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Stephan Mueller Spec. Publ. Ser., 4, 65–70, 2009 www.stephan-mueller-spec-publ-ser.net/4/65/2009/ Special © Author(s) 2009. This work is distributed under Publication the Creative Commons Attribution 3.0 License. Series

Multi-phase tectonic structures in the collision zone of the -Omolon microcontinent and the eastern margin of the North Asian craton, Northeastern

A. V. Prokopiev and V. S. Oxman Diamond and Precious Metal Institute, Siberian Branch, Russian Academy of Sciences, Yakutsk, Russia

Abstract. The sequence of formation of structures is es- part of the section, of Lower Devonian carbonate rocks over- tablished in the zone of junction of the eastern margin of lain by Carboniferous-Permian hemipelagic volcanogenic- the North Asian craton and the northeastern flank of the terrigenous-siliceous rocks exposed in a narrow band along Kolyma-Omolon microcontinent, in the area of bend of the the Nal’chan . The upper part of the section consists of Kolyma structural loop. Detailed structural studies revealed Triassic and Jurassic sandy-clayey flysch deposits up to 1 km two phases in the formation of Mesozoic structures – an early in total thickness, making up most of the ’s area. On thrust phase and a late strike-slip phase. Structures formed the south, the terrane is adjoined by the tectonic zone of the during each of the phases are described. Thrust structures are Polousnyy synclinorium that is composed of the Lower to represented by the Setakchan on which the minimum Middle Jurassic turbidites with a thickness exceeding 1.5 km amount of horizontal displacement is estimated at 13–15 km. (Parfenov and Kuz’min, 2001). It is generally assumed (Par- Later superposed left-lateral strike-slip faults have a north fenov, 1995; Prokopiev, 2000; Oxman, 2000; Oxman and strike. Formation of these latter structures occurred during Prokopiev, 2000; Prokopiev and Kaskevich, 2000; Parfenov the second phase of collision between the Kolyma-Omolon and Kuz’min, 2001; Parfenov et al., 2003) that thrust struc- microcontinent and the eastern margin of the North Asian tures in the zone of junction of the Kolyma-Omolon micro- craton. continent and the North Asian craton margin originated dur- ing frontal collision between the microcontinent and the cra- ton, subsequent to completion of subuction of the oceanic crust of their separating paleoocean, and that strike-slip mo- 1 Introduction tions occurred during the following motion of the micro- continent from southeast to northwest (here and hereafter in The study region is located on the northwestern side of the present-day coordinates) and the closure of a small gulf of Kolyma-Omolon microcontinent, in the area of the bend of the South Anyui ocean. the Kolyma structural loop, where the structures change This paper is based on the results of structural and geo- their strike from northwest to northeast (Fig. 1). From west metric analyses by the authors during a large-scale geologic to east, the microcontinent here includes the Polousnyy syn- survey on the Selennyakh and Uyandina Rivers (northwest clinorium, the Nagondzha turbidite terrane, and the north- tributaries of the Indigirka River) (Fig. 1). The investigation ern Omulevka miogeoclinal terrane composed mainly of Or- was aimed at establishing the sequence of formation of struc- dovician to Lower Carboniferous carbonate and terrigenous- tures within the two areas, Khulidzhyun and Setakchan, in an carbonate rocks (Parfenov and Kuz’min, 2001). The stud- attempt to interpret the Late Mesozoic deformation history of ies were mainly conducted on the northwestern side of the the region. Nagondzha terrane, in the area of its junction with struc- tures in the Polousnyy synclinorium along the Setakchan thrust. In the east, the terrane makes contact with the rocks of the Omulevka terrane along the Nal’chan fault 2 The Khulidzhyun area (Fig. 1). The Nagondzha terrane is composed, in the lower The area (upper reaches of Khulidzhyun Creek, the northeast tributary of Tirekhtyakh Creek, Selennyakh River basin) oc- Correspondence to: A. V. Prokopiev curs within the limits of the Setakchan nappe and is confined ([email protected]) to the hanging wall of the regional Setakchan thrust (Fig. 1).

