Great Lyakhovsky Island
Encyclopedia
Bolshoy Lyakhovsky Island , or Great Lyakhovsky, is the largest of the Lyakhovsky Islands
belonging to the New Siberian Islands
archipelago between the Laptev Sea
and the East Siberian Sea
in northern Russia
. It has an area of 4,600 km², and a maximum altitude of 270 m (Emy Tas).
The peninsula projecting towards the west of the island is the Kigilyakh Peninsula (Poluostrov Kigilyakh).
Off Bolshoy Lyakhovsky Island's southwestern cape lies a small islet called Ostrov Khopto-Terer.
The Lyakhovsky Islands are named in honour of Ivan Lyakhov
, who explored them in 1773.
metamorphic rock
s and turbidites; Mesozoic
turbidites and igneous rocks; and Cenozoic
sediments. Exposed in southeastern part of this island, the older Precambrian. Early Proterozoic
, metamorphic rocks consist of schist
s and amphibolite
s. Small exposures of Late Proterozoic schistose, quartzose sandstone
s and phyllitic, sericite
-quartz
schist
(turbidites) also occur in the southeastern part of Bolshoy Lyakhovsky Island. The bulk of this island consists of Late Jurassic
to Early Cretaceous
turbidites composed of interbedded fine-grained sandstones, thinly bedded siltstone
s, and argillite
s. The Precambrian and Late Jurassic to Early Cretaceous rocks are intruded by Late Cretaceous granite
s and granodiorites.
A blanket of unconsolidated Cenozoic
sediment
s blankets most of Bolshoy Lyakhovsky Island. These sediments include Paleocene
to Eocene
colluvial
, alluvial
, and deltaic gravel
s, sand
s, clay
s, and coal
s and Oligocene
to Miocene
alluvial, lacustrine, deltaic, and nearshore marine
sands and clays that contain beds and lenses of gravel. Overlying these sediments are Pliocene
to Pleistocene
colluvial, alluvial, and nearshore marine sands, silts, and clays clays that contain occasional gravel layers. The nearshore marine sediments contain the shells of marine mollusks and pieces of lignitized wood. Thick permafrost
characterized by massive ice wedges has developed in these sediments. Contrary to the interpretations of Baron von Toll and earlier geologists, glacial deposits and ice are completely absent within Bolshoy Lyakhovsky Island.
Detailed geological studies, which included the radiocarbon dating of bones, ivory, and plant remains; optically stimulated luminescence dating bone-bearing sediments; and uranium-thorium dating
of associated peats, have clarified the stratigraphy, origin, and age of the sediments and permafrost that Baron von Toll found exposed in the southern sea cliffs of Bolshoy Lyakhovsky Islands. Dr. Romanovsky and Dr. Andreev and others found that these bone- and wood-bearing sediments described by Baron von Toll consist of Middle to Late Pleistocene floodplain and thermokarst, eolian, and lake sediments underlying different terrace levels. Later studies determined that alders, Alnus fruticosa, lived within the New Siberian Islands only during relatively brief periods of warm interstadial and interglacial climates. Dr. Makeyev and others found that over the last 15,000 years, Alnus fruticosa occupied these islands from 12,200 to 12,500 radiocarbon years BP during an interstadial that was unrelated to Baron von Toll's "mammoth period". Dr. Andreev and others dated the sediments also containing alder pollen and Baron von Toll's alder tree to the last, Kazantsevo (Eemian), Stage about 114 to 130 thousand years ago. They found that other vertebrate fossils ranged in age from 114,000 to 26,000 BP. These Pleistocene sediments, overlie a Pliocene paleosol
and are cemented by permafrost.
Baron Eduard von Toll
made an interesting discovery. Under a peat composed of water mosses covering what is described as the "perpetual ice", Baron von Toll found fragments of willow and the bones of post-Tertiary mammals, like the shoulder-bone of a saber-toothed tiger. It also reported having found in a frozen, sandy clay layer and lying on its side, a complete tree of Alnus fruticosa 15 to 20 ft (4.5 to 6 m) in length, including roots, with leaves and cones adhering. Various authors, i.e. Dr. Digby and Dr. Kropotkin misreport this tree as being 90 feet (27.4 m) high. Other publications, i.e. Fingerprints of the Gods and Earth's Shifting Crust not only incorrectly state that this alder tree is 90 feet (27.4 m) high, but also they also repeat fictional claims from unreliable sources that this tree was either a “fruit tree” or “plum tree” and had "green leaves"and green fruit" still attached. Lacking modern radiocarbon dating techniques, Baron von Toll assigns this tree to what it calls the "mammoth
period". It concludes that this alder tree is proof that tree-vegetation had reached the seventy-fourth degree of latitude, three degrees farther north than currently.
