What is Petrographic Analysis? Sedimentary lithofacies analysis

Petrographic analysis refers to:The advantages and disadvantages of the material production process will be reflected in its lithofacies structure, therefore, through petrographic analysis, the production process can be improved and the performance of the product can be improved. The petrographic analysis includes two parts: the identification of the facies composition of the material products and the study of the microstructure characteristics.

There are three types of phase composition of material products: crystalline phase, glass phase and gas phase. The analysis and identification of facies composition is the premise and basis of lithofacies analysis of materials.

What it does:

In the process of glass dissolution, it contains gaseous volatile components, and cannot escape from the surface of the molten glass, which often forms an elliptical shape due to the flow of the molten glass, and is completely extinction under orthogonal microscope. Streaks and nodules are vitreous defects.

The large one can be directly observed, and the small one can be determined by observing the change of the interference color of the glass surface with a microinterferometer and an interferoreflectometer. Calculus is the most common and dangerous defect in glass, it is a crystalline substance, the expansion coefficient is very different from the surrounding glass, seriously damage the mechanical strength and thermal stability of the product. Petrographic analysis is convenient and effective for stone detection, and is commonly used.

The above content refers to Encyclopedia - Petrographic Analysis.

Petrographic analysis is simply to observe and analyze the phase composition and microstructure of rocks by using various test methods. Test methods include reflective microscopy, polarizing microscopy, scanning electron microscopy, X-ray diffraction (XRD), differential heat, weight loss, infrared spectroscopy, etc.

Research Interests. It mainly studies the mineral composition, chemical composition, structure, occurrence, classification and nomenclature of rocks, as well as understanding the genesis of rocks, the interrelationships between various rocks and their evolution. It is the basis of petrological research.

Course content. Petrofacies analysis of ceramics.

Section 1: Types and Preparation of Ceramic Materials.

1. Varieties and classification of ceramic materials.

Second, the preparation process of ceramic materials.

Section 2: Microstructural Characteristics of Ceramic Materials.

1. Crystalline phase and grains.

Second, the glass phase.

Third, chaotic and rough gas phase.

Fourth, the surface and interface.

5. Grain boundaries Section 3 Petrographic analysis of several ceramic materials.

1. Petrographic analysis of ceramic glaze.

2. Petrographic analysis of electric porcelain.

3. Alumina porcelain.

Fourth, talc porcelain.

5. Silicon nitride porcelain and carbon dismantling silicon porcelain.

Petrographic analysis of glass materials.

Section 1: Formation and defects of glass materials.

First, the formation of glass products.

2. The formation of glass-ceramic.

3. Defects in the vitreous.

Section 2: Types and petrographic analysis of glass stones.

1. Powder stones.

2. Refractory stones.

3. Crystallization stones.

Section 3: Petrographic Analysis of Amorphous Defects.

1. Glass bubbles.

2. Vitreous inclusions.

Third, it is early to suppress his amorphous defects.

Section 4: Petrographic analysis of glass-ceramic.

1. Preparation of glass-ceramic.

2. Petrographic analysis of glass-ceramic.

3. Types of glass-ceramic.

f.et al. proposed that the identification of fluid flow units is to identify three-dimensional rock masses with similar petrophysical properties. This method adds information about pore types and fluid flow to the petrographic analysis, so it is different from sedimentary microfacies.

The steps are as follows: firstly, the data of the coring well are studied, and the reservoir is divided into lithofacies with specific sedimentary and diagenetic characteristics; Then, the results of the core study were applied to the non-coring wells, and the discriminant function of the non-coring wells was established by discriminant analysis to identify the lithofacies of the non-coring wells. The challenge was how to determine the seepage barrier and the distribution of the flow unit between the wells.

1.Lithofacies of intrusive rocks.

The lithofacies of intrusive rocks refers to the different appearance characteristics of intrusive rocks at different depths and different structural parts, mainly the characteristics of structural structure. Intrusive lithofacies can generally be divided into deep facies (formation depth of 10 km), medium deep facies (formation depth of 3 10 km) and shallow facies (formation depth of .

Plutonic facies is a rock mass formed by magma intrusion in a deeper part of the cooling, and its temperature drops slowly, so the crystals are generally coarse, forming a coarse-grained to giant-grained structure, and local pegmatite structures can appear, and often appear in huge rock foundations, the rock mass is mainly granite, and the boundary between the rock mass and the surrounding rock is often unclear.

The depth of formation of medium-deep facies is between the deep-formed facies and the superficial facies, often forming medium-grained, medium-coarse-grained and porphyritic structures, and the occurrence of rock mass is mostly rock strains and small-scale rock foundations, and some are rock basins and rock walls.

Epifacies is a magmatic rock mass formed by magma intrusion and cooling close to the surface, and the magma temperature drops rapidly when formed, the crystallization is fine, and it often has the characteristics of fine grains, cryptocrystalline structure and porphyry structure. Most of the rock masses are small intrusions, such as rock walls, rock beds, rock caps and small rock strains.

2.Lithofacies of ejecta rocks.

Ejecta rocks are formed by magma erupting from or near the surface and are mainly composed of various lava and volcaniclastic rocks. According to the formation conditions, eruption intensity and genesis of volcanic activity products, they are subdivided into 6 categories:

The volcanic neck facies is also known as the volcanic channel facies. It refers to the rock mass formed by the original passage of magma to the surface, and later filled with lava, volcanic debris and rock avalanche on the channel wall, also known as rock neck and rock tube. The cross-section of the volcanic neck facies rock mass is approximately circular, with steep occurrences and slender and long morphology (Fig. 6-23a).

The volcanic passages of the fissure eruption are mostly in the form of rock walls. Xiangzhou.

Fig.6 23 Volcanic necks and lava flows.

Overflow phase refers to the lava flow or lava cover formed after the eruption of less viscous and easy to flow magma. The most common overflow facies rock is basalt (Fig. 6-23b), followed by andesite.

Eruption refers to the rock mass formed by the accumulation of pyroclastic materials on the surface of a volcanic eruption by a strong volcanic eruption. Medium- and acidic magmas rich in volatile matter and high viscosity are conducive to the formation of explosive facies rocks. The size of the pyroclastic material is related to the distance from the crater, with coarse volcanic breccia and agglomerates generally accumulating near the crater and fine-grained tuff away from the crater.

Invasion refers to the acidic and acidic magma in the sensitive limb with high viscosity and difficult flow, and the rock mass formed by extrusion from the crater after a large amount of gas is released. It is often used in and near the crater to build bridges and feasts, accumulating rock bells, rock needles, dome mounds and other special shapes. It usually forms late in an eruption, especially after a violent eruption.

Subvolcanic facies refers to rock masses of the same origin as ejecta rocks, but are ultra-shallow (within the surface) intrusions. The lithology is similar to that of ejecta rock, which has the appearance of lava and the occurrence of intrusive rocks, such as rock walls, rock beds, rock caps, rock branches, etc.

Volcanic sedimentary facies refers to the rocks formed by alternating volcanic eruptions and normal sedimentation, which are characterized by the symbiosis of volcanic lava, volcaniclastic rocks and normal sedimentary rocks. The bedding is relatively developed, and it is mostly distributed far away from the crater.