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Pakistan is a large country with diverse geology and geography. It possesses many industrial rocks and minerals, including precious stones, marble and granite. Some metallic mineral deposits, and large reserves of coal/lignite, oil and natural gas also occur. Pakistan’s mining industry is dominated by thousands of artisanal and small-scale mines, which lack capital, technical know how, modern equipment and trained manpower. Further, local mining practices cause much damage to mineral deposits and are very hazardous to the health of mine workers and the environment. The mining sector is backward due to lack of political will and pragmatic mining laws, and absence of technical and financial support by the government agencies to the small mining units. Moreover, the narrow base of the domestic mineral industry leads to poor demand in the local market and low mineral production. Additionally, the lack of infrastructure and the poor law and order situation adversely affect the mineral industry. Further, mineral-rich districts of the country are socio-economically backward due to hilly terrain or arid climate and, hence, less suitable for agriculture. Sustainable development of artisanal and small-scale mines is possible if the necessary legal, technological, financial, commercial, social and environmental support is provided on a long-term basis.

An attempt has been made to assess the arsenic contamination and role of anthropogenic activities on its release in the groundwater of alluvial aquifers occurring on deltaic flood plain of Indus River. Groundwater collected from three semi-urban union councils of Tando Muhammad Khan district revealed that the groundwater has bad quality for drinking which varied in the order of UC-2 > UC-1 > UC-3. Anoxia is prevalent in the aquifers of study area which is indicated by high HCO

: The Gunga barite deposits occur in carbonate clastic marine sequence of Jurassic age. These rocks are widely spread in Khuzdar‐Lasbela belt which host important stratabound barite and zinc‐lead deposits of Pakistan. These rocks are intricately folded and extensively faulted. The Gunga are low temperature hydrothermal deposits occurring as a series of disconnected lenses a few meters thick. Two mineralized horizons are recognized: barite in the upper zone, sphalerite and galena in the lower zone. Four types of barite mineralization occurs in Gunga stratabound replacement associated with 1) fracture filling, 2) open space fillings in solution collapsed breccia, 3) replacement in fault, and 4) veinlets associated with all these three types. The wall rocks of the Gunga deposits have also been altered by silicification, leaching and ferruginization. The sulfur isotope values of most of the Gunga barite samples range from 23.8 to 27.8 per mil with an average of 26.4 per mil, which is very close to the average of isotopic values of epigenetic carbonate hosted Late Paleozoic Missouri barite deposits. The Gunga like other barite and sulfide deposits of Khuzdar‐Lasbela belt are Mississippi Valley type, stratabound and of replacement origin precipitated from connate brines expelled during the incipient rifting of India from Gondwana land in the Late Jurassic and Early Cretaceous periods. The low content of copper, lead and zinc in the Gunga barite deposits suggests that these deposits were not formed in proximity to an igneous source of the ore solution. The Gunga deposits are epigenetic and stratabound as their mineralization is structure controlled. There is an evidence of transgressive nature of host rock and wall rock alteration which are absent in stratiform or bedded deposits.

Alluvial aquifers are the main source of groundwater worldwide. In Hyderabad area of Sindh province, aquifers are naturally polluted by arsenic (As) like other alluvial aquifers of the world. Present study was carried out to decipher the mobilization mechanism of arsenic in Holocene aquifers of Indus river basin, where a large population is at the risk of arsenic ingested diseases. Fifty groundwater samples were collected from Hyderabad and its surrounding areas to examine their physical, chemical and microbiological characteristics. In 80% of the groundwater samples, TDS is above the WHO limit. Dominant (40%) hydrofacies in groundwater of study area is NaCl, which shows water-rock interaction and cation exchange mechanism. In order to investigate the source of arsenic, eleven near-surface soil samples were also collected and analyzed for elemental and mineral composition using XRD and AES techniques. Correlation Coefficient, Principal Component Analysis (PCA) and multivariate statistical analyses were used to interpret the data. Arsenic ranges between 10-150 µg/L in groundwater, while in soil samples it ranges from 77 and 137µg/kg. Findings showed that arsenic is mobilized in the alluvial aquifers of Indus river through dissolution/ leaching of iron oxyhydroxides under anoxic conditions. Arsenic is mainly leached from mica and phlogopite under reducing conditions. Meandering of Indus river through different historical time periods is an important factor for the distribution of redox zones created by mirco-biodegradation of organic matter rich with clayey sediments. Irrigation return flow, infiltration of sewerage in groundwater and unlined sanitation are also important anthropogenic factors for creating local anoxic conditions to mobilize arsenic in groundwater.

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