Lyakhovsky Islands
The Lyakhovsky Islands are the southernmost group of the New Siberian Islands in the arctic seas of eastern Russia. They are separated from the mainland by the Laptev Strait , and from the Anzhu Islands group by the Sannikov Strait...
belonging to the New Siberian Islands
New Siberian Islands
The New Siberian Islands are an archipelago, located to the North of the East Siberian coast between the Laptev Sea and the East Siberian Sea north of the Sakha Republic....
archipelago between the Laptev Sea
Laptev Sea
The Laptev Sea is a marginal sea of the Arctic Ocean. It is located between the northern coast of Siberia, the Taimyr Peninsula, Severnaya Zemlya and the New Siberian Islands. Its northern boundary passes from the Arctic Cape to a point with co-ordinates of 79°N and 139°E, and ends at the Anisiy...
and the East Siberian Sea
East Siberian Sea
The East Siberian Sea is a marginal sea in the Arctic Ocean. It is located between the Arctic Cape to the north, the coast of Siberia to the south, the New Siberian Islands to the west and Cape Billings, close to Chukotka, and Wrangel Island to the east...
in northern Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
. It has an area of 4,600 km², and a maximum altitude of 270 m (Emy Tas).
The peninsula projecting towards the west of the island is the Kigilyakh Peninsula (Poluostrov Kigilyakh).
Off Bolshoy Lyakhovsky Island's southwestern cape lies a small islet called Ostrov Khopto-Terer.
The Lyakhovsky Islands are named in honour of Ivan Lyakhov
Ivan Lyakhov
Ivan Lyakhov , died around 1800, was a Russian merchant who explored large sections of the New Siberian Islands in the 18th century.Lyakhov began his explorations in the spring of 1770 on dogsleds in order to explore the islands off the northern Siberian coast reported by Yakov Permyakov and...
, who explored them in 1773.
Geology
Bolshoy Lyakhovsky Island consists of highly folded and faulted PrecambrianPrecambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
metamorphic rock
Metamorphic rock
Metamorphic rock is the transformation of an existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and pressure causing profound physical and/or chemical change...
s and turbidites; Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
turbidites and igneous rocks; and Cenozoic
Cenozoic
The Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...
sediments. Exposed in southeastern part of this island, the older Precambrian. Early Proterozoic
Proterozoic
The Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life"...
, metamorphic rocks consist of schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
s and amphibolite
Amphibolite
Amphibolite is the name given to a rock consisting mainly of hornblende amphibole, the use of the term being restricted, however, to metamorphic rocks. The modern terminology for a holocrystalline plutonic igneous rocks composed primarily of hornblende amphibole is a hornblendite, which are...
s. Small exposures of Late Proterozoic schistose, quartzose sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
s and phyllitic, sericite
Sericite
Sericite is a fine grained mica, similar to muscovite, illite, or paragonite. Sericite is a common alteration mineral of orthoclase or plagioclase feldspars in areas that have been subjected to hydrothermal alteration typically associated with copper, tin, or other hydrothermal ore deposits...
-quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
(turbidites) also occur in the southeastern part of Bolshoy Lyakhovsky Island. The bulk of this island consists of Late Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
to Early Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
turbidites composed of interbedded fine-grained sandstones, thinly bedded siltstone
Siltstone
Siltstone is a sedimentary rock which has a grain size in the silt range, finer than sandstone and coarser than claystones.- Description :As its name implies, it is primarily composed of silt sized particles, defined as grains 1/16 - 1/256 mm or 4 to 8 on the Krumbein phi scale...
s, and argillite
Argillite
An argillite is a fine-grained sedimentary rock composed predominantly of indurated clay particles. Argillaceous rocks are basically lithified muds and oozes. They contain variable amounts of silt-sized particles. The argillites grade into shale when the fissile layering typical of shale is...
s. The Precambrian and Late Jurassic to Early Cretaceous rocks are intruded by Late Cretaceous granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
s and granodiorites.
