Thermal Evolution of Plutons and Uplift Process of the Yanshan Orogenic Belt

Thermochronological dating was used to study the thermal evolution of the Mesozoic plutons and uplift history of the Yanshan orogenic belt. The results show that the cooling history of the plutons is complicated, corresponding to the inhomogeneous uplift process of the Yanshan orogenic belt. The Panshan granite cooled fast during 226.48-204.95 Ma at a rate of 10.22℃/Ma after its emplacement at a depth of about 10 km, and its fast uplift occurred in about 96-35 Ma at an average rate of 0.115 mm/a. The Wulingshan pluton cooled fast during 132-127.23 Ma at a rate of 94.34℃/Ma, and its rapid uplift occurred in 86-45 Ma at an average rate of 0.186 mm/a. The Yunmengshan granite cooled fast during 143-120.99 Ma at a rate of 19.51℃/Ma, and its rapid uplift occurred in 106-103.95 Ma and 20-0.0 Ma at a rate of 1.06 mm/a and 0.15 mm/a respectively. The Sihetang granite-gneiss uplifted rapidly since 13 Ma at an average rate of 0.256 mm/a. The Badaling granite uplifted rapidly since 6 Ma at an average rate of 0.

Thermal properties of harzburgite and dunite at 0.8–3 GPa and 300–823 K and implications for the thermal evolution of Tibet

Thermal diffusivity(D)and thermal conductivity(κ)of harzburgite and dunite from Luobusha ophiolite were simultaneously measured up to 3 GPa and 823 K using the transient plane-source method in a multi anvil apparatus.The results show that the values of D andκof both samples systematically decrease with increasing temperature and increase with increasing pressure.By combination of the thermal physical data of rocks and minerals and geophysical constraints,we performed numerical simulation on the thermal evolution of Tibet vary over depth,distance and geologic ages.The present results provide new constraints on occurrence of partial melting and its geophysical significance beneath Tibetan crust.

Thermal evolution characteristics of Triassic coal in Chuxiong Basin and its geological significance

Chuxiong Basin in Yunnan is a typical Mesozoic foreland basin which is enriched in widely distributed Triassic coal resources with thick deposits and of important strategic significance. By applying vitrinite reflectance measurement, inclusion thermometry, fission track dating and EASY% Ro numerical simulation, the Triassic coal thermal evolution history of the Chuxiong Basin was analyzed, and the results were concluded. The vitrinite reflectance of Chuxiong Basin is higher in the west and south in general.Vertically, in the east, west, and north of the basin, the vitrinite reflectance increases with increasing depth, and in the northern part, exceptionally high values occur, and there is no significant regularity in the east. The formation of inclusions inside quartz veins in Chuxiong Basin Triassic coal are unrelated with magmatic hydrothermal fluid, and there are multi-phase inclusions formed in three or four sections of tectonic movements. The main heating period(apparent age) of the Triassic coal is concentrated in the late Cenozoic, during which the coal was subjected to repeated thermal disturbance, resulting in a multimodal distribution of the fission track data, which reveals mild burial features of the early stages of the Late Cenozoic. The Triassic coal of Chuxiong Basin has experienced two major temperature increasing processes, which occurred in the early-mid Yanshan and the early Himalayan, respectively. The first hydrocarbon generation period of coal organic matter occurred in the formation stage of the foreland basin, during which the south and west of the basin generated large amounts of hydrocarbon, but little was preserved. The second generation stage in the Early Himalayan had conditions suitable for high gas accumulation, especially in the western and southern regions. The upper Triassic coal is of moderate burial depth and is less affected by the strike-slip effect. There are key areas of Chuxiong Basin oil and gas exploration, such as the Yanfeng Basin in the north-central, Yongren and Yunlong areas.

