Paleontological fossils are the remains, relics and traces of life activities of organisms in geological history preserved in rock strata through natural processes. Paleontological fossil can be divided into remains fossil, mold fossil, relic fossil, relic fossil, chemical fossil five kinds.
Remains fossils refer to the remains of paleontology themselves preserved in rocks, including whole and partial fossils.Such as mammoth, dinosaur bones, human skulls, siliceous wood and other fossils.Cast fossils are impressions and replicas of biological remains left in strata or surrounding rocks.Such as leaf impressions, shells and other fossil.Relic fossils are traces of ancient life that remain in rock formations.Such as footprints, climb marks, holes, apertures and other fossils.
Equipmets: microscope, electronic scales(0g~100g,±0.01g), adjustable temperature heating plate(50C~300C), ultrasonic cleaner(power:75W~100W), refrigerator, oven.
| 1 | Identification of slake fossil rocks | 6 | Sporopollen analysis |
| 2 | Analysis and identification of calcareous ultramicrofossils | 7 | Analysis and identification of micropalaeobotany |
| 3 | analysis and identification of Foraminifera | 8 | Identification of wood fossils |
| 4 | Analysis and identification of algae | 9 | Identification of large fossils of paleontology(plant、insect vertebrate、) |
| 5 | analysis and identification of Conodont | 10 | Analysis of plant cuticle |
4.1.1 Conception
Calcium carbonate fossils ranging from 1 to 35 microns, which includs coccolithophores produced by the algae and similar fossils, and also include similar size but different shapes associated with granulites, and unidentified extinction groups such as cretaceous microcones and Tertiary astroliths.
4.1.2 Experimental Materials and Reagents
Materials: a) glass slide:76mmx25mmx1mm; b )cover glass: 22mmx22mm or 20mmx20mm, thickness: 0.13mm~0.17mm; c) abies balsam: the refractive index is 1.520-1.549; d) Evaporating dish:50ml or 75ml; e) beaker: 250ml,500ml,1000ml；
f) mortar.
Reagents:a)sodium carbonate(NaCO3), chemically pure; b)Sodium bicarbonate(NaHCO3), chemically pure; c) sodium sulfate(Na2S04), chemically pure; d)ethanol(C2H5OH), chemically pure; e) oil immersion: The refractive index is 1.518.f) distilled water.
4.1.3 Sample Analysis
(1) Sample collection
Mudstone, shale, argillaceous siltstone and limestone were selected as analysis samples.cuttings: the sampling interval is not larger than 20m, the sampling quantity is not less than 20g. Core: the sampling interval is not larger than 1m, the sampling quantity is not less than 20g. The field outcrop: the sampling interval is not larger than 10m, the sampling quantity is not less than 30g. The sampling record shall include the well name/profile, depth/location, lithology, horizon, serial number, sampling date, and sampler.
(2)Sample Handling
Core or outcrop samples should be removed from surface contaminants, oil samples should be treated with oil washing. The loose sample is lightly crushed in a mortar with a pestle and mallet, he compact sample is broken into 1cm fragments. Put the debris samples into beaker,soak in distilled water twice the sample, place in a refrigerated room with the temperature below-5°C, after 12h, move to oven, gradually heat up to 120℃, keep the temperature no less than 8h, and take it out. Add saturated solution of sodium sulfate twice, and place it in the refrigerated room at a temperature below -5°C for no less than 12h.Repeat the above steps until the sample is completely loose and dried.