Published by Copernicus Publications on behalf of the European Geosciences Union. 66 A. V. Prokopiev and V. S. Oxman: Multi-phase tectonic structures of Northeastern Russia

The nappe is formed by allochthonous Upper Triassic (No- rian) mainly sandy rocks overlying, along a low-angle thrust, the autochthonous Lower to Middle Jurassic chiefly clayey

Arctic ocean 700N deposits. The Jurassic rocks in the autochthon display tec-

Chukotka tonic melange´ structures (broken and dismembered forma- C tions), which were described in detail in an earlier publica- SP VFTB h e rs ky tion (Oxman and Prokopiev, 2000). This paper presents new R a North n g data on the structural features of the deformed strata, as well Asian e 600N Craton as the geometric characteristics of the nappe. Geologic map- Bering ping established that the autochthon of the nappe is exposed a tk a sea h c in an erosional , while the to the northwest m a 14 0 K 0 is a tectonic composed, like the southeastern side of 5 E 170 E 500 km the area, of Norian sandstone and siltstone (Fig. 2a). The Okhotsk-Chukotka Kolyma-Omolon magmatic belt microcontinent southeastern contact between the klippe and the Lower to Middle Jurassic melange´ is exposed in a trench where the SP - Siberian platform, VFTB - Verkhoyansk fold-and-thrust belt o Jurassic rocks are found to be in tectonic contact with the 140 Upper Triassic deposits along a plane dipping steeply to the southeast. However, we also established that northwest of the klippe, the Triassic rocks are mainly overturned. From Ir Uy an di these data, we infer that the fault surface is deformed into a na r v. southwest-overturned antiform. The fold is coaxial with nu- Deputatskii merous small folds in the tectonic melange´ zone within the window (Fig. 2a, stereograms 2 and 5). The folds are mainly S T U e le conical, with a width from a few decimeters to a few tens n n ya U-S of meters. The allochthon rocks are deformed into cylindri- kh r cal folds ranging up to several hundred meters wide. In the v. S 1 2 tectonic melange´ of the autochthon, the has a pre-

o dominantly southeast or south dip and is subparallel to the 68 40' N axial planes of tight to isoclinal folds of the first generation (F1) that are inclined mainly to the northwest. In some areas, the intensity of deformation is high enough for the bedding to become parallel to cleavage S1 (Fig. 2a, stereograms 2, 0 30 km 3 and 5). In this case, the cleavage becomes transpositional (Passchier and Trouw, 1996), and F1 folds are rootless, with their limbs isolated from the hinge zone in isoclines whose axial surfaces are parallel to the cleavage. Fold hinge lines b1 Polousnyy synclinorium and of the cleavage and bedding intersection L0x1 Nagondzha terrane plunge gently to the southwest and northeast. Within the ex- posed part of the autochthon, the apparent thickness of the Omulevka terrane Lower to Middle Jurassic rock units, as measured perpendic- Aptian-Upper Cretaceous volcanogenic rocks ular to the cleavage, exceeds 10 km. Since the thickness of of the Dzhakhtardakh field deposits of that age does not exceed a few kilometers, even in Early Cretaceous granitoids the central part of the Polousnyy synclinorium, one may as- (T-Takalkan pluton) sume that the Jurassic sequence in the autochthon is repeated along the thrusts traceable in the melange´ zone. Cenozoic sediments (U-S - Upper Selennyakh basin; U- Uyandina basin) In the allochthon, wide (up to 1 km) and linear, com- monly overturned, F1 folds are associated with low-angle Thrust (Ir-Irgichan, S - Setakchan, N - Nal'chan) thrusts that form a northwest-verging imbricate fan. These structures, like the tectonic melange´ of the autochthon, were Study areas (1 - Setakchan, 2 - Khulidzhyun) formed during the first deformation stage in the region, syn- chronously with the thrusts. Detachment at the allochthon Fig. 1. Tectonic map of the southern sector of the Polousnyy syncli- base is traced along the bottom of the Norian rock sequences, norium and the Nagondzha terrane. After Grebennikov et al. (1995) and Parfenov and Kuz’min (2001), modified by the authors. Inset and the minimum horizontal displacement of the allochthon map – location of the study area. is estimated at 13–15 km (Fig. 2b).

