A new ‘bone-cracking’ dasyurid (marsupialia), from the Miocene of Riversleigh,northwestern Queensland

Ganbulanyi djadjinguli gen. et sp. nov. is described on the basis of an upper molar and premolar from an early-late Miocene site in Riversleigh, northwestern Queensland. The paucity of material constrains certainty in the determination of it's phylogenetic position. But, among dasyuromorphians, and dependent on the interpretation of tooth homology, this species shows unequivocal synapomorphies only with the derived dasyurine Sarcophilus, and/or Barinya wangala, a possible sister taxon to the modern dasyurid radiation (i.e., Sminthopsinae, Phascogalinae, Dasyurinae). Other apomorphies, evident in G. djadjinguli, are common to both carnivorous thylacinids and dasyurids within the order. Some dental features of Ganbulanyi djadjinguli are treated as adaptations to a ‘bone cracking’ habitus. If this interpretation is correct, then this species represents the only pre-Pliocene Australian taxon known to occupy such a niche and perhaps the smallest specialist ‘bone-cracker’ within Mammalia.     

Opposing peace: English political pamphlets against the Treaty of Madrid in 1630

ABSTRACT

In November 1630 the Treaty of Madrid was signed between Philip IV, king of Spain, and Charles I, king of England. During the peace negotiations several pamphlets critical of the pro-Spanish policy of Charles I were printed in England. These publications contributed to the development of an increasing criticism of Charles I, by identifying his neutral European policy with pro-Spanish policies. The anti-Spanish and anti-Catholic rhetoric, which formed the basis of this criticism, was used to promote an aggressive foreign policy and consequently an active opposition to the king. The following pamphlets are discussed in this paper: Considerations T ouching a W arre with Spaine; The M erchandises of Popish P riests; The English Spanish Pilgrim; Further O bservations of the English Spanish Pilgrim; The P ractise of P rinces; The P resent E state of Spayne; and Three S everall T reatises C oncerning the T ruce.     

Shackleton Limestone archaeocyaths

A new monotypic genus of cheirurine trilobite, Azyptyx, is described based on the new species A. toongabbiensis from Early Devonian (late Lochkovian) limestones of the Wurutwun Formation near Toongabbie, Victoria. A feature of the genus that is unusual for the subfamily is a continuous basal glabellar furrow (S1) that does not normally meet the occipital furrow medially.     

3D numerical modeling of hydrothermal processes during the lifetime of a deep geothermal reservoir

Understanding hydrothermal processes during production is critical to optimal geothermal reservoir management and sustainable utilization. This study addresses the hydrothermal (HT) processes in a geothermal research doublet consisting of the injection well E GrSk3/90 and production well Gt GrSk4/05 at the deep geothermal reservoir of Groß Schönebeck (north of Berlin, Germany) during geothermal power production. The reservoir is located between ?4050 to ?4250 m depth in the Lower Permian of the Northeast German Basin. Operational activities such as hydraulic stimulation, production (T = 150°C; Q = ?75 m³ h^?1; C = 265 g l^?1) and injection (T = 70°C; Q = 75 m³ h^?1; C = 265 g l^?1) change the HT conditions of the geothermal reservoir. The most significant changes affect temperature, mass concentration and pore pressure. These changes influence fluid density and viscosity as well as rock properties such as porosity, permeability, thermal conductivity and heat capacity. In addition, the geometry and hydraulic properties of hydraulically induced fractures vary during the lifetime of the reservoir. A three‐dimensional reservoir model was developed based on a structural geological model to simulate and understand the complex interaction of such processes. This model includes a full HT coupling of various petrophysical parameters. Specifically, temperature‐dependent thermal conductivity and heat capacity as well as the pressure‐, temperature‐ and mass concentration‐dependent fluid density and viscosity are considered. These parameters were determined by laboratory and field experiments. The effective pressure dependence of matrix permeability is less than 2.3% at our reservoir conditions and therefore can be neglected. The results of a three‐dimensional thermohaline finite‐element simulation of the life cycle performance of this geothermal well doublet indicate the beginning of thermal breakthrough after 3.6 years of utilization. This result is crucial for optimizing reservoir management. Geofluids (2010) 10 , 406–421     

Emwadea microcarpa gen. et sp. nov.—anatomically preserved araucarian seed cones from the Winton Formation (late Albian), western Queensland,Australia

Dettmann, M.E., Clifford, H.T., Peters, M., June 2012. Emwadea microcarpa gen. et sp. nov.—anatomically preserved araucarian seed cones from the Winton Formation (late Albian), western Queensland, Australia. Alcheringa, 217–237. ISSN 0311-5518.

