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Proof of the Glacier Origin of Tabular Massive Ice
V.I. Solomatin, N.G. Belova Lomonosov Moscow State University, Department of Geography, Moscow, Russia

Abstract
This paper examines the problem of the genesis of tabular massive ice and suggests a new definition of tabular massive ice. According to this definition, tabular massive ice includes large deposits of ground ice that have the following properties: multi-meter thickness and the length of tens and hundreds of meters; discordant upper contact; inclusions of detritus including large boulders; a wide range of structural and textural characteristics of different scales including dynamic metamorphic structures; and ultra-fresh chemical composition. The discordant upper contact with overlying sediments is irrefutable proof of the buried genesis of massive ice. The paper gives a number of other genetic characteristics of the tabular massive ice structure that prove its buried glacial nature. Keywords: buried glacial ice; discordant contact; glacial deformations; tabular massive ice.

Introduction
Almost all experts recognize the existence of remnants of ancient glacial ice buried in permafrost. Therefore, it is important to be able to reasonably distinguish the aforementioned formations from other genetic types of ground ice, primarily from the ice of various intrasedimental genesis. At the same time, as even a superficial analysis of the literature shows, the nature of tabular massive ice remains acutely discussed because the solution to this problem determines the understanding of many theoretic and applied issues of cryolithology and paleogeography. Traditionally, the adherents of the marine concepts dominate in geocryology and cryolithology, and naturally they continue to seek the evidence of the intrasedimental genesis of the thick massive ground ice bodies (Vtyurin 1975, Dubikov 2002, Badu 2010, Vasilchuk et al. 2009, Slagoda, Melnikov & Opokina 2010, and others). It was earlier shown (Ershov 1982, Parmuzina 1978, Solomatin 1986, 1993, and others) that the segregated ice formation develops not at the surface (front) of crystallization but in a layer of ground of a certain thickness with the limit temperature values 0° - Tcr (where Tcr is the temperature of ground supercooling that is required to initiate the crystallization of the bound moisture of ground). Hence the physical nature of the process allows us to state that the segregation mechanism can lead to the formation of numerous thin ice lenses, but not to the growth of a single ice interbed with a certain thickness. We also showed (1986, 2008, and other works) that there are no convincing arguments in favor of the possibility of the confined ground water intrusion into monolithic frozen ground, especially if we take into account that the massive ice thickness exceeds tens of meters and its length often exceeds many hundreds of meters. For this reason, we think that the adherents of the intrasedimental growth of massive ice need to seek the physical, cryolithological, structural, petrographical, and other arguments for the segregated or intrusive mechanism of ground ice formation. The latest developments of the spore and pollen method of proving the "non-glacial" nature of tabular massive ice suggested by A.K. Vasilchuk and Yu.K.Vasilchuk (2010) will apparently require some time for this method's analysis and testing as well as for the collection of factual evidence. It is necessary to explain how pollen and spores get into a layer. The 427

segregated mechanism is absolutely incompatible with the presence of any particles in the ice that are foreign to the given ground. On the contrary, injected ice can contain absolutely any foreign (chemical and biogenic) elements characteristic of the water and ground environment of ice formation. Furthermore, quite a wide range of landscape conditions is possible for the periphery of the contemporary areas of surface glaciation: from the arctic tundras to tropical forests and savanna vegetation that serve as a source of spores and pollen source for glacial mass. Therefore, it is necessary to find serious proof of the possibility of the spore and pollen method for the genetic identification of massive ice. First of all, it should be emphasized that the term "tabular massive ice" has for a long time been regarded as the one having the genetic content. Initially it had a strictly morphologic meaning due to the fact that G.I. Dubikov and M.M. Koreysha (who in 1964 were the first to describe tabular massive ice as a separate type of ground ice) did not manage initially to determine the mechanism of its formation. The confusion in the understanding of formation mechanisms of tabular massive ice bodies can be to a certain extent connected with the lack of clear terminological definitions. As a result, many different genetic types may indeed be attributed to tabular massive ice and on this basis the tabular massive ice bodies may be regarded as polygenetic. But what sense does it make to unite the ice types having different genesis under one name? Meanwhile, it is also obvious that morphologically identical ice types cannot have different genesis. When we speak about typical profiles of tabular massive ice having all its structural characteristics, we should admit that it is a single morphogenetic type occupying its position in the classification system of ground ice, while the notions of the polygenetic nature of massive ice have no basis and would indicate misunderstanding of the nature of the examined formations. Or in each case when we attribute different genesis to separate ice types, we require the corresponding proof of one or the other specific mechanism of ice formation based on appropriate arguments as well as on structural, genetic, and other characteristics. The ability to distinguish the initial surface types (intrasedimental and buried) of ground ice could be a considerable step on the way to the solution of the examined


