Acta Geologica Polonica , Vol. 58 (2008), No. 3, pp. 261-285

The of Western Karakorum (Pakistan)

MAURIZIO GAETANI 1, RUTH MAWSON 2, DARIO SCIUNNACH 3 & JOHN A. TALENT 2

1Dipartimento di Scienze della Terra, Università di Milano, Via Mangiagalli 34, 20133 Milano , Italy. E- mail: [email protected] 2Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia 3Regione Lombardia, Infrastruttura per l’ Informazione Territoriale, Via Sassetti 32, 20124 Milano, Italy

ABSTRACT :

GAETANI , M., M AWSON , R., S CIUNNACH , D. & T ALENT , J.A. 2008. The Devonian of Western Karakorum (Paki- stan) . Acta Geologica Polonica , 58 (3), 261-285 . Warszawa.

Devonian rocks crop out in several thrust sheets in the sedimentary belt of North-Western Karakorum, both to the south and to the north of the Reshun Fault. Gently metamorphosed Devonian dolostones and volcanics are also pres - ent in the Tash Kupruk Zone north of the thrust sheet system. The most complete succession is found in the Karam - bar Thrust sheet where dolostones and recrystallized limestones (Vandanil Formation) lie above the black and siltstones of the Baroghil Group. The age of the Vandanil Formation is poorly defined, approximating latest Sil - urian or earliest Devonian at its base and proven to be Pragian in the 4 th of its 5 lithozones. The overlying Chilmarabad Formation is divided into two members. The lower member is a mixed siliciclastic–carbonate package, present in most southern and western thrust sheets. The upper member is ubiquitous; it consists of dolostones, often stroma - tolitic. The calcareous part of the Tash Kupruk Zone consists of similar facies. The carbonate flats of the Chilmarabad Formation display a trend towards emersion towards the top, and are overlain, with regional unconformity, by the basal unit of the Shogrām Formation . The base of the latter consists of arenite and fine conglomerate (deposited in an alluvial setting) overlain by alternating marine bioclastic limestones and litharenites with one or two coral baf - flestones in the middle to upper part. The age of the lowermost part of the Shogrām Formation is Givetian, extend - ing through the Frasnian and seemingly into the Famennian, but the last is poorly documented (contrasting with the classic Shogrām and Kurāgh sections of Chitral); it reflects a return to fine terrigenous input. The inferred palaeogeography accords with the Northern Karakorum having been part of the Gondwana mar - gin during the Devonian. A wide, mostly calcareous platform, characterised extensive areas of the Karakorum, Cen - tral Pamir, Badakhshan and, in a minor way, Central Afghanistan (Helmand Block). The sandstone petrography suggests that clastics polluting the carbonates originated from erosion of a pre-existing sedimentary cover. During the Givetian a first rifting episode, possibly echoing the opening of an ocean to the east, affected the whole area, with volcanic outpourings in the rifts, while eroding shoulders fed the basins, though never extending as deep as the crys - talline basement. A minor volcanic input is also recorded. The tectonic pulse almost ceased during the Frasnian, gradually resuming towards the end of the Devonian.

Key words: Stratigraphy, Sandstone petrography , Palaeo-Tethys, Devonian, , Brachiopods .

INTRODUCTION that during the Palaeozoic was part of the Gondwana margin (Text-fig. 1) . From south to north, the Karako - The Karakorum Range, in its geological extension rum Block consists of two major structural elements: (GAETANI 1997), contains a lithosphaeric fragment i) the Southern Metamorphic Belt and the Karakorum 262 MAURIZIO GAETANI & al.

Batholiths, separated in the west by the Intermediate J.A.T ALENT and R.A.K. T AHIRKHELI , who visited Sedimentary Belt, and ii) the crystalline and Palaeo - the Baroghil area in 1973, found a Devonian sequence zoic- sedimentary rocks of the Northern with -coral-brachiopod faunas ( TALENT & Karakorum Terrain (Text-fig. 2). Recognition of De - MAWSON 1979; TALENT & al . 1982), apparently in - vonian sedimentary successions has been possible cluding HAYDEN ’s above locality. only in the Northern Karakorum Terrain where a M. G AETANI investigated the Devonian of the re - major metamorphic imprint is absent. gion in 1992, 1996, 1999, and 2004, with field assis - The first collection of Devonian rocks from the tance from his wife LIA and from L. A NGIOLINI , A. Karakorum was made by I.H. G RANT in 1898 from the ZANCHI and A. N ICORA in the Chillinji area. Some De - vicinity of the Baroghil Pass; the fauna was described vonian samples were collected by P. L E FORT during by REED (1911) as Early Devonian. HAYDEN (1915) in - the 1992 expedition. A. Z ANCHI made the geological sisted this fauna must have come from the vicinity of map ( ZANCHI & al . 2007) from which the geological Showar Shur and gave precise coordinates for the sup - sketches reproduced here are derived. In 1999 and posed locality. We were unable to duplicate the GRANT – 2004 respectively, Devonian outcrops around Baroghil REED fauna in that region nor in the Ribat Valley. were visited by participants of the IGCP 421 project Incidentally, the locality and surroundings of Showar and the PR01 Field Excursion of the 32 nd International Shur about 20 km to the east are (Text-fig. 3). Geological Congress ( GAETANI & al . 2004b). Results The first geological reconnaissance in the area may thus concerning the Devonian from the above expeditions have been made by HAYDEN (1915); it involved sam - have been published ( GAETANI 1997; GAETANI & al. pling the ridge immediately west of Gharil in front of 1996, 2004 a; TALENT & al . 1999; SCHRÖDER 2004; our Yarkhun River section but he seems not to have vis - HUBMANN &GAETANI 2007). ited Showar Shur. A poorly preserved spiriferid “from Soviet and Afghan geologists working in the 1970s the Baroghil Pass” was identified as Spirifer cf. medio - on the Afghan side of the Baroghil Pass ( KAFARSKIY & textus D’A RCHIAC & DE VERNEUIL (REED 1922), though al . 1974; KAFARSKIY &ABDULLAH 1976) reported a HAYDEN (1915) reported “badly preserved specimens Devonian sequence more than 1000 m thick in their of Spirifer … [that] may be Sp. Verneuili ” [= Cyrtospir - Tash Kupruk Zone near the village of Sarhad; their ifer ] “on the southern shore of a small lakelet at the data are summarized by ABDULLAH &CHMYRIOV southern end of the Dasht-i-Baroghil”. (1980).