A new genus and species, Emwadea microcarpa Dettmann, Clifford & Peters, is established for ovulate/seed cones with helically arranged cone scales bearing a centrally positioned, inverted ovule from the basal Winton Formation (late Albian), Eromanga Basin, Queensland. The cones are small, prolate ellipsoidal (9.5–14 mm vertical axis, 6.3–8.7 mm transverse axis) with wedge-shaped cone scales bearing winged seeds attached adaxially to the scale only by tissues surrounding the vasculature entering the ovule. Ovuliferous tissue that is free from the cone scale extends distally from the chalaza; the seeds' lateral wings are derived from the integument. Foliage attached to the cones is spirally arranged, imbricate and with spreading and incurved bifacial blades with acute tips; stomata are arranged in longitudinal files and are confined to the adaxial surface. The cone organization testifies to placement within the Araucariaceae, and is morphologically more similar to Wollemia and Agathis than to Araucaria.

Mary Dettmann [mary.dettmann@qm.qld.gov.au] and Trevor Clifford, Queensland Museum, PO Box 3300, South Brisbane, Q 4101, Australia; Mark Peters, PO Box 366 Gumeracha, SA 5233, Australia. Received 31.3.2011; revised 23.8.2011; accepted 5.9.2011.

     

ATTENUATION RELATIONSHIP FOR LOW MAGNITUDE EARTHQUAKES USING STANDARD SEISMOMETRIC RECORDS

Northwestern Italian weak-motion data were used to study attenuation characteristics of horizontal peak ground acceleration (PGA) and horizontal peak ground velocity (PGV) from earthquakes of local magnitudes (M _l ) up to 5.1. Data have been provided by the RSNI (Regional seismic network of Northwestern Italy) and RSLG (Regional seismic network of Lunigiana-Garfagnana) waveform database. The database consists of more than 14000 horizontal components recorded in the period 1999-2002 by both broadband and enlarged band seismometers. The accuracy of the procedure used to extract PGA values from the velocity recordings was verified comparing observed and derived PGA values at station STV2, which was equipped with both a temporary K2 Kinemctrtcs accelerometer and Guralp CMG40 broadband sensor. The attenuation of both peak ground acceleration and peak ground velocity was found to be logarithmically distributed with a strong attenuation for low distances (less than 50 km) and low M _l values (<3.0). The resulting equations are:

Log(PGA)=?3.19+0.87M?0.042M ²?1.92 Log(R)+0.249S,

Log(PGA)=?4.23+0.76M?0.018M²?1.56 Log(R)+0.230S,

where PGA is expressed in g, PGV is expressed in m/s, M is local magnitude, R is the hypocentral distance in kilometers and S is a dummy variable assuming values of 0 and 1 for rock and soil respectively. For increasing distance and magnitude, both PGA and PGV values show a linear distribution. The validity range of the obtained attenuation relationships is 0–200 km for distances and M _l up to 4.5. Sensitivity studies performed by analysis of residuals, showed that predicted PGA and PGV values are stable with respect to reasonable variations of the model and distances providing the data. Comparisons with attenuation relationships proposed for Italian region, derived from strong motion records, are also presented.     

