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- Recent Developments in Logging Techniques and Interpretation in IndonesiaPublication . Pirard, Yves; Prins, Wliliam J.; Cramez, Carlos
- Allochthonous salt, structure and stratigraphy of the north-eastern Gulf of Mexico. Part I: StratigraphyPublication . Wu, Shengyu; Vail, Peter R.; Cramez, CarlosMajor sequences boundaries associated with eustatic sea level changes are correlated to the general stratigraphy of the north-eastern Gulf of Mexico.
- Allochthonous salt, structure and stratigraphy of the north-eastern Gulf of Mexico. Part II: StructurePublication . Wu, Shengyu; Bally, Albert W.; Cramez, CarlosThe Kinematic evolution of allochthonous salt in the north-eastern Gulf of Mexico proceeds in three stages. (1) Since the Middle Jurassic deposition, the Louann Salt was loaded by sediments causing episodic basinwartd movement of the salt, ultimately leading to large concentrations of salt masses in a slope environment by the end of the Lower Cretaceous. (2) A regime of starved sedimentation during Late Cretaceous and Early Oligocene is responsible for the stabilization of these early salt accumulations. (3) With renewed rapid accumulation of sediments, during the Neogene and pliocene, extensive allochthonous salt tongues and shetts formed by gravity spreading within the younger sediments of the slope. Autochthonous salt,allochthonous salt and detached allochthonous salt are typical stages of evolution. Major down to the basin growth faults separate allochthonous salt sheets from their original feeder stocks. Extension along down to the basin master growth faults in compensated mainly by salt withdrawal and partly by basinward shortening.
- Stratigraphic Cycles and Major Marine Source RocksPublication . Duval, Bernard C.; Cramez, Carlos; Vail, Peter R.
- Large range coherence tuned fiber optic interferometric system for application in accelerometersPublication . Lobo Ribeiro, Antonio B.; Santos, J. L.; Jackson, D. A.A low coherence interferometric system with large tracking range and self‐initialization to be used for remote signal processing of fiber optic accelerometers is investigated. The tracking range of the low coherence system is 1.1 mm at low frequency. Phase resolution better than 1 mrad/√Hz at frequencies below 600 Hz is obtained, with a dynamic range of ≊90 dB. Data are presented which show that if the system were used to process the output from a compliant cylinder‐type accelerometer, resolutions of ∼10−7 g/√Hz could be achieved.
- Optical Morphology of Hydrocarbons and Oil Progenitors in Sedimentary Rocks- Relations with Geochemical ParametersPublication . Alpern, B.; Lemos de Sousa, M. J.; Pinheiro, H. J.The objective of the present research...
- Raft tectonics in the Kwanza Basin, AngolaPublication . Duval, Bernard; Cramez, Carlos; Jackson, M. P. A.Raft tectonics (tectonique en radeaux) allows the extreme thin-skinned extension of overburden over a dêcollement of thin salt or other evaporites.
- Simple multiplexing scheme for a fiber-optic grating sensor networkPublication . Jackson, D. A.; Reekie, L.; Archambault, J. L.; Lobo Ribeiro, Antonio B.A new approach for the interrogation of a large number of fiber-optic grating sensors is proposed and demonstrated for a small number of sensors in which signal recovery is achieved by matching a receiving grating to its corresponding sensor. This technique is demonstrated for both quasi-static and periodic measurands, and the resolution achieved for a single sensor–receiving grating pair for quasi-static strain is 4.12 μ∊.
- Detection and evaluation of hydrocarbons in source rocks by fluorescence microscopyPublication . Alpern, B.; Lemos de Sousa, M. J.; Pinheiro, H. J.; Zhu, X.In pursing the detection of hydrocarbons in sedimentary rocks by conventional petrological methods, an attempt has been made to correlate standard fluorescence parameters with the quality and quantity of hydrocarbons present in crushed rocks embedded in epoxy resin. The capacity of the embedding resin, commonly used in the preparation of petrographic samples, to extract and physically fix hydrocarbons is recognized. This phenomenon permits one to measure monochromatic fluorescence parameters, I and
- A methodology for parameter estimation in seaweed productivity modellingPublication . Duarte, Pedro; Ferreira, JoãoThis paper presents a combined approach for parameter estimation in models of primary production. The focus is on gross primary production and nutrient assimilation by seaweeds. A database of productivity determinations, biomass and mortality measurements and nutrient uptake rates obtained over one year for Gelidium sesquipedale in the Atlantic Ocean off Portugal has been used. Annual productivity was estimated by harvesting methods, and empirical relationships using mortality/ wave energy and respiration rates have been derived to correct for losses and to convert the estimates to gross production. In situ determinations of productivity have been combined with data on the light climate (radiation periods, intensity, mean turbidity) to give daily and annual productivity estimates. The theoretical nutrient uptake calculated using a 'Redfield ratio' approach and determinations of in situ N and P consumption by the algae during incubation periods have also been compared. The results of the biomass difference and incubation approaches are discussed in order to assess the utility of coefficients determined in situ for parameter estimation in seaweed production models.