FN Archimer Export Format PT J TI Alteration, fractional crystallization, partial melting, mantle properties from trace elements in basalts recovered in the north atlantic BT AF BOUGAULT, Henri JORON, Jean-Louis TREUIL, Michel AS 1:;2:;3:; FF 1:;2:;3:; TC 0 UR https://archimer.ifremer.fr/doc/1979/publication-5253.pdf LA English DT Article DE ;Histoire Ifremer AB .-Alkali metals prove to be very sensitive to alteration process even if this process is moderate. It is very difficult to use these elements to trace magmatic processes since their concentration may Vary within an homogeneous "unaltered" unit. From all the basaltic units investigated, a classification of "low partition coefficient" elements is presented (Sc, Ti, V, Y, Zr, Nb, La-Tb , Hf, Ta, Th) . The incompatible elements ratios (Y/Tb, Zr/Hf, Nb/Ta) are constant in the samples studied and are nearly equal to the same ratios in chondrites. This is consistent with the existence of an homogeneous primordial mantle at the scale of the North Atlantic, compatible with a chondritic composition of the earth. [NOT CONTROLLED OCR] PY 1979 SO 2nd Maurice Ewing Symposium PU AGU BP 352 EP 368 ID 5253 ER EF