A review of the Quaternary Tayassuidae (Mammalia,Artiodactyla) from the Tarija Valley,Bolivia

Five successive events can be widely recognized in the Tremadoc to early Arenig graptolite sequences of the world: 1, appearance of Dictyonema flabelliforme s.l. at the base; 2, appearance of Anisograptus; 3, appearance of Clonograptus and/or Adelograptus; 4, appearance of Temnograptus, Kiaerograptus, large Clonograptus and Tetragraptus; and 5, appearance of Tetragraptus approximatus at the base of the Arenig. The five events are used as a basis for distinguishing 5 successive graptolite assemblages and for correlating Tremadoc sequences. The most precisely and confidently correlated horizon is that of event 5, the appearance of T. approximatus; the next best is that based on event 4. Derivation of the biradiate Anisograptids, Clonograptus, and Adelograptus, from their presumed ancestor, Dictyonema flabelliforme, now appears to have passed through a stratigraphically, if not phyletically, intermediate stage represented by the triradiate Anisograptus, Triograptus and Bryograptus.     

Correlation between dental occlusal wear and approximal facet length

The aim of this paper is to examine the relationship between occlusal surface wear and approximal facet length in a North American archaeological sample of modern human hunter–gatherers (n = 111) and agriculturalists (n = 123). First maxillary molars (M¹) were selected. The approximal wear facet was measured on the mesial surface of each M¹ at the widest breadth using needle tipped digital callipers. Digital images were taken of the occlusal surface and wear was recorded as the percentage of dentine exposed to the total occlusal surface. Independent age estimate was based on age‐related changes, (pubic symphysis and auricular surface). Results show the hunter–gatherers had a significantly faster rate of wear on both tooth surfaces compared to the agriculturalists in each of the four age groups. Both lifeway groups showed a positive correlation between the two tooth surfaces during the early stages of tooth wear (less than 25% occlusal wear), where the percentage of occlusal wear and the length of the approximal facet increased at a similar rate. During the middle and final stages of tooth wear (occlusal wear greater than 35%) there was a strong negative correlation between the two surfaces in both groups. It is suggested this pattern is due to the shape and function of the M¹. Both correlations were more extreme in the hunter–gatherers than the agriculturalists. When the per cent of occlusal wear exceeded 35% the length of the approximal facet started to decrease, and it is therefore recommended studies that include approximal wear exclude molars with heavy occlusal wear. Copyright © 2010 John Wiley & Sons, Ltd.     

The morphology of dayside Birkeland currents

Intense (10⁵ A) electric currents flow into and from the Earth's two polar ionospheres near magnetic noon. These currents, called Birkeland or magnetic field-aligned currents, are the agent by which momentum couples from the flowing solar wind plasma to drive plasma motions in the high latitude ionosphere. Coupling is strongest when the interplanetary magnetic field (IMF) has a southward component and when this occurs there exist two principal regions of Birkeland current near magnetic noon called the region 1 and the cusp systems. We present a simple model bringing theoretical order to the many patterns proposed previously for the morphology of these dayside Birkeland currents as observed by orbiting satellites in the topside polar ionosphere. Specifically we show that the cusp Birkeland current system is not a latitudinally separate region but is instead the extension in longitude of the region 1 Birkeland current from either dawn or dusk; which particular one depends on the sign of the east-west (Y) component of the IMF. The presence of an IMF Y-component therefore leads to two region 1 current systems near magnetic noon, with the poleward one being that previously called the ‘cusp’ system.     

FROM SUSA TO ANURADHAPURA: RECONSTRUCTING ASPECTS OF TRADE AND EXCHANGE IN BITUMEN‐COATED CERAMIC VESSELS BETWEEN IRAN AND SRI LANKA FROM THE THIRD TO THE NINTH CENTURIES AD*

In contrast with artefactual studies of long‐distance trade and exchange in South Asia during the Prehistoric and Early Historic periods ( Ardika et al. 1993 ; Gogte 1997 ; Krishnan and Coningham 1997 ; Tomber 2000 ; Gupta et al. 2001 ; Ford et al. 2005 ), few scientifically orientated analyses have focused on artefacts from the region's Historic period. During excavations at the ancient city of Anuradhapura, Sri Lanka, a number of buff ware ceramics with a putative organic coating on the interior were recovered ( Coningham 2006 ). Dated stylistically to between the third and ninth centuries ad , analysis of the coatings using gas chromatography–mass spectrometry (GC–MS) and stable isotope analysis (carbon and deuterium) confirmed that the coatings are bitumen—an organic product associated with petroleum deposits. There are no known bitumen sources in Sri Lanka, and biomarker distributions and isotopic signatures suggest that the majority of the samples appear to have come from a single bitumen source near Susa in Iran. The relationship between the bitumen coatings and the vessels is discussed, and it is suggested that the coatings were used to seal permeable ceramic containers to allow them to transport liquid commodities. This study enhances our knowledge of networks of trade and exchange between Sri Lanka and western Asia during Historic times.     

