in the south, the climate gets drier due to less rainfall and it becomes more desert-like. In some areas, however, water from karstic sources makes things greener. The plant life of this southeastern steppe region is less diverse than the steppes of central and eastern Anatolia because the dry season is longer here. Perennial xerophytes like Astragalus, Verbascum, Phlomis, Centaurea, and Cirsium predominate. In some sheltered valleys, though, pockets of Mediterranean flora still exist – remnants of what was once a more widespread distribution prior to a climactic shift in the region sometime in the past. Geology Most of Şanlıurfa province consists of Cenozoic formations. Calcareous formations are predominant on the Fatik plateau, west of the Urfa-Harran plain, and in the Tektek Mountains to the east of the plain. Among these are vast Eocene deposits north and west of Urfa, as well as younger Oligocene-Miocene deposits on the Tektek and lower Fatik plateaus. There are also basalt deposits, dating from the Pliocene-Quaternary periods, just north of the city of Urfa itself. These are associated with the Karacadağ Formation. These basalt deposits are generally covered by just 5 to 10 cm of soil deposits; in some places, though, there is thick enough topsoil for agriculture. On the Harran plain, more recent alluvial deposits from the Quaternary period predominate. Economy Agriculture is the largest economic sector in Şanlıurfa province. As of 2000, 43% of the province's GDP is in agriculture, 40% service, 11% industry, and 6% in construction. The total GDP is $1.85 billion USD. Agriculture Şanlıurfa province is a major producer of cotton, wheat, and barley. Cotton production in particular increased dramatically after the GAP was initiated in 1995. The influx of irrigation availability meant that many farmers could switch from dry to irrigated agriculture, and cotton's high market value enticed a majority of farmers to start planting it. The province's annual cotton yield rose from 277,000 tons in 1995 to 708,602 tons in 2004. By 2021, the province produces 42% of all cotton in Turkey. As of 2008, the province also produced 11% of all dry legumes, 6.4% of barley, and 4% of wheat in the country. Other crops include red lentil, pistachio, grape, sesame, and various vegetables. In terms of animal husbandry, sheep and goats are the most important. As of 2015, about 32% of the province's workforce is employed in agriculture. However, the employment share of agriculture has