a newly discovered skull of the temnospondyl amphibian dendrerpeton acadianum owen a virtually complete three dimensional skull of a subadult of the temnospondyl amphibian dendrerpeton acadianum provides new information on the structure of the palate and lower jaw the left stapes appears to lie in a natural position on the quadrate ramus of the pterygoid the proportionately large otic ossicle probably precluded it from having acted as a transmitter of airborne vibrations from a tympanum to the inner ear the use of the term otic notch should be restricted to amphibians or reptiles in which the embayment of the posterior margin of the cheek is accompanied by the presence of a slender rod like stapes that could have functioned as part of an impedance matching system in those species in which a notch is present but the stapes is a massive supporting element the term squamosal embayment should be used rather than otic notch the squamosal embayment in early tetrapods may have been inherited directly from their fish ancestors and had no functional relationship to hearing

fire ecology of the carboniferous tropical zone abstract fossil charcoal fusain indicating the occurrence of wildfire is common in the carboniferous rocks of north america and europe during the carboniferous these regions lay on the southern margins of the laurasian continent and within the tropical zone this study examines the facies distribution and botanical identity of charcoal in order to investigate the influence of fire on carboniferous tropical ecology new data from charcoal bearing units in eastern canada poland and the british isles are presented and synthesised with previously published data of charcoal occurrence tournaisian visean charcoal bearing strata were deposited in volcanic lacustrine alluvial plain and coastal marine environments in these deposits charred floras are dominated by pro gymnospermous plants whilst uncharred compressed or permineralised floras are dominated by lycopsids uncharred lycopsid remains were probably derived from wetland communities growing close to the depocentres whilst charred gymnospermous remains may have been sourced from well drained extrabasinal settings based on the vertical distribution of charcoal layers in annually laminated lacustrine deposits it is estimated that fires occurred with high frequency approximately every 3 35 years palaeoclimatic analysis indicates that southern laurasia at this time was subject to a seasonal monsoonal tropical climate such environments today are characterised by tropical savannas with high fire frequencies and early carboniferous fire prone gymnospermous plant communities may have represented a comparable vegetation biome namurian stephanian charcoal bearing strata were deposited in alluvial plain coastal plain and coastal marine environments channelised sandstone units interpreted as river channel deposits contain charcoal derived from cordaitaleans and conifers this assemblage records fires in extrabasinal coniferopsid forests mudstone units containing coals are interpreted as the deposits of floodbasins and peat mires hollow uncharred lepidodendrid stumps occur in this facies and contain lepidodendrid charcoal in the stump bases and lepidodendrid pteridosperm coniferopsid and sphenopsid charcoal outside the stumps this assemblage records fires in wetland lepidodendrid dominated forests lepidodendrid trunks comprising of a spongy parenchymatous core surrounded by dense periderm became hollowed out during fire events an estimate of fire frequency based on the vertical spacing of charcoal layers in coals implies that fires occurred every 105 1085 years in the peat mires palaeoclimatic analysis indicates that southern laurasia was subject to a humid tropical climate during the late carboniferous such environments today are characterised by tropical rainforests where fires occur rarely and late carboniferous communities may have represented a comparable biome

properties of iron oxides in some new caledonian oxisols abstract oxisols from two toposequences of new caledonia formed from peridotite consist essentially of fe oxides goethite hematite maghemite these fe oxides were characterized by their mineralogy crystal size and morphology al substitution thermal behaviour and dissolution kinetics in 6 m hcl at 25 c in one toposequence the samples were free of hematite goethite only at 1050 m above sea level whereas at lower altitudes hematite was also present al substitution was generally low due to the low al content of the peridotite except in gibbsitic samples on rocks somewhat higher in al the surface areas of goethite and hematite ranged between 50 and 150 m 2 g 1 dithionite extractable ni and cr were between 0 2 and 2 2 ni and 0 3 and 2 3 cr the hematite containing samples tended to be higher in cr and lower in ni whereas the opposite held for samples containing goethite only maghemites had a low unit cell size 8 31 8 32 instead of 8 34 8 35 a which was attributed to al substitution dehydroxylation temperature of goethites was weakly correlated with al substitution dissolution kinetics could be described by a linear form of a modified first order reaction with one straight line for samples containing goethite only and two lines for samples containing goethite plus hematite