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problem. Of course, the buried initial surface types can also include buried sea, river, and lake ice, as well as snow patches. It should be noted that the buried state can be reached by the remnants of the peripheral parts of glaciers where terminal, ablation and other types of moraines as well as actively developed fluvioglacial formations. This periglacial zone is characterized by a high degree of flooding of the surface as well as sediment accumulation. Their freezing leads not only to the preservation of glacier remnants but also to the formation of different kinds of intrasedimental ice simultaneously with them. Therefore, the mere presence of the intrasedimental ice does not contradict the buried glacial nature of tabular massive ice. But it should not be united in one genetic type. In each case, we must have criteria for the genetic type of each of the observed kinds of ice. For instance, sea ice can be easily distinguished through its high salinity, while river ice can be easily determined by its typical structures of the orthotropic growth (Solomatin 1986), and so on.

Structure and Bedding of Tabular Massive Ice
The definition of tabular massive ice By tabular massive ice, we propose to understand large bodies of ground ice that are characterized by multi-meter thickness and the length of tens and hundreds of meters; the discordant upper contact; often abundant inclusions of detritus including large boulders; a wide range of structural and textural characteristics of different scales including dynamic metamorphic structures; ultra-fresh chemical composition and low content of heavy oxygen isotopes. All the ground ice formations that do not have this set of features, distinct characteristics of structure and of the bedding conditions (including those being the consequence of a poor exposure and a profile covered with slumped sediments) should not be attributed to the massive type of ground ice. The discordant contact of tabular massive ice with overlying sediments The discordant contact of the layers (Figs. 1, 2, 5) with overlying sediments is emphasized by the profile of the ice structures (folds, stratification, structural and textural heterogeneities), with the presence of deformations in the ice and with the undisturbed bedding of overlying loose stratifications with the initial structures of sedimentation. Such is the nature of the discordant contact (the contact with erosion) as well as the bedding and structure of the overlying sediments undisturbed since deposited (considering that the ice directly underlying them has the indications of dynamic metamorphism and the structure of macro- and micro-deformations). This may develop under the following conditions: firstly there formed massive ice that underwent deformations and gained its characteristic structural features; and then the ice body was covered (probably with partial thawing) with the sediments of various genesis and preserved in permafrost. Thus the discordant contact represents irrefutable evidence of the buried genesis of tabular massive ice.

Figure 1. The discordant contact of massive ice with overlying sediments on the Gydan Peninsula. Strong indications of forceful deformations are visible in the massive ice, while the overlying sediments have the bedding that was not disturbed since the time of sedimentation.

Figure 2. The mass of the dislocated glacial ice that is not reflected in the relief and is covered with a thin layer of undeformed sediments. Location on the northwestern coast of New Siberia Island. Photograph by V.E. Tumskoy.


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Figure 3. The fold complicated by the shear-fault in the massive ice on the western shore of Baydaratskaya Bay.

