene) age.

A tacheometric survey of a well-exposed solution subsidence complex at the Bees Nest Pit, Brassington, has enabled structure contour maps to be made of key horizons in the succession. Laboratory tests have been conducted which have attempted to duplicate this structure and so indicate the probable subsidence mcchanisms. Results suggest that subsidence was gradual, with block-by-block removal of the host limestone, and took place in deep, steep-sided pipe-like forms.

The depth of subsidence, and hence the elevation of the land surface prior to the deposition of the Brassington Formation, has been determined by estimating the thickness of limestone and Namurian shale which, as suggested by previous research work in the southern Pennines, was once present over the sites of the present subsidence masses. Subsidence can be shown to be of the order of 150–250 m, which implies that the Lower Pliocene land surface of the southern Pennines lay at about 450m O.D.

Based on the evidence of the contemporary sea level, the presence of the Lower Pleistocene deposits of s
e
England, and the sub-Neogene surface of the southern Pennines, a graph has been constructed which suggests broadly that Upland Britain has undergone a regular uplift since the main Alpine episode at a rate of about 1 metre in 15,250 years. In this light, the possible age of other well known planation surfaces is discussed.
A layered plutonic complex of alkali basalt parentage: the Lilloise intrusion, east Greenland
Authors: BROWN PETER E.
Published: December 2007

The Lilloise intrusion is one of the major Tertiary plutonic complexes in east Greenland, The intrusion is composed of layered cumulates, beginning with a great thickness of feldspar-free peridotitic rocks and passing upwards into olivine pyroxene plagioclase cumulates in which small scale rhythmic layering is well developed. The mineral assemblage and composition of the Ca-rich pyroxenes is indicative of an alkali basalt parent magma. The layered rocks are cut by numerous veins and dykes of cognate syenitic material. The most voluminous and advanced stages of differentiation contain aegirine augite and annite-rich mica, while the intermediate members are characterized by kaersutite. These late stage veins and dykes are comparable to the products of differentiation of alkali basalt magma as found elsewhere in shallow intrusive bodies.

Major layered ultrabasic or gabbroic intrusions of alkali basalt parentage are rare, indeed none are unequivocally recorded in the recent summary by
Wager and Brown (1968)
. The Lilloise intrusion, which is one of the major Tertiary plutonic complexes in east Greenland, is such a body. From morainic material collected by
Wager (1934)
the intrusion was previously believed to be an undersaturated syenite and is recorded as such on published maps. The syenite specimens collected by Wager almost certainly originated in the Borgtinderne complex rather than in the Lilloise.
The Cambrian and Ordovician rocks of the Migneint area, North Wales
Authors: LYNAS BRYAN D. T.
Published: December 2007

The stratigraphy, faulting, mineralization and metamorphism of the Upper Cambrian and Ordovician rocks are described. Newly erected formation names are the Afon Gam Formation (Upper Cambrian), the Carnedd Iago, Serw, Llyn Conwy and Rhiw Bach Formations (Ordovician). Two important unconformities, corresponding to the pre-Arenig and pre
graeilis
erosions widely recognized in North Wales, are described. They are controlled by major n-s gravity faulting. Many of the faults

were active as the stratified rocks were being laid down, and intrusions were injected at the same time. This gave very variable deposits and many disconformities in the Lower and Middle Ordovician. An evolutionary relation-ship between the four principal intrusive rock types is proposed to explain the restriction of certain types to particular stratigraphic horizons. Possibly the first British record of hollandite is recorded.
Stratigraphy and structure of the western Moine and the problem of Moine orogenesis
Authors: POWELL DEREK
Published: December 2007

The stratigraphy and major structure of some 650 km
2
of Precambrian, Moine metasediments in western Scotland are discussed and it is shown that at least four major deformation phases involving primary isoclinal folding with fold amplitudes of at least 20 km, and two major metamorphic episodes affect both the Lewisian basement and the Moine cover.

