121
fatty acids
F
facies the appearance and characteristics of a rock unit, usually reflecting the
environmental conditions of its origin without regard to age. e.g.: A sedimentary facies is the sum total of the lithological (lithofacies) and biological
(biofacies) characteristics of a sedimentary deposit. Moreover, a sedimentary
facies analysis reveals a picture of the ancient sedimentary environment,
including the nature of the materials (detrital, ionic), the paleogeographic
position of the area of deposition (littoral, deltaic, shelf, oceanic), the biological environment, etc.
FAD (1) (geol.) first appearance datum, --7biohorizon; (2) (biochem.) flavin adenin
dinucleotid.
fallout (radioactive) during the above-ground bomb-test nuclear explosions of
the years 1945 until 1963, when the nonproliferation act was signed, radioactive fission and neutron-activated products were introduced into the higher
atmosphere and redistributed all around the globe. Subsequent precipitation has taken place for decades, reflecting fission isotopes such as i37Cs
(cesium) and 90Sr (strontium) as major components and 106Ru (ruthenium),
147Pm (prometium), and 144Ce (cerium) as minor components. 239,240pU (1.5
1016 Bq was produced in total) is one of the transuranics formed during the
nuclear explosions, while 60CO (cobalt) is one of the neutron-activated isotopes produced. After 1964, fallout also contained 238pU (4.910 14 Bq) derived
from the burn-up in the atmosphere of the SNAP-9 US space device, using
this isotope as energy source. At present the ratio 238puf2 39 ,240PU in fallout is
0.04, and any deviation from this value indicates other anthropogenic
sources, such as effluents of nuclear reprocessing plants. (Figure see p.
122,123)
fan --7deep-sea fan.
fathom unit of water depth used on fishing charts, 1.828 m. At the time when
depth was sounded with a weighted line one fathom was the distance
between the hands of the sailor stretching both arms (French: bras; English:
broad, hence "broad-fourteens", ca. 25 m deep sea area off the Dutch coast).
fatty acids organic aliphatic acids, found in fats and other lipids, are of various
types: (a) straight-chain saturated acids, with the general formula C n H 2n 0 2
and (b) straight-chain unsaturated acids with one or more double bonds in
fatty acids
F
facies the appearance and characteristics of a rock unit, usually reflecting the
environmental conditions of its origin without regard to age. e.g.: A sedimentary facies is the sum total of the lithological (lithofacies) and biological
(biofacies) characteristics of a sedimentary deposit. Moreover, a sedimentary
facies analysis reveals a picture of the ancient sedimentary environment,
including the nature of the materials (detrital, ionic), the paleogeographic
position of the area of deposition (littoral, deltaic, shelf, oceanic), the biological environment, etc.
FAD (1) (geol.) first appearance datum, --7biohorizon; (2) (biochem.) flavin adenin
dinucleotid.
fallout (radioactive) during the above-ground bomb-test nuclear explosions of
the years 1945 until 1963, when the nonproliferation act was signed, radioactive fission and neutron-activated products were introduced into the higher
atmosphere and redistributed all around the globe. Subsequent precipitation has taken place for decades, reflecting fission isotopes such as i37Cs
(cesium) and 90Sr (strontium) as major components and 106Ru (ruthenium),
147Pm (prometium), and 144Ce (cerium) as minor components. 239,240pU (1.5
1016 Bq was produced in total) is one of the transuranics formed during the
nuclear explosions, while 60CO (cobalt) is one of the neutron-activated isotopes produced. After 1964, fallout also contained 238pU (4.910 14 Bq) derived
from the burn-up in the atmosphere of the SNAP-9 US space device, using
this isotope as energy source. At present the ratio 238puf2 39 ,240PU in fallout is
0.04, and any deviation from this value indicates other anthropogenic
sources, such as effluents of nuclear reprocessing plants. (Figure see p.
122,123)
fan --7deep-sea fan.
fathom unit of water depth used on fishing charts, 1.828 m. At the time when
depth was sounded with a weighted line one fathom was the distance
between the hands of the sailor stretching both arms (French: bras; English:
broad, hence "broad-fourteens", ca. 25 m deep sea area off the Dutch coast).
fatty acids organic aliphatic acids, found in fats and other lipids, are of various
types: (a) straight-chain saturated acids, with the general formula C n H 2n 0 2
and (b) straight-chain unsaturated acids with one or more double bonds in