response of late carboniferous and early permian plant communities to climate change abstract late carboniferous and early permian strata record the transition from a cold interval in earth history characterized by the repeated periods of glaciation and deglaciation of the south

geostatistical modeling of the geological uncertainty in an iron ore deposit abstract this paper addresses the problem of quantifying the joint uncertainty in the grades of elements of interest iron silica manganese phosphorus and alumina loss on ignition granulometry and rock types in an iron ore deposit sampling information is available from a set of exploration drill holes the methodology considers the construction of multiple rock type outcomes by plurigaussian simulation then outcomes of the quantitative variables grades loss on ignition and granulometry are constructed by multigaussian joint simulation accounting for geological domains specific to each quantitative variable as well as for a stoichiometric closure formula linking these variables the outcomes are validated by checking the reproduction of the data distributions and of the data values at the drill hole locations and their ability to measure the uncertainty at unsampled locations is assessed by leave one out cross validation both the plurigaussian and multigaussian models offer much flexibility to the practitioner to face up to the complexity of the variables being modeled in particular 1 the contact relationships between rock types 2 the geological controls exerted by the rock types over the quantitative variables and 3 the cross correlations and stoichiometric closure linking the quantitative variables in addition to this flexibility the use of efficient simulation algorithms turns out to be essential for a successful application due to the high number of variables data and locations targeted for simulation

invertebrate trace fossils and agglutinated foraminifera as indicators of marine influence within the classic carboniferous section at joggins nova scotia canada the sea cliffs at joggins nova scotia are the most extensive and continuous carboniferous section in eastern north america although the section has been considered to have formed within a nonmarine depositional basin paleobiological information indicates that parts of the section were deposited in brackish water the occurrence of a trace fossil assemblage which includes cochlichnus kouphichnium and treptichnus is part of an assemblage of biogenic structures that apparently reflects paleodeposition within fluvial systems that may have experienced distal marine influences presence of agglutinated foraminifera characteristic of brackish water environments supports this interpretation this information provides new evidence of brackish water conditions at joggins such as those now being widely recognized in other carboniferous coal bearing sections

geostatistics in the presence of geological boundaries application to mineral resources modeling abstract this paper addresses the problem of simulating the copper grade and rock type in a chilean porphyry copper deposit recognized by a set of exploration drill holes the application of contact analysis tools cross to direct variogram ratios cross correlograms pseudo cross variograms and lagged scatter plots reveals the coexistence of hard and soft boundaries between rock type domains a quadrivariate coregionalization model is developed to fit the spatial correlation structure of the rock type and grade based on indicator and normal scores direct and cross variograms a two stage approach is first used for simulating the intrusive porphyry and the copper grade in it while the other two rock type domains and their copper grade are jointly simulated in the space not occupied by porphyry such a mixed approach is shown to reproduce the nature of the rock type boundaries and is validated by split sample validation

magnetic enhancement is linked to and precedes hematite formation in aerobic soil 1 soil formation usually increases magnetic susceptibility most often by increasing the concentrations of magnetite and maghemite which are two ferrimagnetic iron oxides here we provide evidence that magnetic enhancement in aerobic soils not affected by detrital magnetic inputs or thermal transformation of other iron oxides is mostly due to the formation of maghemite which is later transformed into hematite the iron oxide that gives red color to soil we show that the maghemite hematite ratio is influenced by the particular environment and the degree of soil development so it constitutes an effective tool for paleoenvironmental and planetary studies

