Geochemistry of Sandstones from the Aghajari Formation, Folded Zagros Zone, Southwestern Iran: Implication for Paleoweathering condition, Provenance, and Tectonic Setting

Abstract

The Late Miocene-Pliocene Aghajari Formation is exposed throughout the Folded Zagros Zone and consists of fluvial sediments. Aghajari Formation sandstones are characterized by low to moderate SiO 2 contents, variable abundances of major elements and a relatively high proportion of ferromagnesian elements. Evidence from discrimination diagrams of sedimentary provenance, tectonic setting, major element geochemistry, and Sc/Th, Cr/Th, Co/Th, Zr/ Sc, La/Sc, La/Co, Cr/Sc, and Y/Ni values show that the Aghajri Formation sediments were derived from felsic and intermediate sources. The chemical index of alteration (CIA: 59.2-77.14) revealed low to moderately weathered source rocks. The major and trace element concentrations indicate deposition in an active continental margin and passive continental margin settings.

Vertebrate footprints from the Agha Jari Formation (late Miocene-Pliocene), Zagros Mountains, and a review of the Cenozoic vertebrate ichnites in the Persian Gulf region

“…Continental to shallow marine conditions generally have reported for the depositional environments of the Agha Jari Formation (Motiei 1993, Ghazban & Motiei 2009, and continental conditions are confirmed by the occurrence of terrestrial vertebrate footprints. The lithofacies of the Agha Jari Formation changes from mostly continental clastic sediments in the Dezful Embayment to marine characteristics in the Coastal Fars (Bahrami 2009, Pirouz et al 2011, Sahraeyan & Bahrami 2012. The Agha Jari Formation is late Miocene to Pliocene in age base on charophytes, microfauna, such as foraminifers and ostracods, and macrofauna such as bivalves (James & Wynd 1965).…”

Gradation and geochemistry of the Fenced Lagoon sediments (Bandar Anzali) with regard to source rock and tectonic location

“…Determination of tectonic location is influenced by factors such as sedimentation, diagenesis and initial composition of sediment (Pettijohn et al, 1987;Bhatia, 1983;Chamley, 1990). Therefore, the main elements of the sand can be used to determine their tectonic position (Bhatia, 1983;Von Eynatten, 2003;Armstrong-Altrin &Verma 2005;Al-Juboury et al, 2009;Sahraeyan & Bahrami, 2012 As shown in Fig. 7, based on changes in the values of the main elements, the cranial rocks of oceanic arch islands,, continental arch islands, active continental margin, and passive margin can be separated from each other.…”

Sedimentology and palaeogeography of conglomerates from the Aghajari Formation in Zagros Basin, SW Iran

“…LCCSC Lithofacies (Aghajari Formation) are the products of alluvial systems, mainly bedload streams. These lithofacies can be interpreted as channel lags [8][9][10]18]. Horizontally stratified or unstratified conglomerates with clast imbrication record deposition on a flat bed with vigorous grain transport such as might occur on the top of a longitudinal bar or on a channel floor and textural variation may relate to water stage changes [19].…”

“…In order to present detailed information about this topic, one of the obvious outcrops of this formation in the southeast of Sarvestan was investigated, and thereby the palaeogeography of the region was determined. Analytical work on sedimentology shows that these coarse-grained clastic rocks were deposited as fluvial deposits by temporary or permanent rivers in response to uplift of the Zagros Mountain range in the Upper Miocene-Pliocene [1][2][3][4][5][6][7][8][9][10]. Tectonically the area is part of a foreland basin [5,11] filled with a thick sequence of predominantly coarse clastic sedimentary rocks.…”

“…Palaeoalluvial structures were examined in a wide range of tectonic settings, including foreland basins. Traditionally, the sediments of foreland basins, also the Aghajari Formation sediments, were considered as continental molasse [8][9][10]12]. …”