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Article

Ancient Aeolian Reservoirs of the East Siberia Craton

1
School of Earth Sciences and Engineering, Tomsk Polytechnic University, 634050 Tomsk, Russia
2
JSC “TomskNIPIneft”, 634027 Tomsk, Russia
3
JSC “KrasnoyarskNIPIneft”, 660098 Krasnoyarsk, Russia
4
The Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia
*
Author to whom correspondence should be addressed.
Geosciences 2023, 13(8), 230; https://doi.org/10.3390/geosciences13080230
Submission received: 9 June 2023 / Revised: 20 July 2023 / Accepted: 21 July 2023 / Published: 29 July 2023

Abstract

:
Fine-grained strata deposited on the Eastern Siberian craton are predominantly considered to mainly consist of Neoproterozoic sandstones. Clastic rocks near the unconformity border of the Ediacaran and the Riphean are represented by sandstone and siltstone layers with thicknesses of several tens of meters, belonging to the Nepa, Tira, and Byuk horizons in the Nepa–Botuoba region. These Neoproterozoic sandstones have features characteristic of aeolianites formed under the action of high wind velocity in the Ediacaran period. Sandstone samples near the Riphean–Ediacaran boundary were collected from five deep wells and characterized for granulometry and mineral composition using optical microscopy, XRD, SEM, and ICP-MS techniques. These sandstones have a high proportion of quartz (60–98%) with minor amounts of feldspars, carbonate, and sulfate cements. Thin sections of the sandy rocks feature bimodal distributions of the grains throughout many sections, with large well-rounded quartz grains being several orders of magnitude greater than the silt matrix grains. The monomineralic quartz rocks have an overgrowth of quartz grains. These rocks can be petroleum reservoirs with good porosity and permeability, but in most of the studied intervals, a high content of anhydrite and dolomite interstitial cement significantly reduces both. The porosity of the rocks is low, while the permeability is very low, which may be associated with a significant amount of clay and cement material. Aeolianites normally contain large amounts of bimodal quartz (due to its high stability and resistance to weathering) and possess the presence of heavy minerals.

1. Introduction

The deposition of aeolian rocks is a well-known process resulting in the sedimentation of clastic particles often adjacent to marine and fluviatile environments. These processes can currently be observed in areas associated with the development of modern wind systems in deserts or near the seaside [1]. However, it is difficult to diagnose aeolian deposits and facies older than the Phanerozoic. Geological time and the degree of diagenesis are key factors that bring about increasing uncertainty when studying clastic rocks. It is not always possible to determine the original source of the supply of clastic material, especially for very ancient deposits. In most cases, sedimentation by predominantly aeolian genesis in sedimentary basins may be associated with other processes supplying clastic material by aquatic, fluvial, glacial, or marine agencies [2].
In the history of the Earth, there have been favorable epochs for the accumulation of aeolian deposits, such as in the Permian–Triassic epoch, but aeolian deposits have also been found in Precambrian sequences [3,4,5,6]. Obviously, Precambrian aeolian deposits were formed under atmospheric conditions different from those of the present day and in the absence of vegetation. Since ancient times, many aeolian successions have been reworked by weathering and other processes.
Specific facies for the accumulation of aeolianites are sabkhas, where particles of aeolian origin are deposited in environments dominated by both chemogenic and carbonate sedimentation, bringing about the occurrence of unique formations with mixed clastic–chemogenic rocks [7]. A modern example is the sabkha deposits in the Arabian region [8,9,10,11]. Probably, these unique formations could have occurred throughout the history of the Earth, with a mixture of these two heterogeneous sources of accumulation.
The aim of this paper is to study sandy rocks that were formed as a result of the activity of Precambrian aeolian processes, which we believe developed and covered huge territories in the Ediacaran period. The current study attempts to consider the history of ancient Ediacaran sandy deposits on the Siberian platform, which occurred within the Neoproterozoic epoch, which was an active time for the development of aeolian processes which were widespread in the cold era.

2. Geological Setting

The Siberian platform (or the Siberian craton) is a large territory within the pre-Cambrian basement between the Yenisei and Lena rivers (Figure 1). It comprises a complex of Archaean granitic terrains (the basement), with prevalent meta-sedimentary dolostone deposits from the Proterozoic Age with, in its upper part, a sedimentary Ediacaran–Phanerozoic cover. It contains several large basins, which were formed during the Meso–Neoproterozoic and Vendian (Ediacaran) mega-cycles [12]. The Siberian platform is bordered by the Siberian basin to the west, the Proterozoic and Palaeozoic formations and a large Jurassic–Cretaceous Yenisei–Khatanga Trough to the northwest, and the Taymyr–Severnaya Zemlya orogen and the Palaeozoic complex of the Cis-Verkhoyansk Trough to the east (Figure 1). The structural map in Figure 1 shows the main structural highs (Anabar, Aldan, Nepa–Botuoba, and the Baikit Anteclise) and some depressions between them (Kureika and Cis-Sayan–Yenisei syneclises) that formed during the Meso–Neoproterozoic Age [12,13].
In its central part, the Siberian platform is mainly composed of sedimentary rocks of the Riphean Age (Meso–Neoproterozoic) covering the time interval of 1600–540 Ma and post-Cambrian deposits with a total thickness of about 12 km or more [15]. The Riphean complexes and granite terrains are overlain by the Ediacaran rocks of terrigenous–chemogenic genesis and covered by thick salt–carbonate deposits mainly of the Cambrian Age. These are covered in turn by the Ordovician, Carboniferous–Permian, and Triassic formations with minor Early Jurassic strata [12] (Figure 2).
Complexes of the Ediacaran strata are widespread across the Siberian craton, but their cumulative thickness varies depending on regions of occurrence: they may be totally absent near the upper part of granitic terrains and the Riphean basement, may be several meters thick in the vicinity of anteclises, and reach over one kilometer in the Kureika syneclise. There are no matching structural patterns of the Riphean and Ediacaran complexes [12]. However, clastic rocks can also be found near the unconformity between the Ediacaran and Riphean, often being represented by sandstone and siltstone layers belonging to the Nepa, Tira, and Byuk horizons in the Nepa–Botuoba region and similar clastic formations occurring in the neighboring regions [16]. These sandy layers can contain petroleum reservoirs with good porosity and permeability (P&P) properties, but, in most cases, they have a high content of anhydrite and dolomite interstitial cement (reaching up to 15–20%) formed as a result of post-sedimentary alteration of the rocks [17]. The sandstone is mainly of alluvial, fluvial, deltaic, or tidal origin [18,19]. Other researchers refer to them as ice tillite formations [20,21,22].
The Early Paleozoic f the Siberian platform is predominantly made up of carbonate and evaporite sediments, mainly of the Cambrian Age. In the Late Palaeozoic, there were a number of great geological magmatic events associated with the basaltic effusions of the Large Igneous Province (LIP) in the Yakutsk–Vilyuy region [23]. During the Permian–Triassic time boundary, the Siberian platform developed under gigantic and enormous magmatic events, which formed the Siberian Traps with more than 2 km thick basaltic effusions [24,25].
The Siberian platform is now of major research interest, especially because of its unique ancient oil and gas basins that are currently under active exploration. The main hydrocarbon reservoirs in the East Siberian basin are located in very ancient formations from the Riphean and Ediacaran to Cambrian and are mainly composed of chemogenic rocks, such as dolomites and limestones, with the active development of multi-kilometer thick salts as regional seals [26].
The paper focus on the area of the central part of the Siberian platform that includes five deep wells within the Katanga saddle and the Nepa–Botuoba uplift (Figure 1 and Figure 2). This paper focuses on the Ediacaran clastic deposits starting with the Nepa formation, mainly of siliciclastic composition, gradually interlayered with carbonate of Tirskaya (mixed siliciclastic-carbonate) and Oskobinskaya (mainly carbonate) formations (Figure 2). Earlier, Petrov [14] identified the Ediacaran sandstones near the basement as being of presumably aeolian origin.