relationships between phosphate sorption and iron oxides in alfisols from a river terrace sequence of mediterranean spain abstract phosphate sorption isotherms for samples of the a and upper b horizons of alfisols situated on a sequence of terraces of the river guadalquivir southern spain showed that phosphate sorbed at an equilibrium concentration of 0 3 g p ml 1 was correlated with several soil properties crystalline fe oxides goethite and hematite appeared to be the most important p sorbing components of the soil samples sorption was highly correlated with percent clay and with dithionite soluble fe this last property was as good a property to predict sorption as the specific surface of crystalline fe oxides which was estimated by line profile analysis of the x ray diffractograms probably because the range of surface areas for goethite and hematite was relatively narrow in the samples and because of the limited accuracy of the method of line profile analysis well drained and imperfectly drained soils differed little in sorption properties in imperfectly drained hematite free soils chroma was correlated with sorption this is promising for it would allow rapid field estimation of sorption the sorption maximum calculated from the fitted langmuir isotherm was about 1 7 mol p m 2 of fe oxides a value similar to those reported in the literature for natural and synthetic oxides

an articulated embolomere skeleton amphibia anthracosauria from the lower pennsylvanian bashkirian of nova scotia recently discovered skeletal material greatly expands our knowledge of the embolomeres from the early pennsylvanian locality of joggins nova scotia these specimens are probably attributable to calligenethlon watsoni steen that has been described previously from this locality but despite their articulated condition and relative completeness this assignment is equivocal inclusion of the most complete specimen nsm 994 gf 1 1 in a previous phylogenetic analysis of the embolomeri results in a sistergroup relationship between nsm 994 gf 1 1 and anthracosaurus however none of the 16 synapomorphies supporting this relationship are unique to these two taxa but rather all occur in one or more of the other taxa in the analysis this indicates extensive homoplasy within embolomeres and emphasizes the difficulties inherent in resolving embolomere interrelationships the dirth of unequivocal synapomorphies is probably also reflects the conservative nature and basal status of embolomeres within the initial pal

geostatistics in the presence of geological boundaries exploratory tools for contact analysis abstract identification and categorization of geological geotechnical or geometallurgical domains is a common practice in the modeling of mineral deposits in order to account for the controls exerted by categorical variables ore type rock type or facies on the quantitative variables of interest the definition of a suitable geostatistical model for spatial prediction or simulation is commonly based on a contact analysis aimed at determining whether or not these quantitative variables are spatially continuous across the domain boundaries in this paper we present several tools such as cross to direct variogram ratios cross correlograms pseudo cross variograms and lagged scatter plots that are useful for such an analysis and discuss their strengths and weaknesses the tools are illustrated with applications to synthetic case studies

a new study of solenodonsaurus janenschi and a reconsideration of amniote origins and stegocephalian evolution a restudy of the holotype and other known specimens of solenodonsaurus a late carboniferous relative of amniotes suggests that this taxon did not have a tympanum its teeth lack labyrinthine infolding and the frontal did not reach the orbit a new phylogenetic analysis of stegocephalians suggests that solenodonsaurus is an anthracosaur and that it is the sister group of cotylosauria it also shows that the problematic taxon westlothiana may not be an anthracosaur not a stem amniote a recent suggestion that diadectomorph cotylosaurs laid amniotic eggs is shown to be based on tenuous evidence although this remains a possibility the evolution of the otic region is studied using parsimony to determine whether the emargination present in solenodonsaurus and in some diadectomorphs is a primitive or a secondary character but this procedure yields equivocal results

response of late carboniferous tropical vegetation to transgressive regressive rhythms at joggins nova scotia fossil plant assemblages are described in their sequence stratigraphic context from the upper carboniferous langsettian joggins formation of nova scotia to elucidate ecosystem response to transgressive regressive rhythms results show that rising base level resulted in retrograding submerged coastal mires co dominated by lepidodendron and lepidophloios which were replaced by short lived paralycopodites communities immediately following mire drowning extensive brackish bays existed during early highstand distally fringed by gymnospermous and putative progymnospermous coastal and or upland vegetation late highstand bay filling generated prograding distributary wetlands dominated by flood disturbed lycopsid pteridosperm sphenopsid communities and locally by cordaite mangroves as base level fell well drained alluvial plains were dominated by fire prone cordaite and or sigillaria communities which persisted until the next phase of base level rise this rhythmic ecosystem succession repeatedly occurred on a c 50 200 ka time scale and was probably driven by glacial interglacial climate rhythms

