Define mining, give three ways minerals occur, and explain how metamorphism, evaporation, and leaching influence mineral occurrence.

Here are the answers to the questions: 7(a)(i) Define mining. Mining is the process of extracting valuable minerals or other geological materials from the earth's crust. 7(a)(ii) Give three ways in which minerals occurs. • Minerals occur as veins and lodes in cracks and fissures within rocks. • They can be found as beds and seams, forming layered deposits within sedimentary rocks. • Minerals also occur as alluvial deposits, which are concentrations of heavy minerals transported and deposited by water. 7(b)(i) State how the following factors influences minerals occurrence. • Metamorphism: High temperature and pressure during metamorphism can cause existing minerals to recrystallize or new minerals to form, often concentrating valuable ores in specific zones. • Evaporation: In arid or semi-arid regions, the evaporation of water from lakes or inland seas leads to the precipitation and accumulation of evaporite minerals like salt, gypsum, and trona. • Leaching: This process involves water percolating through rocks, dissolving soluble minerals and carrying them away, which can lead to the concentration of less soluble minerals or the formation of new deposits elsewhere. 7(b)(ii) State four ways on how the mode of occurrence of minerals influences minerals exploitation. • Depth: Deeply buried minerals require expensive and complex underground mining methods, while shallow deposits can be exploited by cheaper surface mining. • Concentration/Grade: High-grade ores are more economically viable to exploit as they yield more mineral per unit of rock, reducing processing costs. • Form/Structure: Minerals occurring in disseminated forms or extensive beds may be suitable for bulk mining, whereas those in narrow veins require selective mining techniques. • Associated Rocks: The hardness and stability of the surrounding rock influence the choice of mining equipment and methods, impacting safety and cost. 7(c)(i) Describe the processing of Trona in Lake Magadi. The processing of Trona in Lake Magadi involves dredging the trona-rich mud from the lake bed. This material is then pumped to a processing plant where it undergoes washing and crushing to remove impurities. The purified trona is then calcined (heated) to convert it into soda ash (sodium carbonate), which is subsequently dried and packaged for sale. 7(c)(ii) Give two reasons why Kenya import petroleum in form of crude oil. • Kenya lacks significant domestic crude oil reserves to meet its energy demands, making imports necessary. • Kenya has a refinery (historically, the Mombasa refinery) that processes crude oil into various refined products like petrol, diesel, and kerosene, which are crucial for its economy. Importing crude oil allows for domestic value addition and production of these essential fuels. 7(d)(i) Give two activities the students involved in during the study. • Observation: Students would observe the mining operations, the landscape, and any visible environmental impacts. • Data Collection: This could involve taking notes, sketching features, or collecting samples for analysis. 7(d)(ii) State two importance of the information obtained during the study to the local people. • Awareness: It can inform local people about the environmental and social impacts of mining, empowering them to advocate for their rights or better practices. • Economic Opportunities: Understanding the mining process and its by-products might reveal potential local economic opportunities or alternative livelihoods. 8(a)(i) Define the term fishing. Fishing is the activity of catching fish or other aquatic animals from water bodies such as oceans, rivers, lakes, and ponds, typically for food or sport. 8(a)(ii) State three physical factors that influence fishing. • Water Temperature: Different fish species thrive in specific temperature ranges, influencing their distribution. • Depth of Water: Fish species are found at various depths, which dictates the type of fishing gear and methods used. • Ocean Currents/Water Movement: Currents distribute nutrients and plankton, attracting fish and influencing their migratory patterns. 8(a)(iii) List two rivers where fishing is done in the N.E. Pacific fishing ground. • Columbia River • Fraser River 8(b)(i) Give three factors you would consider while choosing the type and method of fishing to use. • Target Species: The specific type of fish being sought determines the most effective gear and method. • Water Body/Environment: Whether fishing in open ocean, coastal waters, rivers, or lakes dictates suitable techniques. • Economic Viability/Cost: The cost of equipment, fuel, and labor versus the potential value of the catch. 8(b)(ii) Describe how drifting method of fishing is done. The drifting method involves setting gillnets or longlines in the water and allowing them to drift freely with the currents. The net or line, often extending for a considerable distance, is deployed from a boat. Fish swim into the gillnets and get entangled by their gills, or are caught on hooks on the longline. After a period of drifting, the gear is hauled back to the boat, and the catch is removed. 8(c) State two problems facing fishing in Lake Victoria. • Overfishing: Excessive fishing pressure has led to the depletion of many fish stocks in the lake. • Pollution: Industrial, agricultural, and domestic waste contaminates the lake, harming fish and their habitats. 8(d) Explain four measures taken by the Kenyan government to conserve fisheries. • Legislation and Regulations: The government enacts laws to control fishing activities, such as setting minimum mesh sizes for nets, establishing fishing seasons, and imposing quotas to prevent overfishing and protect juvenile fish. • Establishment of Marine Protected Areas (MPAs) and Fish Sanctuaries: Specific areas are designated where fishing is restricted or prohibited to allow fish stocks to recover, breed, and serve as nurseries for various species. • Promotion of Aquaculture (Fish Farming): The government encourages fish farming to reduce pressure on wild fish stocks, providing an alternative source of fish for consumption and income for communities. • Monitoring, Control, and Surveillance (MCS): Implementing patrols and surveillance systems helps to detect and deter illegal, unreported, and unregulated (IUU) fishing activities, ensuring compliance with fishing laws. 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