(3) Wafer Preparation
1) Wafer preparation should follow the principle of formation from new to old or the principle of depth from shallow to deep;
2) The alkaline analysis solution was prepared by adding 0.2g sodium bicarbonate and 0.15g sodium carbonate to 1L distilled water;
3) Take about I0g sample and put it into evaporation dish, add alkaline analysis solution to soak, stir it gently with glass rod or vibrate it in ultrasonic cleaner for 5min to form suspension layer;
4) Use dropper to absorb suspension layer drops in the middle of the slide and distribute them evenly, airing them or dry them on an electric heating plate not exceeding100°C;
5) Put an appropriate amount of fir gum on the sample of the glass slide, heat and melt, cover the cover glass, and squeeze out the bubbles;
6) After the sample flakes are cooled, soak them in ethanol for 10s to 30s, remove the remaining fir gum with a brush, rinse with water, and dry it;
7) Label the sample number, well number/profile.depth;
8) Please refer to Table A. 1 for processing record and format of sample filling
(4) Fossil Identification
1) Dip thin slices in oil and put it under the polarizing microscope to identify and Statistical fossil;
2) Distinguish stones and non-stone according to whether there is cross extinction image under orthogonal polarization.
3) The species of stone fossils are divided according to the characteristics of interference images under orthogonal polarization and perspective images under single polarization,The generic features include, a)the shape and size of stone; b)Shape, number and thickness of stone rings; c)Structural changes in the central region; d)The arrangement of calcite grains.
4) Non-granular and rocky fossils are classified according to the characteristics of perspective images under single polarization, image features include: a)the shape and size of crystals,b)the number of crystal; c)the arrangement of crystal.
5) The relative abundance of individual fossil species is calculated in the unit of field diameter 0.24mm (eyepiece 10x, objective lens 100x) by the following six orders of magnitude: a)VA(very abundant); b)A(abundant）一6~25coin/horizon;
c)C(normal)一1~5coin/horizon;d)F(less)一1coin/(2~10 horizon; e)R(rare)一1coin/11〜50horizon; f)VR(poor)一less than1coin/50horizon.
6) The statistical method of total fossil abundance was based on the view area diameter of 0.24mm, counting total number of fossils in 20 horizons. If the total number of fossils is less than 400, continue counting until the total number reaches 4(X), finish counting the horizon, and recording total number of horizons and total number of fossils. If the total number of horizons counted is still less than 400, end the statistics and record the total number of horizons and fossils.The total fossil abundance is converted from the total number of fossils counted in 100 horizons.The recorded fossil abundance format is shown in Table A.4.
7) Fossil abundance statistics should exclude chipping, mud contamination and redeposition of fossils.
8) Record the state of fossil preservation according to the following labels: a)G(good)The overall shape and structure of a fossil is clear and well preserved; b)M(sceondary)the overall shape and structure of a fossil are basically clear, relatively intact preservation, but slight dissolution or proliferation phenomenon; c)P(bad) fossil grain structure is not completely preserved, or severely dissolved, or yangong hyperplasia, or wide crystallization.
9) The total abundance of calcareous nannofossils was calculated according to 5.2.6, and drawn acomprehensive map of fossil analysis .
Foraminifera have been distributed from Cambrian to modern times. There are many foraminifera species, with more than 1,000 known genera and over 30,000 known species. They have many different types in shell wall composition, atrioventricular arrangement, shell mouth property, interior structure and shell decoration. The characteristics of foraminiferal identification mainly include shell wall, room, shape, shell mouth, sutures and diamante. In addition to these physical features, some foraminifera’ dissepiment have complex plumbing systems (shch as Elphidium). Some Foraminifera shell orifice have toothed plates and other structures (shch as Uvigerina), both are important basis for classification and identification.
4.2.1The General Characteristics of Foraminifera
Foraminifera is a subclass (Sarcodina) of the class Rhizopoda(carnipoda) of the phylum protozoa, it is a tiny eukaryotic cell. The insect body is composed of a mass of protoplasm and has a shell formed by protoplasm secretions or secretions cementing other foreign particles outside the body. They are distributed from Cambrian to modern times and reached their peak in Tertiary. Foraminifera are of great variety in Quaternary Marine strata and are important reference fossils.
A. Foraminifera Form
The size of foraminifera is generally less than 1mm, the largest one can reach about 110mm, it consists of one or more cavities, according to the shape, number and arrangement of the compartments, foraminifera can be divided into unilocular test, bilocular test and multilocular test.