Stephan Mueller Spec. Publ. Ser., 4, 65–70, 2009 www.stephan-mueller-spec-publ-ser.net/4/65/2009/ A. V. Prokopiev and V. S. Oxman: Multi-phase tectonic structures of Northeastern Russia 67

The second stage of deformation is related strike-slip mo- 139o40' (a) tion on northwest-striking faults. The S-shaped (in plan) 2 km small F2 folds and numerous indicate that the strike-slip is left-lateral. As a result of strike-slip motions, 68o55' 1 b ,L I the early thrusts, linear folds of the allochthon and cleavage 1 0x1

πS of the tectonic melange´ of the autochthon were deformed into 0 πS1 a large S-shaped (in plan) F fold up to 6 km wide (Fig. 2a). III 2 b1,L0x1 This deformation of the early structures is established from o 2 30 the distribution of the poles of the S1 cleavage planes of the tectonic melange´ in the arc of a small circle, indicating a con- ical geometry of F folds, as well as from changing orienta- πS 2 1 b ,L 1 0x1 II tion of hinge lines (b1) of the early F1 folds (Fig. 2a, stere- 45o 68o50' ogram 2). Hinge lines (b2) of F2 folds plunge steeply to the 139o40' IV east-southeast (Fig. 2a, stereogram 5). 3 4 5 6

πS1 πS1 πS IIS 0 1 b2 b1,L0x1

b1 pS0 πS0 b 3 The Setakchan area 1

(b) I II-III IV The area is located east of the Khulidzhyun area, within km Tr Tr3 km 0 2 km 3 Jr the Nagondzha terrane, in the middle reaches of Setakchan 1 1-2 1 Creek the northeast tributary of Tirekhtyakh Creek, Uyand- 0 0 ina River basin) (Fig. 3). Here in the canyon, there are perfect Upper Triassic Hinges of the second generation of folds Lower to Middle Jurassic exposures of multiply deformed flysch deposits of the No- (dashed line shows a general dip Antiform Synform of cleavage in the tectonic melange zones) rian age. The structures described here are characteristic of Quaternary Poles on stereograms Late Jurassic-Early Cretaceous πS0 the central zone of the Nagondzha terrane, located between quartz diorite and lamprophyre dikes Bedding

Thrusts of the first generation πS Cleavage in the tectonic melange zones 30o (assumed thrust is shown by a dashed line, 1 the Nal’chan and Setakchan thrusts (see Fig. 1). The east- (πSoIIS1 - cleavage subparallel to bedding) figures designate dip of the fault surface)

b1 Hinges of the first generation of folds and ern part of the area consists mainly of sandstone of the local Strike-slip fault of the second generation L lineation of the cleavage and bedding intersection 0x1

Hinges of the first generation of folds b zone Otapiria ussuriensis from the middle part of the Norian, 2 Hinges of the second generation of folds and antiform while in the west there are exposures of mainly argillaceous Fault surface of the first generation of thrusts and synform rocks of the local zone Monotis ochotica from the lowermost Overturned anticline and antiform Arcs of the great and small circles