Electrical and thermal conductivity of Earth's core and its thermal evolution——A review

The Earth’s core is composed of iron,nickel,and a small amount of light elements(e.g.,Si,S,O,C,N,H and P).The thermal conductivities of these components dominate the adiabatic heat flow in the core,which is highly correlated to geodynamo.Here we review a large number of studies on the electrical and thermal conductivity of iron and iron alloys and discuss their implications on the thermal evolution of the Earth’s core.In summary,we suggest that the Wiedemann-Franz law,commonly used to convert the electrical resistivity to thermal conductivity for metals and alloys,should be cautiously applied under extremely high pressure-temperature(P-T)conditions(e.g.,Earth’s core)because the Lorentz number may be P-T dependent.To date,the discrepancy in the thermal conductivity of iron and iron alloys remains between those from the resistivity measurements and the thermal diffusivity modeling,where the former is systematically larger.Recent studies reconcile the electrical resistivity by first-principles calculation and direct measurements,and this is a good start in resolving this discrepancy.Due to an overall higher thermal conductivity than previously thought,the inner core age is presently constrained at~1.0 Ga.However,light elements in the core would likely lower the thermal conductivity and prolong the crystallization of the inner core.Meanwhile,whether thermal convection can power the dynamo before the inner core formation depends on the amounts of the proper light elements in the core.More works are needed to establish the thermal evolution model of the core.

Thermal evolution effects on the properties of converting Cs-polluted soil into pollucite-base glass-ceramics for radioactive cesium immobilization

The Fukushima nuclear accident in Japan on March 11,2011,produced large amounts of Cs-polluted soil which must be controlled to prevent the spread of hazardous Cs into the environment.In this paper,the effects of heat treatment on the structure and properties of Cs-containing glass-ceramics,as a simulated nuclear waste form,were systematically investigated.Cesium atoms are chemically bonded in the pollucite structure,and the amorphous phase further encapsulates the pollucite crystals in the glassceramics,thus providing an extra protective layer for the immobilized Cs.XRD analysis,Raman and FT-IR studies on the glass-ceramics synergistically indicated that the optimum crystallization temperature for pollucite is around 1000℃.The pollucite is predominantly the main crystalline phase with a narrow crystal size distribution between 0.5 and 2 mm.Standard leaching test results show that the leaching rate of Cs was very low(3.0×10^(-3) g/(m^(2)·d)).The study offers a practical method for immobilizing Cs in pollucite-base glass-ceramics.Moreover,the experimentally obtained data may provide some important references for converting Cs-polluted soil into pollucite-base glass-ceramics waste form.

Rotational energy conversion and thermal evolution of neutron stars

Pulsars are rapidly spinning, strongly magnetized neutron stars. Their electromagnetic dipole radiation is usually assumed to be at the expense of the rotational energy. In this work, we consider a new channel through which rotational energy could be radiated away directly via neutrinos. With this new energy conversion channel, we can improve the chemical heating mechanism that originates in the deviation from β equilibrium due to spin-down compression. The improved chemical and thermal evolution equations with different magnetic field strengths are solved numerically. The results show that the new energy conversion channel could raise the surface temperature of neutron stars, especially for weak field stars at later stages of their evolution. Moreover, our results indicate that the new energy conversion channel induced by the non-equilibrium reaction processes should be taken into account in the study of thermal evolution.

Geological factors controlling deep geothermal anomalies in the Qianjiaying Mine,China

Here,the geological factors controlling deep geothermal anomalies in mines were studied based on the geotemperature,lithologic thermal conductivity,and related geological data collected from the Qianjiaying Mine,China.A simulation of the change in magma waste heat,conducted using the ANSYS Workbench,revealed the distribution characteristics of geothermal anomalies in this mine and the corresponding geological control factors.The results revealed the following points.(1)First-degree heat hazard level(temperature=31-37℃)occurred in the central and southwestern parts of the mine at an^600-m depth,while second-degree heat hazard level(temperature≥37℃)occurred at an^800-m depth.The geotemperature and geothermal gradient in the southwestern part of the mine were anomalously high.(2)The geotemperatures measured in the mine generally reflected a standard increase with depth,while the geothermal gradient remained unchanged with depth.The geothermal gradient and its average value in the study area were 0.70-4.23 and 2.12
C·hm^-1,respectively.(3)A combination of stratum characteristics,geological structure,and groundwater characteristics led to geothermal anomalies in mines;additionally,the waste heat from magma had no significant effect on the geothermal field.