B. Composition of foraminifera shell wall
The shell wall of foraminifera consists of different components, including pseudochitin test, cemented or sandy shell, siliceous shell and calcareous shell. Calcareous shells are the most common among them. Most foraminifera have calcareous shells including porcelain shells, calcareous microshells and calcareous transparent shells.
C. Foraminifera shell wall structure
Foraminifera are famous for the pores in their shell walls, which include three types: oral pores, adjacent pores and shell wall micropores. On the shell wall there are many ornamentation, such as tumors, ribs, ridges, thorns and so on. Holes and ornamentation are important indicators of foraminifera identification.
Two main suborders of Quaternary foraminifera: the suborders pentaphylla minor and rotifers, the former has only one super class-Micromiliaceae, the latter includes 11 super classes(超科）, which coccidioides are planktonic foraminifera and the rest are benthic foraminifera.
4.2.2 Requirement of Sample
Each sample weighs about 100-200 grams, but it must be determined by lithology and lithofacies, such as 50 grams or even 10 grams of dry sample deposited in fossil-rich Marine facies.
4.2.3 Sample pretreatment in laboratory
Different kinds of microfauna fossils are analyzed in different ways. For example, conodont is treated with acetic acid, and ultramicrofossils are treated with xylene or boiling water. The following are the most commonly used methods for microfossil treatment, it applies to foraminifera, ostracoda, radiolaria and other categories of microbody animal fossils.
1) Broken Sample: pound the rock,but should not be broken to less than 2-4 mm, should not grind, so as not to damage the fossil,.it is best to use a gradual crushing method, loose sediments such as formation samples and borehole samples should not undergo this procedure.
2) Bulk sample: the soft rocks fall apart after being soaked in water for a certain time, tighter rocks can be boiled in water, or boiled with sodium hydroxide or sodium carbonate to break them apart.consolidate hard rock should needs other methods: such as limestone can be heated to several hundred degrees in maofu furnace after cold water, so that the split;marl can be heated and baked in the oven to nearly 100 degrees after pouring with gasoline (but to prevent burning), and then replaced with cold water, so that the rock scattered.Loose sediments, such as formation samples and borehole samples, are immersed in cold water in beakers until the samples disperse themselves.
3) Rush the sample: Flushes away the muddy particles in the loose sample, leaving behind coarser particles that may contain fossils. It can be washed with water over a copper sieve(aperture from 0.05 to 0.1mm, depending on the size of the fossil selection) or repeatedly panned in a vessel until the mud is clean.
4) Pick the sample: the remaining samples (crude components) were placed under binocular binocular stereomicroscope to select fossils for fine components. If it is a modern or modern sedimentary sample, when the shell is hollow and not abandoned, it can be flotation with carbon tetrachloride (specific gravity close to 1.6), so that the lighter fossils float on the liquid level, and the heavier quartz and other mineral particles sink to the bottom, and then the liquid is filtered to enrich the fossils on the filter paper, which can reduce the burden of sample selection.
4.2.4 Identification
It was performed under binocular solid lens,sometimes in order to understand the internal structure, it is necessary to grind the slice and observe it with polarizer.
4.2.4Conclusion
According to the results, the identification list of each sample is made, and sometimes necessary quantitative statistics must be carried out.
Algae are low – grade autotrophic plants that contain chlorophyll and other auxiliary pigments.There are many kinds of fossil algae. Modern algae include blue-green algae, diatoms, chara, golden algae, dinoflagellates and so on. The algae fossils include rotunda fossil, diatom fossil, dinoflagellate fossil, golden algae siloflagellate fossil, chlorophyta discus fossil and so on.
4.3.1 Classification
(1) chara
Rotifers are multi-cellular protophytes with complex shapes. Plant bodies are anchored in the underwater mud with false roots. There are “stems” and whorled “false leaves” on the ground, without differentiation of real roots, stems and leaves.Oocysts are highly calcified and are often preserved as fossils in Quaternary strata. The fossil of the rock alga refers to its calcified egg depositary. The size of the oviposis is between 0.2 mm and 3.5mm, and the common shape is oval, spherical, ellipsoid, spindle, column and bottle. The calcareous shell of the oviposis is composed of several (5 for Quaternary period) long columnar encapsulated cells, which start from the bottom of the oviposis and rise upright or coiled to the top of the oviposis, the bottom has a bottom hole and a bottom plug, the top has a top hole or closed, nodules, mid ridges, transverse bars and undulation were found on the surface of the encapsulated cells. The rotifers belong to the class rotifers of the phylum rotifers, which includes three orders and nine families. Quaternary round algae species monotonous, only one order, one family, nine genera.