Fig. 1. Index map of the Karakorum and surroundings regions. Acronyms: MMT – Main Mantle Thrusts, the boundary between Indian Plate and the Kohistan Arc; NKSZ – North Kohistan Suture Zone; RSZ – Rushan – Pshart Zone, the boundary between Central and South Pamir; WABZ – Wanch-Ak Baital Zone, the boundary between Central and North Pamir ACTA GFOLOGICA POLONICA VOL. 58 M. GAETANI & al. , FIG. 2

Fig. 2 . Simplified geological map of the Western Karakorum and Eastern Hindu Kush. Devonian rocks have been recognized in the Siru Gol/Lasht; Baroghil/Laskkargaz, and Karambar Thrust sheets to the north of the Reshun Fault and in the Chillinji/Axial Thrust sheets to the south of the Reshun Fault. Acronyms: Ba-P = Baroghil Pass, Ch-P = Chillinji Pass, KK = Khan Kun village; Ka-P = Karambar Pass;. Re-F = Reshun Fault, SJ-P = Shah Jinali Pass ACTA GFOLOGICA POLONICA, VOL. 58 M. GAETANI & al. , FIG. 3

Fig. 3. Baroghil–Ribat area (after ZANCHI & al. 2007 and in progress, simplified), with location of measured sections, isolated sample locality, and pictures (Text-figs 7, 10) THE DEVONIAN OF WESTERN KARAKORUM 263

MCMAHON & HUDLESTON (1902) were the first to mid- accretion of the Karakorum Block to draw attention to the Devonian around Kurāgh and the Pamir Blocks. The Tirich Boundary Zone is inter - Shogrām in Chitral, studied subsequently by HAYDEN cepted tectonically east of the Shah Jinali Pass by north - (1915), DESIO (1963, 1966), STAUFFER (1975) and es - east–southwest left-lateral strike-slip faults and the pecially by TALENT & al . (1982, 1999). This succes - Palaeozoic Wakhan and Misgar slates of the Wakhan; sion provides the framework for correlation through these are stacked directly against the Karakorum units. the present region. The faunas collected were illus - The North Karakorum Terrain includes several trated by REED (1922), SARTENAER (1965), VANDER - thrust sheets showing complex geometrical relation - CAMMEN (1965), SCHOUPPÉ (1965), TALENT & al . ships (Text-figs 2, 3 ). To the northwest, the Tash (1999) and FEIST & al . (2001). Kupruk Zone contains alkali basalts, tuffs and dolo - The aim of the present paper is to illustrate and stones bounded by shear faults. The dolostones are summarize the general stratigraphical and geological mildly metamorphosed and contain Devonian Tabu - setting of the Devonian successions measured and lata ( HUBMANN &GAETANI 2007). Devonian rocks are sampled during our field investigations. R. M AWSON present in at least three thrust sheets south of the Tash worked on the conodonts, and D. S CIUNNACH on sand - Kupruk Zone: the Siru Gol, Lashkargaz/Baroghil, and stone petrography. Brachiopod identifications are by Karambar thrust sheets (Text-figs 2 -5) . Southwards, a CHEN &TALENT (work in progress). major disjuncture is marked by the Reshun Fault (PUDSEY & al . 1985; ZANCHI & al . 1997, 2000) join - ing with the Upper Hunza Fault in the east, and ex - REGIONAL GEOLOGY tending for more than 200 km (Text-figs 1-3 ). The tectonic units south of this fault include locally pre- The North Karakorum Terrain, as defined recently crystalline basement and Palaeozoic– (ZANCHI &GAETANI 1994; GAETANI & al . 1996; ZANCHI Mesozoic sediments of reduced thickness. Devonian & al. 2000), consists of a thick, polyphase stack of rocks are mostly absent, but in the Chillinji Unit an al - thrust sheets lying north of the Karakorum Batholiths most complete Palaeozoic succession, unconformably (LE FORT &GAETANI 1998) ( Text-figs 1, 2 ). In the Chi - overlying pre-Ordovician intrusives, is exposed (Text- tral region, this terrain is separated from the East Hindu fig. 5). Kush–Wakhan by the Tirich Boundary Zone, a left-lat - The southern margin of the sedimentary units of eral shear zone including deformed ultramafic rocks the Northern Karakorum Terrain is intruded by Creta - (ZANCHI & al . 1997, 2000). These rocks record pre- ceous to Paleogene plutons, the Karakorum Batholiths