3. Materials and Methods

Sampling. Sandstone samples from near the Riphean–Ediacaran boundary were collected from 5 deep wells (A-5, P-4, D-3, V-2, and S-1; Figure 1 and Figure 2). The mineralogical characterization of the studied samples was carried out using a combination of optical microscopy, X-ray diffraction (XRD), and scanning electron microscopy with an energy-dispersive spectrometer (SEM-EDS). Porosity and permeability of the samples were estimated using methods described below. Additionally, sandstones were disintegrated in HCl and water for measurement of granulometry and further SEM investigations.
Petrography. All the samples for petrographic studies were impregnated with blue resin to highlight porosity. Thin sections were examined using a polarizing light microscope (Olympus BX51, Tokyo, Japan), and their modal composition was evaluated by point counting (300 points per thin section). The following characteristics were studied: texture and structure, mineral composition, and authigenic and accessory minerals.
Granulometry. Grain-size distribution was assessed using a Microtrac S3500 laser granulometer, which records diffraction and scattering measurements (Microtrac Inc. Retsch GmbH, York, PA, USA). The study was carried out after the samples were dispersed in distilled water, and 10 g were further pretreated with HCl to remove carbonates. The grain-size distribution showed up to 50 size grades in the range between 0.20 and 1400.00 μm. The granulometry of sandstones was also estimated under a polarizing light microscope.
X-Ray Diffraction. XRD patterns were recorded using Rigaku Ultima IV X-ray diffractometer with a Cu anode, an X-ray tube voltage of 40 kV, a current of 30 mA, and a power of 1.2 kW. Crushed bulk rock samples were scanned through a range of 5 to 60° 2θ at a scanning speed of 1° per minute with a step of 0.02°. Quantitative mineralogical analyses of the whole rock data were performed by Rietveld analysis [27] using PDXL and Siroquant 3.0 software [28].
SEM. Separated grains of sandstones were scanned under a TESCAN VEGA 3 SBU scanning electron microscope (SEM) and OXFORD X-Max 50 energy-dispersive adapter at 20 kV accelerating voltage, specimen current of 5–12 nA, and spot diameter of approximately 2 μm. In addition, an accelerating voltage of 20 kV with a beam current of 11.5 nA and a counting time of 60 s was used to analyze the chemical composition of the grains by SEM-EDS.
Inductively-coupled plasma/mass spectrometry (ICP/MS). The concentrations of 41 elements in 32 representative samples from well D-3 were analyzed by ICP/MS. The samples were ground to ≤0.071 mm and dissolved in a mixture of concentrated nitric, hydrofluoric, and hydrochloric acids. The ICP-MS analysis was carried out using ELAN DRC-E equipment at the Chemical-Analytical Center “Plazma” (Tomsk). In our opinion, the determination of Zr, Hf, Th, U, and REE element concentrations plays an important role in the identification of accessories in quartz-rich sediments.
Porosity and permeability (P&P). All samples in Table 1 were plugged orthogonally to the long axis of the core where P&P measurements were fulfilled, typically from a plug ~4.0 to 4.5 cm in length and ~3 cm in diameter. All plugs were further subjected to extraction in an alcohol–benzene mixture, washed in distilled water, and dried to a constant weight. Porosity (%) was determined using a Boyle’s law method, where helium invaded the evacuated sample. Permeability (millidarcy unit, with Klinkenberg correction) was determined by flowing helium along the long axis of the plug and measuring the pressure drop at different flow rates (permeameter AP-608). All measurements were made according to standard procedures for “routine core analysis” [29].

4. Results

Within the Nepa Formation, the poorly sorted sandstones occur close to the Riphean basement and are characterized by a cross-bedding structure (Figure 3). The debris is usually well-rounded with a distinct bimodal structure. Mineralogically, the core fragments mainly consist of quartz grains with a low proportion of clay and mica minerals, as well as feldspars. As a rule, the fragments are enclosed in chemogenic anhydrite or carbonate cement, which fills the entire intergranular space (Figure 3). However, some almost monomictic quartz-rich sandstones have a porosity of 8 to 15%, where they have either no or minimal cement content. The thickness of sandstones usually attains only a few meters but can occasionally reach tens of meters.

4.1. Well Descriptions

Well A-5. This well was drilled between 3013 and 3340 m through the terrigenous sequence with four cored intervals between the uncored layers (Figure 4, Table 2). A significant proportion of quartz (60–98%) was found in all four intervals, with minor amounts of feldspars (up to 4%). Occasionally, carbonate (dolomite and siderite) and sulfate cements occurred but only sporadically. The thin sections of sandy rocks feature a bimodal distribution of grains throughout all sections (Figure 4). In cored intervals, rocks of monomineralic quartz were observed along with quartz grains showing features of strong quartz overgrowth cementation. In the lowest interval (between ~3330 and ~3370 m), very large well-rounded quartz grains were several orders of magnitude greater than the silt matrix grains (Figure 4; sample A5-33). The porosity of the rocks in the well indicates low values (from 0 to 12%, with an average of about 6%), while the permeability of the samples is very low (rarely higher than 0.1 mD), and this distribution may be associated with a significant content of clay material. The well basement was not reached during drilling.
Well P-4. This well was drilled through about 120 m (between 3365 and 3490 m) of terrigenous rocks ranging from clayey siltstone to sandstone, with a significant content of the siltstone component. However, sandy facies occur sporadically throughout the section. The rock fragments mainly consist of quartz (up to 80% on average, sometimes up to 95%), but here the content of clay material is significantly higher (up to 12% in the uppermost layer and up to 8% in the middle part of the section) along with fragments of feldspars (usually ranging from 2 to 5%). Dolomite and sulfate cements are present throughout the section, but they only occur sporadically. In the absence of sulfates and carbonates, quartz grains display features of the quartz overgrowth cementation with signs of pressure solution. The grains throughout the studied section display excellent maturity; they are well-rounded and often show a bimodal size distribution. The average porosity of the rocks in the section is relatively high (up to 9%), and this value is associated with the practically complete absence of sulfate and carbonate cements. The permeability of the rocks is low, but there are some samples with higher permeability, up to 38 mD (Table 2). The basement in the well is represented by monolithic dolomite of the Riphean Age with lower P&P (Figure 5).
Well D-3. This well was drilled through about 60 m of a terrigenous sequence of siltstone to sandstone. Sandy facies are found in the upper and lower parts of the sequence (Figure 6; Table 2). They have good maturity with very well-rounded grains. The main mineral components are quartz grains buried in dolomite and anhydrite cement (Figure 6). The highest concentration of quartz is observed in the lower part, where it reaches 75–80 (samples D3/22-40). The rock consists of only two minerals: well-rounded quartz grains and anhydrite poikilitic cement (Figure 6; sample D3/38). In the lower part, a layer of almost monomineralic quartz is exposed (up to 95%, samples 36–39) with a minor content of dolomite and sulfate cements having good P&P characteristics for a potential hydrocarbon reservoir (porosity 9–17%, permeability 3–236 mD). In the middle siltstone part of the sequence, there are bimodal and alternating layers with fine and coarse well-rounded grains (Figure 6; sample D3-19). The basement in the well is represented by monolithic dolomite of the Riphean Age having low P&P properties.
Well V-2. This well was drilled about 100 m through a clastic sequence that consists of four distinct layers: the lowermost layer (samples 1 to 16) contains a mixture of clastic rocks (36%), represented mainly by silty and sandy material, with substantial amounts of sulfate (25%) and carbonate (35%, consisting of dolomite and magnesite) materials, and clayey material (approx. 5%). The clastic components are characterized by good roundness with a bimodal distribution of the fragments (Figure 7; sample V2-5).
The second layer is represented by an almost monomineralic quartz sandstone with equal proportions of feldspars and clays of about 7–8% each. The clastic debris is well-rounded and immersed in a moderate amount of carbonate–sulfate cement (Figure 7; sample V2-18).
The third layer (sample V2-34) is represented by siltstone with a proportion of quartz up to 65%, clays (15%), and carbonates (20%) with a minor amount of sulfate cement (Figure 7; Table 2). The main carbonate mineral in this layer is siderite and, to a lesser extent, dolomite. The clastic rocks are characterized by well-rounded features and a clear bimodal distribution of the fragments—sand and silt grains (Figure 7; sample V2-35).
The most interesting part of the sequence is the fourth layer of sandstone (samples 35–45) with 70% quartz and containing a significant amount of feldspar grains; the proportion of the clastic components is almost 90% with an insignificant content of carbonates (siderite and dolomite up to 8%), sulfates (2%), and clays (3–4%). Along with the coarse quartzous grains, there is a small admixture of magnetite grains (Figure 7; sample V2-45, small black grains).
The porosity of the rocks in well V-2 ranges from 0 to 12%; the permeability of the samples is extremely low (less than 0.1–1.0 mD). These low values of permeability are associated with a high content of sulfate and carbonate cements in the rocks, which dramatically reduces P&P properties (Table 2). The Riphean rocks in the well basement are probably indicative of a granite foundation.
Well S-1. This well was drilled through over 200 m of the terrigenous sequence, which is represented by three short cores between the uncored layers (Figure 8). All three intervals contain sandy successions with a high content of quartz grains and minor feldspar and lithic fragments, as well as a clay fraction. The two upper intervals consist of porous sandstones with intermittent alternating thin layers of fine and coarse sandstone (Figure 8; samples S1-01 and S1-07). Sandstones near the basement (samples S14–24) are monomineralic quarzitic rocks submerged in anhydrite cement with a minor admixture of dolomite. The granulometry chart (Figure 8) shows that all sandstones have bimodal grain distributions where the coarse mode decreases upwards from medium- to fine-grained sand; however, a second peak corresponds to a fine-to-very-fine silty fraction. The same tendency is observed in thin-section microphotographs (Figure 8).