(2) Diatom
Diatoms are single-celled algae, belonging to the class diatoms of the phylum diatoms. There are 190 genera of ancient and modern diatoms, 120 of which are living species. Diatoms are tiny, about 1~200μm, with two siliceous shells and various shapes, including long elliptic, round, triangular and pentagonal, all kinds of ornamentation, longitudinal groove and interlace of shell mask can be used as an important sign of identification. According to the cell morphology of diatoms, diatoms can be divided into two orders, namely mesopoedia and pinetophyta. Most of the former are Marine planktonspecies while most of the latter live in fresh water.
The distribution of diatoms is determined by a number of factors, including the ph, salinity, dissolved oxygen, nutrients and water temperature. For example, freshwater diatoms are mainly controlled by salinity, pH and nutrient status, while sea surface temperature and upwelling of nutrients at the junction of warm and cold currents all affect the distribution of marine diatoms, the changes of various factors will have a profound impact on the composition and structure of diatom population (Sancetta etc., 1991; Taxi, etc., 1993). The sensitivity of diatoms to salinity changes in Quaternary studies can explain two aspects: sea-level changes and environmental information in closed lake basins.In addition, the diatom population is also sensitive to changes in nutrition. Under the condition of outbreak, the diatom population can rapidly grow to a relatively fixed large biomass and remove a large amount of carbon and nutrients from the water, which is a good indicator of the nutritional status of the water.
4.3.2 Methods for Pre-laboratory Treatment of Calcareous Fossil
1)Preprocessing stage: drying – washing – drying;the experimental sample weight is between 50-150g; use 250-well, 0.061mm copper screen for washing.
2)component: the pre-treated samples were filtered with a 100-well, 0.154mm copper sieve, separated the particles with radius <0.154mm, then used a large copper sieve to remove the larger particles.
3)Heavy liquid flotation: the pre-treated samples were put into CCl4 solution and isolated with filter paper by using the gravity flotation principle of micropalaeontology.
4)Observation preparation: the processed samples were observed under a microscope and further selected for specimen preparation. The solution of siliceous fossils such as diatoms is similar to that of phytolith.
Conodonts, the remains of ancient animals with a variety of sharp teeth or serrations, is one of the important research contents of micropaleontology. Conodonts may be tiny fossils formed from the bones or organs of a class of extinct marine animals.Conodonts are very small, from less than 0.1 mm to about 4 mm, and have various forms, or simple, or complex. Unmodified conodonts generally amber luster, light brown yellow, gray white, transparent or opaque. Its main chemical component is calcium phosphate, which is composed of apatite minerals arranged in fibrous or lamellar form. Conodonts are also called gondolella because they look like the teeth of some fish or the jaws of annelids.
The taxonomic location of conodont has not been determined. Conodonts are widely distributed but limited to marine sediments. From the Cambrian began to appear, after several ups and downs, extinction in the Triassic. Conodonts evolve very rapidly and play an important role in the classification and correlation of standard fossils, especially underground strata.
Conodont is widely distributed in all kinds of sediments, most of which are limestone and shale, followed by dolomite and chert, and even can be found in sandstone and conglomerate. However, conodont is confined to Marine sediments, both shallow sea and open sea sediments. However, conodont is only found in Marine sediments, both shallow and open sea sediments, and has not been found in non-marine sediments. Conodonts began to appear in the Cambrian period of Paleozoic, and then went extinct in the Triassic period of Mesozoic. The evolution of conodonts has reached 300 million years, conodont evolved rapidly during this period, making it possible to become a standard fossil for effective stratigraphic division and correlation. Conodonts also have the advantage of being small in size and being found in a small number of cores and rocks in drilling projects over other large fossils. Conodont is playing an increasingly important role in stratigraphic division and correlation, especially in underground strata.
