Source area and tectonic provenance of Paleocene-Eocene red bed clastics from the Kurdistan area NE Iraq: bulk-rock geochemistry constraints
Paleocene-Eocene Red Beds exist along a narrow belt in the NW-SE oriented imbricate zone in northeastern Iraq and are composed of clastic rocks including conglomerate, sandstone and mudstone. Trace elements show that the lower part of the Red Beds (unit one) was derived mainly from mafic and ultramafic rocks. A decrease in mafic and ultramafic components in the upper part of the Red Beds is accompanied by an increase in felsic components indicating the exposure of both felsic and intermediate igneous bodies in the source areas. Trace elements normalized to upper continental crust confirmed the mafic and ultramafic source for the lower part of the Red Beds. Unit two and the overlying unit four reflect a style showing felsic and mafic trends with transition elements being depleted in these parts. The intervening unit three shows various patterns partly similar to units one and two depending on clast abundance. The concentrations of rare earth elements in the mudstone reaches up to 60% of the main chemical elements, therefore it is useful to concentrate on this facies for geochemical studies.