Horizons presenting rock phosphate are those of Precambrian-Cambrian-Late Jurassic-Early Cretaceous, Paleocene, Eocene and Oligocene. Most of the rock phosphate deposits of Pakistan are confined to the Indus Basin and Axial Belt out of which only the Precambrian Cambrian phosphat of Hazara is meritorious.Hazara phosphorite occurs along with dolomiteand berty dolomite in the upper part of Abbottabad Formation of Cambrianage.The exposures are widely scattered and arc also traceable into Kashmir. Phosphorite occurs in thin (about one metre) discontinuous lentils scattered within the widerange of horizons of thick dolomitic rocks.Structural disturbance is also common, thus rendering reserve estimates difficult. The deposits are spread over area of 155 km2. Major localities are located in Kakul, Mirpur, Lagaran, Baghla Gali, Kalu-De Bandi, Dhola and Sirban (Bhatti, 1972). At one locality, Kakul-Mirpur, more than 1.5 million tonnes of grade 18% - 40% P205 have been established. Phosphorite is usually palatal, hard, compact, siliceous, grey to black in colour with bluish phosphoratic bloom.At a locality near Dhola,15m thick.
phosphorite horizon has been recently discovered which holds a good promise in the area.Generally, more-precise and optimum range of phosphate content is 10% to 30%. The reserve of phosphate rock is estimated to be 22.9 million tones(Hassan et al.,1986).
Parts of Chichali Formation (Late Jurassic-Early Cretaceous) exposed in Kohat area of Upper Indus Basin contain phosphatic nodules within the dark glauconitic shale. P2Os percentage is, however, low (5% to 15%). The nodules develop around a nucleus, which in certain cases may be an ammonite. Several localities of phosphatic nodule localization have been reported out of which the one extending between Khwari and Gandab Khwar is perhaps the most promising.
In Kala Chitta Range, near Chhoi, 20 m thick phosphatic limestone has been noticed in the Kawagarh Formation (Late Cretaceous). The extent and grade of this phosphorite horizon is not available.
Low grade (5% to 20%) phosphatic nodules are also known from the Patala Formation of Palcocene age from various places in eastern and central Salt Range. The occurrences are sporadic and are not commercially exploitable. Phosphatic rocks are also reported from various Cenozoic formations along the length of Sulaiman Range in Middle Indus Basin. Investigations have been made in the Rakhi gorge, where indications of phosphate have been noted in Khadro Formation (Paleoccnc), Ghazij Group of Eocene age (basal part) and Nari Formation (Oligocene). The Nari portion is important since it has a bed of about 30 cm thick with 20% P2Os content. Ghazij horizon contains noduleswith5%-20% P2Os.
In other areas c.g., Marri-Bugti hills of Middle Indus Basin, Moro formation of Late Cretaceous to Paleocene age is reported to contain phosphatic nodules and pebbles in a heterogeneous lithology of elastics, limestone and chert. One sample gave 11% P205. Phosphatic nodules in theshales of lower part of Khadro Formation(Paleocene) are reported from Pabni Chawki and Naka Pabni in Pab Range in the southern part of Lower Indus Basin. The nodules are scattered or as lenticular layers. All the nodules are not phosphatic and it is sometimes difficult to recognize the phosphatic nodules by appearance only. P205 content is low, between 5%-15%. These deposits are at present uneconomical.
phosphorite horizon has been recently discovered which holds a good promise in the area.Generally, more-precise and optimum range of phosphate content is 10% to 30%. The reserve of phosphate rock is estimated to be 22.9 million tones(Hassan et al.,1986).
Parts of Chichali Formation (Late Jurassic-Early Cretaceous) exposed in Kohat area of Upper Indus Basin contain phosphatic nodules within the dark glauconitic shale. P2Os percentage is, however, low (5% to 15%). The nodules develop around a nucleus, which in certain cases may be an ammonite. Several localities of phosphatic nodule localization have been reported out of which the one extending between Khwari and Gandab Khwar is perhaps the most promising.
In Kala Chitta Range, near Chhoi, 20 m thick phosphatic limestone has been noticed in the Kawagarh Formation (Late Cretaceous). The extent and grade of this phosphorite horizon is not available.
Low grade (5% to 20%) phosphatic nodules are also known from the Patala Formation of Palcocene age from various places in eastern and central Salt Range. The occurrences are sporadic and are not commercially exploitable. Phosphatic rocks are also reported from various Cenozoic formations along the length of Sulaiman Range in Middle Indus Basin. Investigations have been made in the Rakhi gorge, where indications of phosphate have been noted in Khadro Formation (Paleoccnc), Ghazij Group of Eocene age (basal part) and Nari Formation (Oligocene). The Nari portion is important since it has a bed of about 30 cm thick with 20% P2Os content. Ghazij horizon contains noduleswith5%-20% P2Os.
In other areas c.g., Marri-Bugti hills of Middle Indus Basin, Moro formation of Late Cretaceous to Paleocene age is reported to contain phosphatic nodules and pebbles in a heterogeneous lithology of elastics, limestone and chert. One sample gave 11% P205. Phosphatic nodules in theshales of lower part of Khadro Formation(Paleocene) are reported from Pabni Chawki and Naka Pabni in Pab Range in the southern part of Lower Indus Basin. The nodules are scattered or as lenticular layers. All the nodules are not phosphatic and it is sometimes difficult to recognize the phosphatic nodules by appearance only. P205 content is low, between 5%-15%. These deposits are at present uneconomical.
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