Route Huludao Wanghai Temple seaside route

The main observation contents of the seaside route of Wanghai Temple in Huludao are as follows: ① Mesoproterozoic Great Wall System and sedimentary rocks; ② Geological function of coastal zone.

I. Mesoproterozoic Great Wall System and Sedimentary Rocks

(A) the purpose and requirements of observation

1) By observing the contact relationship between Changzhougou Formation of the Great Wall System and porphyry granite, the field identification marks and research methods of unconformity surface are mastered, and the space-time concept of tectonic movement is established.

2) By observing the Changzhougou Formation (1st and 2nd member) and Chuanlinggou Formation, we can master the lithology, rock assemblage characteristics and grouping (segment) marks of the above groups (segments) in this area. On this basis, the meaning and division basis of "group" and "section" lithostratigraphic units are further understood.

3) Master the field work methods of terrigenous clastic rocks and endogenetic sedimentary rocks, and understand their guiding significance to sedimentary environment and sedimentary facies.

4) Master the observation methods of common bedding and bedding structure, and analyze the formation environment of bedding and bedding structure.

5) Draw the stratigraphic profile of random route and the sketch of typical geological phenomena.

6) According to the observation contents of this route, summarize the main differences and identification marks between magmatic rocks and sedimentary rocks.

(2) observation tips

Observation of porphyry granite

Mineral composition: light-colored minerals include potash feldspar and quartz, and dark-colored minerals include amphibole and biotite, both of which can be phenocrysts. Among them, the porphyritic crystals of potash feldspar are large, fleshy red and tabular, and the particle size is generally 2~ 10mm, and the maximum is 2cm.

Structural structure: porphyritic structure, massive structure.

The fresh surface of porphyry granite is grayish purple, which is an acidic intrusive rock.

2. Differences and identification marks between magmatic rocks and sedimentary rocks

Magmatic rocks are formed by magma condensation. Magmatic rocks can be divided into ultrabasic rocks, basic rocks, intermediate rocks and acid rocks by composition, and can be divided into plutonic rocks, hypabyssal rocks and volcanic rocks by occurrence. Sedimentary rock is a kind of geological body formed on the surface and not too deep below the surface. It is a rock transformed from materials formed by weathering, biological action and partial volcanism at normal temperature and pressure.

The difference between magmatic rocks and sedimentary rocks is mainly caused by their different formation conditions, and their identification marks mainly include the following points:

(1) structural structure

First of all, sedimentary rocks are layered macroscopically. There are many kinds of bedding in sedimentary rocks, such as granular bedding, oblique bedding and cross bedding. Sedimentary rocks have some layered structures, such as ripples, cracks and raindrops. Sedimentary rocks are clastic structures, while magmatic rocks are porphyritic, crystalline and granular structures.

(2) Mineral composition

The mineral composition of magmatic rocks is complex, and the common minerals are olivine, pyroxene, amphibole, mica, quartz and feldspar. The composition of sedimentary clastic rocks is relatively simple, mainly composed of clastic particles (quartz, feldspar and cuttings), matrix and cements (calcareous, siliceous and argillaceous, etc.). ) and pores. Minerals in magmatic rocks have complete crystal morphology, while minerals in sedimentary rocks are clastic and have no complete crystal morphology.

3. Observation of sedimentary contact interface between Mesoproterozoic Changzhougou Formation and porphyry granite.

Focus on observing the contact interface shape, whether there is ancient weathering crust, and whether there is bottom conglomerate or rock block and gravel containing underlying rock mass at the bottom of overlying strata.

1) There is an obvious interface between sandstone and porphyry granite in Changzhougou Formation, and the interface is uneven (Figure 2-2- 1). Porphyry granite has obvious weathering crust characteristics, mainly characterized by strong alteration and fading of porphyry granite, indicating that porphyry granite has undergone a long period of weathering. Sandstone composition at the bottom of Changzhou Gou Formation above this interface is injected into granite pit.