A blanket of unconsolidated Cenozoic
Cenozoic
The Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...
sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
s blankets most of Bolshoy Lyakhovsky Island. These sediments include Paleocene
Paleocene
The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...
to Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
colluvial
Colluvium
Colluvium is the name for loose bodies of sediment that have been deposited or built up at the bottom of a low-grade slope or against a barrier on that slope, transported by gravity. The deposits that collect at the foot of a steep slope or cliff are also known by the same name. Colluvium often...
, alluvial
Alluvium
Alluvium is loose, unconsolidated soil or sediments, eroded, deposited, and reshaped by water in some form in a non-marine setting. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand and gravel...
, and deltaic gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...
s, sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
s, clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
s, and coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
s and Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
to Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
alluvial, lacustrine, deltaic, and nearshore marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
sands and clays that contain beds and lenses of gravel. Overlying these sediments are Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
to Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
colluvial, alluvial, and nearshore marine sands, silts, and clays clays that contain occasional gravel layers. The nearshore marine sediments contain the shells of marine mollusks and pieces of lignitized wood. Thick permafrost
Permafrost
In geology, permafrost, cryotic soil or permafrost soil is soil at or below the freezing point of water for two or more years. Ice is not always present, as may be in the case of nonporous bedrock, but it frequently occurs and it may be in amounts exceeding the potential hydraulic saturation of...
characterized by massive ice wedges has developed in these sediments. Contrary to the interpretations of Baron von Toll and earlier geologists, glacial deposits and ice are completely absent within Bolshoy Lyakhovsky Island.
Detailed geological studies, which included the radiocarbon dating of bones, ivory, and plant remains; optically stimulated luminescence dating bone-bearing sediments; and uranium-thorium dating
Uranium-thorium dating
Uranium-thorium dating, also called thorium-230 dating, uranium-series disequilibrium dating or uranium-series dating, is a radiometric dating technique commonly used to determine the age of calcium carbonate materials such as speleothem or coral...
of associated peats, have clarified the stratigraphy, origin, and age of the sediments and permafrost that Baron von Toll found exposed in the southern sea cliffs of Bolshoy Lyakhovsky Islands. Dr. Romanovsky and Dr. Andreev and others found that these bone- and wood-bearing sediments described by Baron von Toll consist of Middle to Late Pleistocene floodplain and thermokarst, eolian, and lake sediments underlying different terrace levels. Later studies determined that alders, Alnus fruticosa, lived within the New Siberian Islands only during relatively brief periods of warm interstadial and interglacial climates. Dr. Makeyev and others found that over the last 15,000 years, Alnus fruticosa occupied these islands from 12,200 to 12,500 radiocarbon years BP during an interstadial that was unrelated to Baron von Toll's "mammoth period". Dr. Andreev and others dated the sediments also containing alder pollen and Baron von Toll's alder tree to the last, Kazantsevo (Eemian), Stage about 114 to 130 thousand years ago. They found that other vertebrate fossils ranged in age from 114,000 to 26,000 BP. These Pleistocene sediments, overlie a Pliocene paleosol
Paleosol
In the geosciences, paleosol can have two meanings. The first meaning, common in geology and paleontology, refers to a former soil preserved by burial underneath either sediments or volcanic deposits , which in the case of older deposits have lithified into rock...
and are cemented by permafrost.
Baron Eduard von Toll
Eduard Toll
Eduard Gustav von Toll was a Baltic German geologist and Arctic explorer in Russian service. Often referred to as Baron von Toll or as Eduard v. Toll, in Russia he is known as Eduard Vasiliyevich Toll . Eduard Toll was born on and he died in 1902 in an unknown location in the Arctic Ocean)...
made an interesting discovery. Under a peat composed of water mosses covering what is described as the "perpetual ice", Baron von Toll found fragments of willow and the bones of post-Tertiary mammals, like the shoulder-bone of a saber-toothed tiger. It also reported having found in a frozen, sandy clay layer and lying on its side, a complete tree of Alnus fruticosa 15 to 20 ft (4.5 to 6 m) in length, including roots, with leaves and cones adhering. Various authors, i.e. Dr. Digby and Dr. Kropotkin misreport this tree as being 90 feet (27.4 m) high. Other publications, i.e. Fingerprints of the Gods and Earth's Shifting Crust not only incorrectly state that this alder tree is 90 feet (27.4 m) high, but also they also repeat fictional claims from unreliable sources that this tree was either a “fruit tree” or “plum tree” and had "green leaves"and green fruit" still attached. Lacking modern radiocarbon dating techniques, Baron von Toll assigns this tree to what it calls the "mammoth
Mammoth
A mammoth is any species of the extinct genus Mammuthus. These proboscideans are members of Elephantidae, the family of elephants and mammoths, and close relatives of modern elephants. They were often equipped with long curved tusks and, in northern species, a covering of long hair...
period". It concludes that this alder tree is proof that tree-vegetation had reached the seventy-fourth degree of latitude, three degrees farther north than currently.
