GEOCHEMISTRY OF PALEOGENE RED BEDS IN THE NORTHERN IRAQ FORELAND BASIN: EVIDENCE FOR PROVENANCE

The Paleogene Red Bed deposits in northern Iraq crop out as a narrow northwest-southeast trending belt within the thrust zone in an active foreland basin developed adjacent to the Zagraos orogenic belt. The Red Beds are divided vertically into four units. The lower part (unit 1) is mainly composed of red mudstone and siltstone. The middle part (unit 2) is mainly composed of sandstone with thin interbeds of red siltstone. The upper part is composed of conglomerate (unit 3) covered by 100-120 m of red mudstone, siltstone and sandstone (unit 4). The geochemical stratigraphy shows an increase in transition elements and REEs while LILE and HFSE elements decrease in the lower part of the sequence. These features indicate that a mafic source supplied detritus during the deposition of the lower Red Beds and decreased in importance during the deposition of the middle and upper parts as a result of erosion or tectonic activity.