Fig. 2-2- 1 sedimentary contact relationship between sandstone and porphyry granite of Changzhou Formation in Wanghai Sitan, Huludao

Figure 2-2-2 Granite Gravel at the Bottom of Sandstone in Changzhou Gou Formation, Wanghai Sitan, Huludao

2) At the bottom of the sedimentary strata of Changzhougou Formation covered by porphyritic granite, a large number of mineral debris such as feldspar and quartz from porphyritic granite components can be seen, and coarse-grained porphyritic granite gravel (Figure 2-2-2) can be seen locally, with a particle size of 2-300 mm and a certain degree of rounding, that is, there is a bottom conglomerate at the bottom of Changzhougou Formation.

3) The Changzhougou Formation is a set of metamorphic sandstone, and its formation age is about 1800Ma. It shows that the porphyry granite was formed at least before 1800Ma.

4. Observation on lithology, sedimentary assemblage and division marks of Mesoproterozoic Changzhougou Formation (1st and 2nd members) and Chuanlinggou Formation.

Focus on observing the lithology, rock assemblage and sedimentary cycle characteristics of each group and section, whether the boundaries of each group and section are basically straight or undulating, the symbolic lithologic characteristics of typical groups (or sections), whether the lithology above and below the boundary changes suddenly or gradually, and whether the occurrence of upper and lower strata on the boundary is consistent.

(1) Member 1 of Changzhou Gou Formation

The conglomerate with Suizhong granite gravel at the bottom is not integrated on porphyry granite (Figure 2-2-2), and the lower part is grayish black medium-thick grained sandstone, and the upper part is grayish black medium-thin mica-bearing fine sandstone (Figure 2-2-3). The deposition of the first member of Changzhougou Formation obviously constitutes a sedimentary cycle from coarse to fine and from thick to thin.

(2) The second member of Changzhougou Formation

It is composed of medium-fine grained sandstone in yellow-gray and gray-white medium-thick layers, and the grain size of upper sandstone becomes smaller (Figure 2-24-). The bottom of the second member is separated from the underlying first member of Changzhougou Formation by coarse debris in yellow-gray rock, thick rock and sandstone. Clear boundary, consistent occurrence of upper and lower strata; From the characteristics of sedimentary rock layer color, rock layer thickness and sudden coarsening of cuttings size, it represents the beginning of a new sedimentary cycle

Figure 2-2-3 Gray-black medium-thin mica-bearing fine sandstone in the upper part of Changzhougou Formation of Wanghaisi, Huludao

Figure 2-2-4 Thin-time sandstone mixed with silty shale in the second member of Changzhougou Formation in Wanghaisi, Huludao.

(3) Chuanlinggou Formation

It consists of gray-black and black silty shale and shale. The boundary with the second member of the underlying Changzhou Gou Formation is clear. Red iron sandstone (including oolite and iron stromatolite, etc. ) is often developed at the bottom of Chuanlinggou Formation in the area, and iron deposits are formed in some areas, that is, Long Xuan-type iron deposits.

5. Observation of terrigenous clastic rocks

Focus on observing the composition, content, size, rounding and sorting of debris; Composition, content and cementation type of cement; Sedimentary structure, etc.

Main characteristics of terrigenous clastic rocks:

1) Normal sedimentary clastic rocks are usually called clastic rocks, which are mainly formed by mechanical crushing products (clastic substances) of parent rocks after handling, deposition, compaction and cementation.

2) The structure of clastic rocks includes three aspects, namely, the characteristics of clastic particles themselves (granularity, roundness and sorting), the characteristics of cements and the relationship between detritus and cements (types of cements).

Particle size division of clastic rocks: gravel >; 2mm, sand 2~0.05mm, silt 0.05~0.005mm, mud (clay) < 0.005mm..

Roundness of wear debris: The roundness of wear debris is divided into five grades, namely, grade 0 (angular), 1 grade (sub-angle), grade 2 (sub-circle), grade 3 (circle) and grade 4 (polar circle) (Figure 2-2-5).