Composition and Evolution of Hydrogen Isotopes of n-Akanes Generated from Anhydrous Pyrolysis of Sediments from Lake Gahai,Gannan,China

To understand the thermal evolution of lacustrine sedimentary n-alkane hydrogen isotopic composition(δD),especially bacterially derived n-alkanes,anhydrous thermal simulation experiments were performed with sediments from Lake Gahai(Gannan,China).We analyzed the original and pyrolysis-generated n-alkanes and theirδD values.The results showed that thermal maturity and n-alkane origins significantly affected the distribution of pyrolysis-generated n-alkanes.In immature to post-mature sediments,the bacterial-derived medium-chain n-alkanes generally had depletedδD values.The maximum difference in averageδD values between the bacterial-and herbaceous plant-derived medium-chain n-alkanes was 32‰,and the maximum difference in δD values among individual n-alkanes was 59‰.We found that the averageδD value of pyrolysis-generated n-alkanes from different latitude was significantly different in immature to highly mature sediments,but similar in post-mature ssediments.The hydrogen isotopes of sedimentary n-alkanes can be used as indicators for paleoclimate/paleo-environment conditions only when sediments are immature to highly mature.During thermal evolution,the δD value of generated individual n-alkanes and the averageδD value increased with thermal maturity,indicating that hydrogen isotopes of sedimentary n-alkanes can be used as an index of organic matter maturity.We established mathematical models of average δD values of generated n-alkanes from immature to post-mature sediments using n C_(21)^(-)/nC_(21)^(+)and average chain lengths.These results improve our understanding of the distribution andδD value of sedimentary n-alkanes derived from herbaceous plants in mid-latitude plateau cold regions.

Tectonic evolution of the Huangling dome and its control effect on shale gas preservation in the north margin of the Yangtze Block, South China

Significant breakthroughs of shale gas exploration have been made in Lower Cambrian and Sinian shale in the north margin of the Yangtze Block,South China.The drill wells with industrial gas flow located in the southern margin of the Huangling dome.Base on the geological survey,2D seismic,geochronological and drill wells data,the tectonic evolution history of Huangling dome was studied,and its control effect on the preservation condition of shale gas was discussed.The result shows that the Huangling dome might undergo four tectonic stages:(1)About 800 Ma,granite intrusion in the Huangling dome basement,primarily of granites replaced metamorphism rocks;(2)800-200 Ma,no significant tectonic movement with slowly buried history;(3)From 200 Ma,multi-phase uplift and the sedimentary rocks was eroded in the core of the Huangling dome.Shale gas in the Cambrian and Sinian strata was well preserved in the margin of the Huangling dome as the following reasons:(1)The Sinian shale was buried about 7.8 km indepth during Middle Jurassic,source rocks have a suitable thermal maturity for shale gas;(2)The rigid basement of the Huangling dome was mainly composed by homogeneity granite,without intensive deformation.As the main challenges of the widely distributed Lower Cambrian and Sinian shale are highmaturity and intensive deformation,a geological unit with a dome probably is a favorable zone for the old age shale gas.Therefore,it indicates that the adjacent zone of the Xuefengshan,Shennongjia and Hannan are the geological units with a dome and probably have potentials for the exploration of shale in the Lower Cambrian and Sinian.

