Changes

Bicadinanes are among the very few compounds that give substantial peaks in both the m/z 191 and 217 fragment ions. Bicadinane resins are derived from terrestrial plants that evolved in the Tertiary. The primary source plants, dipterocarps, spread slowly through Southeast Asia during the middle to late Tertiary. Bicadinanes are rare in other places and at other times, except from the Tertiary of New Zealand and Australia, where they probably originated from other species.<ref name=ch08r34>Murray, A., P., Summons, R., E., Bradshaw, J., Pawih, B., 1993, Cenozoic oil in Papua New Guinea—evidence from geochemical analysis of two newly discovered seeps, in Carman, G., J., Carman, Z., eds., Petroleum Exploration and Development in Papua New Guinea: Proceedings of the Second PNG Petroleum Convention, Australian Geological Survey, p. 489–498.</ref> Bicadinanes are often found together with oleanane.

Bicadinanes are among the very few compounds that give substantial peaks in both the m/z 191 and 217 fragment ions. Bicadinane resins are derived from terrestrial plants that evolved in the Tertiary. The primary source plants, dipterocarps, spread slowly through Southeast Asia during the middle to late Tertiary. Bicadinanes are rare in other places and at other times, except from the Tertiary of New Zealand and Australia, where they probably originated from other species.<ref name=ch08r34>Murray, A., P., Summons, R., E., Bradshaw, J., Pawih, B., 1993, Cenozoic oil in Papua New Guinea—evidence from geochemical analysis of two newly discovered seeps, in Carman, G., J., Carman, Z., eds., Petroleum Exploration and Development in Papua New Guinea: Proceedings of the Second PNG Petroleum Convention, Australian Geological Survey, p. 489–498.</ref> Bicadinanes are often found together with oleanane.

Figure 8-30 shows bicadinanes in an oil sample from Myanmar. Note that the bicadinane peaks (indicated by solid dots) appear in all three fragment ions.

[[:file:oiloil-and-oilsource-rock-correlations_fig8-30.png|Figure 8]] shows bicadinanes in an oil sample from Myanmar. Note that the bicadinane peaks (indicated by solid dots) appear in all three fragment ions.

==C_x and C_z triterpanes==

==C_x and C_z triterpanes==

[[file:oiloil-and-oilsource-rock-correlations_fig8-31.png|thumb|{{figure number|8-31}}From Philp and Gilbert<ref name=ch08r42 />); reprinted with permission from Elsevier.]]

[[file:oiloil-and-oilsource-rock-correlations_fig8-31.png|thumb|{{figure number|8-31}}From Philp and Gilbert<ref name=ch08r42 />); reprinted with permission from Elsevier.]]