Lower Aptian Rudist Faunas (Bivalvia, Hippuritoidea) from Croatia

Lower Aptian rudist faunas from Croatia consist of Requienia? zlatarskii PAQUIER, Toucasia sp., Agriopleura sp., Glossomyophorus costatus MASSE, SKELTON & SLISKOVIC, Himeraelites sp. and Offneria sp. This assemblage has a clear Southern Tethyan (Arabo–African) significance and typifies the Early Aptian. Faunas from the interior of the Adriatic Carbonate Platform in Istria are dominated by Requieniidae while those from the northeastern area in the vicinity of Tounj–Ogulin, close to the platform margin, exhibit a higher diversity and include, beside requieniids, Caprinidae, Caprotinidae and Monopleuridae, in conjunction with evidence of open marine conditions

Charge and energy dependence of the residence time of cosmic ray nuclei below 15 GeV/nucleon

The relative abundance of nuclear species measured in cosmic rays at Earth has often been interpreted with the simple leaky box model. For this model to be consistent an essential requirement is that the escape length does not depend on the nuclear species. The discrepancy between escape length values derived from iron secondaries and from the B/C ratio was identified by Garcia-Munoz and his co-workers using a large amount of experimental data. Ormes and Protheroe found a similar trend in the HEAO data although they questioned its significance against uncertainties. They also showed that the change in the B/C ratio values implies a decrease of the residence time of cosmic rays at low energies in conflict with the diffusive convective picture. These conclusions crucially depend on the partial cross section values and their uncertainties. Recently new accurate cross sections of key importance for propagation calculations have been measured. Their statistical uncertainties are often better than 4% and their values significantly different from those previously accepted. Here, these new cross sections are used to compare the observed B/C+O and (Sc to Cr)/Fe ratio to those predicted with the simple leaky box model

Source spectral index of heavy cosmic ray nuclei

From the energy spectra of the heavy nuclei observed by the French-Danish experiment on HEAO-3, the source spectra of the mostly primary nuclei (C, O, Ne, Mg, Si, Ca and Fe) in the framework of an energy dependent leaky box model (Engelmann, et al., 1985) were derived. The energy dependence of the escape length was derived from the observed B/C and sub-iron/iron ratios and the presently available cross sections for C and Fe on H nuclei (Koch-Miramond, et al., 1983). A good fit to the source energy spectra of all these nuclei was obtained by a power law in momentum with an exponent gamma = -2.4+0.05 for the energy range 1 to 25GeV/n (Engelmann, et al., 1985). Comparison with data obtained at higher energy suggested a progressive flattening of these spectra. More accurate spectral indices are sought by using better values of the escape length based on the latest cross section measurements (Webber 1984, Soutoul, et al., this conference). The aim is also to extend the analysis to lower energies down to 0.4GeV/n (kinetic energy observed near Earth), using data obtained by other groups. The only nuclei for which a good data base is possessed in a broad range of energies are O and Fe, so the present study is restricted to these two elements

Hypelasma salevensis (FAVRE, 1913) from the Upper Kimmeridgian of the French Jura, and the Origin of the Rudist Family Requieniidae

The requieniid rudist species ‘Matheronia’ salevensis FAVRE, first described from the Tithonian of Mont Saleve, eastern France, is transferred to the genus Hypelasma PAQUIER, which is distinguished from Matheronia by possession of a posterior myophoral ledge in the left (attached) valve. Diminutive specimens from the Upper Kimmeridgian of the southern Jura are described and placed in this species. Hence, Hypelasma salevensis (FAVRE) is the stratigraphically oldest known member of the Family Requieniidae. It may also provide another example of phyletic size increase among rudists. Revised diagnoses are given for the family, genus and species. The main distinction between the requieniids and the diceratids, from among which they arose, concerns the angle between the coiling axis of the left valve and the commissural plane. In diceratids, this angle is large, such that the often sub-equal umbones tend to twist outwards from the commissural plane, so avoiding mutual interference. In requieniids, by contrast, this angle is small, such that the prominent umbo of the left valve tends to coil across the commissural plane in trochospiral to helicospiral fashion, while that of the right valve is suppressed in compensation, producing an exogyriform morphology. The requieniid modification of growth geometry, already present in H. salevensis, generated an extended basal surface on the flattened anterior wall of the left valve, implying specialized adaptation of these rudists as frictional or attached clingers. Requieniid ancestry should be sought among species of the pre-existing diceratid genera Epidiceras or Plesiodiceras, which also attached by the left valve. Although Plesiodiceras is favoured by its already more or less operculiform right valve and relatively small size, the derived condition of its posterior myophoral organisation is problematical. However, its juvenile shell shows some similarity of external form to H. salevensis, suggesting the possibility of paedomorphic evolution

SPECIE NUOVE DI FORAMINIFERI BENTONICI DELL'APTIANO INFERIORE CARBONATICO DELLE MURGE (ITALIA MERIDIONALE)

Three new species of benthic Foraminifera are here described from the Lower Aptian limestones of the Murge Region (Apulia, Southern Italy). The identified species are: Pseudolituonella conica sp. n., Voloshinoides murgensis sp. n., Archaeosepta coratina sp. n

Balloon test project: Cosmic Ray Antimatter Calorimeter (CRAC)

Cosmic ray observations from balloon flights are discussed. The cosmic ray antimatter calorimeter (CRAC) experiment attempts to measure the flux of antimatter in the 200-600 Mev/m energy range and the isotopes of light elements between 600 and 1,000 Mev/m