Simulation of methane adsorption in diverse organic pores in shale reservoirs with multi-period geological evolution

In shale reservoirs,the organic pores with various structures formed during the thermal evolution of organic matter are the main storage site for adsorbed methane.However,in the process of thermal evolution,the adsorption characteristics of methane in multi type and multi-scale organic matter pores have not been sufficiently studied.In this study,the molecular simulation method was used to study the adsorption characteristics of methane based on the geological conditions of Longmaxi Formation shale reservoir in Sichuan Basin,China.The results show that the characteristics of pore structure will affect the methane adsorption characteristics.The adsorption capacity of slit-pores for methane is much higher than that of cylindrical pores.The groove space inside the pore will change the density distribution of methane molecules in the pore,greatly improve the adsorption capacity of the pore,and increase the pressure sensitivity of the adsorption process.Although the variation of methane adsorption characteristics of different shapes is not consistent with pore size,all pores have the strongest methane adsorption capacity when the pore size is about 2 nm.In addition,the changes of temperature and pressure during the thermal evolution are also important factors to control the methane adsorption characteristics.The pore adsorption capacity first increases and then decreases with the increase of pressure,and increases with the increase of temperature.In the early stage of thermal evolution,pore adsorption capacity is strong and pressure sensitivity is weak;while in the late stage,it is on the contrary.

Influence of deep magma-induced thermal effects on the regional gas outburst risk of coal seams

The thermal effect caused by deep magma intrusion can not only accelerate the metamorphism of coal body,but also bring additional thermal field that changes the mechanical environment of coal seams,thereby affecting the permeability of coal seams.Different from shallow coal resources,deep coal resources are in a mechanical environment characterized by limited stress and strain.Thus,the thermal effect has a more significant influence on the distribution and permeability characteristics of deep coal seams.In this study,the evolution history of highly metamorphic coal seams in Yangquan mining area was analyzed,and the main effect of magmatic activity on coal seams was obtained.Based on the determined vitrinite reflectance data of typical mines in Yangquan mining area,the maximum paleotemperature was calculated by adopting the Barker’s method.Furthermore,the paleotemperature distribution in Yangquan mining area was summarized,and its relationship with the metamorphic degree was acquired.Then,a new permeability model considering the thermal strain was proposed to analyze the permeability evolution in deep coal seams at different ground temperatures.Finally,through a combination of the results of gas pressure and outburst number in Sijiazhuang Mine,Yangquan No.5 Mine and Xinjing Mine,the influence of ground temperature on the gas outburst risk in Yangquan mining area was explored.The following conclusions were drawn:The maximum paleotemperature in Yangquan area can be 303C.In addition,the paleotemperature in the south is higher than that in the north of Yangquan mining area.The various temperatures at different depths bring about different degrees of thermal stress to different coal seams,leading to different strains.Under the fixed displacement boundary conditions in the deep,the coal seam folds and bends to varying degrees.Moreover,the difference in the ground temperature raises the a value of coal seams and lowers the permeability,which promotes the formation of gas-rich zones and increases the risk of coal seam outburst.The research results can help mines to make proper gas disaster prevention plan for different zones.

The cooling models of Earth’s early mantle

The thermal state of the early Earth’s interior and its way of cooling are crucial for its subsequent evo-lution.Earth is initially hot as it acquired enormous heat in response to violent processes during its formation,e.g.,the Moon-forming giant impact,the segregation and formation of its metallic core,the tidal interaction with the early Moon,and the decay of radioactive elements,etc.In the meantime,the cooling mechanisms of early Earth’s mantle remain elusive despite their importance,and the previously proposed cooling models of the mantle are controversial.In this paper,we first reviewed several prevalent parameter-ized thermal evolution models of the early mantle.The models give unrealistic predictions since they were estab-lished solely based on a single tectonic regime,such as the stagnant-lid regime,or relied on the disputable existence of the plate tectonics prior to-3.5 Ga.Then we argue that the mantle should have started to cool down from a very hot state after the solidification of the ferocious magma ocean.Instead of using one single scaling law to describe a single-stage model,we suggest that an episodic multi-stage cooling model(EMCM)of the early mantle could be more plausible to account for the mantle’s early cooling process.The model reconciles with the fact that the mantle cools down from a hot state prior to*3.5 Ga and can also explain the well-constrained post-3.5 Ga thermal history of the mantle.