4.2. Optical Microscopy

In general, in the studied wells, the majority of Ediacaran sandstones are monomineralic quarzitic rocks with a minor admixture of feldspars and accessories submerged in sulfate (anhydrite) or dolomitic cement. Authigenic minerals include sulfides (pyrite) and magnetite, sometimes up to 1%. The well-rounded shapes of the grains strongly suggest an aeolian origin for these sandstones (see thin sections in Figure 4, Figure 5, Figure 6, Figure 7 and Figure 8). Observations in thin sections showed well-sorted distributions of grains in separate layers that predominantly consist of rounded to well-rounded grains of quartz, rare feldspar, lithic clasts, and other accessory minerals. All the studied rocks show a high degree of overgrowth cementation for quartz grains with characteristic rims around them. The distribution of individual layers in sandstones showed intermittent streaky structures with different granulometric compositions and sizes. Individual layers are similar to the inverse layers suggested by Simpson et al. [30], where such features enable the identification of wind-ripple laminations.

4.3. X-ray Diffraction

XRD patterns for all five studied wells showed that the rocks are mainly sandstones with predominantly quartz-rich compositions, the content of which can reach 99%. Quartz grains are usually submerged in cement, represented by high contents of anhydrite or dolomite with local clusters of other carbonates (siderite and magnesite). The clay mineral content varies widely from 0 to 35% and is mostly represented by illite and chlorite in well A-5 (Figure 4, Figure 5, Figure 6, Figure 7 and Figure 8).

4.4. Scanning Electron Microscopy

SEM images of disintegrated sandstone samples are shown in Figure 9. The morphology showed well-rounded quartz grains that exhibit a low relief with smooth surfaces formed presumably by grain-to-grain collisions. This indicates the final result of a long smoothing process in a windy environment that enabled good roundness. Unsurprisingly, almost monomineralic quartz facies are found here, with only a few grains of feldspar, mica, and lithic clasts. Their surfaces, however, are not always perfect, showing minor scratches due to the conchoidal structure of quartz. The abrasive character of quartz grains in the studied samples reflects the long process of grain collisions resulting in the roundness of grains and creating a mature sediment. This might indicate that it took a long time for the sand grains to round their surfaces. The analysis of grain surface features by SEM, especially quartz grains, indicates well-rounded to relatively sub-rounded quartz grains with conchoidal fractures and smooth surfaces, characteristic of transportation processes in aeolian environments (Figure 9). Artificial experiments carried out by Costa et al. [31] showed that after continued grain wear, the clean silica grains acquired the typical features of aeolianites.

4.5. Grain-Size Analysis

Chart of grain-size distributions for wells A5, P4, D3, and V2 are shown in Figure 10. The sandstone shows either lognormal or bimodal distributions of grains. The modal diameter of grains tends to be medium- to fine-grained sand with a variable proportion of silt (Figure 10). Such bimodal grain-size distributions indicate that the aeolian transportation probably occurred near a marine or lacustrine setting.

4.6. ICP-MS Data

The most quartz-rich sandstone samples (Table 2) from well D-3 were investigated using ICP-MS (Table 3), where the concentrations of chemical elements corresponded to typical concentrations for sedimentary clastic rocks. However, rare anomalies of titanium and radioactive minerals, as well as strontium and barium, are observed (Table 3). Their origin is further discussed in the discussion.

5. Discussion

This section will discuss the main characteristics of Neoproterozoic sandstones of the East Siberian craton, including their origin, mineral composition and texture of aeolianites, and bimodality as one of their specific features, along with climatic conditions of the epoch, P&P properties of reservoirs, and connection to radioactive and heavy elements.

5.1. Texture of Aeolianites

It is realistic to assume that aeolian sedimentation has a high deposition rate and cross-bedding stratification, which are the most common features for aeolianites. The cross-bedding texture of sandy arenites layered with wind-ripple strata is also a specific feature of the architecture of dunes [32,33,34,35]. In addition, multi-hundred-meter sequences of clean aeolian or mixed (aeolian–marine) sedimentary sequences could have been formed in the Proterozoic Age as well as in the Permo–Triassic Age characterized by very strong paleo-winds [33,35]. Our study also shows a significant development of cross-bedding (Figure 3A), and we assume a wind-blowing activity forming clastic sediment with a complicated streaky structure: quartz-rich and non-quartz-rich and coarse-grained and fine-grained. For example, the distribution of grain-size patterns in well A-5 with coarse streaks possibly indicates high wind strengths or stormy conditions, while fine streaks represent calmer conditions.
Some images of thin sections in a high resolution showed the graded strata ranging in thickness from 2 to 10 mm (Figure 11 and Figure 12). Individual strata consist of fine- to medium-grained, often monomineralic quartz-rich sandstones. This type of graded stratification could be the product of wind-ripple migration, as was argued by some researchers [36,37,38], or the result of wind events characterized by various wind velocities. Other typical textural features of aeolianites are good roundness [39] and maturity [40], and both characteristics were also observed in the studied rocks (Figure 4, Figure 5, Figure 6 and Figure 7). Earlier, Kuenen [41] had argued the high abrasive loss of quartz volume in aeolian deposits accompanied by the significant rounding of grains in comparison with fluvial sand particles.
Quartz-rich sandy facies consistently displayed substantial rounding of quartz grains. Therefore, it can be concluded that the good roundness of prevailing quartz grains and textural maturity of the sandstones (Figure 4, Figure 5, Figure 6 and Figure 7) may suggest a direct relationship with the aeolian processes.

5.2. Mineral Composition of Aeolianites

Quartz is the main constituent of the studied sandstones, and its content reaches, on average, 87% (Table 2), along with subordinate feldspars and a few lithic fragments. It is also the main mineral present in aeolianites due to its high stability and resistance to weathering. Heavy minerals are represented mainly by pyrite, zircon, tourmaline, and rutile, which are typical associates with modern aeolian and ancient deposits [42,43].
Sandstones, mostly quartz-rich, near the Archaean (AR) and Phanerozoic (PRZ) basement, contain anhydrite and, to a lesser extent, dolomite cements. Presumably, anhydrite could have been introduced to the rocks either by sand particles deposited into shallow sulfate-bearing seas and bays (sabkha or saline mud flat) or by the paleo-winds carrying quartz along with fine anhydrite dust and particles. The results of the study of productive Rotliegend sandstones indicated a detrital origin of sulfate grains, which were transported by the winds and deposited together with the coarse-grained fraction of layered sands in the aeolian sand plains environment, where they created anisotropic features of the reservoir structure with low and high permeability values [44].
The alternative interpretation for finding quartz grains together with anhydrite cement is the possibility of a rapid flooding of aeolian deposits by seawater that happened, for example, in the Middle Jurassic Entrada dunes in New Mexico [45]. The association of the two main minerals, quartz and anhydrite, is not so rare. Gypsiferous quartz sands and gypsites were deposited as aeolian sand sheets and within sabkha pans [9,46]. Some part of the fine gypsum component could be aeolian, reworked from deflating gypsite pans as argued by Gunatilaka and Mwongo [8], as a result of the interstitial precipitation of gypsum and minor carbonate from saline groundwater. Interstitial gypsum was probably formed as a capillary fringe evaporite just above the water table within sandy inland sabkha pans. In rare cases, gypsum precipitation was so abundant that its growth displaced the sand grains to form sandy gypsite layers just beneath the sediment surface [8]. Recently, Shaldybin [47] suggested the idea that anhydrite could be formed as a result of acid rains.
Alternatively, sedimentation of aeolian particles could be fast and directly deposited on the ground or in the water basin (lake or marine) deficient in other admixture materials. In this case, monomictic and monomineralic quartz rocks will form, creating a possibility for quartz overgrowth during diagenesis. This was observed in all wells where numerous rims of overgrowths around detrital grains formed the monomineral quartzose aggregates (Figure 13). Hence, the presence of sedimentary clastic rocks with a high content of quartz and, in particular, with the presence of sandy and silty well-rounded grains indicates the importance of aeolian processes in terrigenous sedimentation.