The effect of growth on stable nitrogen isotope ratios in subadult bone collagen

Stable nitrogen isotopes have been used to reconstruct infant feeding practices as nursing infants have elevated δ¹⁵N ratios compared with their mothers. However, infancy is also a time of rapid growth, which may alter nitrogen isotope diet‐to‐tissue spacing. Several studies have documented a decrease in δ¹⁵N during growth in tissues with relatively fast accretion rates. This study investigates the effect that the growth of long bones, via collagen accretion, has on δ¹⁵N ratios. Long bones from individuals aged seven to nineteen years were obtained from a protohistoric ossuary in Ontario, Canada. Analysis of juveniles and adolescents permitted the examination of growth in a group who were not also nursing. It is concluded that a nitrogen isotope growth effect is not detectable in bone collagen from juveniles and adolescents, because: (1) δ¹⁵N ratios are not significantly different among the epiphyses, metaphyses and diaphysis of a growing long bone; (2) δ¹⁵N ratios are not significantly different between faster‐growing versus slower‐growing metaphyses; and (3) δ¹⁵N ratios are not significantly different between bones (or areas of a bone) that are still undergoing growth, versus bones that have ceased growing. The relatively slow speed of collagen accretion may explain why a growth effect is not manifested. Ultimately this research lends support to the use of nitrogen isotopes from bone collagen for infant feeding reconstructions. Copyright © 2009 John Wiley & Sons, Ltd.     

Aging mountain gazelle (Gazella gazella): refining methods of tooth eruption and wear and bone fusion

This paper refines current methods for aging mountain gazelle (Gazella gazella), one of the most common species hunted by prehistoric humans in the southern Levant. Most importantly, we present a new tooth wear scheme for aging the lower deciduous fourth premolar (dP₄), the lower permanent molars (M₁, M₂, M₃) and the lower fourth premolar (P₄) of the gazelle. Broader wear stages for complete mandibles and individual teeth and bone fusion stages are also provided. Finally, a comparison of the tooth wear and bone fusion data indicates that the two methods can be linked at the important transition when a gazelle reaches adulthood (ca. 18 months of age). The completion of the fusion of the gazelle skeleton corresponds directly to the replacement of the dP₄ by the P₄ and the beginning of wear of the M₃. The coincidence of these aging indicators allows for direct comparison of gazelle bone fusion and tooth wear data.     

Repairs to an injured early Middle Cambrian Trilobite,Elkedra area,Northern Territory

Wang, Y., Shih, C., Szwedo, J. &; Ren, D. iFirst article. New fossil palaeontinids (Hemiptera, Cicadomorpha, Palaeontinidae) from the Middle Jurassic of Daohugou, China. Alcheringa, 1–12. ISSN 0311-5518.

A new genus and species assigned to the extinct family Palaeontinidae, Synapocossus sciacchitanoae Wang, Shih &; Ren, is described from the Middle Jurassic of Daohugou in Inner Mongolia, China. This new genus is established based on well-preserved fossil specimens with body and complete forewings and hind wings. It differs from other described genera by the following characters: small body size, RP and M₁ coalescing for an interval on the forewings and M_3 + 4 without bifurcation on the hind wings. The RP coalescence with M₁ in Synapocossus Wang, Shih &; Ren previously reported only in Turgaiella Becker-Migdisova &; Wootton, seems to be associated with strengthening of the anterior wing margin. The intra-specific and individual variations of Synapocossus and numerous other insect fossils of northeastern China probably indicate long-lasting ecological stresses and a competitive environment in the Middle Jurassic to Early Cretaceous ecosystems.     

