Nallamalla Hills

Nallamala Hills నల్లమల్ల కొండలు
The Nallamalas
The Nallamalas Hills
Highest point
Peak	Bhairani Konda (Sikhareswaram)
Elevation	3,608 ft (1,100 m)
Coordinates	15°40′41″N 78°47′10″E / 15.67806°N 78.78611°E / 15.67806; 78.78611Coordinates: 15°40′41″N 78°47′10″E / 15.67806°N 78.78611°E / 15.67806; 78.78611
Dimensions
Length	90 mi (140 km) north-south
Geography
Country	India
Provinces/States	Andhra Pradesh and Telangana
Geology
Age of rock	Proterozoic

The Nallamalas (also called the Nallamalla Range) are a section of the Eastern Ghats which stretch primarily over Kurnool, Nellore, Guntur, Prakasam, Kadapa and Chittoor districts of the state of Andhra Pradesh and Mahabubnagar, Nalgonda districts of the state of Telangana, in India. They run in a nearly north-south alignment, parallel to the Coromandel Coast for close to 430 km between the rivers, Krishna and Pennar. Its northern boundaries are marked by the flat Palnadu basin while in the south it merges with the Tirupati hills. An extremely old system, the hills have extensively weathered and eroded over the years. The average elevation today is about 520 m which reaches 1100 m at Bhairani Konda and 1048 m at Gundla Brahmeswara. Both of these peaks are in a north westerly direction from the town of Cumbum. There are also many other peaks above 800 m.

The rocks of the Nallamala ranges belong to the Kadapa system which is a series some 20,000 ft. thick. The primary rocks are Quartzite overlaid with an irregular slaty formation. Some sandstone is also to be found. The rocks here are very irregular and soft in texture thus rendering commercial exploitation impossible. These rocks are among the oldest in the world and have been formed as a result of large scale volcanic activity hundreds of millions of years ago. The evidence of the volcanic forces are evident in the foldings into which the rocks have been forced, in some cases the folds have been completely inverted.

The Nallamalas have a rather warm to hot climate throughout the year. Rainfall averages about 90 cm and is concentrated in the months of the South West Monsoon (June–September). The fissured rocks prevent any water from percolating underground and hence most of the discharge runs off as mountain streams to join the Gundlakamma River, the largest river to arise in these hills. Winters are mostly cool and dry with the average temperature around 25 degrees Celsius.