Figure 2-2-5 Khabarov's gravel rounding grade is 0- angular; 1 class-subangular; Level 2-sub-cycle; Level 3-round; Level 4-Very round

Sorting: Sorting refers to the uniformity of particle size in clastic rocks. Classification means that the content of main particle size components is >: 75%, or the particle size is nearly equal; The separation medium means that the content of main particle size components is 50% ~ 75%; Poor sorting means that there is no particle size with a component content greater than 50%, or the particle size is very different.

Generally speaking, the longer the sediment transport distance, the better the roundness and separation degree.

(1) fine conglomerate

It is produced in the form of a thin interlayer or lens. Gravel size range is 2-4mm, medium sorting and sub-circular. Gravel composition is mostly felsic and granitic rocks, and a few are plagioclase amphibolite. The interstitial materials are sand and silt.

(2) Sandstone

According to the composition of detritus in sandstone Q(Q= timely+flint+quartzite+siliceous detritus), F(=F feldspar+granite detritus+granite gneiss detritus) and R(R= other detritus except Q and F, including volcanic rocks and their variation products, slate, phyllite, crystalline schist, siltstone, mudstone and carbonate rocks.

According to the composition maturity, the sandstone in this route can be divided into two categories: one is gray-white, meat-red, gray-purple medium-coarse grained feldspar timely sandstone, with a timely detritus content of more than 80%, round, sorted and siliceous cementation; The other is flesh-red medium-fine grained feldspathic sandstone, with feldspar detritus content above 30%, medium grinding, argillaceous and iron cementation.

Figure 2-2-6 Classification Diagram of Sandstone "Three Ends"

(3) Siltstone

Gray-black, thin gray layer, fine clastic structure, with horizontal bedding.

(4) Shale

Shales in this observation point are very developed, especially iron-bearing shale, argillaceous shale and sandy shale containing mica powder, with well-developed foliation.

6. Observation of sedimentary structure

This observation route includes oblique bedding (cross bedding), parallel bedding, horizontal bedding, granular bedding, wavy bedding and bedding structure (ripple mark).

Grain boundaries are parallel to each other, either horizontal bedding (composed of fine sand and clay particles) or parallel bedding (composed of sand particles); Fine layers intersect with series boundaries at a certain angle, or series boundaries intersect with each other, which is oblique bedding (cross bedding). In addition, there is no kind of bedding called block bedding.

Grain-order stratification The inside of each grain-order layer has the characteristics of tapering from coarse to fine (or vice versa), and the grains are roughly parallel and do not intersect.

Figure 2-2-7 Surface Wave Marks of Quartz Sand in the Lower Member of Changzhou Gou Formation in Wanghai Sitan, Huludao

Ripple is a regular horizontal fluctuation phenomenon. It is a sand wave relic formed by the migration of a layer of sandy sediment on the surface of sediment under the action of water (Figure 2-2-7). The shape of wave marks is very similar to waves on the water surface, which are divided into peaks and valleys. On the profile, the front water surface (upstream side) and the back water surface (downstream side) are almost equal or quite different, that is, symmetrical or asymmetrical wave marks.

(3) The measured profile of Changzhougou Formation of Wanghaisi Great Wall System in Huludao (Figure 2-2-8)

Guide to field practice in earth science: Xingcheng geology

Figure 2-2-8 Measured Profile of Changzhougou Formation of the Great Wall System along Wanghai Temple in Huludao

Homework and thinking

1. When was the sedimentary contact interface between Changzhougou Formation and porphyry granite formed and its geological significance?

2. What geological features can be used as the basis for determining the boundaries of strata units of "Formation" and "Section"?

3. What are the important signs of bedding and bedding structure in distinguishing sedimentary environment?

Second, coastal geological processes

(A) the purpose and requirements of observation

1) Understand the refraction of waves in shallow water and their wave energy distribution characteristics.

2) Understand the types and main features of marine erosion landforms on the headland of bedrock coast.