Upper Norian. This indicates the rocks generally dip to the Overturned syncline and synform east. The intermediate local zone Monotis scutiformis is ei- ther absent from the sequence or faunal remains of this age have not yet been found. Eastward, beyond the borders of Fig. 2. Tectonic map of the Khulidzhyun area with stereographic the area, poorly fossiliferous Lower to Middle Jurassic rocks projections of structures (a) and geologic section along the I-II-III- make their appearance. Two stages of deformation are rec- IV line (b). For location see Fig. 1. ognized here. Structures of the first stage include low-angle thrusts with fault surfaces that dip gently to the east and northeast. In fact, the rock mass represents a set of pack- ages of thrust sheets, each up to a few hundred meters thick, the Upper Triassic strata prevents estimating the total amount that are separated by thrust surfaces. The thickness of the of motion on the thrusts. The estimated shortening is high, mylonitized rocks in the fault zones attains a few decimeters. ranging up to 40–50% on some thrusts. Therefore, the total Cleavage is either present in narrow discrete zones or ab- displacement on the thrusts may have been several tens of sent altogether. This fact and the lack of metamorphic alter- kilometers. ation imply the formation of structures at relatively shallow In thin (about 1.5 km) zones of the syn-thrust tectonic depths. The thrust structures are mainly typical ramps that melange,´ restricted to the thrust planes (Fig. 4d), there are form imbricate fan-like systems (Fig. 4a and b). F1 folds are disrupted sandstone beds in the form of lenses embedded in concentric, including both upright to slightly inclined folds a schistose matrix of argillaceous rocks, representing a typi- and recumbent isoclines (Fig. 4c). The trend of gentle hinge cal “broken formation” (Raymond, 1984). The long axes of lines b1, and the strike of axial surfaces of F1 folds and thrust the lenses are subperpendicular to the thrust planes, parallel surfaces changes from west to north (Fig. 3). Common fold to the westward movement of the rock masses. A character- thrusts are characterized by low-angle thrusts that die out up- istic feature of the interstratal detachment zones are numer- dip in the cores of folds (Fig. 4a). The amount of horizontal ous small-scale and low-amplitude thrust duplexes (Fig. 4e, f, displacement on some of the thrusts is a few meters, rarely and g). Kinematics of the thrusts depend on the up to 10–15 m. However, the absence of marker horizons in of the host rocks: in largely argillaceous rocks interstratal www.stephan-mueller-spec-publ-ser.net/4/65/2009/ Stephan Mueller Spec. Publ. Ser., 4, 65–70, 2009 68 A. V. Prokopiev and V. S. Oxman: Multi-phase tectonic structures of Northeastern Russia

11 12 16 b1

πS0 b1 7 πS0 9 πS0 b1 4 b 13 1 18 b2 b1

πS0 8 b πS0 2 πS0 b2 b 5 πS1 1 b2 3 b1 F πS 1 πS 0 0 b1 πS0 F2 o 60 75 60 F1 F 50 55 1 60 F2 b1 80 80 50 68o51'40"

40 '

F1 7

b1 0 b o 1 o 0

40 4

40 1 F1 10 F 1 F2 F e nor3) 2 Cr. cal zon a (Tr3 17 30 chan lo ochotic 20 F ak otis 14 2 et ne ) Mon F1 S ocal zo nor2 F1 l sis (Tr3 15 25 40 F1 urien 5 ria uss Otapi b1 b1 10 10 b F 2 45 1 o 68 51' 40 πS b2 " F 0 5 60 40 1 πS

4 6 0 πS ' 0 πS0 8

5 F b o 1 1 19 21

9 2 3 πS0 15 1 1 b1

b1 b2 b2 b1 b1 πS πS0 b2 0 πS b1 0 πS 0 πS b 1 2 b2 b 1 1 km

Thrust of the first generation Rock bedding o Sites of faunal remains 40 (figures show dip of the fault surface) Large sandstone lenses Poles of strike-slips of the second generation in the tectonic melange zones Reverse left-lateral fault

Tectonic melange zones 40 Bedding attitude See figure 2 for other symbols.

Figure 3.

Fig. 3. Tectonic map and stereographic projections of structures along Setakchan Creek. For location see Fig. 1. detachment thrusts and micro-duplexes are developed, while earlier inclined planar structures results in conical geometry the rocks with a high percentage of sandstone are deformed of almost all F2 folds and distribution of the poles in the arcs into imbricate fans and ramps. As in the Khulidzhyun area, of small circles on the stereograms (Fig. 3). The axial planes coaxial structures are found here, which are associated with of F2 folds dip steeply and are oriented at an angle to the the final stage of thrusting in the same tectonic field. strike of the reverse left-lateral faults. Like the earlier F1 The second-stage structures include faults of dip-slip and folds, F2 folds are of concentric type. strike-slip kinematics and tectonic melange´ zones of north Large F2 folds have been mapped from changes in the strike and east dip. The strike-slip faults have associated strike of the bedding, the fault surfaces of the early thrusts, folds of the second generation (F2) superposed on the earlier and F1 fold hinge lines. This is most easily observed on the structures (Fig. 4h). Numerous slickensides and S-shaped western side of the area. Comparison of the orientation data F2 folds indicate reverse left-lateral strike-slip kinematics. for the planar and linear structures presented in stereograms The amplitude of F2 folds varies from a few decimeters to 1–8 (Fig. 3) shows the early structures have been deformed 2–3 km. Since this folding involves the previously intensely into a large F2 fold with an amplitude of several kilometers. deformed rock units, b2 hinge lines of small F2 folds plunge, The calculated hinge line of the fold plunges to the northeast as a rule, in different directions and their plunges depend on at an angle of 50–70◦. the dip of the earlier deformed bedding or fault surfaces of Zones of the second generation of reverse left-lateral faults the thrusts – the steeper dip, the greater the plunge of the range from a few decimeters to 150 m in width. They include hinge lines of the superposed F2 folds. Deformation of the the tectonic melange´ observed at the center and in the eastern