4.5.1Definition
Pollen consists of spores and pollen, spores are germ cells of fungi, algae, moss plants and ferns for asexual reproduction. The organs of the cells that produce spores are called sporangia. Pollen is the male microgametophyte of gymnosperms and angiosperms. The organ that produces pollen is called anther or anther.
Classification system can be divided into 3 categories at present.①Natural classification system: according to the classification system of modern plants, the palynological fossils were respectively placed into different classification elements and given corresponding names. This method is applicable only to the classification of living species and pollen fossils from the Quaternary and some neogene periods, such as ceratopteris thalictroides.②Semi-natural classification: For Mesozoic and paleogene pollen fossils, because it is difficult to exactly according to botanical classification system for its classification, generic name appears only in organs, namely first according to its likely from belong to certain types of plant and gives a corresponding word, and then to its own characteristics to give a corresponding word, the two together to form a pollen fossil taxa, such as Caryapollenites triangulus, Calamospora micronugosa, Ephedripites major, pro-teacidites, etc. ③ Morphological classification (artificial classification): the external morphology of pollen fossils is the main basis for classification and nomenclature, regardless of their genetic relationship. It is mainly used in early Mesozoic and Paleozoic pollen. Accordingly, there are three groups of natural genus + natural species, natural or semi-natural genus + morphological species and morphological genus + morphological species in the solution of pollen fossil species. At present, the most controversial classification and nomenclature of pollen fossils are the genera from late Cretaceous to Early Tertiary, and there are different opinions on whether they should be artificial classification, semi-natural classification or natural classification. At present, there are about 5 ~ 6 artificial classifications of pollen used in different ranges.
pollen analysis is mainly to invert the corresponding palaeo-vegetation evolution through the fossil pollen assemblages of different layers in typical sections, and derive the corresponding paleoclimate and its change process. Then, according to the evolution sequence of paleovegetation, deducing the corresponding paleoclimate and its change process, and reconstructed the evolution sequence of fossil pollen-pollen vegetation-paleoclimate. Moreover, pollen analysis can help to classify and correlate the Quaternary strata. Therefore, pollen analysis is the most effective method to study Quaternary paleoclimate and reconstruct paleoenvironment.
4.5.2 Pollen Analysis Method
Quantitative analysis of palaeoenvironment based on pollen spectrum is bound to involve the species and quantity of palynology. Pollen species reflect the vegetation composition of palaeoenvironment, and to reflect the vegetation composition of palaeoenvironment, in order to reflect the vegetation composition of the palaeoenvironment, the number of pollen must be counted.
The pollen percentage scheme, concentration scheme and deposition rate scheme are widely used in pollen analysis. The percentage schema refers to relative pollen statistics, while the concentration schema and deposition rate schema refer to absolute pollen statistics. This paper was adopted pollen percentage scheme. Percentage pollen content refers to the proportion of a certain type of pollen in a certain total number of pollen, expressed as a percentage. This pollen count can be the total of all types of pollen, or of all woody plants: pollen count, tree pollen count, etc.
The analysis methods of argillaceous rock sporopollen include: physical and chemical treatment of rock samples, separation, collection and preparation of fossil palynological samples from rocks.
(1) Instruments, Materials and Reagents
Main instruments: a) biological microscope: binocular, X100-650; b)percussive rock crusher; c)centrifuge: 500~4000r/min; d)electric furnace: 1000〜2000; e)density meter: 1.5〜2.5g/cm3; f)Counter balance:10 mg. g) anti-corrosion fume hood.