Satellite image analysis of changes in glacier cover in Canada's northern Mackenzie Mountain Range (1987–2017)

The state of a group of glaciers in the northern Mackenzie Mountains across the Yukon‐Northwest Territories border was investigated over a period of three decades, using Landsat TM and OLI imagery from 1987, 1994, 1999, 2004, 2013, and 2017 to examine changes in glacier extents. A thresholded red/shortwave infrared band ratio image was used to delineate glacier boundaries. The total area of 74 glaciers in the study area decreased from 52.78 ± 1.32 km² in 1987 to 24.89 ± 0.62 km² in 2017, a loss of 27.89 ± 1.39 km² or 52.8 ± 2.6%, with a mean rate of reduction of 1.8% · a^?1. Smaller glaciers experienced larger relative changes in area. In this study, the rates of reduction are high compared to decreases reported for other glaciers in the region in the late 20^th century. Based on linear extrapolation of the trend in values of total glacier area, it is predicted—subject to uncertainties in how glaciers diminish in size and eventually disappear—that the study area could be free of visible glacier cover within three decades.     

Geochemistry and origin of natural gases dissolved in brines from gas fields in southwest Japan

Previous geochemical studies indicated that most natural gases dissolved in brines in Japan are of microbial origin, consisting of methane produced via carbonate reduction. However, some of those from gas fields in southwest Japan contain methane relatively enriched in ¹³C, whose origin remains to be clarified. To address this issue, chemical and isotopic analyses were performed on natural gases and brines from the gas fields in Miyazaki and Shizuoka prefectures, southwest Japan. Methane isotopic signatures (δ¹³C ≈ ?68‰ to ?34‰ VPDB; δ²H ≈ ?183‰ to ?149‰ VSMOW) suggest that these gases are of microbial (formed via carbonate reduction) or of mixed microbial and thermogenic origin. The relatively high δ²H‐CH₄ values and their relationship with the δ²H‐H₂O values argue against the possibility of their formation via acetate fermentation. The δ¹³C‐CO₂ values (≈?5‰), together with the slope of the correlation between δ²H‐CH₄ and δ¹³C‐CH₄ (Δδ²H‐CH₄/Δδ¹³C‐CH₄ ≈ 1), contradict the possibility of their formation via carbonate reduction followed by partial oxidation by methanotrophs. The ³He/⁴He ratios of the gases from Miyazaki (≈0.11–1.3 Ra) and their low correlation with δ¹³C‐CH₄ values do not support an abiogenic origin. It is inferred therefore that the high δ¹³C‐CH₄ values of natural gases dissolved in brines from gas fields in southwest Japan are indications of the contribution of thermogenic hydrocarbons, although whether abiogenic hydrocarbons contribute significantly to the gases from Shizuoka requires further investigation. This study has clarified that, for the future exploration of natural gases in southwest Japan, we should adopt the strategies for conventional thermogenic gas accumulations, such as checking the content, type and maturity of organic matter in the underlying sedimentary rocks.     

Solubility of quartz in crustal fluids: experiments and general equations for salt solutions and H2O–CO2 mixtures at 400–800°C and 0.1–0.9 GPa