petrology of selected carbonaceous limestones and shales in late carboniferous coal basins of atlantic canada carbonaceous limestones and shales are associated with coal in late carboniferous alluvial to coastal successions of nova scotia the units are thin 45 km they consist of micrite and or illitic and kaolinitic clay and some contain abundant bivalves ostracodes pyrite up to 11 vol and phosphatic and sideritic nodules trace fossils are scarce to absent the organic material 2 43 toc is characterised as type ii iii and is mainly of terrestrial derivation predominantly vitrinite and sporinite with lamalginite and telalginite as minor constituents vitrinite reflectance measurements indicate immaturity ro 0 5 but are lower than those of associated coals source rock and hydrocarbon recovery potentials are good to very good and the potentials of some units compare favourably with those of alginite rich carboniferous oil shales in adjacent basins the carbonaceous units were deposited in shallow lakes and or interdistributary bays with aerobic to anaerobic bottom waters at times of minimal detrial input

role of evaporite withdrawal in the preservation of a unique coal bearing succession pennsylvanian joggins formation nova scotia the pennsylvanian joggins formation in the cumberland group of nova scotia is widely regarded as the world s best exposure of coal bearing carboniferous strata this 1 5 km thick coal bearing unit is famous for upright fossil lycopsid trees and is preferentially preserved in the athol syncline in the western cumberland basin new seismic profiles show that the athol syncline is atop a salt weld and that the joggins formation thins on the flanks of adjacent evaporite cored anticlines these observations indicate that during deposition of the joggins formation at least 1 km of syndepositional subsidence was facilitated by flow of underlying salt into the adjacent anticlines in contrast halo kinesis was mainly active during the mississippian in the eastern cumberland basin tatamagouche syncline minibasins were filled by mabou group sediments whereas the cumberland group is thin and lacks significant coals this basinwide comparison shows that much of the subsidence responsible for the preservation of the coal bearing joggins formation was the result of salt withdrawal at depth

phosphate sorption and desorption by thai upland soils abstract phosphate p sorption and desorption characteristics have been investigated for sixty two representative samples of the major thai upland agricultural soils which are oxisols and ultisols formed on diverse parent materials and under various climatic conditions p sorption characteristics are well described by langmuir and freundlich equations values of langmuir p sorption maximum xm and b coefficient range from 47 to 1250 g g 1 soil and 0 5 to 30 ml g 1 respectively and the freundlich k varies between 12 and 1694 g g 1 and b coefficient 0 09 and 0 67 soils derived from basalt have larger values of p sorption maximum than soils on other parent materials both p sorption maximum and freundlich k are closely related to ph naf ssa total titanium aluminum and iron dithionite and oxalate extractable fe and al and other soil properties that reflect specific surface area soil ph in naf is highly effective in predicting the p sorption capacity of thai upland soils explaining 79 of the variation in p sorption by these soils p desorption curves for adsorbed p are well described by the freundlich equation the freundlich kd coefficient for p desorption is highly linearly related to the freundlich k coefficient of p sorption indicating that the above soil factors that contribute to p sorption similarly affect p desorption

architecture of coastal and alluvial deposits in an extensional basin the carboniferous joggins formation of eastern canada abstract the joggins formation was deposited in the cumberland basin which experienced rapid mid carboniferous subsidence on bounding faults a 600 m measured section of coastal and alluvial plain strata comprises cycles tens to hundreds of metres thick the cycles commence with coal and fossiliferous limestone siltstone intervals interpreted as widespread flooding events these intervals are overlain by coarsening upward successions capped by planar based sandstone mounds up to 100 m in width that represent the progradation of small river generated delta lobes into a standing body of open water developed during transgression the overlying strata contain sand rich heterolithic packages 1 8 m thick that are associated with channel bodies 2 3 m thick and 10 50 m wide drifted plant debris calamites groves and erect lycopsid trees are preserved within these predominantly green grey heterolithic sediments which were deposited on a coastal wetland or deltaic plain traversed by channel systems the cycles conclude with red siltstones containing calcareous nodules that are interbedded with thin sandstones and associated with both single storey channel bodies 1 1 5 m thick and 2 3 m wide and larger multistorey channels 3 6 m thick with incised margins numerous channel bodies at the same level suggest that multiple channel anastomosed river systems were developed on a well drained floodplain many minor flooding surfaces divide the strata into parasequences with dominantly progradational and aggradational stacking patterns multistorey channel bodies are relatively thin fine grained and modestly incised and palaeosols are immature and cumulative the abundance and prominence of flooding surfaces suggests that base level rise was enhanced whereas the lack of evidence for abrupt basinward stepping of facies belts coupled with the absence of strong fluvial incision and mature palaeosols suggests that base level fall was suppressed these architectural features are considered to reflect a tectonic architectural signature in accordance with the high subsidence basinal setting evidence for restricted marine influence and variation in floral assemblages suggests modulation by eustatic and climatic effects although their relative importance is uncertain