Stephan Mueller Spec. Publ. Ser., 4, 65–70, 2009 www.stephan-mueller-spec-publ-ser.net/4/65/2009/ A. V. Prokopiev and V. S. Oxman: Multi-phase tectonic structures of Northeastern Russia 69

(a) part of the area (Fig. 3). The rocks are intensely cleaved in W E the melange´ zones. The long axes of the lenses of disrupted sandstone beds embedded in the matrix of schistose siltstone and mudstone are either subhorizontal or slightly inclined to 5 m Setakchan Cr. the south, and have a west strike. There are numerous slick- (b) ensides with subhorizontal or very gently plunging striations. W (c) E A gradual transition is typical from the broken formation at the periphery of the melange´ zone to the dismembered for- mation (Raymond, 1984) developed in its central part. As 2,5 m 5 m in the case of the first generation of thrust structures, it is Setakchan Cr. Setakchan Cr. (d) E (e) W highly difficult to estimate the amount of displacement along W E the strike-slip faults because of the absence of reliable strati- graphic markers. In course of 1:50 000 geological survey in the region, the horizontal motion along the strike-slips was estimated at 1–2 km. The presence of numerous small re- Setakchan Cr. 1,5 m Setakchan Cr. verse left-lateral faults suggests the total amount of motion W (f) (g) E on northwest-striking strike-slip faults could have been sev- eral tens of kilometers. Farther east, in the Nal’chan fault zone, at the contact of the Nagondzha and Omulevka ter- ranes (Fig. 1), two deformation stages have also been de- scribed, which are associated with the early thrusting and Setakchan Cr. Setak 1,5 m chan Cr. subsequent reverse left-lateral faulting (Prokopiev, 2000; Ox- W (h) E man and Prokopiev, 2000).