Discussion Other genetic features of the tabular massive ice structure and other arguments of their buried glacial genesis are: 1) The deformations (Figs. 1, 2, 4, 5) of many different types and scale are observed in massive ice (fold, shear, fault, microfold deformations, etc.). They vary within the profile and along the length of the ice body. These consequences of the dynamic metamorphism of the ice are absolutely incomparable with any cryogenic processes and completely identical with the glacial tectonics of glacial ice. These arguments make us inevitably conclude that the ice has glacial origin. 2) All types of detritus and boulders with the diameter of more than 1 m were encountered in the massive ice (Fig. 4). The presence of coarse detritus in the ice is incomparable with any type of the intrasedimental ice formation and is rather natural for glacial ice. 3) Massive ice has (in practically 100% of cases) the ultrafresh chemical composition (Solomatin 1976, 1986, Belova et al. 2008) that absolutely differs from that of segregated ice and of the water extract of the enclosing sediments. This fact contradicts the intrasedimental genesis of tabular massive ice bodies and is natural for glacial ice. 4) The chemical and isotope content of the ice has no directed alterations in the profile but exhibit certain variations with depth that probably reflect a change in the conditions of ice formation and in the conditions of the isotope and oxygen content formation (Solomatin 1976, 1986, 2005, Belova et al. 2008). This is in contradiction with the crystallization of the volume of groundwater in and with the segregated ice formation of bound water, since the fractionation of the composition and the direct enrichment of the chemical and heavy isotope contents with depth are inevitable in both cases. 5) In many cases the layers having all the typical peculiarities of the structure of this ice lie in the sandy mass, which does not correspond to the conditions for the development of the segregated process even at a minimum scale or on the scale of massive ice bodies (Solomatin 1986).

Figure 4. The schistosity emphasized with the ground inclusions; the consequence of layer-by-layer plastic deformations.

Figure 5. A boulder in massive (glacial) ice at the Ledyanaya Gora exposure on the Yenisey River at the latitude of the Polar Circle. Photograph by E.G. Karpov.

6) Most of the layers bed statistically at the contact between the covering fine-dispersed sediments and the underlying coarse-dispersed sediments. This contrasts with the mechanism of the intrusive processes of ice formation, as the generation of hydrostatic and dynamic tension in the water-bearing sand horizon at least requires its partial freezing and, thus, the narrowing of the sectional area of the ground flow. This means that the injected ice must be located not at the contact of a water-bearing layer but at some distance below it (Solomatin 1986).


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Figure 6. The massive ice with forceful dislocations that is exposed directly under the active layer and is not reflected in the relief. Location is the western coast of Baydaratskaya Bay. Photograph by F.A. Romanenko.

7) In many cases, thick ice layers are covered only with a very thin layer of frozen ground (Fig. 2, 5). In case of intrusive origin of massive ice, an injection of the pressurized ground water and a deformation of the overlying ground with the formation of the frost mound with the intrusive ice core there should have occurred. Therefore, it is absolutely inexplicable why, instead, there occurred a rupture in the stratification of the frozen ground to a considerable distance (up to 1 km?) with the uplift of the ground layer to the height of a few tens of meters without any disturbances. Such a version contradicts all the concepts of physics and mechanics of frozen ground. The very possibility of splitting the low temperature frozen ground by the confined ground water sounds unconvincing. 8) Finally, the absence of the corresponding forms of ground heaving in the relief contradicts the intrasedimental genesis of tabular massive ice (Figs. 2, 5). Geomorphologically the areas with tabular massive ice are, as a rule, indistinguishable from the adjacent territories. The observed mound and ridge relief in some areas with tabular massive ice does not correspond to the formation of thick intrasedimental ice bodies. However, it bears a resemblance to the relief of the areas of the dead ice belonging to retreating glaciers (Solomatin 1986).

variety of conditions of its bedding and its structure. It is characterized by a considerable length that exceeds by many times the vertical dimensions, by the discordant contact with the overlying sediments, by the complex structure varying within the profile and along the length, and by various bedding conditions. There are no reasons to regard a single (in terms of morphology and structure of ice bodies) type of ground ice as polygenetic and to divide it into different formations by genesis. The materials, experimental data, and theoretical concepts collected at the present time lead to the clear conclusion that tabular massive ice represents a single and separate genetic type of ground ice: the buried remnants of glaciers that formed during deglaciation of the ancient glaciation areas.

Acknowledgments
This paper was prepared within the framework of State Contract P516 of the "Scientific and Pedagogical Staff in Innovative Russia" federal targeted program.

References
Astakhov, V.I., Kaplyanskaya, F.A., & Tarnogradsky, V.D. 1996. Pleistocene permafrost of West Siberia as a deformable glacier bed. Permafrost and Periglacial Processes Vol. 7: 165-191. Badu, Yu.B. 2010. Cryolithology: Textbook. Moscow: KDU, 528 pp. (in Russian).

Conclusions
It should be emphasized once again that tabular massive ice belongs to a single morphogenetic type, despite the entire


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