Climate
The Cape Shalaurova meteorological station, which lies on the southeast coast of Bolshoy Lyakhovsky Island, at 73° 11' N 143° 56' E provides climatic data for this island. The mean precipitation is 184 mm/year as calculated for a 7 year period between April 1994 and September 2000 as calculated from National Oceanic and Atmospheric Administration data. The heaviest precipitation, about two-thirds of the yearly total, occurs between June and September. As calculated from the same data for the same period of time, the mean temperature at Cape Shalaurova is −13.6°C. January is the coldest month with a mean temperature of −31.0°C and August is the warmest month with a mean temperature of 2.4°C. Mean daily temperatures range as low as −40.5°C and as high as 9.4°C.Vegetation
The vegetation of Bolshoy Lyakhovsky Island is a mixture of rush/grass, forb, cryptogam tundra, cryptogam herb barren, and sedge/grass,moss wetland. The rush/grass, forb, cryptogam tundra covers the bulk of Bolshoy Lyakhovsky Island. It consists mostly of very low-growing grasses, rushes, forbs, mosses, lichens, and liverworts. These plants typically cover about 40–80 percent of the surface of the ground. The soils are typically moist, fine-grained, and often hummocky. The cryptogam herb barren consists of dry to wet barren landscapes with scattered, herbs, lichens, mosses, and liverworts. Sedges, dwarf shrubs, and peaty mires are normally absent. These plants form a sparse (2–40%) and low-growing plant cover that often occurs as dark streaks on the otherwise barren lands, composed largely of bryophytes and cryptogamic crusts. Sedge/grass,moss wetlands, which occur on the northwest and southeast ends of Bolshoy Lyakhovsky Island, consist of wetland complexes dominated by sedges, grasses, and mosses. These wetlands occupy low, perennially wet parts of the landscape.External links
- Anisimov, M.A., and V.E. Tumskoy, 2002, Environmental History of the Novosibirskie Islands for the last 12 ka. 32nd International Arctic Workshop, Program and Abstracts 2002. Institute of Arctic and Alpine Research, University of Colorado at Boulder, pp 23–25.
- anonymous, nda, New Siberian Islands. aerial photographs of New Siberian IslandsNew Siberian IslandsThe New Siberian Islands are an archipelago, located to the North of the East Siberian coast between the Laptev Sea and the East Siberian Sea north of the Sakha Republic....
- anonymous, ndb, Bol'shoy Lyahkovskiy. aerial photograph of Bolshoy Lyakhovsky Island.
- Babinski, E.T., nd, A Frozen Ninety Foot Tall Plum Tree. examination of reports of a 90 feet (27.4 m) fossil plum tree being found in Bolshoy Lyakhovsky Island of the New Siberian Islands.
- Espinoza, E.O., and M.-J. Mann, 1993, The history and significance of the Schreger Pattern in Proboscidean ivory chracterization. Journal for the American Institute for Conservation. vol. 32, no. 3, Article 3, pp. 241–248.
- Kuznetsova, T.V., L.D. Sulerzhitsky, Ch. Siegert, 2001, New data on the “Mammoth” fauna of the Laptev Shelf Land (East Siberian Arctic), 144 KB PDF file, The World of Elephants – International Congress, Rome 2001. Consiglio Nazionale delle Ricerche, Centro di Studio per il Quaternario e l'Evoluzione Ambientale, Università di Roma, Roma, Italy.
- Schirrmeister, L., H.-W. Hubberten, V. Rachold, and V.G. Grosse, 2005, Lost world – Late Quaternary environment of periglacial Arctic shelves and coastal lowlands in NE-Siberia. 2nd International Alfred Wegener Symposium Bremerhaven, October, 30 – November 2, 2005.