Geochemistry of siliciclastic rocks from the Shemshak Group (Upper Triassic–Middle Jurassic), northeastern Alborz, northern Iran: implications for palaeoweathering, provenance, and tectonic setting

Abstract

Com bined petrographic and geo chem i cal data of the siliciclastic sed i men tary rocks from the Shemshak Group in the northeast ern Alborz Moun tains, north of Iran are de scribed, to gether with their im pli ca tions for palaeoweathering, their prov enance, and tec tonic set ting. Based on field ob ser va tions and modal com po si tion, the sand stones are clas si fied as litharenites. The chem i cal in dex of al ter ation (CIA) in di cated that the source ter rains un der went a mod er ate in ten sity of chem i cal weath er ing. The in dex of chem i cal vari a tion (ICV) val ues in di cated that the Shemshak Group rocks were im ma ture and re lated to a source area with an ac tive tec tonic re gime. Ma jor, trace and rare earth el e ment (REE) data sug gested the dom i na tion of mixed sed i men tary (re cy cled) and ig ne ous rocks in the source area of the Shemshak Group. Petrographic and geo chem i cal char ac ter is tics of Shemshak Group rocks sug gest an ac tive con ti nen tal mar gin (ACM), which cor re sponds to the col li sion of the Iran plate with the Turan plate.

Geochemistry of surface sediments from the northwestern Gulf of Mexico: implications for provenance and heavy metal contamination

“…Hence, the low Zn con tent of this study may sug gest that the or i gin of Zn is terrigenous. The av er age val ues of tran si tion trace el e ments Cr (75 ±16) and Ni (31 ±5) are also near to the ERL val ues of marine sed i ments (81 and 20.9 µgg -1 , re spec tively) re ported by Long et al (1995), in di cat ing terrigenous or i gin (Ramos-Vázquez et al, 2018;Taheri et al, 2018). A wide vari a tion in Zr (~117-211 µgg -1 ) and Sr (~122-449 µgg -1 ) con tents in sed iments among sta tions prob a bly in di cates the frac tion ation of min er als dur ing trans por ta tion and de po si tion (Tapia -Fernandez et al, 2017).…”

Evolution of the Permo‐Triassic Satpura Gondwana Basin, Madhya Pradesh, India: Insights from geochemical provenance and palaeoclimate of the siliciclastic sediments

“…The major and trace element abundances of siliciclastic sediments are valuable indicators for the determination of tectonic settings for a sedimentary basin (Absar, 2021; Bhatia & Crook, 1986; Roser & Korsch, 1986; Taheri et al, 2018; Verma & Armstrong‐Altrin, 2013, 2016). In the SiO 2 versus K 2 O/Na 2 O diagram (Roser & Korsch, 1986) the mudstone samples from the younger formations of the Satpura Basin dominantly plot in the field of passive continental margin (PCM) (Figure 10a), whereas the mudstone samples from the Talchir Formation (i.e., the lowermost Formation) cluster towards active continental margin (Figure 10a).…”