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| Hekinian, Roger; Chaigneau, M.; Cheminee, J.l.. |
| During the 1972 Midlante* cruise of the RV Jean Charcot to survey a limited area of the rift valley south of the Azores, a dredge (CH-DR11) was taken at a depth of 1,360 fathoms in a depression near the foot of the eastern wall at latitude 36° 49.3' N and longitude 33° 15' W. Two types of rocks were recognized from their structure and their degree of weathering. One type is "slab-like" rock, 2 to 13 cm in diameter and 1 to 2 cm thick (Fig. la and b). The other type of rock consists of oval glassy pebbles (1 to 5 cm in diameter, Fig. 1c) which were observed to jump and explode, one or two at a time, for 3 d after the dredge haul was emptied on to the deck of the ship. [NOT CONTROLLED OCR] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1973 |
URL: http://archimer.ifremer.fr/doc/1973/publication-5155.pdf |
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| Chaigneau, M.; Hekinian, Roger; Cheminee, J.l.. |
| Magmatic gases extracted and analysed from basaltic rocks collected in the FAMOUS area near 36° 50' N in the Atlantic ocean show that the total amount of gas included in the samples varies between about 500 pprn to 1600 ppm. The main gaseous phases included in the various types of basalts consist of CO2 (270-700 ppm), CO (150-800 ppm), HCI (100-1000 ppm), H2 (0-50 ppm), SO2 (up to 175 ppm), N2 (up to about 213 ppm) and traces of hydrocarbons (up to about 24 ppm). The relative amount of CO, CO2 and SO2 varies with both the degree of crystallinity of the rock and with fractional crystallization and/or fractional melting.The glassy margin of pillow lavas have a higher CO/C02 ratio than the more crystalline interior. The most fractionated rocks of the series... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1980 |
URL: http://archimer.ifremer.fr/doc/1980/publication-5266.pdf |
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| Bellaiche, G.; Cheminee, J.l.; Francheteau, Jean; Hekinian, Roger; Le Pichon, Xavier; Needham, H.d.; Ballard, R.d.. |
| THE Rift Valley of the Mid-Atlantic Ridge, within which lies a segment of the accreting plate boundary between Africa and North America, is well defined between 36°40'N and 36°55' N. It is about 30 km wide and 1.5 km deep in that area (Fig. 1). This small portion of the rift, WSW of the Azores, was chosen as the primary target of the French-American Mid-Oceanic Undersea Survey (FAMOUS) programme, and many surface ship studies have heen conducted already. We report here preliminary results of seven dives into the deepest part of the Rift Valley that were made by the bathyscaphe Archimède during the summer of 1973. [NOT CONTROLLED OCR] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1974 |
URL: http://archimer.ifremer.fr/doc/1974/publication-5443.pdf |
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