Mian materials: a)centrifuge tube: glass or nylon products; b)plastic cup: 100〜1000ml; c)glass beaker: 100〜1000ml; d)glass rod; e)plastic rod; f)sieve: standard sieve(aperture0.15〜5mm)、stainless steel sieve(aperture200^)、nylon sieve the aperture is less than lOftm); g)slide: d=l〜1.2mm, first grade; h) cover glass: d=0.15〜0.18mm; Lxb=20mmx20mm, 24mmx24mm, first grade; i)eye ophthalmic forceps; Curved lip teeth; j)plastic bucket: 5〜10L; k)medical gloves; l)glass bottom sample: 2〜5ml。
Main reagents: a)hydrochloric acid: analysis of pure; b)hydrogen acid: analysis of pure; c)nitric acid: analysis of pure; d)acetic acid: analysis of pure;
(2)Sample Collection
Outcrop or core (including borehole wall coring) should be collected layer by layer and section by section according to stratigraphic sequence, with each sample taking 200g, rock chip samples are generally taken at an interval of 5 ~ 20m in a pack. The quality of each sample after selection should not be less than 20g, and the mixed sample should not be less than 200g.
(3) Sample Crushing and Weighing
Hard rock samples were crushed by an impact crusher, particle size is 0.45 ~ 0.6cm. Muted argillaceous rock should not be less than 20 ~ 30g, gray green, red argillaceous rock should not be less than 100g.
(4) Analysis Steps:
Hydrofluoric acid treatment, acid and base treatment, the fossil pollen was identified by biological microscope.
(5) Determination of Spore Pink Variation Index
Material requirements, without oxidation treatment of pollen sample.
Pollen color grades can be divided into 6 grades: a)light yellow, first grade; b)yellow, second grade; c)brownish yellow, third grade; d)brown, forth grade; e)dark brown, fifth grade; f)black, sixth grade.
4.5.2 Instruments
Palaeobotany is the study of plants and their lives in historical times.
4.6.1 Fossil Types
Pressure fossils: these are the more common fossils. Plant remains are buried in swamps, lakes, rivers, and Marine deposits. After a few years, most of the organic matter has broken down, leaving the unbroken parts crushed and preserved as fossils, such as cuticle, corneous layer, etc., are usually preserved with impression fossils.
Model fossils: The organic tissue of this fossil no longer exists. Plant bodies leave only external impressions on rocks, and by filling the lumen of plant bodies with mud and sand and leave intimal impressions, which are preserved as fossils (such as the intima of fern leaves, xyloids and stems of corda). Impression fossils are most common in strata.
Petrochemical fossil: The infiltration of siliceous, iron, or calcareous solutions into plant tissues, preserving plant bodies or parts of plant bodies as fossils, e.g. siliceous plants, calcified plants, coal nuclei (a calcareous or dolomitic nodule), etc.
In addition to the above three species, there is also a microfossil, preserved in sedimentary rocks. The cell walls of spores and pollen contain sporophenin, the cell walls of some single-celled algae contain chitin or pseudochitin, and the cell walls of diatoms contain silica and other plant xylem, cork, cuticle and other fragments, which are often preserved in sedimentary rocks and fail to decompose, becoming microfossils or microfossils.
4.6.2 Research Methods
Pressed fossils can be treated with acids and bases, or Schulze’s solution, and sometimes with fluoric or hydrochloric acid to dissolve the rock and remove the undecomposed plant residues from rocks that cling to them. It is then treated with acid and base or schultz solution, after removing the organic impurities accumulated in and out of the plant residues, they are observed under a microscope.
Petrochemical fossils can be sliced with a rock slicer, glued to a glass slide and ground into thinner sheets, which can be examined under a microscope, or cut the petrochemical fossils, polish the cut surface, erode with hydrochloric or fluoric acid, after washing, then dry it and coated with a solution of cellulose acetate or cellulose nitrate, after drying again, tear off the plant tissue and observe it.
4.6.3 Subdiscipline
The ancient phycology: Study ancient algae
The ancient palynology: Study spores and pollen preserved in sediments or sedimentary rocks.
The ancient wood learn: Study ancient fossil stems
Ancient seeds learning: Study ancient seeds and fruits.