Sandstone Thrust

Siltstone Antiform hinge

4 Age of dislocations Mudstone Talus

Set akchan Cr. F2 2,5 m In both of the areas, the age of deformation is presum- ably Late Jurassic-Early Cretaceous. The Takalkan granite- porphyry pluton located 15 km to the north (Trunilina et Fig. 4. Structures in the Upper Triassic strata, Setakchan area. (a, b) al., 1999) with 40Ar/39Ar whole rock ages of 96.4±0.4 – thrusts and folds of the first generation. (c) – overturned antiform and 97.0±0.6 Ma (Layer et al., 2001) and a quartz diorite and thrust of the first generation. (d, e, f, g) – thrust microduplexes stock with 40Ar/39Ar biotite ages of 134.3±0.4 Ma intruded of the first generation. (h) – antiform of the second generation with the folded strata and caused contact metamorphism. The a steeply plunging hinge line. Khulidzhyun area contains dikes of Early Cretaceous diorite- porphyry and Late Jurassic lamprophyres concordant to the tectonic melange´ structures of the first generation and de- the first phase of the collision were not seen in the study ar- formed, together with the tectonic melange´ zone, by a second eas located west of the frontal collision zone (Fig. 5a). In generation of strike-slip faults (Fig. 2). In the Setachan area, the Late Late Jurassic–Early Cretaceous, closure of a small the tectonic melange´ disrupts a lamprophyre of Late gulf of the South Anyui ocean (Parfenov and Kuz’min, 2001) Jurassic age. This suggests a Late Jurassic-Early Cretaceous caused lateral motion of the microcontinent to the northwest, age of the first-stage deformation and a pre-Hauterivian age forming left-lateral strike-slips along the whole length of the of the second-stage deformation in the study area. Chersky Range. This second phase of collision resulted in folding and faulting in the study region, and crystallization of granitoids of the Northern batholith belt (Fig. 5b). Early 5 Conclusions in this phase, the collision of the northwestern margin of the microcontinent and the craton produced low-angle thrusts of Our analysis of the fold and fault structures we have de- the first generation (Fig. 6a). The thrusts of the Setakchan scribed led us to propose the following paleotectonic sce- area may be regarded as deformation structures within the nario for the structural evolution of the region. In the Late allocththon of the Setachan nappe, with its frontal part ex- Jurassic, a paleoocean, separating the Kolyma-Omolon mi- posed within the Khulidzhyun area. At the end of the phase, crocontinent and the eastern margin of the North Asian cra- the continued motion of the microcontinent led to the forma- ton closed and the first phase of frontal collision occurred. tion of reverse left-lateral faults and fault-plane contractional Synchronously the granitoids of Main batholith belt crystal- duplexes (Prokopiev and Kaskevich, 2000), and by the defor- lized (Prokopiev et al., 2007). The deformations caused by mation of the earlier thrust structures (Fig. 6b). www.stephan-mueller-spec-publ-ser.net/4/65/2009/ Stephan Mueller Spec. Publ. Ser., 4, 65–70, 2009 70 A. V. Prokopiev and V. S. Oxman: Multi-phase tectonic structures of Northeastern Russia

Acknowledgements. The authors thank David Stone and Cather- Late Jurassic late Late Jurassic to Early Cretaceous ine Hanks for critical comments, and Wesley K. Wallace for help- (a) (b) SOUTH - ANYUI OCEAN SOUTH - ANYUI OCEAN ful review and for comments and corrections which were taken

° NORTHERN ° into consideration in the final manuscript preparation. Research 5 OLOY ARC 5 7 BATHOLITH 7 UYANDINA - OLOY ARC BELT was supported by projects RFBR (07-05-00743, 06-05-96070) and YASACHNAYA MAGMATIC BELT KOM ONZ-7.10.2.

