During this period, for example, the city center was heavily lined with mango trees transported from India and development inspired by the model of Paris. With the decline of the two cycles of rubber (1870–1920 and 1940–1945), came a distressing economic stagnation, which stopped in the 1960s and 1970s, with the development of agricultural activities in the south of the state. From the decade of 1960s, but mainly in the 1970s, growth was accelerating with the exploitation of minerals mainly in the southeastern region of the state, as with iron extraction in the Serra dos Carajás and the Serra Pelada gold.