The solubility of quartz has been measured in a wide range of salt solutions at 800°C and 0.5 GPa, and in NaCl, CaCl₂ and CsCl solutions and H₂O–CO₂ fluids at six additional P–T conditions ranging from 400°C at 0.1 GPa to 800°C at 0.9 GPa. The experiments cover a wide range of compositions along each binary. At P–T conditions where the density of pure water is low (0.43 g cm^?3), addition of most salts produces an enhancement of quartz solubility at low to moderate salt concentrations (salt‐in effect), although quartz solubility falls with further decrease in X_H2O. At higher fluid densities (0.7 g cm^?3 and greater), the salt‐in effect is generally absent, although this depends on both the cation present and the actual P–T conditions. The salt‐in effect is most readily produced by chloride salts of large monovalent cations, while CaCl₂ only produced a salt‐in effect at the most extreme conditions of high‐T and low‐P investigated (800°C at 0.2 GPa). Under most crustal conditions, the addition of common salts to aqueous fluids results in a lowering of quartz solubility relative to that in pure water (salt‐out effect). Comparing quartz solubility in different fluids by calculating X_H2O on the basis that all salts are fully associated under all conditions yields higher quartz solubility in solutions of monovalent salts than in solutions of divalent salts, absolute values are also influenced by cation radius. Quartz solubility measurements have been fitted to a Setchenow‐type equation, modified to take account of the separate effects of both the lowering of X_H2O and the specific effects of different salts, which are treated as arising through distinct patterns of non‐ideal behaviour, rather than the explicit formation of additional silica complexes with salt components. Quartz solubility in H₂O–CO₂ fluids can be treated as ideal, if the solvation number of aqueous silica is taken as 3.5. For this system the solubility (molality) of quartz in the binary fluid, S is related to its solubility in pure water at the same P–T conditions, S^o, by: Quartz solubility in binary salt systems (H₂O–RCl_n) can be fitted to the relationship: where salt concentration mRCl_n is expressed as molality and the exponent b has a value of 1 except under conditions where salting‐in is observed at low salt concentrations, in which case it is <1. Under most crustal conditions, the solubility of quartz in NaCl solutions is given to a good approximation by: We propose that quartz solubility in multicomponent fluids can be estimated from an extended expression, calculating X_H2O based on the total fluid composition (including dissolved gasses), and adding terms for each major salt present. Our experimental results on H₂O–NaCl–CO₂ fluids are satisfactorily predicted on this basis. An important implication of the results presented here is that there are circumstances where the migration of a fluid from one quartz‐bearing host into another, if it is accompanied by re‐equilibration through cation exchange, may lead to dissolution or precipitation of quartz even at constant P and T, with concomitant modification of the permeability structure of the deep crust.     

‘Oh motherland I pledge to thee …’: a study into nationalism,gender and the representation of an imagined family within national anthems

In this paper, we argue that beyond understanding nations as imagined communities, the metaphor of an ‘imagined family’ or ‘filial community’ is a more useful concept towards understanding links between gender and nationhood as family relations in four ways: (1) providing a clear, hierarchical structure; (2) prescribing social roles and responsibilities; (3) being linked to positive affective connotations; and (4) reifying social phenomena as biologically determined. In order to empirically substantiate our claim, we will explore the prevalence and use of family metaphors in a key symbol of nationhood discourses. Through a qualitative analysis of national anthems as ‘mnemonics of national identity’, we demonstrate the widespread presence of family metaphors, discussing how they reproduce ideas of family and gender. Finally, we discuss how the ‘imagined family’ as present in anthems and other forms of national representation could inform future studies of nationalism and national politics.     

New material referable to Wakaleo (Marsupialia: Thylacoleonidae) from the Riversleigh World Heritage Area,northwestern Queensland: revising species boundaries and distributions in Oligo/Miocene marsupial lions

Gillespie, A.K., Archer, M., Hand, S.J. & Black, K.H., 2014. New material referable to Wakaleo (Marsupialia: Thylacoleonidae) from the Riversleigh World Heritage Area, northwestern Queensland: revising species boundaries and distributions in Oligo/Miocene marsupial lions. Alcheringa 38, 513–527. ISSN 0311–5518.

New material of Wakaleo oldfieldi and W. vanderleueri from the Miocene freshwater limestones of the Riversleigh World Heritage Area, northwestern Queensland, is described. This material includes the first known upper dentition of W. oldfieldi and dentaries of both species bearing the previously undescribed and morphologically distinct M₃. Previously, the two species were distinguished only by size differences in P3 and the size of P₃ relative to M1. Wakaleo oldfieldi exhibits a more plesiomorphic M₃ that retains a well-developed talonid basin in contrast to W. vanderleueri, which has lost this structure. The phyletic succession and geological occurrences of Wakaleo species make this genus an important taxon in biochronological analyses of Australian Cenozoic assemblages. At Riversleigh, W. oldfieldi is found in deposits allocated to Faunal Zone B and Faunal Zone C, which are regarded as early and middle Miocene in age, respectively. The presence of this species in the Kutjamarpu Local Fauna of central Australia suggests that fauna may be of a similar age. Broader faunal correlations have suggested Faunal Zone C correlates with the middle Miocene Bullock Creek Local Fauna, which contains the more derived W. vanderleueri. Based on stage-of-evolution arguments, W. oldfieldi should occur in older deposits than those yielding W. vanderleueri. The presence of both species of Wakaleo in Faunal Zone C assemblages at Riversleigh suggests that current presumptions about the contemporaneity of the many Faunal Zone C Sites should be examined more rigorously.