3) Understand the characteristics of the sediments in the bay gravel beach under the action of strong waves.

4) Understand the impact of human activities on the coastal environment.

(II) Main observation contents

1) Observe how the waves in the coastal area are refracted.

2) Observe the morphological characteristics of marine niches, marine cliffs, wave cutting platforms and marine terraces at the headland of bedrock coast.

3) Observe the sedimentary characteristics of beach and gravel beach between high tide line and low tide line in the bay.

4) Observe the environmental pollution caused by municipal solid waste.

5) Understand the engineering geological conditions of port construction and the impact of port construction on coastal environment.

(3) observation tips

1) wave enters shallow water area, and its propagation speed decreases with the shallower water depth due to the friction between water quality point and seabed (c=(gz) 1/2, where c is the wave velocity, g is the gravity acceleration and z is the water depth). If the waves come from the direction inclined to the coast, the wave direction line will gradually tend to be perpendicular to the coastline, resulting in the so-called wave refraction phenomenon.

Assume that the isobath is roughly parallel to the coastline. Take the isobath AC in Figure 2-2-9 as an example. Suppose there is a small oblique incidence peak line. When one end reaches the point A of the sounding line, the other end is still at the deep point B. After △t time, the two ends of the peak line move by AD and BC respectively, and the original peak line AB moves to DC, and the included angle α 1 between the peak line and the isobath becomes α2.

Figure 2-2-9 Wave refraction

By definition, the crest line is perpendicular to the wave direction line, so:

sinα 1 = BC/AC =(△t c 1)/AC

sin α2=AD/AC=(△t c2)/AC

Because c = (gz) 1/2, c1>; C2, so sin α1>; sin α2，α 1 & gt； α2。 Therefore, as a result of wave refraction, the included angle between the crest line and the coastline gradually decreases, and the crest line tends to be parallel to the coastline.

Wave propagation is a kind of energy propagation, and its energy propagation direction is the direction of wave rays (wave direction line). Wave energy is the sum of kinetic energy and potential energy of a wavelength, unit width (crest line) and water quality point from the sea surface to the depth of wave influence. Wave energy E=pgλh2/8(ρ is seawater density, g is gravitational acceleration, λ is wavelength, and h is wave height).

In the straight coastal zone, when the angle between the wave direction line and the coastline (wave incident angle) is close to 90, the wave refraction is the weakest; If the incident angle is small, the wave refracts strongly, the wave diverges and the crest line is elongated, which reduces the energy per unit width of the wave.

In the coastal zone between the headland and the bay, due to wave refraction, the wave direction line diverges in the bay, and the wave energy decreases and accumulates. At the headland, the wave direction converges linearly, the wave energy increases, and there is a trend of erosion (Figure 2-2-9). In the shadow area covered by offshore objects, the wave refraction is strong and the wave energy is obviously reduced.

2) At the starting point (the first observation point) of Wanghai Temple route (y = 40 41'50.970 "n, x =120 56' 58.782" e, h = 1.5m), it can be observed above the high tide surface.

Looking west from the starting point of the route, you can see the first-class ocean terrace opposite the bay and the ocean cliff in front of the ocean terrace (Figure 2-2- 1 1). The surface of the first-class marine erosion terrace is relatively flat, the terrace surface inclines gently to the sea, and the sea cliffs at the front of the terrace are steep.

About 150m to the west from the starting point of the route, it can be observed that the modern beach is sandy sediment at the bottom of the bay, and the wave energy is weak (Figure 2-2- 12). Under the repeated action of surge inflow and outflow, the sandy accumulation on the beach is continuously sorted, with coarse particles piled up on the shore and fine particles piled up on the ocean surface.

Figure 2-2- 10 Marine niches developed on Suizhong granite and Changzhou Gou Formation sandstone at the starting point of Wanghaisi route.

Figure 2-2- 1 1 Wanghaisi route starts from the first-class ocean terrace and the ocean cliff in front of the ocean terrace.

