FN Archimer Export Format
PT J
TI X-ray synchrotron diffraction study of natural gas hydrates from African margin - art. no. L22303
BT 
AF BOURRY, Christophe
   CHARLOU, Jean-Luc
   DONVAL, Jean-Pierre
   BRUNELLI, M
   FOCSA, C
   CHAZALLON, B
AS 1:1;2:1;3:1;4:2;5:3;6:3;
FF 1:PDG-DOP-DCB-GM-LGM;2:PDG-DOP-DCB-GM-LGM;3:PDG-DOP-DCB-GM-LGM;4:;5:;6:;
C1 IFREMER, Brest Ctr, Dept Geosci Marines, Lab Geochimie Met, Plouzane, France.
   European Synchrotron Radiat Facil, F-38043 Grenoble, France.
   Univ Lille 1, CNRS, UMR, Phys Lasers Lab, F-8523 Villeneuve, France.
C2 IFREMER, FRANCE
   ESRF, FRANCE
   UNIV LILLE, FRANCE
SI BREST
SE PDG-DOP-DCB-GM-LGM
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
IF 2.744
TC 10
UR https://archimer.ifremer.fr/doc/2007/publication-3511.pdf
LA English
DT Article
DE ;synchrotron X ray diffraction;thermal expansion;natural clathrate hydrates
AB Natural gas hydrates recovered from the Congo- Angola basin and Nigerian margins are analyzed by synchrotron X- ray powder diffraction. Biogenic methane is the most abundant gas trapped in the samples and others minor components (CO2, H2S) are co-clathrated in a type I cubic lattice structure. The refinement for the type I structure gives lattice parameters of a = 11.8646 ( 39) angstrom and a = 11.8619 ( 23) angstrom for specimens from Congo- Angola and Nigerian margins respectively at 90 K. These values, intermediate between the lattice constant of less pure methane specimens and pure artificial methane hydrates, indicate that lattice constants can be affected by the presence of encaged CO2, H2S and other gas molecules, even in small amounts. Thermal expansion is also presented for Congo- Angola hydrate in the temperature range 90 - 200 K. The coefficients are comparable with values reported for synthetic hydrates at low temperature and tend to approach thermal expansion of ice at higher temperature.
PY 2007
PD NOV
SO Geophysical Research Letters ( GRL )
SN 0094-8276
PU American Geophysical Union
VL 34
IS 22
UT 000251345300001
DI 10.1029/2007GL031285
ID 3511
ER

EF