The geological characteristics of the large-and medium-sized gas fields in the South China Sea

By the end of 2019,more than 220 gas fields had been discovered in the South China Sea.In order to accurately determine the geological characteristics of the large-and medium-sized gas fields in the South China Sea,this study conducted a comprehensive examination of the gas fields.Based on the abundant available geologic and geochemical data,the distribution and key controlling factors of the hydrocarbon accumulation in the South China Sea were analyzed.The geological and geochemical features of the gas fields were as follows:(1)the gas fields were distributed similar to beads in the shape of a"C"along the northern,western,and southern continental margins;(2)the natural gas in the region was determined to be composed of higher amounts of alkane gas and less CO2;(3)the majority of the alkane gas was observed to be coal-type gas;(4)the gas reservoir types included structural reservoirs,lithologic reservoirs,and stratigraphic reservoirs,respectively;(5)the reservoir ages were mainly Oligocene,Miocene,and Pliocene,while the lithology was mainly organic reef,with some sandstone deposits;and(6)the main hydrocarbon accumulation period for the region was determined to be the late Pliocene-Quaternary Period.In addition,the main controlling factors of the gas reservoirs were confirmed to have been the development of coal measures,sufficient thermal evolution,and favorable migration and accumulation conditions.

Quantitative study on hydrocarbon expulsion mechanism based on micro-fracture

The significance of source rocks for oil and gas accumulation has been indisputably acknowledged.Moreover,it has been gradually realized that there is difference between hydrocarbon generation capacity and hydrocarbon expulsion capacity,and this has prompted research on hydrocarbon expulsion efficiency.However,these studies dominantly highlight the results of hydrocarbon expulsion,and investigation into the corresponding process and mechanism is primarily from a macroscopic perspective.Despite its wide acceptance as the most direct hydrocarbon expulsion mode,hydrocarbon expulsion through micro-fractures is still not sufficiently understood.Therefore,this study obtains observations and performs experiments on two types of source rocks(mudstones and shales)of the Chang 7 oil group of the Yanchang Formation in Ordos Basin,China.Microscopy reveals that organic matter is non-uniformly distributed in both types of source rocks.Specifically,mudstones are characterized by a cluster-like organic matter distribution,whereas shales are characterized by a layered organic matter distribution.Thermal evolution simulation experiments demonstrate that the hydrocarbon generation process is accompanied by the emergence of micro-fractures,which are favorable for hydrocarbon expulsion.Moreover,based on the theories of rock physics and fracture mechanics,this study establishes micro-fracture development models for both types of source rocks,associated with the calculation of the fracture pressure that is needed for the initiation of fracture development.Furthermore,the relationship between the fluid pressure,fracture pressure,and micro-fracture expansion length during micro-fracture development is quantitatively explored,which helps identify the micro-fracture expansion length.The results indicate that the development of micro-fractures is commonly impacted by the morphology and distribution pattern of the organic matter as well as the mechanical properties of the source rocks.The micro-fractures in turn further affect the hydrocarbon expulsion capacity of the source rocks.The results of this study are expected to provide theoretical and practical guidance for the exploration and exploitation of tight oil and shale oil.

Thermal simulation experiment of organic matter-rich shale and implication for organic pore formation and evolution