4.7.1 Conception
Petrified wood is a fossil wood that was quickly buried underground at least 100 million years ago and the part of the woods exchanged with SiO₂ in groundwater. It retains the wood structure and texture of the trees, color for earth yellow, light yellow, yellow brown, red brown, gray, gray black, etc. The polished surface may be glassy, opaque or slightly transparent, due to the texture of some wood fossils present jade texture, also known as silicified wood or tree jade.
4.7.2 Clasified by Mineralogy
Classified by mineralogy: quartz wood fossil, chalcedony wood fossil, protein wood fossil. Mainly quartz, followed by chalcedony, opal is very rare. According to the analysis of the residual structure of wood fossils, some opalinite wood fossils have been transformed into quartz wood fossils, and there are still bending cracks under the action of dehydration. Due to a long period of time, stress, heat and aging, the opalinite fossils formed in the Mesozoic have been transformed into quartz fossils, and only the Cenozoic opalinite fossils have been preserved.
Special wood fossil
1) Flat, twisted wood fossils: after the formation of fossil wood in different geological structure, the shape of the display is also different, the author has found that cypress fossil quartz wood in cretaceous strata is flattened under late compressive stress, in another part of the Jurassic strata, which is surrounded by twisted folds, there are conifer-like quartz wood fossils with “S” shaped trunks.
2) Carbon quartz fossil: there was a carbon quartz fossil with a trunk about two meters high and a trunk diameter of more than one meter. The peculiarity is that more than two-thirds of the trunk was silicified, so hard quartz fossil was formed, and one-third was charred to form combustible charcoal. This formation mechanism is speculated that the tree trunk was hit by lightning thunder when growing and burned charcoal, and then buried underground silicification.
3) Jasper fossil wood: jasper fossil wood crystallization is delicate and compact, after iron immersion into the color of brown quartz fossil wood, chalcedony fossil wood, protein fossil wood, due to stress atmospheric pressure flat shape.
4) Algae attached wood fossils: trees fall into the river and sea, before the formation of fossils, river and sea organisms, algae derived on it, and then geological movement formed biological wood fossils. This kind of fossilized wood has algae and other derivative layers, indicating that it is not after the formation of fossilized wood and algae parasitization, but in the wooden form (and in the state of dead wood, the original geological movement caused trees to fall into the water, algae and other layers of soft wood structure, resulting in three-dimensional and multi-plane invasion of the interior). Lotus pond moonlight cricket call, from the analysis on a lot of rain flower stones algae parasitic petrified wood, split, cross section are algae, that is not formed after the petrified wood, parasitic in algae (algae won’t be able to go deep into the interior, because petrochemical petrified wood is hard, soak for a long time in low temperature after the formation of calcium carbonate in the liquid, the formation of algal layer lines package.
5) Crystal petrified wood: after the formation of petrified wood, it is subjected to the action of SiO2 many times, forming the second and third generation of crystal in the favorable area and space of petrified wood.
Paleontological fossils are biological remains and active remains in the strata, including plants, invertebrates, vertebrates, insects and other fossils and their remains. Paleontological fossils are fossils of ancient creatures that can be seen by the naked eye.
4.8.1 Sample Requirements
Sampling requirements: sample size depends on the size of the fossil, try to collect the whole fossil; but the surrounding rocks other than fossils should be removed as far as possible; microfossil samples should be collected from fresh surface. For loose fossils, consolidation treatment is first followed by collection; large vertebrate fossils should be made into 1x1m2 grids, numbered and photographed, and collected by grids as a whole. Fossils are preliminarily sorted out in the field.
For fossils, the sample number should be written on the surrounding rock with marker pen, and the place where fossils need to be identified should be padded with soft paper or cotton to prevent wear and tear. The samples are divided into items and categories. Attached with the sample is a detailed sample submission sheet, including sample number, sampling location, general layer, identification requirements, sample submission unit, sample submission person and contact information, and ensure that the number of each sample is consistent with the submission sheet.
4.8.2 Record
After the specimen has been identified, it should be described. A complete description of a paleontological species, including, in order, the following: scientific name, plate, homology, type (population) specimen number and location, identification points, description, measurement and discussion of other data, place of origin and stratification.