paleobotanical and paleoecological constraints on models of peat formation in the late carboniferous of euramerica abstract the dominant plants of the late carboniferous lowland tropics were taxonomically and structurally distinct from those of any later time periods dominance was distributed among lycopsids ferns sphenopsids pteridosperms and cordaites and each of these groups had distinctive and different ecological preferences and amplitudes peat forming habitats were dominated by lycopsids throughout the westphalian with a significant cordaitean element in the middle westphalian during the stephanian tree ferns were dominant following major extinctions near the westphalian stephanian transition each of the major plant groups had distinctive architectures and tissue composition trees contributed up to 95 of the peat biomass and tree forms of lycopsids psaronius and medullosa lack good modern analogues the cordaites were the only woody plant group to contribute significantly to peat and then only during the mid westphalian structurally wood like lycopsid bark is the major woody tissue encountered in most westphalian coals tree ferns and pteridosperms were largely parenchymatous in construction the stigmarian root systems of lycopsids also were largely parenchymatous the tissue structure of these dominant plant suggests the need for extreme caution in the inference of mire ecological conditions or vegetational structure from coal petrographic data peat formed under arborescent ferns or pteridosperms or peat repeatedly exposed to decay and rerooting by stigmarian root systems of lycopsids would have a distinctly non woody signature and yet would have formed in a forested environment a summary is presented of the autecology and synecology of mire plants emphazing the structural framework provided by lycopsids during the westphalian certain constraints in the links between peat biomass and miospore palynology are discussed in terms of over representation under representation and non representation the formulation of smith s four phase hydroseral model is discussed and compared with more recent data available from plant paleoecology the current debate over an ombrotrophic vs rheotrophic origin of late carboniferous peats relies in large part on paleobotanical data almost entirely palynological in combination with petrographic analyses ecological studies of miospores and of coal ball and compression macrofossils and the linkage of miospores to source plants permit the re evaluation of mire successional models evidence for tree lycopsids sphenopsids pteridosperms and cordaites suggests growth mainly in rheotrophic mires tree ferns are likely candidates for growth in domed mires although evidence is ambiguous and some tree ferns clearly grew under rheotrophic conditions densospores produced by at least sporangiostrobus lycopsid subtrees have been considered diagnostic of ombrotrophic conditions abundant evidence refutes this simplistic interpretation and suggests broad ecological amplitudes for densospore producers including growth under rheotrophic conditions although plant fossils alone can not resolve most of the major debates in modern coal geology paleobotany does contribute significantly to our understanding of ancient mires an approach combining paleobotanical data with petrography sedimentology and geochemistry on a case by case basis is most likely to produce a clear picture

a recently discovered amphibian trackway dromillopus quadrifidus at joggins nova scotia in 1990 a hypotype of the ichnospecies dromillopus quadrifidus matthew 1905 was discovered preserved as a cast in a rockfall of fine grained pennsylvanian westphalian b sandstone at joggins nova scotia the hypotype of this tetrapod trackway while possessing all the morphological features evident in the holotype is about five times larger it also exhibits relatively subtle salamandroid affinities thus helping confirm the original assignation minimum length of the adult amphibian trackmaker is estimated at 20 cm