5.3. Origin of Aeolian Sandstones

Aeolian sandstones have been documented in the Precambrian record from 3.2 Ga [30]. Proterozoic and Neoproterozoic aeolianites have been found in many parts of the world [4,34,36,37,38,48,49,50,51,52]. Many of them are coeval with glaciogenic events of the Marinoan and Cryogenian glaciogenic successions [53,54,55,56].
Optical observations of some thin sections with unusual mineral compositions led to the idea that such deposits could be formed only if significant portions of aeolian sands fell into the sulfate–carbonate sediment of shallow seas in a Neoproterozoic basin. However, the presence of a large amount of clastic material within chemogenic rocks can be explained by the very dynamic environment during very high wind velocities in the Ediacaran Age. Allen and Hoffman [57] suggested that the unusually high velocity of Neoproterozoic winds is consistent with several findings of long-period waves of deglaciation. They argued for this effect while studying the giant wave ripple marks in the Marinoan cap carbonates in the Neoproterozoic Ocean [57].
Global winds with velocities of 20 m·s−1 could have caused a considerable input of dust material into the Neoproterozoic Ocean. This could have been widespread but might also have happened as a short-lived phenomenon, such as modern cyclones or hurricanes, and could have covered enormous parts of the Earth. This process, similar to Martian dust storms, can be observed as lasting for several weeks [58]. However, in the case of the Earth’s global storms, these processes could be extinguished by the availability of water (hydrosphere), which could contribute to a slowing down and capturing of clastic particles, burying them into sediment with the prevailing carbonate and sulfate sedimentation.
Sea water played a huge role in the dynamics of the wind drifts resulting in velocity change and further sedimentation of dust particles in the sea. As can be seen from our data, the aeolian deposits in the Ediacaran sediments could have formed with different proportions of clastic and chemogenic material in the Ediacaran sediments (e.g., Figure 6). In some cases, minor amounts of clastic grains (no more than 10–20% of the bulk content) are immersed in the carbonate–sulfate cement forming poikilitic structures. More often, in the studied rocks, the clastic part, mainly represented by quartz, exceeds 80–90%, and the presence of 10% carbonate–sulfate cement is sufficient for the cementation of dense rock. However, in some samples, only 1–2% of chemical cement was present—in these cases, the monomineral quarzitic sandy rocks had good reservoir properties (Figure 4; sample A5-33 and Figure 6; sample D3-38).

5.4. Climate Conditions

Aeolian rocks can be deposited in different climatic conditions, both hot and cold. Traditionally, the main factor for their deposition is the wind that occurs as a result of the pressure difference between various environments: marine and continental, mountain and plain area, and cold and warm regions.
It is believed that formations such as the Chinese loess were formed in cold conditions. Much of the European ice dunes were also formed during the cold period of the Quaternary glaciation. Thus, the climatic factor is key to the formation of aeolian deposits [59,60]. The most significant Paleozoic sediments were formed during the Permian period when a cold climate also prevailed [61,62,63]. In many basins, aeolian deposits often coexisted with glaciogenic deposits of tillites: the upper Carboniferous Merrimelia Formation of the Cooper Basin [64], the Permian Unayzah Formation in Saudi Arabia [65], and Ordovician sandstones near the Saharan glaciation in the Libyan desert [66].
Such epochs with high-velocity aeolian winds could occur as a result of pressure drop after cold periods of the Neoproterozoic deglaciation (concept of “Snowball Earth”) or could be caused by large temperature differences after the thawing of glaciers [67]. The widespread distribution of sandstones associated with glacial diamictites all over the world could be the result of such global interaction. A review of the Riphean–Ediacaran boundary shows a significant development of diamictites associated with monomineralic quartzose sandstones, which may also have been of aeolian origin in Neoproterozoic sedimentary successions following worldwide glacial events in South America [68,69], in Africa [54], in Australia [53,55,70], in North America [71], and in the East Siberian craton, in our case, where such deposits were traced over a distance of more than 800 km from well A-5 to well S-1, indicating a huge magnitude of aeolian processes (Figure 1).
These aeolian deposits of the Ediacaran epoch resemble the widespread Permian–Triassic deposits that also have a wide global distribution [72,73,74,75,76,77,78,79].

5.5. Bimodality

Bimodal texture is defined by a coexistence of well-rounded coarse quartz grains along with fine to very fine quartz sand and silt with high mineralogical maturity (Figure 10, Table 2). Bimodal grain-size distribution in matured sandstones indicates the aeolian type of transportation of sandy and silty particles. We do not exclude Hunter’s point of view, who argued that the bimodal distribution in aeolian deposits was shown by the lamination of silt and fine sand that was trapped in the troughs of wind ripple strata due to grain segregation on the ripples [80,81]. However, bimodality, in our view, is a key characteristic for aeolian deposits; that is, a clastic rock feature with different granulometries presumably caused by changing wind events (rough air) during depositional processes.
The bimodality of sandstones has been observed for many aeolian environments in various geological times and can be found in modern environments where bimodal distribution may be explained by two different wind directions [82]. The Gulcheru Formation may be considered the world’s oldest Palaeoproterozoic aeolian rocks having a bimodal structure [83]. This feature was also detected in other formations all over the world belonging to various geological times. However, in most cases, it is explained by the concordant work of wind and glacial–fluvial transported sediments [34,84,85,86,87,88] because it is very difficult to distinguish aeolian deposits after they have been mixed and reworked with fluvial material [89].
An alternative interpretation of bimodality could be possible if paleo-winds had different trends blowing to form the unique architecture of dunes [90,91] or due to various degrees of hydrodynamic sorting during transportation [92], or to local-scale factors, such as hydrological processes and source materials [93]. Bimodality in the studied region had been detected earlier in well S-1 by Plyusnin [94], who argued that different sizes of clastic grains were formed due to river activity of two fluvial systems in separate river deltas that served as two different sources with high and low dynamics [94].

5.6. Radioactivity of Sandstone and Accessories Enrichment

The aeolian sandstones with a predominance of quarzitic grains should normally contain a small amount of heavy accessory minerals, which were found in some studies [1]. In well D-3, low concentrations of microelements have been found in aeolian deposits unconformably overlaying quartz-rich sandstones, while higher concentrations occur above the arkozic quartz–feldspar rocks (Figure 14).
However, local paleo-winds could have caused the wind sorting whereby abnormally high local contents of accessory minerals occur in some facies. This would have enabled the possibility of finding unusual accessories in sandstones, such as rutile, ilmenite, monazite, pyrite, and baddeleyite [63]. Any high content of these minerals creates large radioactive anomalies in the well log. Thus, high monazite contents and generally high radioactivity in the Vendian (Ediacaran) deposits were recently noted in the studied area [95,96].
Some mineral accessories have been found in the studied wells: magnetite grains (Figure 7; V-2, sample 45) and sub-rounded pyrite grains (Figure 12B).
Large occurrences of Zr and Hf in ancient aeolian sediments are not known, especially when they are compared with modern sediments. However, relatively modern threshold values of their contents in European Quaternary loess were 10 mg·kg−1 for Hf and 318 mg·kg−1 for Zr [97]. At the same time, increased concentrations of other radioactive elements, such as U and Th, were also expected to be found. Figure 14 shows that some concentrations of Th and U in well D-3 exceeded the threshold values of 9 mg·kg−1 and 2 mg·kg−1 in average sandstones [98].
Thus, we conclude that there are clear signs of aeolian sandstones that allow us to differentiate them from other sandy rocks. Features of aeolian sandstones compared with other sandy facies are shown in Table 4.