It is argued that there is sufficient evidence to regard the first two deformation phases together with the earlier metamorphism as Precambrian in age and the subsequent deformations and metamorphism as Caledonian.
Initiation and growth of the East Antarctic ice sheet
Authors: DREWRY DAVID JOHN
Published: December 2007

There appears to be little support for an initiation of continental glacierization in the Palaeogene. The palaeobiological evidence indicates warm–temperate climates in the Antarctic Peninsula and Wilkes Land coast of East Antarctica. Glacial marine sediments from JOIDES Leg 28, oxygen-isotope analyses from Leg 29, global sea level changes and palaeontological investigations favour the development of full-bodied ice sheets from local, longer lived icefields and glaciers only in the late Cenozoic (after the lower Miocene) with a possible maximum about 5 m.y. BP.

Recent geophysical exploration has enabled a model for the evolution of the East Antarctic ice sheet to be developed. The Transantarctic Mountains, the north-eastern sector of the Gamburtsev Mountains and other, smaller subglacial mountain massifs within continental East Antarctica provided growth centres for the ice sheet. Extensive glacial erosion took place within these highland areas at this time. Many glacial valleys in the Transantarctic Mountains were subsequently utilized by outlet glaciers of the ice sheet.

Tectonic implications of the growth model indicate that the Transantarctic Mountains were probably 1500–2000 m lower at the commencement of glaciation, and that the initial vertical movements of the Victoria Orogeny began in the Eocene in response to the crustal separation of the Australian and Antarctic lithospheric plates.
Sediment transport in the Severn Estuary during the past 8000–9000 years
Authors: MURRAY J. W. , HAWKINS A. B.
Published: December 2007

The suspended sediment in the Bristol Channel contains abundant size-sorted Foraminifera with a mean size of ∼140
μ
m. The dead foraminiferal assemblages from the subtidal channels and intertidal mudflats are made up partly of indigenous forms, showing a wide size range, and partly of transported forms, having a mean size of ∼140
μ
m.It is therefore inferred that net transport of fine material is from the west (Celtic Sea and Bristol Channel) into the estuary.

Samples from sixteen boreholes and pits in the Flandrian deposits on the east side of the stuary yield evidence of abundant transported Foraminifera, from which it is inferred that net landward transport of fine material has taken place throughout the past 8–9000 years. Further, the Foraminifera have been used to interpret the environments of deposition of the sediments. It is concluded that sedimentation up to marsh level occurred at different times in different parts of the estuary margin as at present and that there is no foraminiferal evidence supporting the idea of a widespread Romano-British transgression.
Diagenetic sequence in ancient sandstones deposited under desert climatic conditions
Authors: Kessler L. G.
Published: December 2007

Examples from the Ordovician of Western Canada and the Permian beneath the North Sea indicate that ancient desert sandstones of aeolian dune and wadi origin go through a definite early diagenetic history. This paragenesis consists of various combinations of early cementation (gypsum for some dunes, calcite for wadis), infiltration and deposition by clay-rich surface waters, and dissolution of unstable clasts (usually ferro-magnesian grains) by ground-water. Subsurface water chemistry changes induced by these early diagenetic events lead to alteration of infiltrated clay to haematite, accretion of feldspar and quartz overgrowths, and formation of authigenic clays. Late diagenetic events resulting from deep burial and tectonism may destroy original clasts and early diagenetic features, replacing them with authigenic feldspar, quartz and/or clay and calcite, anhydrite or other cements.

The early post-depositional features discussed are diagnostic of desert climatic conditions during deposition and early diagenesis. Preservation of these features precludes later severe deep burial diagenesis.
Observations on diagenesis in North Sea reservoir sandstones
Authors: Sellwood B. W. , Parker A.
Published: December 2007

Pressure solution

If there were a grain-boundary solution phenomenon due solely to pressure it would be a function of depth of burial and have important consequences for the prediction of porosity reduction trends in hydrocarbon reservoirs. However, many of the interpenetrant grain contacts that have been illustrated by speakers at this meeting and termed 'pressure solution' require additional explanation. From our own work on both outcrop and core materials we have been unable to find any convincing correlation between burial depth and 'pressure solution'—for a variety of facies. Furthermore, Hancock (1978) does not claim to have seen pressure-solution phenomena although his sediments were recovered from a greater depth than any others described at this meeting.