late carboniferous and early permian drainage patterns in atlantic canada paleoflow data have been compiled for late carboniferous late westphalian a to early permian alluvial deposits over a large area of atlantic canada the data which include more than 36 000 measurements of large scale trough cross strata indicate a predominantly northeasterly paleoflow and suggest that a major source area lay to the southwest of the region throughout the 30 ma period represented uplands within the basin deflected paleoflow and probably formed important local drainage and sediment sources tectonostratigraphic analysis suggests that the drainage originated in the fold and thrust belt of the central appalachians and parts of the northern appalachians rivers probably followed northeast oriented structural lineaments through the older acadian mountains of the northern appalachians a considerable proportion of the rising orogen s drainage and probably detritus may have traversed basins along the strike of the mountain belt a situation analogous to that of the modern himalayas

cranial anatomy of the primitive reptile procolophon the skull of the lower triassic reptile procolophon is described on the basis of newly prepared specimens in the collection of the british museum natural history and from casts made from high fidelity natural molds it is concluded that this genus had a large tympanum supported by the supratemporal squamosal and quadratojugal the stapes remains incompletely known but probably functioned as part of an impedance matching system comparable with that of modern lizards the teeth of the upper and lower jaws are inset from the margin of the skull suggesting the presence of cheeks jaw movement is confined to the vertical plane neither resorption pits nor weakly attached crowns provide evidence of tooth replacement the position of the teeth is controlled so that the upper and lower teeth interdigitate exactly with wear facets on the anterior and posterior surfaces a natural cast of the nasal cavities resembles that of triassic cynodont therapsids suggesting the presence of turbinais and extensive olfa

archerpeton anthracos from the joggins formation of nova scotia a microsaur not a reptile new anatomical information provided by reinterpretation of the pectoral girdle and exposure of previously unprepared portions of the holotype reveals that the early tetrapod archerpeton anthracos westphalian a of joggins nova scotia is a microsaurian lepospondyl rather than a reptile as originally described archerpeton anthracos is similar to another joggins microsaur asaphestera intermedia from which it is distinguished by autapomorphies of the appendicular skeleton the discovery that a anthracos is a microsaur increases the number of lepospondyls at joggins to six species and reduces the number of amniotes to two species hylonomus lyelli and protoclepsydrops haplous

heleosuchus an enigmatic diapsid reptile from the late permian or early triassic of southern africa the primitive diapsid reptile heleosuchus griesbachi from the late permian or early triassic of southern africa is redescribed on the basis of a new cast made from the type specimen few diagnostic features of the skeleton are preserved making it difficult to establish specific affinities no characters are known that are uniquely shared with archosauromorphs in common with lepidosauromorphs but in contrast with stem diapsids cervical vertebrae 3 5 are shorter than the anterior trunk vertebrae and the transverse processes are relatively short heleosuchus may be a member of the eosuchia or an otherwise unrecognized lineage of primitive lepidosauromorphs the possibility that this specimen shows thyroid fenestration of the pelvis and a shortened and or hooked fifth metatarsal cannot be unequivocally established

phosphate sorption by calcium carbonate in some soils of the mediterranean part of spain abstract we studied the properties of caco3 and phosphate sorption of 36 calcareous soil samples collected across the mediterranean part of spain owing to its low surface area and to its relatively low phosphate sorption capacity caco3 did not influence sorption markedly other soil components of calcareous soils such as fe oxides or silicate clays appear to be quantitatively more important at least for sorption at low phosphate equilibrium concentrations

mineralogy of iron oxides in two soil chronosequences of central spain abstract the iron oxide mineralogy of soils of two river terrace sequences of the rivers jarama and henares central spain which are in close proximity was studied the degree of weathering increases with age as shown by several mineralogical and geochemical indicators such as the increase in the ratio dithionite extractable free fe total fe low values for oxalate extractable fe indicate that the fe oxides are essentially crystalline in the jarama sequence goethite is the dominant pedogenic fe oxide in the henares sequence both goethite and hematite are present in significant amounts the difference is attributed to pedoenvironmental differences such as the lower ph and the moister pedoclimate of the jarama sequence soils the sensitivity of the goethite hematite system to pedoenvironmental factors shows the limited value of iron oxides for the estimation of paleoclimatic conditions or relative age in chronosequences even in relatively small geographical areas

