Magmatic activities and tourist routes of Yansai Lake in Shanhaiguan

Route: Base-Yansai Lake-Shanhaiguan-Base

Task:

/|||| 0/) Observation of rock plants and dikes.

2) Visit Yansai Lake to learn about the water resources in Qinhuangdao.

3) Visit Shanhaiguan, a patriotic education base.

Preview content:

1) invasion.

2) The fifth chapter of this book is about human geography, water resources and tourism resources.

No.23

Venue: Yansai Lake Quarry.

Significance: observation point of plutonic and hypabyssal intrusive rocks.

Observation content:

/|||| 0/) Strain of syenite rock.

2) syenite porphyry dike.

3) Diabase veins.

Teaching content:

Students are required to observe the size and color of syenite intrusion, the characteristics of joints, syenite veins and diabase veins, and then each student will make three specimens (one syenite, one syenite and one diabase) to describe lithology.

/|||| 0/) Synenite intruded in the form of rocks, with an exposed area of about/|||| 0/km2. Weathered surface is grayish yellow, and fresh surface is light meat red. The mineral composition is mainly orthoclase (about 80%) and syenite (about 7%), with a small amount of biotite (about 5%), amphibole (about 2%) and epidote, which looks like spots. The phenocryst is orthoclase, the size of phenocryst is about 6 mm× 12 mm, the crystal center is grayish white, and the transition outward is light flesh red. The matrix consists of orthoclase, syenite, biotite and amphibole, and the particle size is 0.6 ~/|||| 0/mm.

Basic separated bodies can be seen in the rock mass, with a diameter of about 2 ~ 6 mm, dark color, fine particles, irregular shape and transitional boundaries. Joints are developed in the rock mass, and the joint surface is flat. Generally, there are chloritization, which is light gray green.

2) syenite porphyry occurs in syenite in vein form (plate Ⅲ-5), with vein occurrence of 335 ∠ 58, pulse width of 3 ~ 5m, gray weathered surface, light gray fresh surface, porphyry structure and massive structure. The phenocryst is orthoclase with a particle size of 2mm×5mm and a content of about/|||| 0/0%. The matrix is coarse in the middle and aphanitic, and gradually tapers to both sides. In the intrusive contact zone, a glassy condensation edge with a width of about 10cm and a baking edge with a lighter surrounding rock color are developed (Plate Ⅲ-6).

3) Diabase dikes intrude along the joints of syenite, and the fresh surface is grayish green, and the weathered surface is grayish green with brown. The main mineral components are plagioclase (about 60%) and pyroxene (about 30%), with diabase structure and massive structure. The grain size in the middle of the dike is coarse, which is 1 ~ 2mm, and it becomes thinner to both sides, and transits to aphanitic. At the contact part between dike and rock mass, the condensation edge and baking edge are obviously visible and the color becomes lighter. The dike width is/|||| 0/.5 ~ 2m, the strike is 330, and the dip angle is 75 ~ 80. Structural joints in dikes develop and extend to surrounding rocks.

There are almond-shaped structures and stomatal structures in diabase veins, the former is more. The cross section of amygdala is round, oval or irregular, with a diameter of 3 ~ 8 mm, and the main component is calcium. The pores are fine, most of them are 2 ~ 3 mm in diameter, and some are close to/|||| 0/0 mm.

Emphasis and difficulty: field identification characteristics and lithologic description of magmatic rocks.

Time: 50 minutes.

Q: How to understand the condensation edge and baking edge caused by magmatic activity? What are their characteristics?

24(th)

Venue: Lake Yansai.

Significance: Visit the dammed lake and learn about the important role of the reservoir in the national economic construction.

Observation content:

The dammed lake, also known as shihe reservoir, was built 700 meters north of Little Chen Zhuang Pass in the west of Shanhaiguan District. /|||| 0/972 April/|||| 0/6, which was completed and put into use on June 28th/|||| 0/975. It is a medium-sized reservoir that mainly supplies water and has comprehensive functions such as flood control, irrigation, power generation and tourism. The basin area is 560km2, which is about 9 1% of the Shihe River basin area. The total storage capacity is 68 million m3, the flood control storage capacity is 47 million m3, the storage capacity of Li Xing is 565,438+630,000 m3, and the annual regulated water volume is/||||| 0/|| | 0/100 million m3.