5.7. Aeolian Petroleum Reservoirs

The investigation of all five studied wells led to an assessment and finding of oil and gas reservoirs. Some specimens actually contain petroleum as well as solid bitumen as traces of oil migration in the void space of the reservoirs.
The most famous and well-studied aeolian reservoirs are the Permian Rotliegend Formation, widespread over middle Europe with a prevalence of gas fields [99,100,101,102], and the Norphlet Formation in the USA [103,104]. Other aeolian reservoirs have been found and studied in various regions of the world [81,85,105,106,107,108].
The wells under study were planned to be initially surveyed for petroleum and P&P measurements. Earlier measurements of the porosity of reservoirs in this area showed that these measurements varied over a wide range, from 0.0 to 31.8%, with an average of 14.2% [96]. Our data from four of the studied wells showed approximately the same data—porosity changes from 0.0 to 19.1%, with an arithmetic mean of 6.36% (Table 2; Figure 15A).
It is obvious that there is very little chance of finding good reservoirs with high P&P values in very ancient clastic formations. For the East Siberian Ediacaran reservoirs, the initial P&P data have extremely low values due to extensive cementation with anhydrite and carbonate cements, along with poor pore connectivity for fluid migration (Figure 15B). Anhydrite and dolomite create barriers for permeability, causing the reservoir compartmentalization; however, good reservoirs with reasonable P&P values have also been found in all four wells, although only in certain stratigraphic intervals. Notwithstanding that high quartz contents improve and enhance P&P properties, no obtained data confirmed this pattern in our case (Figure 15C). All sandstone reservoirs in well A-5 with the bulk content of quarzitic grains over 90–95% showed a high rate of overgrowth and low values of P&P. Hence, secondary quartz overgrowth/cement precipitation is a negative process here, reducing pore spaces and connectivity in the reservoirs (Figure 13).
However, anomalously high P&P values were found in zones of sandy and silty facies where no anhydrite and/or dolomite cements were present, along with a low content of clay fraction. For example, in well D-3, the interval 2520–2526 m has a strata presenting good reservoirs with porosity over 14% and permeability in excess of 10 mD (Figure 6).

6. Conclusions

The Ediacaran clastic deposits that initially developed near the unconformity between the Ediacaran and Riphean within the East Siberian craton consist of siliciclastic rocks interlayered with carbonate and sulfate formations. Such deposits could only have formed if significant portions of aeolian sands were deposited into the sulfate–carbonate sediment of shallow seas in a Neoproterozoic basin. However, the presence of large amounts of clastic material within chemogenic rocks can only be explained by a very dynamic depositional process caused by very high wind velocity (about 20 m·s−1) in the Ediacaran Age, consistent with long-period waves of deglaciation. The giant wave ripple marks in the Marinoan cap carbonates in the Neoproterozoic Ocean indicate that these processes could have caused extensive aeolian sedimentation of clastic particles and buried them in the sediment with the prevailing carbonate and sulfate sedimentation.
Climate conditions could have played a crucial role in the formation of aeolian deposits. A significant formation of monomineralic quartz-rich sandstones was observed in the East Siberian craton, which may have an aeolian origin in the Neoproterozoic sedimentary succession at the Riphean–Ediacaran boundary. Such deposits extended over a distance of more than 800 km.
Bimodal grain-size distribution in the studied region was detected in all wells, which suggests that different sizes of debris may come from two different wind sources. The bimodality of Neoproterozoic sandstones in the East Siberian craton is possible if paleo-winds had different trends forming the unique architecture of dunes or various degrees of hydrodynamic sorting during transportation, or local-scale factors, such as hydrological processes and source materials. Bimodality is an inherent structural feature of aeolianites caused by changing wind strength and direction. Other typical features are the good roundness and local enrichment of accessory minerals with high content of REE, Ti-rich accessory minerals, and some other elements, such as U, Th, Ba, and Sr.
For the East Siberian reservoirs, the P&P values are extremely low due to extensive cementation with anhydrite and carbonate cements, along with poor pore connectivity available for fluid migration. However, reservoirs with good P&P values have also been found in all five wells, but only in certain stratigraphic intervals. In addition, secondary precipitation of quartz cement reduces pore spaces and connectivity in some potential reservoirs. However, some high P&P values were found in zones of sandy and silty facies where no, or minor, anhydrite and/or dolomite cements were present, along with a low clay content.

Author Contributions

Conceptualization, M.V.S.; methodology, M.V.S.; formal analysis, M.V.S. and M.R.; investigation M.V.S.; data curation, M.V.S., S.K., M.R., A.P. and I.K.; writing—original draft preparation, M.V.S.; writing—review and editing, M.V.S., S.K., M.R., A.P. and I.K.; project administration, M.V.S. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the project FSWW-2023-0010.

Data Availability Statement

The data used in this research work are available upon request from the corresponding author.

Acknowledgments

The authors are very thankful to PAO “Rosneft” and JSC “Irkutsk Oil Company” for providing data. The authors are very grateful to Jeffrey M. Wilson and Lyudmila Wilson from the James Hutton Institute (Scotland) for their constructive comments and suggestions made for improvement of the manuscript.

Conflicts of Interest

The authors declare no conflict of interest.

