Petrological and geochemical characteristics of medium acid

<> "Crustal Structure & Hydraulic Properties of Rocks.

The structural composition of the earth's crust.

Definition: The Earth's crust is the outermost layer of the Earth's solid sphere, an important part of the lithosphere, and refers to the part of the lithosphere with inconsistent thickness between the surface and the Moho surface.

Composition: sedimentary crust; granitic shell; Basalt shell.

Classification: continental crust (continental crust) - average thickness 35km; Oceanic crust (oceanic crust) - average thickness 5 km.

structure (top-down); Weathered crust: Located at the most surface layer of the ground. Sedimentary rock formations:

Discontinuous, the thickness is about 4-5km, and in a few places it can reach 10km. Silicon-aluminum layer: The main components are silicon and aluminum, and the main components are granite and granodiorite.

Silicon-magnesium layer: The main components are silicon and magnesium, which are mainly composed of basalt.

Hydraulic properties of rocks.

Summary: Definitions.

Loose: The rock has pores and hard rocks have cracks, and soluble rocks have holes. Water exists in these voids in different forms.

When the rock and the water cherry tree interact, it shows different water holding capacity, water holding capacity, water supply and water permeability. This is the hydraulic nature of the rock.

Description: A brief introduction to each nature.

Water holding capacity: The ability of a rock to hold water, expressed in terms of water capacity. The ratio of the volume of water contained in a rock to the volume of a rock is known as the water holding capacity of a rock.

When a rock void is completely filled with water, the volume of water is equal to the volume of the rock void. The water holding capacity of rocks is mainly related to the size and number of voids in rocks.

Water holding capacity: Under the action of gravity, the property of a rock to maintain a certain amount of water in the void by relying on molecular force and capillary force is called water holding capacity, which is expressed as water holding capacity. Under the influence of gravity, the ratio of the amount of water held in the voids of the rock to the total volume of the rock is the water-holding capacity of the rock.

The particle size of the rock has a great influence on the water holding capacity, and the smaller the particles, the higher the water holding capacity of the rock.

Water feedability: The performance of a certain amount of water flowing out of a water-saturated rock under the action of gravity is called the water supply property of the rock. The ratio of the volume of outflow to the volume of the rock that stores water is called the degree of water supply. The particle size of the rock has a great influence on the water feed, and the smaller the particles, the smaller the water feed of the rock.

Water permeability: The water permeability of the rock, the size and number of voids, and whether they are connected to each other, have a significant impact on the water permeability.

The geological environment of Hunan Province is diverse, and various geological processes are very developed, so there are many types of rocks formed. At the same time, the river and lake water systems are developed, and the alluvial and silt are widely distributed. The types of soil-forming parent rocks and parent materials can be summarized into eight categories, and their lithological characteristics are listed in Table 1-1.

Table 1-1 Characteristics of soil-forming host rocks and parent materials in Hunan Province.

Continued. Among the above eight categories, the Quaternary laterite and the Quaternary alluvial and silt sediments are the soil-forming parent materials, which are sediments transported by flowing water after weathering different lithologies in different regions, and the rest are soil-forming parent rocks.