Plan du canton de Plimouth et partie des Baradéres.

Manuscript, pen-and-ink and watercolor.Relief shown by hachures.Oriented with north to the bottom.Shows eastern limits as of 1781 and 1790 and names of owners of real property tracts

Les roches basiques de l'Ayrole (commune de Fraïsse-sur-Agout, Hérault), massif de l'Agout, Montagne Noire. Étude chimique

The basic rocks from the Ayrole area (Montagne Noire, France) are plutonic rocks emplaced as sills between the basement complex (Somail series) and its cover (La Salvetat series). They are comagmatic and belong to a calc alkalic (with some slight tholeitic affinities) differentiated series. The chemical as well as the petrographic studies show : — early ferromagnesian cumulates, transformed by the metamorphism into gabbros with large poikililitic amphiboles, and, — mostly plagioclasic cumulates — some garnet bearing — with hypautomorphic granular texture. After the magmatic stage, these rocks have been chemically modified (lost of CaO and Na₂O, enrichment of K₂O and locally SiO₂) and have undergone catazonal metamorphism.Les roches basiques de l'Ayrole (commune de Fraïsse-sur-Agout, Montagne Noire, France) sont des roches plutoniques disposées en sills antétectoniques au contact de la série du Somail (socle) et de la série de la Salvetat (couverture). Ces roches sont des roches comagmatiques dérivées d'une série calco-alcaline (à faibles affinités tholéitiques) différenciée. L'étude chimique rejoint l'étude microscopique pour distinguer : — des cumulats ferro-magnésiens précoces, que le métamorphisme a transformés en gabbros à grandes amphiboles pœcilitiques ; — des cumulats surtout plagioclasiques à texture grenue hypidiomorphe ; certaines de ces roches contiennent du grenat. Postérieurement à ce stade magmatique, ces roches ont été modifiées (départ de CaO, Na₂O, apport de K₂O, silicification éventuelle) et ont subi un métamorphisme catazonal.Demange Michel, Frignet Bernard. Les roches basiques de l'Ayrole (commune de Fraïsse-sur-Agout, Hérault), massif de l'Agout, Montagne Noire. Étude chimique. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 100, 2, 1977. pp. 114-122

Traité des avaries communes et particulières suivant les diverses législations maritimes. Tome 1 / par Ernest Frignet,...

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Études financières sur les chemins de fer americains. I, Missouri, Kansas and Texas railway / par Ernest Frignet

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The effect of gauge length on axially incident P-waves measured using fibre optic distributed vibration sensing

© 2016 European Association of Geoscientists & Engineers Distributed vibration sensing, also known as distributed acoustic sensing, is a relatively new method for recording vertical seismic profile data using a fibre optic cable as the sensor. The signal obtained from such systems is a distributed measurement over a length of fibre referred to as the gauge length. In this paper, we show that gauge length selection is one of the most important acquisition parameters for a distributed vibration sensing survey. If the gauge length is too small, then the signal-to-noise ratio will be poor. If the gauge length is too large, resolution will be reduced and the shape of the wavelet will be distorted. The optimum gauge length, as derived here, is a function of the velocity and frequencies of the seismic waves being measured. If these attributes vary considerably over the depth of a survey, then the use of different gauge lengths is recommended. The significant increases in data quality resulting from the use of multiple gauge length values are demonstrated using field data

Vertical seismic profiles: Now just another log?

© 2015 SEG.Due to the limited number of receivers employed, acquiring a vertical seismic profile is time consuming and is therefore often excluded from a logging job to save time. The combination of a fiber optic DVS recording system, a GPS-time-based source controller, and an easily adaptable QC and visualization system results in the time required to acquire a simple VSP survey being reduced from hours to minutes. If the data are acquired as part of a conventional logging job then the acquisition does not require any additional well or rig-up time. The results shown here demonstrate that the results acquired with such a system are consistent with conventional VSP tools, even in suboptimal coupling conditions (a water-filled vertical hole)