Figure 2-2- 12 Sand accumulation on the modern beach near the starting point of Wanghai Temple route

From the starting point of the route to the north of 70m, the wave cutting platform can be observed. The surface of the wave-cutting platform is slightly undulating, generally inclined to the sea, and there are a few sea erosion piers (sea erosion residual hills formed by hard rocks) distributed on it. Behind the wave cutting platform are marine cliffs and first-class marine terraces (Figure 2-2- 13).

Figure 2-2- 13 Wave-absorbing platform at low tide and submerged wave-absorbing platform at high tide at the starting point of Wanghaisi route (right).

3) The high tide can be observed at the second observation point of Wanghai Temple route (y = 40 42 ′16.164 ″ n, x =120 57 ′ 06.468 ″ e, h = 1.5m). Observe the shape, size, lithology, sorting and roundness of gravel. There are a certain number of cement blocks and bricks in the gravel, and some cement blocks and bricks have been abraded into flat gravel (Figure 2-2- 15), which shows that the intensity of wave action here is great. There are many shells on the gravel beach in some areas (Figure 2-2- 15).

Figure 2-2- 14 Gravel Beach at the Second Observation Point of Wanghaisi Route

Figure 2-2- 15 Shells, bricks and cement blocks on the gravel beach at the second observation point of Wanghaisi route

At this time, we can also observe the sea caves developed on the surface of a sandstone in Changzhou Gou Formation above the high tide line (Figure 2-2- 16).

Fig. 2-2- 16 marine niches developed on the sandstone surface of Changzhou Gou Formation, the second observation point of Wanghaisi route (partially enlarged on the right).

Fig. 2-2- 17 sandstone profile of changzhougou formation covered by domestic garbage

About 50m to the east from the second observation point, it can be seen that the domestic garbage almost completely covers the sandstone profile of Changzhou Gou Formation (Figure 2-2- 17). In hot summer, these domestic wastes give off a disgusting smell. When it rains, it will also bring pollutants from garbage into the ocean and pollute the coastal environment. If people don't pay attention to protecting the environment, our side will be full of rubbish. Please take care of the earth and love our home!

Near the end of the stratigraphic section of Changzhou Gou Formation, a marine niche developed on the sandstone surface of Changzhou Gou Formation above the high tide line can also be observed (Figure 2-2- 18). The vertical distance between the modern average sea level and the highest position of marine niche distribution is the range of sea level change.

Fig. 2-2- 18 marine niches developed on the sandstone surface of Changzhou Formation near the end of Wanghaisi route (the right part is enlarged).

4) At the third observation point of Wanghaisi-Daoli route (Huludao Port Building Monument), learn about the basic situation of port site selection. The basic conditions of port location are: ① bedrock coast, hard rock; (2) The fault structure in the rock is undeveloped, especially there are no active faults; (3) At the headland of landform or the front of peninsula, the underwater bank slope is steep and the water depth is very deep; ④ There is no siltation in the coastal zone; ⑤ No geological disasters such as collapse and landslide; ⑥ There are few reefs near the sea, which is convenient for navigation.

Huludao Port is located on Huludao Peninsula in the northwest of Liaodong Bay, 90 nautical miles southwest of Qinhuangdao Port and 60 nautical miles east of Yingkou Port. Hong Kong is divided into an inner port and an outer port by a breakwater. With an area of 2km2 and a water depth of 7~9m, the port is wide and deep, sheltered from wind and waves in summer and slightly frozen in winter, making it an ideal ice-free port in northern China.

Huludao Port was founded in 19 10, but due to the Revolution of 1911, the port construction project was suspended. 19 13 started again, but it was finally closed due to lack of funds. 1929, General Zhang Xueliang, then commander of the Northeast Border Guard, visited Huludao and decided to rebuild the port. In June, 1930, 1 signed a contract with Dutch port management company, which is expected to be completed in five and a half years. On July 2nd 1930, General Zhang Xueliang personally presided over the foundation stone laying ceremony of Huludao Port and held a grand unveiling ceremony of the monument. The white marble monument is 1.8m high, with seven characters engraved on the front, and the inscription is written by General Zhang Xueliang. The "September 18th Incident" caused the port construction project in Huludao to die unfortunately, but the monument to the commencement of port construction is still erected on the west slope of Huludao (Figure 2-2- 19).