metalliferous coals of the westphalian a joggins formation cumberland basin nova scotia canada petrology geochemistry and palynology abstract five coals of westphalian a early middle pennsylvanian age were sampled from the joggins formation section exposed along chignecto bay at joggins nova scotia coal beds along the bay were mined beginning in the early 17th century yet there have been few detailed published investigation of the coal beds of this classic section the lowermost coal the upper coal 28 upper fundy is a high vitrinite coal with a spore assemblage dominated by arboreous lycopsid spores with tree ferns subdominant the upper portions of the coal bed have the highest ratio of well preserved to poorly preserved telinite of any of the coals investigated coal 19 clam coal has 88 total vitrinite but unlike the fundy coal bed the telinite has a poor preservation ratio and half the total vitrinite population comprises gelocollinite and vitrodetrinite the latter coal bed is directly overlain by a basin wide limestone bed the lower kimberly coal shows good preservation of vitrinite with relatively abundant telinite among the total vitrinite the middle kimberly coal which underlies the tetrapod bearing lycopsid trees found by lyell and dawson in 1852 exhibits an upward decrease in arboreous lycopod spores and an upward increase in the tree fern spore punctatisporites minutus telinite preservation increases upwards in the middle kimberly but overall is well below the preservation ratio of the upper fundy coal bed the coals all have high sulfur contents yielding up to 13 7 total sulfur for the lower lithotype of the upper fundy coal bed the kimberly coals are not only high in total and pyritic sulfur but also have high concentrations of chalcophile elements zinc ranging up to 15 000 ppm ash basis is present as sphalerite in fusain lumens arsenic and lead each exceed 6000 ppm ash basis in separate lithotypes of the kimberly coals together these data are consistent with elevated ph in planar mires the source of the elemental enrichment in this presumed continental section is enigmatic

upland ecology of some late carboniferous cordaitalean trees from nova scotia and england abstract permineralised logs and charcoal fragments composed of dadoxylon type wood and derived from cordaitalean trees are described from the upper carboniferous westphalian of nova scotia and england they exclusively occur in sandstone bodies interpreted as the deposits of braided meandering and anastomosing river channels the architecture and ecology of this type of cordaitalean has not yet been satisfactorily described estimates of tree height using an allometric approach suggest that the largest trees attained an approximate height of ca 45 m the absence of true growth rings in the logs indicate that they grew under non seasonal humid tropical conditions however the presence of charred wood fragments implies that droughts of sufficient intensity to permit wildfire did occasionally occur the charcoal fragments are usually associated with incised poorly sorted chaotically bedded channel facies interpreted as flood deposits dramatic increases in runoff and sediment discharge are known to follow the destruction of vegetation in modern wildfire events and the high energy charcoal bearing channel facies described may represent a similar geomorphic response to cordaitalean vegetation fires geomorphic sensitivity to fire is greatest for steeply sloping terrains and it is therefore probable that the cordaitaleans described in this paper occupied upland settings this palaeoecological interpretation is supported by occurrence of the cordaitalean remains in river channel deposits immediately downstream of regions of palaeo upland and by the palynological record the presence of upland forests in late carboniferous times has important implications for numerical modelling of global geochemical cycles

new embolomerous tetrapod material and a faunal overview of the mississippian aged point edward locality nova scotia canada embolomerous tetrapods moderately sized to large aquatic predators form a major faunal constituent of permo carboniferous tetrapod communities embolomeres are recognized by their distinct circul

on the discovery of a unique terrestrial faunal assemblage in the classic pennsylvanian section at joggins nova scotia a rich fossil assemblage discovered from the classic pennsylvanian locality of joggins nova scotia is here described for the first time the 2 m thick hebert sandstone within the lower joggins formation of early langsettian age is the most productive stratum at joggins of terrestrial tetrapods and the pulmonate gastropod dendropupa vetusta exclusive of the historic fossil forest locality of dawson and lyell and the most productive pennsylvanian locality in the world of the large unionoid bivalve genus archanodon although the land snail archanodontid bivalve tetrapod assemblage of the hebert sandstone comprises a unique late paleozoic terrestrial dryland biota individual taxa were not endemic to drylands alone

