Geographical environment of sinan county

The exposed strata in Sinan County are Cambrian, Ordovician, Silurian, Permian and Triassic in turn from old to new. Triassic and Permian strata are most widely exposed, followed by Silurian and Ordovician, and Quaternary is rare. The missing strata are Devonian, Carboniferous, Jurassic and Cretaceous.

Sinan county is located in the west edge of Xuefeng ancient land stable platform in geological structure, and in the northeast structural deformation zone of Fenggang with the Zunyi fault arch in Tailong, northern Guizhou. Therefore, the development of faults and folds has created a unique geological and geomorphological environment in Sinan County.

Sinan county is mainly characterized by Sinan compression-torsion fault and Tangtou compression-torsion fault, both of which are large-scale regional faults. According to the internal and external dynamics and surface morphology of landform formation, the landform in this area can be divided into four types: structural erosion, dissolution, low mountain valley, dissolution, erosion and accumulation.

Sinan lies between Wuling Mountain and Dalou Mountain. Controlled by structure, lithology and Wujiang river system, it presents many landforms such as peak cluster mountains, gentle hilly valleys, river valleys and stone forests. Sinan County is located in the humid climate of mid-subtropical monsoon, with the characteristics of long spring and summer, short winter and autumn, hot summer and warm winter. The annual average temperature 17.3℃, 1 month is the coldest and July is the hottest. The extreme maximum temperature on August 27th, 0972 was 65438+40.7℃,1the extreme minimum temperature on October 30th 1970 65438+ minus 5.5℃. The temperature in Wujiang river basin is high, and the temperature in northwest, southeast and marginal areas is low. The temperature in winter and spring is lower than that in summer and autumn.

Southeast wind and south wind are the most common in Sinan County. The wind power is generally 2 ~ 4, and the maximum wind speed can reach 8, and the maximum wind speed is 18m/ s. The annual evaporation of water surface is between 510.8 ~ 935.3mm.

Sinan county is a county with more disastrous weather, and the main disasters are drought (spring drought and summer drought), hail, strong wind, late spring cold, freezing and heavy rain. Severe droughts include spring drought and summer drought. Barite deposit is a low-temperature hot night deposit, which is distributed in Wenjiadian Town and Dabachang Town.

Mercury deposits include Shachang mercury deposit and six wells mercury deposit, both of which are hot night deposits. Shachang mercury mine and six wells mercury mine are located in Tianqiao Township and Changba Township respectively, and Shachang mercury mine is located in Dabachang anticline.

Iron ore, marble and coal resources

Lead-zinc deposit is located in the axis of Daheba anticline and occurs in the secondary fault zone, which belongs to hot night deposit.