Stratigraphie et sédimentologie des « calcaires à Productus » du Carbonifère inférieur de la Montagne noire (Massif central,France)Stratigraphy and sedimentology of the Lower Carboniferous ‘Calcaires à Productus’ of the Montagne Noire (Massif Central,France)

The ‘Calcaires à Productus’ of the Montagne Noire are microbial build-ups. Two formations are defined and dated respectively as Uppermost Visean (Upper Warnantian–Brigantian) and Serpukhovian on the basis on corals. That makes these limestones out to be younger than previously stated (Lower and base of Upper Warnantian–Asbian and base of Brigantian) and indicates that the development of the olistoliths and thrusts including them, due to the Variscan orogeny, was at least as young as the Upper Serpukhovian. The Serpukhovian limestones of the Montagne Noire are correlated with the Lanet Limestone (Mouthoumet Massif, Corbières) and Ardengost Limestone (central Pyrenees). To cite this article: É. Poty et al., C. R. Geoscience 334 (2002) 843–848.     

Osmium isotopes in the aerosols of the mantle volcano Mauna Loa

Aerosols and reactive gases from the spring 1984 eruption of Mauna Loa Volcano on Hawaii were collected and analyzed for osmium and its isotopic composition. The measured¹⁸⁷Os/¹⁸⁶Os ratio of1.14 ± 0.03 is close to the ratio in matter with solar systemRe/Os abundance. This result shows that the aerosols from Mauna Loa originated in the mantle and that their composition was not or only slightly influenced by their contact with the crust.     

The role of experimental work in hydrological sciences – insights from a community survey

ABSTRACT

This opinion paper summarizes the results of an online survey on the role of experimental work in the hydrological sciences. The 20 survey questions covered various topics, such as advancements, needs, potentials and challenges in the hydrological sciences, and also touched on the issue of data sharing and data publication. A total of 336 hydrologists with both modelling and experimental backgrounds participated.     

Why and when it is useful to publish and share inconclusive results and failures: reply to “Reporting negative results to stimulate experimental hydrology”*

ABSTRACT

We thank van Emmerik et al. for their discussion of our opinion paper. We do not fully agree that publication of negative results will be very effective in promoting experimental hydrology. Instead, we think that experimental hydrology is considered to be more risky than modelling studies because of difficulties in publishing inconclusive results and the potential for failure.     

Observations of teleseismicPn phases

Summary Numerous observations of teleseismicPn phases have been made on short-period seismograph records in Sweden. The observations now cover the distance range of 2360 to 4670 km, that is about six times the distance range reported in an earlier paper. The propagation paths are exclusively confined to the Russian platform, which means that a very homogeneous structure is required for the propagation ofPn to large distances. The relation between travel-timet (sec) and distance along the earth's surface (km) ist=: (8.20±0.12)+(0±6), based on 30 observations. The real velocity ofPn (underneath Moho) is 8.15±0.12 km/sec and the corresponding Poisson's ratio, obtained by combination with the teleseismicSn velocity (4.72 km/sec), is 0.248. These are averages for the Russian platform. The problem of the relative occurrence ofPn andSn in teleseismic records is briefly discussed.     

An analysis of the time term method in refraction seismology

Linear arrangements of earthquake epicenters in Sweden suggest the existence of linear fracture zones in the lower part of the granitic layer. The geometry of the fracture zones (position, length, width, depth) and their dynamics (“accumulated” magnitude, seismic risk) are calculated. Relations to geology are briefly discussed.     

Earthquake recurrence of a particular type

The recurrence relation for Turkish earthquakes, expressed as the single-frequency versus magnitude dependence, exhibits significant maxima and minima, reflecting true physical conditions. Various mathematical formulations are developed to fit the observed data for the single or the cumulative frequency and are compared with each other as regards their accuracy and simplicity. The results may be applicable to regions with high seismicity.