Anna K. Gillespie [a.gillespie@unsw.edu.au], Michael Archer [m.archer@unsw.edu.au], Suzanne J. Hand [s.hand@unsw.edu.au] and Karen H. Black [k.black@unsw.edu.au] School of Biological Earth and Environmental Science, UNSW 2052, Sydney, Australia. Received 3.1.2014, revised 21.2.2014, accepted 21.3.2014.     

Rates of dentine mineralization in permanent human teeth

Previous experimental studies have estimated linear rates of dentine formation in modern humans to be close to 4μm day⁻¹. In this study a method similar to that first adopted by Kawasaki, Tanaka and Ishikawa⁵ was used to estimate linear rates of dentine mineralization over a period of 1200 days in both the cusps and cervical regions of several permanent tooth types. All teeth were from the same individual. Rates in the cusps of teeth with the tallest crowns were estimated to be between 5 μm day⁻¹ and 6 μm day⁻¹. This is higher than previous estimates in permanent tooth crowns, although rates in the cusp of a first permanent molar, where cusps were less tall and cuspal dentine therefore less thick, were close to previous estimates of 4 μm day⁻¹. Despite this variation in cuspal rates, mineralization rates were linear in all cusps studied over a long period of time. Rates in the cervical region, either close to the enamel dentine junction or to the cement dentine junction, were estimated to be between 1.3 μm day⁻¹ and 1.5 μm day¹¹, much slower than reported previously. Rates in the mid-portion of the dentine, in both the lateral part of the crown and in the cervical one-third of the root, rose steadily to match rates in the cuspal region, but then slowed towards the pulp chamber. These data extend the findings of previous studies on permanent human dentine. They demonstrate a wide range of mineralization rates in permanent dentine and provide a more secure basis for judging different rates in different locations of different human tooth types.     

Gas breakthrough experiments on fine-grained sedimentary rocks

The capillary sealing efficiency of fine‐grained sedimentary rocks has been investigated by gas breakthrough experiments on fully water saturated claystones and siltstones (Boom Clay from Belgium, Opalinus Clay from Switzerland and Tertiary mudstone from offshore Norway) of different lithological compositions. Sand contents of the samples were consistently below 12%, major clay minerals were illite and smectite. Porosities determined by mercury injection lay between 10 and 30% while specific surface areas determined by nitrogen adsorption (BET method) ranged from 20 to 48 m² g ^{? 1}. Total organic carbon contents were below 2%. Prior to the gas breakthrough experiments the absolute (single phase) permeability (k_abs) of the samples was determined by steady state flow tests with water or NaCl brine. The k_abs values ranged between 3 and 550 nDarcy (3 × 10^?21 and 5.5 × 10^?19 m²). The maximum effective permeability to the gas‐phase (k_eff) measured after gas breakthrough on initially water‐saturated samples extended from 0.01 nDarcy (1 × 10^?23 m²) up to 1100 nDarcy (1.1 × 10^?18 m²). The residual differential pressures after re‐imbibition of the water phase, referred to as the ‘minimum capillary displacement pressures’ (P_d), ranged from 0.06 to 6.7 MPa. During the re‐imbibition process the effective permeability to the gas phase decreases with decreasing differential pressure. The recorded permeability/pressure data were used to derive the pore size distribution (mostly between 8 and 60 nm) and the transport porosity of the conducting pore system (10^‐5–10^‐2%). Correlations could be established between (i) absolute permeability coefficients and the maximum effective permeability coefficients and (ii) effective or absolute permeability coefficients and capillary sealing efficiency. No correlation was found between the capillary displacement pressures determined from gas breakthrough experiments and those derived theoretically by mercury injection.