A thermal simulation experiment of diagenesis,hydrocarbon generation and evolution of the organic matter-rich shale was carried out to investigate formation and evolution of organic pores under the constraint from immature,low mature,mature,high mature to overmature geological conditions.The argon ion polishingefield emission scanning electron microscope was used to analyze microscopic features of original samples and simulated samples of various evolution stages.Results showed organic pores could be formed during hydrocarbon generation from biochemical and hypothermal processes in the immature and low mature stages,and the shale shallow-buried depth might be favorable for preservation of organic pores;the generation and evolution of organic pores were of heterogeneity,and the maturity was not a decisive factor which controlled formation and development of organic pores,while the difference in physiochemical structure of organic matter played an important role in formation and evolution of organic pores;the organic pore development was obviously related with the retained oil,and the organic pores formed in the oil generation stage were easily filled by pyrolysis asphalt;organic contraction fractures/organic marginal pores might be important storage spaces for shale gas occurrence,and their development was mainly controlled by the physiochemical structure and evolution degree of organic matters when the chemical adsorbed organic matter was converted into the physical adsorbed organic matter and the free organic matter.

RECORD OF BLOCK ROTATION AND MAGNETIC FIELD REVERSALS IN THE TETHYAN HIMALAYA(HIDDEN VALLEY,CENTRAL NEPAL)

Metasediments from the Tethyan Himalaya (TH) were sampled for paleomagnetic studies in several areas. In this paper, we will present the first results from Carboniferous and Early Triassic marly limestones from Hidden Valley (Central Nepal).. The paleomagnetic directions reflect a Tertiary overprint probably synchronous with the metamorphism. In this area, the metamorphic conditions reached during Tertiary are poorly constrained. Temperatures are probably in between 300 and 400℃. The age of the thermal event is still debated. No geochronological data is available in this area. Previously published geochronological data from the northern part of TH metasediments in India ranges from 47 to 42Ma (Ar/Ar Illite) after Weissman et al. (1999) and Bonhomme and Garzanti (1991). While in the southern part (close to HHC), biotite Ar/Ar data ranges from 30 to 26Ma in Marsyandi Valley (Coleman and Hodges, 1998) and muscovite Ar/Ar ranges from 18 to 12Ma in the upper Kali Gandaki Valley (Godin et al., 1998).. In this context, the age of the magnetization can′t be defined with precision.

Effect of crustal porosity on lunar magma ocean solidification

The lunar ferroan anorthosites,formed by plagioclase flotation from the crystallization of the lunar magma ocean,have an age span of over~200 Ma.However,previous thermal models predicted a much shorter time range.We propose that a much smaller thermal conductivity of anorthositic crust due to its high porosity may have delayed the solidification of the lunar magma ocean.Our thermal simulation results,using the thermal conductivity of porous lunar crust,show that crystallization of a 1000 km deep magma ocean could be prolonged to tens of millions of years,and up to 180 Ma under some extreme conditions.The porous crust alone can’t explain the large crustal age span,however.Other circumstances must be taken into consideration,such as a thick lunar soil.

Stimulated Brillouin scattering evolution and suppression in an integrated stimulated thermal Rayleigh scattering-based fiber laser

The spectral purity of fiber lasers has become a critical issue in both optical sensing and communication fields.As a result of ultra-narrow intrinsic linewidth, stimulated thermal Rayleigh scattering(STRS) has presented special potential to compress the linewidth of fiber lasers. To suppress stimulated Brillouin scattering(SBS), the most dominant disturbance for STRS in optical fibers, a semi-quantitative estimation has been established to illuminate the mechanism of suppressing SBS in a periodic tapered fiber, and it agrees with experimental results. Finally, a linewidth compression device based on STRS is integrated into a single-longitudinal-mode ring-cavity fiber laser with secondary cavities, and its linewidth is verified to be 200 Hz through a self-heterodyne detecting and Voigt fitting method.

