 
 <prompt> Wetin black shale bin dey use be? Based on di previous question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: ```Di climate of di Cretaceous dey less certain and dey more widely disputed. Higher levels of carbon dioxide for di atmosphere dey make world temperature gradient from north to south almost flat: temperatures dey almost di same across di planet. Average temperatures dey higher pass today by about 10°C. Infact, by di middle Cretaceous, equatorial ocean waters (perhaps as warm as 20 °C for di deep ocean) fit don dey too warm for sea life,[dubious – discuss][citation needed] and land areas wey dey near di equator fit don dey deserts despite their proximity to water. Di circulation of oxygen to di deep ocean fit also don dey disrupted.[dubious – discuss] For dis reason, large volumes of organic matter wey no fit decompose accumulate, eventually dey deposited as "black shale".``` 