robert lynn carroll an appreciation this issue of the canadian journal of earth sciences is dedicated to robert l carroll in honour of his extensive contributions to vertebrate paleontology and evolution this career resume presents an appreciation of his major contributions and lists his numerous scientific publications

mineralogy composition and alteration of mars pathfinder rocks and soils evidence from multispectral elemental and magnetic data on terrestrial analogue snc meteorite and pathfinder samples major element multispectral and magnetic properties data were obtained at ares vallis during the mars pathfinder mission to understand the compositional mineralogical and process implications of these data we obtained major element mineralogical and magnetic data for well crystalline and nanophase ferric minerals terrestrial analogue samples with known geologic context and snc meteorites analogue samples include unaltered palagonitic and sulfatetic tephra from mauna kea volcano hydrolytic and acid sulfate alteration steam vent material from kilauea volcano hydrolytic alteration and impactites from meteor crater relithification salient results for mars pathfinder include 1 band depths bd530b and bd600 and the reflectivity ratio r800 r750 are consistent with the dominant ferric mineral being nanophase ferric oxide associated with an unknown amount of h2o and occurring in composite particles along with subordinate amounts of other ferric minerals hematite and hematite plus nanophase goethite are most consistent with the data but maghemite akaganeite schwertmannite and nanophase lepidocrocite are also possible interpretations ferric oxides that are consistently not favored by the data as sole alteration products are jarosites and well crystalline goethite and lepidocrocite 2 the strength of the ferric adsorption edge r750 r445 implies the fe3 fe2 values for pathfinder rock and soil are within the ranges 0 7 3 and 3 20 respectively 3 ferrous silicates are indicated for subsets of pathfinder rocks and soils one subset has a band minimum near 930 nm that can attributed to low ca pyroxene alternatively the band could be a second manifestation of certain ferric oxides including nanophase goethite maghemite akaganeite and schwertmannite another subset has a negative spectral slope from 800 to 1005 nm which could result from the high energy wing of a high ca pyroxene and or olivine band a mixture of bright and dark materials and for rocks thin coatings of bright dust on dark rocks 4 chemical data on pathfinder rocks and soils are consistent with two component mixtures between an andesitic rock with low mgo and so3 concentrations soil free rock and a global basaltic soil with high mgo and so3 concentrations rock free soil pathfinder rock free soil can be modeled as a chemical mixture of snc meteorites and the pathfinder soil free rock 5 pathfinder soil cannot be obtained by chemical alteration of pathfinder rocks by any of the hydrolytic and acid sulfate alteration processes we studied presumably global mixing has obscured and possibly erased the elemental signatures of chemical alteration 6 the strongly magnetic phase in palagonitic and sulfatetic tephra is titanomagnetite and possibly its oxidation product titanomaghemite fe ti spinels the saturation magnetization of the tephra samples 0 5 2 0 am2 kg is at or below the low end of the range inferred for martian dust 4 2 am2 kg implying that lithogenic fe ti spinels are a possible candidate for the martian strongly magnetic phase 7 the predominantly palagonitic spectral signature and magnetic nature of martian soil and dust are consistent with glassy precursors with imbedded fe ti spinel particles comparison with lunar glass production rates suggests that production of sufficient quantities of glassy materials on mars by volcanic and impact processes is sufficient to account for these observations

tetrapod remains from the late mississippian pomquet formation near grand etang nova scotia isolated amphibian bones are preserved in freshwater sediments of the namurian a pomquet formation near grand etang nova scotia this assemblage resembles other late mississippian lakebed or estuarine faunas in that most of the remains can be confidently attributed to one or more taxa of embolomere order anthracosauria or to the order colosteoidea although they are indeterminate at the level of genus and species however a number of tetrapod elements of uncertain affinities suggests a much more diverse fauna

the pennsylvanian tropical biome reconstructed from the joggins formation of nova scotia canada the pennsylvanian langsettian joggins formation contains a diverse fossil assemblage first made famous by lyell and dawson in the mid 19th century collector curves based on c 150 years of observation suggest that the joggins fossil record is relatively complete a key feature of the site is that fossils occur in par autochthonous assemblages within a narrow time interval