Plant to plant differences in fractionations between dD values of n-alkyl compounds and their precipitation source may introduce the greatest error in interpreting rainfall amount.

Terwilliger, Valery J. , Eshetu, Zewdu , Disnar, Jean-Robert , Jacob, Ji¿½ri¿½my , Paul Adderley, W. , Huang, Yongsong , Alexandre, Marcelo , Fogel, Marilyn L.

Environmental changes and the rise and fall of civilizations in the northern Horn of Africa: An approach combining ?D analyses of land-plant derived fatty acids with multiple proxies in soil

Terwilliger, V. J., Eshetu, Z., Disnar, J.-R., Jacob, J., Paul Adderley, W., Huang, Y., Alexandre, M. and Fogel, M. L.: Environmental changes and the rise and fall of civilizations in the northern Horn of Africa: An approach combining δD analyses of land-plant derived fatty acids with multiple proxies in soil, Geochimica et Cosmochimica Acta, 111, 140–161, doi:10.1016/j.gca.2012.10.040, 2013.

HP 6890 GC, AS 200 autosampler, Finnigan GC Combustion III module, Finnigan MAT Delta+ XL mass spectrometer at Brown University and Trace ThermoFisher GC, Finnigan GC Combustion III module, Finnigan MAT Delta+ XL mass spectrometer at Carnegie Institution

VG Isocarb system attached to a SIRA-II mass spectrometer

; archiveType changed - was originally Speleothem (SP)

Replication of analyses on four stalagmites from the same cave

The oxygen fractionation between these modern straw stalactites and the average drip water corresponds to the equilibrium fractionation calculated from the O?Neil et al. (1969) calcite?water calibration at cave temperatures of 16i¿½C (Peqiin) and 18i¿½C (Soreq).

The association of minimum d18O values in speleothems with high cave water stands indicative of increased rainfall on land, and the coincidence of the corresponding low d18O G. ruber values with sapropel events indicative of enhanced rainfall above the Mediterranean Sea, demonstrate that both land and sea systems simultaneously experienced enhanced rainfall during these events

The modern analog supporting the association of enhanced rainfall with minimum speleothem I´18O values is the present-day relationship between decreasing rainfall I´18O and increasing annual rainfall amount (Fig. 4).