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Figure 1. Map showing the location of wells within the East Siberian basin, including Petrov’s finding [14].
Figure 1. Map showing the location of wells within the East Siberian basin, including Petrov’s finding [14].
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Figure 2. Geological sections showing the studied wells: (A) general for the East Siberian basin, simplified from the “Batholith project” [12,13]; (B) local showing only the Ediacaran, Riphean, and AR-PRZ granitic basement. Wells: A-5, P-4, D-3, V-2, S-1. Age: R—Riphean, Є—Cambrian, O—Ordovician, C-P—Carboniferous-Permian, T—Triassic, J—Jurassic.
Figure 2. Geological sections showing the studied wells: (A) general for the East Siberian basin, simplified from the “Batholith project” [12,13]; (B) local showing only the Ediacaran, Riphean, and AR-PRZ granitic basement. Wells: A-5, P-4, D-3, V-2, S-1. Age: R—Riphean, Є—Cambrian, O—Ordovician, C-P—Carboniferous-Permian, T—Triassic, J—Jurassic.
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Figure 3. Photograph of a typical core fragment of the Ediacaran sandstone showing cross-stratification (wind ripple laminated structure) and thin sections in plane and cross-polarized light: (A) well A-5—porous sandstone with quarzitic monomineral composition; (B) well V-2—sandstones with anhydrite cement with well-rounded grains having bimodal distribution; (C) XRD pattern for sample V2-1 (Q—quartz, An—anhydrite, Fs—feldspar).
Figure 3. Photograph of a typical core fragment of the Ediacaran sandstone showing cross-stratification (wind ripple laminated structure) and thin sections in plane and cross-polarized light: (A) well A-5—porous sandstone with quarzitic monomineral composition; (B) well V-2—sandstones with anhydrite cement with well-rounded grains having bimodal distribution; (C) XRD pattern for sample V2-1 (Q—quartz, An—anhydrite, Fs—feldspar).
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Figure 4. Section of well A-5 with cored columns, sampling plan, and mineral and petrographic composition according to legend, photos of thin sections, and XRD patterns for some samples.
Figure 4. Section of well A-5 with cored columns, sampling plan, and mineral and petrographic composition according to legend, photos of thin sections, and XRD patterns for some samples.
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Figure 5. Section of well P-4 with cored columns, sampling plan, mineral and petrographic composition, photos of thin sections, and XRD patterns for some samples.
Figure 5. Section of well P-4 with cored columns, sampling plan, mineral and petrographic composition, photos of thin sections, and XRD patterns for some samples.
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Figure 6. Section of well D-3 with cored columns, sampling plan, mineral and petrographic composition, photos of thin sections, and XRD patterns for some samples.
Figure 6. Section of well D-3 with cored columns, sampling plan, mineral and petrographic composition, photos of thin sections, and XRD patterns for some samples.
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Figure 7. Section of well V-2 with cored columns, sampling plan, mineral and petrographic composition, photos of thin sections, and XRD patterns for some samples.
Figure 7. Section of well V-2 with cored columns, sampling plan, mineral and petrographic composition, photos of thin sections, and XRD patterns for some samples.
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Figure 8. Section of well S-1 with cored columns, sampling plan, mineral and petrographic composition, photos of thin sections, and granulometric fractions.
Figure 8. Section of well S-1 with cored columns, sampling plan, mineral and petrographic composition, photos of thin sections, and granulometric fractions.
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Figure 9. Scanning electron microscopy images (SE and BSE) of isolated quartz particles: (A) well D—sample 36; (B) well D—sample 39.
Figure 9. Scanning electron microscopy images (SE and BSE) of isolated quartz particles: (A) well D—sample 36; (B) well D—sample 39.
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Figure 10. Granulometry chart for wells A-5, P-4, D-3, and V-2 showing lognormal and bimodal distributions in the Nepa–Tira and Vanavara formations.
Figure 10. Granulometry chart for wells A-5, P-4, D-3, and V-2 showing lognormal and bimodal distributions in the Nepa–Tira and Vanavara formations.
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Figure 11. Photo of thin section in high resolution in polarized light. Sandstone (well A5—sample 33) showing two grain-size modes or bimodal successions of silty and coarse-grain intersecting streaks as a result of two different paleo-wind events. Mineral composition: quartz—99%, illite—1%. Width of photo 3 cm.
Figure 11. Photo of thin section in high resolution in polarized light. Sandstone (well A5—sample 33) showing two grain-size modes or bimodal successions of silty and coarse-grain intersecting streaks as a result of two different paleo-wind events. Mineral composition: quartz—99%, illite—1%. Width of photo 3 cm.
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Figure 12. Photos (well A5—sample 28): (A) core sample with quartz-rich streaks embedded in a cross-bedding structure; (B) thin section in high resolution in plain and cross-polarized light. Sandstone of quartz (95%) in an anhydrite cement with minor admixture of the clay and monomineral quartz streak (white layer in center) with pyrite accessories grains (black grains); (C) pyrite sub-rounded grains in plain and reflected light; (D) the same pyrite grains after granulometric disintegration in SEM (BSE) images with EDS spectrum.
Figure 12. Photos (well A5—sample 28): (A) core sample with quartz-rich streaks embedded in a cross-bedding structure; (B) thin section in high resolution in plain and cross-polarized light. Sandstone of quartz (95%) in an anhydrite cement with minor admixture of the clay and monomineral quartz streak (white layer in center) with pyrite accessories grains (black grains); (C) pyrite sub-rounded grains in plain and reflected light; (D) the same pyrite grains after granulometric disintegration in SEM (BSE) images with EDS spectrum.
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Figure 13. Microphotographs in plain and cross-polarised light showing quartz overgrowths (arrowed) with numerous rims of quartz overgrowth cementation on the well-rounded grains: (A) sandstone with quartz (98%) in anhydrite (2%) cement (well A5—sample 16); (B) sandstone with quartz (90%) in anhydrite (10%) cement (well P4—sample 9).
Figure 13. Microphotographs in plain and cross-polarised light showing quartz overgrowths (arrowed) with numerous rims of quartz overgrowth cementation on the well-rounded grains: (A) sandstone with quartz (98%) in anhydrite (2%) cement (well A5—sample 16); (B) sandstone with quartz (90%) in anhydrite (10%) cement (well P4—sample 9).
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Figure 14. Chart showing contents of Zr, Hf, Th, and U for well D-3 where local anomalies exceed threshold values. For further explanation, see text.
Figure 14. Chart showing contents of Zr, Hf, Th, and U for well D-3 where local anomalies exceed threshold values. For further explanation, see text.
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Figure 15. P&P relation; (A) database for well V-2, D-3, P-4, A-5 with rare good reservoirs (D); (B) the same chart with various contents of sulfate and carbonate cement causing in most cases full cementation (E); (C) the same chart with various contents of quartz.
Figure 15. P&P relation; (A) database for well V-2, D-3, P-4, A-5 with rare good reservoirs (D); (B) the same chart with various contents of sulfate and carbonate cement causing in most cases full cementation (E); (C) the same chart with various contents of quartz.
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Table 1. Investigations were carried out in specific wells shown above.
Table 1. Investigations were carried out in specific wells shown above.
Research Method/Wells* S-1V-2D-3P-4A-5