We suspect that the nature of the pore fluids flushing through the sediment is very important, particularly where grain-boundary reactions have been catalysed by surfactant coatings such as clays and micas. Reservoir sandstones did not become 'closed systems' until hydrocarbon emplacement was completed. Before this occurred pore-fluid evolution was probably continuous.

Fibrous illite

In our own studies on offshore core material from probable Old Red Sandstone in the Buchan Field, we have found fibrous outgrowths on clays and micas (Pl 1, fig. 1) in fractures. In this case, therefore, the fibres post-dated fracture development.

We are not convinced that the fibres are simple illites (as has been proposed by several speakers) for the following reasons:

1. Using non-dispersive X-ray analysis it may be possible to show that the fibres are composed mainly of K
2
O,
The Paleocene/Eocene boundary in the Anglo-Paris Basin
Authors: Costa L. , Denison C. , Downie C.
Published: December 2007

Palynological and micropalaeontological evidence is employed to correlate the beds adjacent to the Paleocene/Eocene boundary in the Anglo-Paris Basin. The base of the Sables de Cuise Inférieurs (Cuisian
s.l)
and of the Ypresian are contemporaneous; the base of the Eocene should be taken at this level. The position of the Blackheath and Oldhaven Beds relative to this boundary remains uncertain. The Sparnacian and Thanetian Zone III of the Paris Basin belong to the same dinocyst zone and correlate with the Woolwich Beds of England. The Thanetian Zone II correlates with the Thanet Sands.

A new dinocyst species,
Wetzeliella astra,
is described.
Metallogenesis in the western United States
Authors: Guild P. W.
Published: December 2007

Although the Mesozoic-Cenozoic metallogeny of the western United States unquestionably resulted from convergence of the North American and Pacific Ocean plates, subduction alone does not adequately explain the distribution of the ore deposits in Laramide and post-Laramide time, when magmatism and mineralization extended irregularly eastward at least 1500 km from the continental margin. Stable isotopes (lead and initial
87
Sr/
86
Sr) indicate derivation of some rock- and ore-forming elements from continental rather than oceanic lithosphere. A gross east-west metals zonation lacks the clearcut divisions evident to the north and south in the Cordillera. Lineaments, difficult or impossible to document unequivocally, seem nevertheless to have played some role in localizing mineral belts transverse to plate boundaries.

It is suggested that mantle convection in a reactivated ensialic back-arc, triggered at least in part by subduction on one or more Benioff Zones, became increasingly important both with time and with distance eastward from the Mesozoic trench. Small magma pockets were generated episodically by partial fusion of the continental lithosphere, itself probably in-homogeneous, where deep crustal flaws, many ancient but some perhaps newly created, relieved pressure and provided access to the upper crust.
Geological aspects of volcano prediction
Authors: Baker P. E.
Published: December 2007

Evidence drawn from the long-term geological history of a volcano can rarely contribute to short-term prediction of a particular event. Only very general prophesies are possible from such an approach, though these are by no means without value. Geological study gives perspective to the historic record, creating a more realistic awareness of a volcano's potential and providing a constraining background for planning and further development around the volcano. Since volcanoes tend to have somewhat individual characteristics, in the event of an eruption it is important to have some knowledge of the previous history and behaviour as a possible guide to the come that the current eruption may take. In many instances precedents are available from well-documented historic eruptions but this is not always so and it is often necessary to rely upon geological evidence of prehistoric activity. Very occasionally the detailed reconstruction of short-term events from the geological record and the recognition of past patterns of activity may allow comparisons to be made with the current situation and have some predictive value.
An analysis of hazard from Mount Etna volcano
Authors: Guest J. E. , Murray J. B.
Published: December 2007

