عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The siliciclastic Dahu Strata (Early Cambrian), in the Central Iran, 280 metres thick, in the Gazouieyeh area, rests with an erosional surface on Protrozoic-Early Cambrian sedimentary rocks (Dezu Series). This strata disconformably overlain by Middle Cambrian-Late Cambrian marine carbonate rockse (Kouh-Banan Formation). Based on field and Laboratory studies, 3 association facies, shale-sandstone and conglomerate have been identified. Mainly, sandstones are rich in quartz, feldspars, and rarely contain rock fragments (metamorphic and sedimentary). The sandstones have a wide compositional range from quartzarenite to arkose, feldspathic litharenite and rarely litharenite (chertarenite). According to plots of feldspar garins, total quartzose grains, and total unstable lithic fragments, they were derived from craton interior, transitional continental, and recycled orogen sources. The Dahu sandstones experienced diagenetic events that included compaction and pressure solution, cementation (mostly by silica, carbonate, Fe-oxide, clay and rarely by barite), grain fracturing, alteration of unstable grains, dissolution and replacement. Based on petrological and geochemical studies, we interpreted the diagenetic history for the Dahu sandstones, which consists of early, deep burial and late stages. The above results are based on surface studies, but it might be changed during increasing the depth.