Figure 2-2- 19 Huludao Port Construction Monument

1948 1 1 Huludao was liberated and the port was rebuilt and utilized. Huludao Port has become an important military port in China. Bohai Shipyard was completed and put into operation on 1960, becoming an important base of China shipbuilding industry. 1984 65438+February 6th, Huludao Port was opened to the outside world,1999 65438+1October 2nd1day, the State Council approved Huludao Port to be officially opened to the outside world on May 7th, 2000, and became a national first-class port.

After nearly a hundred years of continuous construction and maintenance, Huludao Port has a considerable production and operation capacity, with four existing production berths and an annual comprehensive throughput of 100× 104t. It is an ordinary freight port, mainly used to transport petrochemical products, grain and building materials. Huludao Port Phase I expansion project 1× 104t wharf and port highway have been completed, and 2× 104t wharf and 3.5× 104t wharf are under construction. In the second phase of the project, six berths above 10,000 tons were expanded, with a total investment of 10× 108 yuan.

Figure 2-2-20 Huludao Port

1930 Although it has been more than 80 years since Huludao Port was built, the oil storage tanks built at the initial stage of port construction are still well preserved (Figure 2-2-2 1). Although these dilapidated oil storage tanks have been abandoned for a long time, there are still oil stains and stains on the bottom of the tanks (Figure 2-2-22), which will leak down with groundwater and cause serious pollution to the coastal environment.

Figure 2-2-2 1 Cement pouring oil storage tank on the west side of Huludao Port

Figure 2-2-22 Residual oil at the bottom of oil storage tank on the west side of Huludao Port

At this time, you can also see the memorial to the repatriation of overseas Chinese prisoners of war in Japan (Figure 2-2-23). After World War II, 1946 From May 7 to September 20, 105 1047 Japanese overseas Chinese prisoners of war were repatriated to Japan from Huludao Port. Although the criminal war launched by Japanese militarism brought great disasters and losses to the people of China, and countless anti-Japanese heroes shed blood on the battlefield, we repatriated a large number of Japanese overseas Chinese prisoners in a timely manner based on humanitarian principles. I hope the Japanese people can take this as a mirror, take history as a mirror, and have a long-term friendship with the people of China.

Figure 2-2-23 Japanese Overseas Chinese Prisoner of War Repatriation Monument on the west side of Huludao Port

Looking west at this time, you can also see Huludao New Port under construction and operation. Huludao New Port was established on the basis of land reclamation, and it is a port mainly exporting coal. Piles of coal are piled up in the open air in the port, and the covering dust caused by coal loading and unloading and vehicle transportation covers the port (Figure 2-2-24). The impact of metal and the roar of the motor are intertwined, giving people a deafening feeling. In the past, this used to be a blue bay. Seagulls soar in the sky, sometimes preying at sea, and sometimes resting on offshore pillars (Figure 2-2-25), giving people a feeling of intoxication. Now, with the construction and operation of Huludao New Port, this beautiful scenery will never come back. In the past, beautiful sea pillars were blown flat in the sea reclamation, which used gravel. In the process of developing and utilizing natural resources, building ports and developing economy, if people do not pay attention to protecting the environment, it will cause serious damage to the natural ecological environment. As future geological engineers and geologists, we should enhance our awareness of environmental protection and protect the earth on which we live.

Figure 2-2-24 Huludao New Port shrouded in dust

Figure 2-2-25 Blue Bay before the construction of Huludao New Port

Homework and thinking

1. Why was Huludao Port built here?

2. Why do the corners of Wanghai Temple suffer from ocean erosion, while the bays on both sides suffer from ocean accumulation?

3. How much debris do you usually accumulate on high-energy beaches? Why?