The five mountains refer to Mount Tai, Huashan, Hengshan, Songshan and Hengshan. 1. Mount Tai runs through central Shandong, within the territory of Tai 'an, between Tai 'an, Jinan and Laiwu. It was called "Daishan" in ancient times and "Daizong" in the Spring and Autumn Period. Mount Tai is adjacent to Qufu, Confucius' hometown, and backed by Jinan, the spring city. Mount Tai originated in the eastern part of North China Plain, above Qilu Plain, bordering the sea in the east, the Yellow River in the west and the waters of Wenzhou, Suzhou and Huaihe River in the south. It is about 200 kilometers long from east to west and 50 kilometers wide from north to south. The main vein and branch vein involve more than ten surrounding counties, the lying vein covers an area of 426 square kilometers, and the elevation of the main peak Yuhuangding is 1545 meters. Mount Tai is the highest mountain range in the hills of Shandong Province, and the stratum is a typical basement and caprock structural area of North China platform. The southern uplift is relatively large, and the caprock is weathered off, exposing a large basement-Taishan complex, that is, the Archaean Taishan Group stratum, with an absolute age of about 2.5 billion years, which is one of the oldest strata in China. The rise in the north is small, and the caprock preserves the Paleozoic strata developed on the typical North China platform. Taishan landform can be divided into four types: alluvial-diluvial platform, denudation and accumulation hills, structural denudation low mountains and erosion structure medium-low mountains. In terms of spatial image, from low to high, the mountains are stacked and towering into the sky, forming a landscape composed of various terrain groups. 2. Huashan is a whole granite with deep intrusive rocks and coarse-grained porphyritic granite (granularity 5 mm) at the top; The middle part is medium-grained (2-5 mm) granite gabbro and gneiss granite. According to the radioactive isotope determination of geological scientists, the formation period of Huashan granite was about 1.2 1 100 million years ago, and the crust in Huashan area moved. In the process of being squeezed, folded and broken, magma began to rise, invaded the surface crust along cracks, cooled at a depth of 3-6 kilometers and condensed into rocks. Huashan Mountain is far from the ocean, located in the westerly belt between 30 and 60 north latitude, with a continental degree of 53 7', and belongs to the continental monsoon climate of warm temperate zone. Because the mountain is straight and steep, the vertical temperature gradient (or direct cooling rate) at the foot of the mountain and the top of the mountain: from the county to the top of the mountain, the temperature will drop by 0.44℃ for every rise of 100m at the northern foot and by 0.5℃ for every rise of 100m at the southern foot. Mount Hengshan is built on a huge granite. Due to the erosion and strong erosion of surface sediments, granite is exposed in a large area. Pegmatite granite is interspersed in the time pulse, and its width varies greatly, reaching 40 cm, which can accelerate the weathering of granite. The red soil covering the bedrock contains a lot of timely sand, which proves that it was formed by weathering of granite. The rocks around granite can be divided into three types: Silurian purple shale and gravel quartzite, Devonian sandstone and shale, Tertiary red sandstone and shale. In terms of nature, gravelly quartzite is the hardest and purple shale is the softest, showing different landforms on rocks in the same period. Due to the weather and climate, the weathering and erosion of running water, wind and heat have formed the unique landscape of modern Hengshan Mountain. The ancient landform of Hengshan Mountain is closely related to the development of Hunan landform. From Silurian to Ordovician to the end of Jurassic, the eastern part of Hunan is the ancient Cathaysian continent, the western and northern parts are the ancient Jiangnan continent, and the south-central part is Dawan. Seawater is a Himalayan anticline, which intrudes into Hunan through Guangxi and reaches Changsha as far north as possible. In the bay, the seawater advances and retreats, deep and shallow, and Hengshan is on the way of seawater advancing and retreating. 4. Hengshan Mountain is a mountain in the north-central part of Wuyue Mountain in China. Its mountains originate from Yinshan Mountain, Guancen Mountain and Taihang Mountain. It winds along the northeast, rushes up and down, passes through the fortress, stretches for 500 miles from east to west, and has a splendid 108 peak. Tianfengling, the main peak of Hengshan Mountain, is located in Hunyuan, with an altitude of 20 16. 1 m. It is known as "the pillar of mankind in the north" and "the absolute famous mountain". It is magnificent and is known as the ancestor of the mountains in the north. Hengshan Mountain is a fault mountain formed by the second orogeny and previous crustal movements. The rock formation is CAMBRIAN Ordovician limestone, which is 500 million years old. The bedrock is exposed, severely weathered, broken, with sharp peaks and valleys and deep cutting, and the relative height difference exceeds 1 000m. The whole mountain range extends from northeast to southwest for hundreds of kilometers, and is known as the first mountain in the cold Xinjiang, with "China as the side and Gong Shenjing as the guardian". Hengshan Mountain starts from Taihang Mountain in the north, crosses the Great Wall, connects Yanshan Mountain in the east, Yanmen in the west, Sanjin in the south and Daiyun in the north, and stretches for 500 miles from east to west (across Ningwu, Shuozhou, Daixian, Yingxian, Fan Shi, Yinshan, Hunyuan and Lingqiu in Shanxi). It is a tributary of Haihe River, Sanggan River and Hutuo River. 5. The geological structure of Songshan Mountain is famous at home and abroad for its ancient rock age, complex structure, complete stratum development and good outcrop. After many tectonic movements, various structural relics have been preserved. The development and formation of Songshan Mountain is the product of internal and external geological processes in the long geological history (Archean, Proterozoic, Paleozoic, Mesozoic and Cenozoic). The geological structure of Songshan Mountain is dominated by folds, which are generally composed of a series of anticlinal domes near east-west direction. Faults are mainly in the northwest, southwest and east, which divide Songshan into three parts. The bending phenomenon of Songshan rock is called fold. Include syncline and anticline. Under the action of tectonic movement, or under the action of low stress, rocks have changed the original attitude of rock strata, which not only makes the rock strata tilt, but also mostly forms various bends. Fold is the result of plastic deformation of rock strata and one of the basic forms of geological structures widely developed in the crust. A fault structure with obvious displacement of Songshan rock block along the fault plane is called a fault. The scale of faults is large and small, and the depth of influence is deep and shallow (deep can cut through the lithosphere or crust, shallow can cut through the cover or only on the surface), which was formed in the era of old and new alternation; Some are the result of one tectonic movement, some are the result of many tectonic movements; Some are inactive and some are still active; The mechanical properties of faults are different, such as tension, compression and shear.