Number of samples studied2445424840
Thin sections+++++
XRD++++
Granulometry+++++
ICP-MS/SEM+ (32)
* the data were processed by the JSC “Irkutsk Oil company”.
Table 2. Data for wells V-3, D-3, P-4, and D-5 for sandstones showing the depths of sampling (m), mineralogical composition, and P&P properties.
Table 2. Data for wells V-3, D-3, P-4, and D-5 for sandstones showing the depths of sampling (m), mineralogical composition, and P&P properties.
SampleDepth, mQuartzClasticCarbonateSulfateClaySum, %Porosity, %Perm,
mD
Well A-5
A5-12993.5970.673.50.00.026.51002.470.00
A5-22995.4964.465.50.01.333.21002.090.00
A5-32999.0894.294.21.61.82.41002.260.00
A5-43000.8192.092.01.81.74.510016.130.01
A5-53001.9495.595.50.04.50.01004.400.00
A5-63005.4663.863.81.634.60.01000.230.00
A5-73007.1094.594.52.21.41.91008.970.02
A5-83008.8784.884.80.00.015.21002.860.00
A5-93010.7081.681.611.65.81.01008.960.02
A5-103013.3692.692.60.00.07.410011.610.02
A5-113015.4789.289.20.01.09.81008.330.01
A5-123017.2795.295.20.01.03.81009.720.02
A5-133018.7296.296.20.00.03.81007.230.02
A5-143073.7985.886.81.70.011.51006.250.09
A5-153076.7493.093.00.01.06.01005.440.01
A5-163078.6398.298.20.01.80.01003.530.00
A5-173080.3997.697.61.01.40.01002.630.01
A5-183082.5297.697.60.01.31.11006.810.05
A5-193083.5296.096.00.01.82.21008.960.23
A5-203085.3697.697.60.01.41.01008.920.62
A5-213087.4790.690.60.01.08.410012.950.02
A5-223089.2593.893.80.02.14.110012.500.02
A5-233122.7068.968.90.01.130.01002.190.00
A5-243124.6888.288.20.05.86.0100--
A5-253127.8565.665.60.00.034.41003.300.00
A5-263132.3261.162.10.01.036.91003.370.01
A5-273134.7096.196.10.01.02.91007.740.01
A5-283135.2395.195.10.01.03.91008.470.02
A5-293137.6594.794.70.01.43.91006.080.01
A5-303138.7995.895.80.01.23.01003.240.01
A5-313141.4294.494.40.01.04.61002.230.00
A5-323143.2924.524.548.95.121.51001.750.00
A5-333334.0098.898.80.00.01.21000.840.03
A5-343338.3292.495.00.00.05.01003.15-
A5-353338.7686.890.10.00.09.91002.34-
A5-363339.0666.670.60.00.029.41001.7425.48
A5-373339.4476.078.90.00.021.11001.250.02
A5-383339.8579.681.40.00.018.61001.8612.78
A5-393340.0892.093.00.00.07.01001.519.41
A5-403340.4592.293.20.00.06.81001.040.00
Well P-4
P4-13365.8463.167.50.03.429.11006.7729.70
P4-23366.5254.761.30.03.135.61005.5931.80
P4-33368.8590.998.00.00.02.01006.830.07
P4-43369.4097.999.00.00.01.01009.480.05
P4-53371.8668.670.60.011.318.11005.6710.80
P4-63372.4493.596.00.00.04.01005.810.22
P4-73372.7885.5100.00.00.00.010010.440.20
P4-83373.8087.495.50.04.50.010010.184.95
P4-93375.4489.489.40.010.60.0100--
P4-103375.6772.175.70.01.123.21006.0738.53
P4-113376.9588.489.40.00.010.61007.180.06
P4-123380.6366.368.90.01.729.41003.120.81
P4-133386.8391.092.00.08.00.01007.920.06
P4-143387.2861.068.00.00.032.01007.793.00
P4-153389.1166.972.90.00.027.11006.262.73
P4-163390.4496.796.70.00.03.3100--
P4-173391.8194.596.50.00.03.510010.290.24
P4-183392.0795.495.40.00.04.610010.000.05
P4-193395.9297.097.00.00.03.010019.113.10
P4-203396.9597.098.00.02.00.01009.891.19
P4-213397.4980.983.80.00.016.21004.9117.00
P4-223407.3479.684.06.00.010.01001.810.70
P4-233409.2589.093.00.00.07.01006.240.11
P4-243417.7990.691.90.00.08.110014.300.48
P4-253418.1490.291.70.03.05.310014.710.67
P4-263419.7794.095.00.00.05.010014.920.40
P4-273420.1594.894.80.00.05.210013.600.19
P4-283421.3192.392.30.00.07.71006.582.39
P4-293422.1791.593.70.00.06.310011.130.02
P4-303424.2774.977.40.015.07.610012.880.04
P4-313428.4178.682.60.011.06.41008.210.04
P4-323429.0482.888.00.00.012.010012.330.05
P4-333430.8680.085.20.00.014.8100--
P4-343431.3589.491.50.03.05.510011.880.32
P4-353432.7686.695.00.00.05.010012.030.54
P4-363435.9972.380.80.011.18.11009.660.27
P4-373456.4078.282.40.08.39.310015.850.62
P4-383461.2393.293.20.05.81.0100--
P4-393473.3381.282.21.214.62.0100--
P4-403478.2382.193.22.20.04.61005.800.01
P4-413472.4788.891.90.08.10.010012.820.65
P4-423480.9356.459.56.234.30.01004.090.20
P4-433485.7585.297.20.00.02.81004.110.08
P4-443487.5672.492.47.60.00.01006.900.58
P4-453487.8065.170.528.30.01.21006.431.50
P4-463488.0584.090.93.92.32.91007.670.29
P4-473488.790.00.096.04.00.01000.33-
P4-483490.230.00.0100.00.00.01000.380.15
Well D-3
D3-12476.7941.245.46.832.215.61007.100.21
D3-22477.5459.669.39.412.09.31007.000.25
D3-32478.7977.283.50.00.016.510010.400.02
D3-42479.5782.486.20.07.86.01007.200.10
D3-52481.4376.677.67.215.20.01001.800.02
D3-62482.6894.394.30.00.05.71006.900.30
D3-72483.1386.386.38.91.92.91003.800.10
D3-82486.1687.989.90.00.010.11006.000.30
D3-92487.0673.473.40.00.026.610013.000.27
D3-102489.7259.459.40.015.525.110011.100.64
D3-112491.9230.030.013.222.234.61009.806.22
D3-122495.2258.463.70.010.525.810011.000.74
D3-132496.6844.247.10.047.05.91001.900.14
D3-142497.6261.362.51.612.823.110010.400.05
D3-152498.6257.361.40.014.524.110010.300.05
D3-162501.0961.266.20.028.05.81005.300.16
D3-172502.2757.058.90.039.12.01000.000.02
D3-182505.4263.867.20.032.80.01001.800.09
D3-192506.7176.977.90.021.11.01002.800.20
D3-202509.1062.063.011.511.613.91008.204.78
D3-212510.8765.565.50.00.034.510012.300.14
D3-222512.6583.187.22.52.67.71005.600.00
D3-232513.1692.394.90.00.05.11007.700.01
D3-242513.6182.084.10.015.90.01004.700.25
D3-252513.8560.260.20.039.80.01001.900.03
D3-262514.6952.952.90.047.10.01000.900.02
D3-272515.2275.575.50.022.02.51003.900.03
D3-282515.9075.075.01.024.00.01002.200.02
D3-292516.9758.058.00.042.00.01000.000.02
D3-302517.8365.065.00.035.00.01001.500.06
D3-312518.5058.058.00.042.00.01000.700.03
D3-322519.1377.077.00.023.00.01001.900.07
D3-332519.9875.075.00.025.00.01002.700.08
D3-342520.8580.080.00.020.00.01003.500.09
D3-352521.4260.060.01.038.01.01006.000.43
D3-362522.2795.795.70.01.52.810017.30235.9
D3-372523.0994.594.52.51.51.510011.905.16
D3-382523.4795.995.91.31.01.810012.4011.61
D3-392525.0397.097.00.02.01.01009.103.15
D3-402525.5763.063.010.026.01.01007.700.81
D3-412530.464.04.094.51.50.01000.910.00
D3-422532.320.00.099.01.00.01000.563.86
Well V-2
V2-12112.3443.252.62.639.25.61000.860.00
V2-22115.124.310.627.256.16.11000.610.01
V2-32117.1017.321.847.326.24.71000.500.00
V2-42118.854.07.630.156.45.91000.060.00
V2-52119.3546.763.313.618.34.81002.760.03
V2-62120.2143.656.416.321.55.81002.010.05
V2-72122.115.421.642.030.46.0100--
V2-82123.4949.563.719.311.75.31001.620.02
V2-92124.3350.659.826.97.75.61001.330.01
V2-102125.6242.153.318.221.66.91003.290.07
V2-112126.751.83.471.520.34.81000.860.00
V2-122127.501.67.580.910.61.01000.990.00
V2-132129.7244.058.216.318.57.01003.980.33
V2-142133.061.16.349.538.85.41000.430.08
V2-152135.1736.242.739.213.34.81000.640.03
V2-162137.0152.558.721.815.63.91000.670.00
V2-172146.4569.284.20.00.015.8100--
V2-182149.0078.485.26.52.26.1100--
V2-192149.8339.043.61.147.87.51001.300.02
V2-202150.3876.081.18.83.96.21003.460.04
V2-212151.3174.082.96.91.78.51006.160.13
V2-222155.1042.352.634.20.013.21003.880.03
V2-232159.2249.557.626.20.016.21005.700.04
V2-242160.7552.259.523.60.016.91009.220.48
V2-252161.6554.962.020.20.017.81009.211.43
V2-262163.0571.680.85.81.012.41009.690.30
V2-272164.2559.268.016.20.015.81008.610.22
V2-282166.1353.362.322.80.014.91005.570.01
V2-292167.0958.363.915.35.615.21008.780.52
V2-302170.2756.972.99.91.016.21009.330.27
V2-312171.7954.964.224.21.99.71007.981.42
V2-322172.4565.074.115.45.84.71006.300.04
V2-332175.6359.365.425.81.57.31006.700.13
V2-342176.6062.368.415.70.015.91008.890.27
V2-352180.3472.181.811.81.35.11003.660.06
V2-362181.7966.280.912.02.94.21006.690.31
V2-372183.5478.686.63.74.75.01005.310.42
V2-382185.0063.989.67.00.03.410010.331.17
V2-392191.3368.988.55.23.82.51003.940.04
V2-402194.1473.282.98.44.44.31006.910.23
V2-412195.6064.392.53.60.03.910010.803.76
V2-422197.1567.689.37.31.02.41009.620.48
V2-432200.5567.789.96.20.03.910012.310.89
V2-442203.4666.389.26.81.12.910012.750.27
V2-452204.7959.878.518.21.51.81005.400.03
Table 3. Trace element analysis (ICP-MS) for sandstones in well D-3 (Figure 6) in ppm (Mg and Fe in %).
Table 3. Trace element analysis (ICP-MS) for sandstones in well D-3 (Figure 6) in ppm (Mg and Fe in %).
LiBeBMgPScTiCrMnFeCoNiCuZnGa
D3-120.17<0.5169.209.0872.93<15720.1343.004178.2714.110.18<1.027.2458.274.39
D3-594.231.39278.270.82188.5422.264901.3342.6734.141.312.0421.3136.4736.1613.75