KOM

S S

I I

B B

E E

R R

I I MAIN A A

N VILYUI BATHOLITH N BASIN P BELT P L L A A

T T UDA-MURGAL F F O UDA-MURGAL O ARC R M ° R M References ARC 60

Craton Subalkaline and alkaline volcanic and plutonic belts Grebennikov, G. A., Epov, O. G., Boyarshinov, V. V., et al.: Geo- Subsided craton margin - passive continental margin Collisional granitoids logic map of Yakutia. Lower Yana block, Scale 1:500 000, Map’s Ocean and sea with oceanic crust Thrust Printing-house of Russian Geological Research Institute, St.- Microcontinent Strike - slip fault Petersburg, 1995 (in Russian). Sense of motion of the Kolyma-Omolon Sedimentary basin microcontinent Layer, P. W., Newberry, R., Fujita, K., Parfenov, L. M., Trunilina, Subduction zone Location of study areas V. A., and Bakharev, A. G.: Tectonic setting of the plutonic belts Subduction-related magmatic arc KOM - Kolyma-Omolon microcontinent of Yakutia, Northeast Russia, based on 40Ar/ 39Ar and trace ele- ment geochemistry, Geology, 29, 167–170, 2001. Fig. 5. Paleogeodynamic reconstructions of the zone of junction of Oxman, V. S.: of the Chersky collisional belt (northeast the Kolyma-Omolon microcontinent and the eastern margin of the Asia), GEOS, Moscow, 269 pp., 2000 (in Russian). North Asian craton: (a) – for the Late Jurassic, (b) – for the Late Oxman, V. S. and Prokopiev, A. V.: Terrigenous tectonic melanges´ Late Jurassic–Early Cretaceous. After Parfenov (1995), Parfenov of the Polousnyy synclinorium, Otechestvennaya Geologiya, 5, and Kuz’min (2001), Parfenov et al. (2003) modified by the authors. 47–50, 2000 (in Russian). Parfenov, L. M.: and formation history of Mesozoic oro- genic belts of east Yakutia, Tikhookean. Geol., 14(6), 32–43, 1995 (in Russian). Parfenov, L. M., Berzin, N. A., Khanchuk, A. I., Badarch, G., Be- (a) lichenko, V. G., Bulgatov, A. N., Dril, S. I., Kirillova, G. L., (a) Kuzmin, M. I., Nokleberg, W. J., Prokopiev, A. V., Timofeev, V. PS The Setakchan The Khulidzhyun area The Setakchan The Khulidzhyun area area F., Tomurtogoo, O., and Yang, H.: A model for the formation of PS The Setakchan S The Khulidzhyun area S areaTr3nor3 S Tr3nor2 Tr3nor3 orogenic belts in Central and Northeast Asia, Tikhookean. Geol., S Tr3nor2 N Jr1-2 S N Jr Jr1-2 Jr1-2 Tr3nor3 S 1-2 Tr3nor2 22(6), 7–41, 2003 (in Russian). N Jr1-2 Ng Jr1-2 Tr nor Ng Om Tr3nor3 Tr3nor2 3 3 Parfenov, L. M. and Kuz’min, M. I. (Eds.): Tectonics, geodynam- Ng 3 2 Om Tr3nor3 Tr3nor2 ics and metallogeny of the Republic (Yakutia), MAIK “Nauka/Interperiodica”, Moscow, 571 pp., 2001 (in Russian). Passchier, C. W. and Trouw, R. A. J.: Microtectonics, Springer, (b) (b) Berlin, 289 pp., 1996. Prokopiev, A. V.: Verkhoyansk-Cherskiy collisional orogen, Geol- The Setakchan The Khulidzhyun area area PS The Khulidzhyun area The Setakchanarea ogy of Pacific Ocean, 15, 891–904, 2000. PS The Khulidzhyun area area Tr nor Prokopiev, A. V., Toro, J., Miller, E. L., Wooden, J., Trunilina, V. Tr3nor2 Tr3nor3 S 3 2 3 3 Tr3nor2 Tr3nor3 Jr1-2 S S Jr1-2 Jr1-2 S Jr1-2 A., and Bakharev, A. G.: Granitoids of the Main batholith belt Jr1-2 S Jr1-2 Ng Tr3nor3 (northeast Asia): new U-Pb SHRIMP geochronological and geo- Ng Tr3nor3 Om Tr3nor2 Ng 3 2 Tr3nor3 Om Tr3nor2 chemical data, Tectonics and metallogeny of the Circum North Pacific and East Asia, Khabarovsk, Institute of Tectonics and N N Geophysics, 286–288, 2007 (in Russian). Prokopiev, A. V. and Kaskevich, G. E.: Strike-slip duplexes of east- p i p l i t

l ern Yakutia (northeast Russia), Otechestvennaya Geologiya, 5, p t

s on the map Tectonic motion s on the map i s - l on the map Tectonic motion s t on the map - u

s on the map Tectonic motion e s u

r on the map - e r k u h i e k 44–46, 2000 (in Russian). r h i r T k t r h i

T in the section

t Line of structural section

in the section r Line of structural section

S in the section T t

in the section S in the section Line of structural section

S in the section Raymond, L. A.: Classification of melanges,´ in: Melanges:´ their nature, origin, significance, Geological Society of America, Spe- cial Paper 198, 7–20, 1984. Fig. 6. Structural-kinematic evolutionary maps and structural Trunilina, V. A., Poev, S. P., Orlov, Yu. S., and Oxman, V. S.: Mag- sections of the zone of junction of the Polousnyy synclinorium, matism of different geodynamic environments (zone of junction Nagondzha and Omulevka terranes. (a) – first stage, (b) – sec- of the Verkhoyansk margin of the Siberian continent and the ond stage of deformation. PS – Polousnyy synclinorium, Ng – Kolyma-Omolon microrontinent), Publishing House of Yakutian Nagondzha terrane, Om – Omulevka terrane. Faults: S – Setakchan, Scientific Centre, Siberian Branch, Russian Academy of Sci- N – Nal’chan. ences, Yakutsk, 152 pp., 1999 (in Russian).

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