4.8.3 Identification of Large Fossils
Identification requirements: name the fossil, describe its features (with photos and sketches), determine its age and determine its environment. Determine a relatively large taxonomic order, be sure to go to the family, use the retrieval table and other information to further check the sample to the genus or species.
Sometimes it is necessary to slice the fossil continuously, so that it is easy to understand the internal structure of the fossi
Stratum corneum（stratum corneum, Latin for ‘horny layer’）is the outermost part of the epidermis and consists mainly of 10 to 20 layers of flat, dead cells without a nucleus. The main role of the stratum corneum is to protect its subcutaneous tissues from infection, dehydration and chemical and mechanica. The plant epidermis is a protective film covering the epidermis of leaves, shoots and other aerial plant organs without periderm. It consists of lipid and hydrocarbon polymers impregnated with waxes and is entirely synthesized by epidermal cells. The plant cuticle is a layer of lipid polymers impregnated with waxes and is present on the outer surface of the major organs of all vascular plants. The plant cuticle has two layers of waxes: the intracutaneous waxes embedded in the cuticle and the epidermal waxes that cover the cuticle.
The chemical composition of vegetable wax is complex, not only the different plant species and different and different parts of the same plant is different.
The main function of the plant cuticle is to act as a permeable barrier to prevent water evaporation from the epidermal surface and also to prevent external water and solutes from entering the tissue. The micro-nanostructure of the cuticle also has special surface properties that protect plant tissues from contamination by external water, dirt and microorganisms.
Plant cuticular wax is long chain (from 20 to nearly 40 carbon) complex mixture of aliphatic and cyclic compounds.The biosynthetic pathways of synthetic aliphatic waxes have two kinds, is a kind of acyl reduction approaches, generate wax “alcohol and ester; the other is a carbonyl way, aldehydes, alkanes generated. In the research so far most of the plants are found in the cuticle of tired chain, fully saturated hydrocarbon skeleton aliphatic compounds, including alkanes, aldehydes, alcohols and fatty acids, the proportion of these compounds is different in different plants.In addition to these common components, but also from some special plants of some special wax compounds found in cuticular wax.Wax class containing 29 or 31 endemic components carbon fully saturated fat chains, usually contains two alcohols or ketones functional groups, the possibility of a heterogeneous position, such as secondary alcohol, the corresponding ketones, alkanes and ketone. Most of the cyclic compound is found in vegetable wax terpene, and at trace levels in most plant species.However, in certain plants, such as bay, grapes, fluffy linden, terpene can accumulate to high concentration. Although more than 200 basic triterpenoid carbon skeletons have been detected, the most abundant triterpenoid components detected in plant waxes are pentacyclic triterpenes and their derivatives. In addition, compounds such as phytosterols, alkaloids, palmitic and stearic acids have been extracted from plant surfaces, but whether they are components of epidermal wax mixtures has not been confirmed. In some plant species, components other than waxes, including diterpenes and flavonoids, are located on or near the plant surface and can be extracted simultaneously with the wax compounds.
To further understand the chemical composition of plant epidermal waxes, some issues to be addressed are presented. First, we need to improve the wax extraction methods to ensure that the different layers of waxes can be extracted quickly and efficiently. Secondly, the exact wax composition of different wax layers must be studied to elucidate the biological functions of each layer of wax. Finally, new strategies to identify some specific wax compounds that are difficult to identify due to the lack of standard samples are explored.
For example, the accumulation of waxes and cuticular monomers in leaves of OE-AaMIXTA1 and AaMIXTA1-RNAi transgenic strains were analyzed by GC-MS at Shanghai Jiao Tong University and compared with the empty vector control strain, especially for the major cuticular waxes, including docosanoic acid, waxic acid, eicosanoic acid and β-coumarinol (lower panel)
Empty carrier (the carrier), OE – AaMIXTA1 and AaMIXTA1 – the epidermis of RNAi transgenic plant artemisia annua load analysis