D3-66.83<0.538.832.6126.0344.74566.0523.872202.219.011.16<1.04.153.171.99
D3-8109.412.58835.661.04<10<154947.39138.9144.32>103.42<1.023.1751.4726.31
D3-980.873.05724.271.05<10<156097.6197.69122.922.1719.3926.3726.86103.4424.65
D3-1060.291.54254.670.98182.7554.385234.3939.262231.294.675.687.2525.0140.2615.78
D3-1210.511.4871.920.2364.7429.381745.7720.1844.330.693.4612.9114.9513.202.46
D3-1575.251.39291.770.83178.1322.894147.5760.85526.992.375.4713.7614.9527.1115.21
D3-1711.17<0.519.200.1439.2856.321301.0632.4483.580.471.5617.976.296.631.18
D3-1869.742.58568.321.14<10<155038.20145.59572.014.4418.4230.0147.7566.5824.42
D3-1915.87<0.590.680.2160.5232.711038.6231.4158.000.401.3718.4412.8811.812.89
D3-2085.820.71271.060.89<10<154223.0680.51163.601.748.1649.4852.9751.6417.00
D3-2160.602.58586.521.20394.73<155430.84107.4768.635.3422.444.4653.9551.7928.72
D3-2334.781.07292.290.25<10<151739.0084.9766.150.442.3516.6319.42<0.55.22
D3-2528.200.62198.670.31192.63<154382.1875.5220.130.642.9519.759.1018.4210.51
D3-263.97<0.556.590.1177.01<152100.7070.5818.750.411.964.0725.5341.682.50
D3-2730.240.52138.220.16199.8618.244232.9356.4216.121.193.347.3643.3345.028.24
D3-2812.22<0.5113.150.20242.2530.153011.2735.039.910.380.9815.0315.1312.497.38
D3-2934.781.79275.420.039<10<15510.4722.9712.140.380.8815.8422.95<0.51.39
D3-303.86<0.514.280.06571.46<15281.5413.8311.320.320.494.6434.303.770.68
D3-314.50<0.541.480.05478.3015.35614.4817.168.570.280.494.0828.3714.300.78
D3-3266.792.50447.780.46<10<154256.27149.3319.041.673.0332.2925.64<0.513.25
D3-335.37<0.518.490.06313.92<15230.7240.698.300.110.5012.5016.297.910.56
D3-346.01<0.516.890.2286.2019.48377.1316.3054.480.291.2418.2130.503.360.52
D3-3514.20<0.523.320.1666.9039.97621.8728.8620.160.372.7326.029.9311.551.30
D3-367.280.6213.530.2848.7227.25391.8516.8378.930.400.8035.466.702.740.87
D3-3718.56<0.529.710.35272.2815.34359.9544.3248.020.580.7733.4115.3613.511.14
D3-3816.650.9342.280.28144.9737.80937.4858.2318.590.391.0625.2331.888.802.00
D3-3913.83<0.513.410.3042.0516.56319.5113.1449.130.541.3736.81109.335.070.78
D3-404.98<0.57.090.1443.9216.73270.5621.2225.030.263.1514.497.8013.010.44
D3-4165.19<0.5196.97>5.0<10<15357.2248.29181.970.391.529.284.54<0.53.24
D3-4254.41<0.5287.21>5.0<10<15462.2236.74308.570.743.138.2218.15483.714.25
SeRbSrYZrNbCdSnSbCsBaLaCePrNd
D3-1<3.015.77177.666.5535.693.060.201.180.240.69128.186.0112.741.645.66
D3-5<3.0101.64279.4725.14223.4117.720.4287.110.194.23270.8739.5074.839.6031.99
D3-66.274.9065.943.0528.251.41<0.1<0.20.070.1816.147.7516.622.137.08
D3-829.56179.03251.2249.83183.8212.070.3216.24214.899.58404.2342.3882.6610.4039.57
D3-9<3.0157.94406.9438.11350.2324.820.433.800.407.95458.9160.65128.3714.5251.41
D3-10<3.095.89241.5032.61294.9915.71<0.12.140.144.01355.9434.0173.249.1531.12
D3-123.0126.171106.1715.12116.734.870.200.470.090.81287.7610.2822.032.5110.82
D3-15<3.074.80596.1926.12255.9512.440.101.680.153.01292.1329.6157.977.3328.89
D3-17<3.018.29363.376.84217.682.910.110.260.100.15255.996.9413.862.156.55
D3-18<3.0111.15238.9326.74180.887.070.1634.14648.194.76283.9731.4858.617.5029.73
D3-195.5221.64643.855.8994.812.76<0.10.350.090.55200.598.6616.372.088.75
D3-201.1478.99617.7425.64232.7111.360.162.130.662.971012.7332.1460.107.5530.22
D3-213.41142.18445.3547.48252.5416.920.132.620.026.41359.8741.2086.559.6836.51
D3-2313.7427.40169.306.57174.714.470.297.64117.070.7897.5028.3960.385.9719.65
D3-255.7739.12223.9522.91685.2512.44<0.11.880.111.6594.2943.28107.387.8423.78
D3-266.025.24500.958.29293.045.280.740.330.100.0813.5812.5644.232.648.30
D3-274.5118.29555.7423.31628.4210.550.21123.330.090.5155.8563.35119.0210.7532.41
D3-284.5119.24352.7720.55336.717.910.390.860.140.5836.8340.7277.929.8041.50
D3-297.804.61868.033.8258.441.590.220.440.850.19255.414.488.471.123.38
D3-307.522.01811.283.8911.590.67<0.132.370.020.084.594.616.240.984.22
D3-315.774.99503.445.5482.041.550.190.260.040.145.905.516.961.234.77
D3-326.8340.75460.5358.58417.188.070.462.220.911.6975.7249.6847.3110.9038.81
D3-33<3.03.36277.343.3125.720.61<0.1<0.20.050.089.394.536.291.094.00
D3-3410.853.14422.923.8336.100.980.37<0.20.060.0646.565.287.161.444.84
D3-354.193.89162.174.7074.441.870.180.300.030.108.126.5812.051.515.11
D3-367.912.2950.693.9648.911.19<0.1<0.20.050.099.115.789.191.294.76
D3-37<3.05.2359.333.7258.060.99<0.10.210.040.138.466.2310.421.394.15
D3-386.426.5782.9811.36213.482.53<0.122.280.090.1413.0114.5929.423.4712.72
D3-394.546.23408.112.4116.110.63<0.17.920.230.0918.414.137.691.082.87
D3-4010.817.01731.102.0826.870.580.16<0.20.070.1944.933.676.620.772.67
D3-41<3.014.4367.073.4323.461.240.210.340.380.5427.264.147.360.944.05
D3-422.2025.0245.074.2421.840.531.722.520.431.02136.235.4912.941.354.99
SmEuGdTbDyHoErTmYbLuHfTaWPbThU
D3-11.040.231.370.261.510.260.800.100.770.100.640.191.1237.651.981.82
D3-55.860.995.571.034.650.902.600.362.970.435.461.261.476.8411.402.57
D3-61.160.221.050.170.590.110.490.050.420.050.800.10<0.51.051.430.29
D3-89.682.0510.171.6710.431.844.940.564.680.673.911.080.669.1713.996.42
D3-910.771.8310.101.406.891.374.610.604.070.595.791.821.4614.3117.343.42
D3-105.611.416.521.105.971.043.310.573.620.607.241.231.607.0112.242.55
D3-121.910.582.890.512.950.521.330.150.970.222.340.330.7111.843.461.12
D3-155.891.217.190.865.210.942.690.342.890.415.460.801.295.6510.532.46
D3-171.930.421.760.321.280.220.580.120.840.095.530.23<0.53.272.620.86
D3-185.561.165.320.864.161.092.840.372.500.403.630.680.837.658.131.58
D3-191.740.381.390.180.910.210.470.060.490.081.900.16<0.52.542.030.67
D3-205.981.377.940.914.740.952.520.471.860.323.980.810.976.177.952.11
D3-218.191.719.711.477.961.744.920.543.690.635.061.131.825.789.472.75
D3-232.220.432.380.311.430.350.850.120.880.173.550.400.183.894.371.00
D3-253.590.844.510.604.550.952.220.403.390.4912.711.001.183.0516.433.83
D3-261.000.221.630.201.620.310.960.191.060.216.270.372.350.834.862.77
D3-274.540.944.720.894.740.952.900.553.840.7014.510.872.033.2315.093.59
D3-289.791.979.800.945.400.802.500.442.920.486.610.520.581.646.442.69
D3-290.790.170.790.130.630.130.380.070.250.071.020.040.251.851.120.43
D3-300.740.090.910.080.750.130.140.040.200.050.29<0.050.600.560.690.34
D3-310.980.121.020.211.090.150.470.110.410.082.110.130.680.861.260.55
D3-326.271.4210.041.5110.472.074.680.704.200.648.920.731.205.089.463.47
D3-330.460.110.870.070.350.110.230.040.110.050.520.05<0.51.350.530.27
D3-340.820.180.770.140.710.140.230.060.180.060.760.12<0.50.671.370.36
D3-350.970.221.130.120.800.160.480.050.330.051.900.11<0.50.761.810.54
D3-360.740.180.950.130.630.120.390.050.310.051.570.070.780.771.660.58
D3-371.100.261.100.180.730.090.250.050.320.051.650.100.980.891.380.53
D3-382.060.332.790.372.590.361.180.170.920.155.200.15<0.51.118.371.28
D3-390.660.150.610.100.380.110.040.040.100.050.35<0.05<0.51.571.020.37
D3-400.520.090.680.070.340.090.180.030.190.050.67<0.051.031.060.760.40
D3-410.330.100.640.120.700.130.350.060.340.070.540.080.181.801.080.34
D3-421.120.221.000.130.780.200.480.100.410.090.590.030.0555.631.540.46
Table 4. Some features of aeolian sandstone compared with other sandy facies.
Table 4. Some features of aeolian sandstone compared with other sandy facies.
FeaturesAeolianFluvial (Limnic, Marine, River)Glacial
RoundnessGoodPoorPoor
SortingPoor to GoodGoodPoor
Prevailing mineralQuartzQuartz, feldspar, lithicQuartz, feldspar, lithic
AccessoriesAbnormal (from very poor to very rich)NormalNormal
BimodalityYesNoNo
Prevailing Secondary processesQuartz overgrowth cementationFeldspar dissolutionFeldspar dissolution
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Shaldybin, M.V.; Kvachko, S.; Rudmin, M.; Plyusnin, A.; Kuznetsov, I. Ancient Aeolian Reservoirs of the East Siberia Craton. Geosciences 2023, 13, 230. https://doi.org/10.3390/geosciences13080230

AMA Style

Shaldybin MV, Kvachko S, Rudmin M, Plyusnin A, Kuznetsov I. Ancient Aeolian Reservoirs of the East Siberia Craton. Geosciences. 2023; 13(8):230. https://doi.org/10.3390/geosciences13080230

Chicago/Turabian Style

Shaldybin, Michail V., Svetlana Kvachko, Maxim Rudmin, Alexey Plyusnin, and Iliya Kuznetsov. 2023. "Ancient Aeolian Reservoirs of the East Siberia Craton" Geosciences 13, no. 8: 230. https://doi.org/10.3390/geosciences13080230

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