Sarvak Fm

Column: Zagros belt (general), Column: Iran East; Sarvak 4, Sarvak 3, Sarvak 2, Sarvak 1 Fm

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It is further divided into Sarvak 4, Sarvak 3, Sarvak 2, Sarvak 1 Fms. The upper 140 feet of the formation is made up of 1-3-foot beds of rubbly, relatively low-weathering limestone with ferruginous red staining and leached zones of breccia. The top is very ferruginous, uneven, and, rubbly. Above the siliceous unit is 1360 feet of very massive, tan to brown limestone containing abundant rudist debris. Large-scale cross-bedding is present in the basal part. Sarvak 1 grades upward into a massive, chalky white to buff limestone 360 feet thick with numerous brownish red, siliceous nodules. Lower 835 feet is composed of fine-grained, dark gray, nodular-bedded, argillaceous limestone with thin, dark gray marl partings. Small ammonite impressions are common throughout.