Since the completion of the reservoir, the inflow peak flow has exceeded 1 000m3/s for four times, and the largest one is 4250 m3/s (/|||| 0/984). After the reservoir operation, there was no flood disaster in Shanhaiguan city and Jingshan railway in the lower reaches of Shihe River. The reservoir not only plays the role of flood control, but also supplies water for four water plants in Qinhuangdao. From/|||| 0/980 to/|||| 0/985, the total water supply of the reservoir reached 27/|||| 0/000000 m3, including urban water supply/||| 0/430000 m3, the average water supply for many years was 23.84 million m3, and agricultural water supply/||| 0/280000 m3, with an average of many years.

Lake Yansai is also a good tourist attraction. The lake is rippling in blue waves, clear and transparent, with strange rocks on the cliffs and pine and cypress reflected in the lake. If you take a motorboat and walk through the winding valley, you will feel that you are in a fairyland, and you can see such landscapes as "Mother-daughter Peak", "Dragon Girl Bath Day", "Lingxing Silver Screen", "Dragon Gate Fish Leaping" and "Huatuo Herb Picking" along the way.

25(th)

Location: Shanhaiguan District is the first pass in the world.

Significance: Visit the first pass in the world, visit the Great Wall Museum and receive patriotic education.

Observation content:

Shanhaiguan is a famous historical city in the world, located about 17km northeast of Qinhuangdao City. In the 14th year of Hongwu in Ming Dynasty (AD 138 1), General Xu Da built the Great Wall and the ancient city of Shanhaiguan. With Yanshan Mountain as its back and Bohai Sea as its south, Xiongguan stands in the middle, hence the name "Shanhaiguan", which is an important pass to the east of the Great Wall of Wan Li.

The ancient city of Shanhaiguan, with a dangerous terrain and a distance of only 7.5km, has always been a battleground for military strategists. Shanhaiguan Great Wall is located at the eastern end of Wan Li Great Wall. The Great Wall of Wan Li is famous for its huge project, magnificent spirit and long history. It is the crystallization of hard work and wisdom of the Chinese nation, which has important political and military significance and high artistic value.

Shanhaiguan City is a brick bag made of earth, with a height of 14m, a thickness of 7m and a circumference of 4km. The whole city is connected with the Great Wall of Wan Li, with the city as the gateway, forming the trend of "Golden Lock Great Wall". There are four gates in the city, the east gate is called Lock East Gate, the west gate is called Ying 'en Gate, and the south gate.

The gate is called Wangyangmen, and the north gate is called Weiyuan Gate. Outside the east and west gates, there is a city circle that extends outward to strengthen defense, called Los Angeles. This ancient city is a combination of natural scenery, historical sites and ancient military fortifications. With its unique geographical environment, unique composition, conceptual implication of scene blending and simple and elegant architectural style, it has formed a beautiful environment with the characteristics of "mountain", "sea" and "vulgarity", which embodies the outstanding architectural art and military talent of the working people in ancient China.

The first pass in the world is the East Gate of Shanhaiguan City. Because it is located in the pass and the eastern starting point of the Great Wall of Ming Dynasty, it is called "the first pass in the world". The first tower in the world was built during the Hongwu period of the Ming Dynasty, with a height of/|||| 0/3.7m, a width of/||||| 0./||| 0/m and a length of 20m from north to south. It is divided into two layers, one is 5.7m, and the other is 8m. There are 68 arrow windows on the north, east and south sides of the tower, which are closed at ordinary times and opened when necessary. There is a huge horizontal plaque hanging on the rostrum, which is 5.9m long and 1.55m wide, and the words "the first pass in the world" are written on it. These five words were written by Xiao Xian, a famous calligrapher and scholar, in the eighth year of Chenghua in Ming Xianzong (/|||| 0/472). This original tablet computer is stored on the first floor of the building. The plaque on the second floor of the building was copied during the Guangxu period of Qing Dynasty (1875), and the plaque outside the building was carved by Yang (/|||| 0/920) in the ninth year of the Republic of China.