The eruptive history of Mt. Etna during the last 400 years is well documented; by assuming that previous activity is representative of that in the future, it is possible to evaluate in a general way the hazard to land and property on different parts of the mountain by lava. Flank eruptions are more likely to occur on the rift zones or other areas of high vent density. Most eruptions occur where there is already more than 1 vent per km
2
, averaging about 1 eruption per 10 years. A map of the area that could be covered by lava from the high vent-density areas shows large sections of the mountain that are protected by topography or distance. Rates of lava resurfacing have been obtained for different areas, the average for the whole volcano being about 0.5 km
2
per year. It is concluded that most towns are relatively safe from normal eruptive activity.
Palaeomagnetic and stratigraphic study of the Loch Shiel marine regression and overlying gyttja
Authors: Thompson R. , Wain-Hobson T.
Published: December 2007

Palaeomagnetic, chemical and pollen analyses have been carried out on cores 6 m long from the SW basin of Loch Shiel, Sootland. A marine regression in one core is dated at 4200 C
l4
years BP. Palaeomagnetic declination and inclination variations in the limnic gyttja are interpreted as reliable records of ancient geomagnetic field changes. Comparison with 4 other British limnic palaeomagnetic sites indicates that systematic errors in C
l4
age determinations have been caused in many of the sites by inwash of old soils and peats. The inwash effect is suggested to have been more pronounced and to have started significantly earlier in England than previously documented. Palaeomagnetic direction correlations and transference of C
l4
age determinations from the palaeomagnetic master curve described, can help overcome these dating difficulties.
A review of the main structural and magmatic features of northern Sumatra
Authors: Page B. G. N. , Bennett J. D. , Cameron N. R. , Bridge D. McC. , Jeffery D. H. , Keats W. , Thaib J.
Published: December 2007

Structural and magmatic features of northern Sumatra are reviewed, based on a continuing programme of reconnaissance mapping. Distinction is drawn between Tertiary sedimentation on the W and that in the centre and E, the dividing line being the main outcrop of the Sumatran Fault System (SFS) which traverses the length of the island. Large transcurrent movements on the SFS are indicated by (
a
) regional slivers of oceanic crust trapped at the leading junction of the western continental plate of Sumatra as it moved NW against the main mass of the island; (
b
) palaeomagnetic evidence (N. S. Haile) here interpreted as showing eastern Sumatra as part of the Malaya block and occupying its equatorial position since the Cretaceous in contrast to the NW tip of Sumatra, W of the SFS, for which more southerly palaeolatitudes have been determined; (
c
) juxtaposition of Li-rich and Li-poor geochemical provinces along the SFS.

The Sumatran magmatic arc commenced at least in the Mesozoic. The offset of the current volcanic arc to the E at Lake Toba is ascribed to a change in the angle of the Benioff Zone, the dividing line suggested being a split in the descending plate which is coincident with prolongation of the Investigator transform fault. The SFS continues N of Sumatra as a transform of the Andaman spreading complex, and terminates in the S in the Sunda Strait area either at the edge of the continental block or against a major plate junction indicated by the commencement of deep focus earthquakes E of Sumatra.
Shape fabric variations in deformed conglomerates at the base of the Laksefjord Nappe, Norway
Authors: Chapman T. J. , Milton N. J. , Williams G. D.
Published: December 2007

Detailed strain mapping of deformed conglomerates at the base of the Laksefjord Nappe, Finnmark, N Norway has been carried out in an attempt to identify strain gradients adjacent to the basal Laksefjord thrust. Statistical analysis of shape fabric orientation data was also undertaken. A rapid ‘harmonic mean’ analysis of deformed clasts has been evaluated in terms of possible error factors in the method, and it is felt that patterns of strain across the area are real, whereas absolute strain values may be subject to only slight errors. Generally, strain magnitude is seen to increase with proximity to the basal thrust and above internal thrusts within the conglomerate unit, reaching a maximum value of ϵ̄
s
= 3.95. The geometry of shape fabric is dominantly flattening (0 <
v
≤ 1) but small, isolated areas of constrictional strain occur (– 1 ≤
v
< 0). A tectonic model involving a variable simple shear component accompanied by a constant component of pure shear is proposed for the origin of the conglomerate shape fabrics.