Shapes,structures,and evolution of small bodies

Small bodies are among the best tracers of our Solar System’s history.A large number of space missions to small bodies(past and future)offer a unique opportunity to use these bodies as a natural laboratory to study the different processes,mechanical structures,and responses that drive the origin and evolution of small bodies,which are connected to the origin,evolution,and current architecture of the Solar System.Images of small bodies sent by spacecraft have revealed unexpectedly rich and complex geological worlds.In addition to very diverse compositions,small bodies in the Solar System have highly diverse shapes and structures,which reflect both different evolutionary paths and material properties.Furthermore,each individual body has diverse geological features on its surface,which include craters of various sizes and depths,boulders of different sizes and morphologies,lineaments,fractures,pits,signatures of landslides,terraces,and ridges.Such a geological richness could not be detected via ground-based observations,and we are still at the beginning of understanding their significance on the low-gravity surfaces on which they manifest.The combination of space mission data and numerical modeling allows us to enrich our understanding of the origin,evolution,and physical properties of these fascinating bodies.For instance,starting from the shape models,bulk densities,and spin rates determined from space mission data,we can investigate the formation mechanisms that lead to the observed properties of small bodies.We can also infer the interior and mechanical properties(e.g.,friction and cohesion)that allow a small body to be structurally stable,as well as its further potential evolution under processes such as a spin rate increase or an impact.Then,considering the various processes that these bodies experience during their evolution,we can investigate how these processes modify their properties and,in turn,how those properties influence the outcome of these processes.This paper reviews our current knowledge of small-body shapes and structures and discusses the various processes that are responsible for their formation and evolution,which can modify the characteristics of the bodies.We separately consider each population of small bodies,although in some cases,such as active asteroids and comets,the distinction between two populations solely in terms of physical properties is not clear.We then summarize the main findings regarding the physical properties of small bodies that have been the target of rendezvous or sample return missions.

Successive formation of secondary pores via feldspar dissolution in deeply buried feldspar-rich clastic reservoirs in typical petroliferous basins and its petroleum geological significance

Clastic rock reservoirs in petroliferous basins are generally rich in feldspars. Feldspar dissolution has developed widely in clastic reservoirs, and the resulting secondary pores are crucial in deeply buried reservoirs. Based on a study of the diagenesis of clastic reservoirs in the Bohai Bay Basin, Tarim Basin, and Pearl River Mouth Basin and physical and numerical simulation experiments of fluid-rock interactions, this paper proposed a successive formation model of secondary pores via feldspar dissolution in deeply buried clastic reservoirs, considering the global research progresses in feldspar dissolution in clastic rocks. Feldspar dissolution can occur from shallow open systems to deep-ultra deep closed systems in petroliferous basins, resulting in the successive formation of secondary pores at different diagenetic stages. The successive mechanism includes three aspects. The first aspect is the succession of corrosive fluids that dissolve minerals. Meteoric freshwater dominates at the Earth’s surface and the early diagenetic A stage. Subsequently, organic acids and COformed via kerogen maturation dominate at the early diagenetic B stage to the middle diagenetic stage. COand organic acids formed via hydrocarbon oxidation in hydrocarbon reservoirs dominate at the middle diagenetic B stage to the late diagenetic stage. The second aspect is the successive formation processes of secondary pores via feldspar dissolution. Large-scale feldspar secondary pores identified in deep reservoirs include secondary pores formed at shallow-medium depths that are subsequently preserved into deep layers, as well as secondary pores formed at deep depths. Existing secondary pores in deeply buried reservoirs are the superposition of successively feldspar dissolution caused by different acids at different stages. The third aspect is a successive change in the feldspar alteration pathways and porosity enhancement/preservation effect. Open to semi-open diagenetic systems are developed from the Earth’s surface to the early diagenetic stage, and feldspar dissolution forms enhanced secondary pores. Nearly closed to closed diagenetic systems develop in the middle to late diagenetic stages, and feldspar dissolution forms redistributional secondary pores. The associated cementation causes compression resistance of the rock, which is favorable for the preservation of secondary pores in deep layers. These new insights extend the formation window of secondary pores in petroliferous basins from the traditional acid-oil generation window to a high-temperature gas generation window after hydrocarbon charging. The proposed model explains the genesis of deep-ultra deep high-quality reservoirs with low-permeability, medium-porosity and dominating feldspar secondary pores, which is significant for hydrocarbon exploration in deep to ultra-deep layers.