Fig. 4 . Location of the Siru Gol section and geology of the surrounding area 264 MAURIZIO GAETANI & al.

Fig. 5. Geological map of the Chillinji area (after ZANCHI & al . 2007 and in progress, simplified), with location of the measured section

(DEBON & al . 1987, 1996; DEBON 1995; DEBON & THE SEDIMENTARY SUCCESSION KHAN 1996; LE FORT &GAETANI 1998). The thrust sheets between eastern Chitral and the From bottom upward, we recognized the follow - upper reaches of the Karambar River consist mostly of ing units (Text-fig. 6): Palaeozoic sequences, and at minor extent Mesozoic, the youngest being Early in age, unconformably Vandanil Formation (here defined) overlain by the Cretaceous Reshun Conglomerate. This contrasts with the central and eastern side of the range This unit, identified only in the Karambar Thrust from the Chapursan Valley to the Hunza Valley and Sheet (Text-fig. 3) and measured along the southeast Shimshal Pass , where the thrust sheets include rocks not side of Ribat Valley above the summer meadows of older than the Permian ( GAETANI & al . 1990; ZANCHI & Vandanil [from which the name originates (Text-figs GAETANI 1994). From within a conglomerate of the Per - 7, 8)] is about 625 m thick. Its base is covered by scree, mian Gircha Formation along the western side of the though the underlying Baroghil Group slates crop out Yashkuk Glacier (see map in ZANCHI &GAETANI 1994), higher in the valley in the core of the anticline. Five we have found the colonial coral Aphyllum testifying to litho-intervals were identified, from bottom to top : the probable former presence of Devonian rocks in that area ( FLÜGEL 1995). Devonian tabulate corals were also 1. Grey, medium to thick-bedded limestone with par - found in debris on the north side of the uppermost Cha - allel lamination or gentle ripple marks. When thinly pursan Valley towards Irshad Owin An (HUBMANN & bedded, it has shaly interbeds; these may alternate GAETANI 2007). with thicker amalgamated beds. Bedding surfaces are THE DEVONIAN OF WESTERN KARAKORUM 265

Fig. 6. Stratigraphic subdivisions of Devonian rocks in the most complete thrust sheets: Karambar, Baroghil-Lashkargaz and Chillinji/Axial planar or gently wavy. They became slightly dolomi - brachiopods, corals, crinoids and nautiloids, all much re - tized upwards. Fossils (crinoid ossicles and brachio - crystallized and sheared. They are overlain by light grey pod fragments ) are rather abundant. Recrystallization dolostone, or partly dolomitized packstone in 30 -40 cm is substantial with fossil cavities filled by large cal - beds, overlain by thinner flattish-bedded dolomitic lime - cite crystals. In its uppermost part there are intervals stone still rich in crinoids. This unit is capped by metre- of well-rounded quartz grains up to 2 -3 mm in di - thick nodular amalgamated beds with ghosts of bioclasts ameter. Conodont samples proved to be barren. and some shaly intercalations. Thickness about 120 m. Thickness (base covered): at least 135 m. 5. Grey dolostone in 30 -50 cm beds alternating with mas - 2. Light grey dolostone with beds 20- 40 cm thick, sive dolostone forming mounds (up to 15 m thick in the totalling about 50 m. lower part ) built by dendroid to phaceloid colonies of ru - gosans, tabulates, and small stromatolitic mounds. Up- 3. Grey to dark grey calcareous siltstone, brownish when sequence the mounds, very rich in corals, are as much as altered, with intercalations of up to 20 m of well-bed - 3-5 m in thickness and are interbedded with thinner bio - ded, grey nodular limestone, slightly arenaceous, and clastic dolomitic limestones. Because of heavy recrys - with a few dolostone banks. This litho-interval is capped tallization, no sampling was undertaken. The mound by about 30 m of calcareous brownish slates with complex interfingers with thin-bedded grey crinoidal crinoids and deformed brachiopod fragments. Thickness limestone, forming along section intercalated packages is uncertain due to the broken slope, but about 150 m. 2-4 m thick. Thickness estimated to be about 170 m.

4. Grey nodular limestone with shaly interbeds, rich in Top: Chilmarabad Formation upper dolostone member. 266 MAURIZIO GAETANI & al.

Fig. 7. The Ribat section in the Karambar thrust sheet, with location of significant samples. For location see Text-fig. 3 (photo courtesy of A. ZANCHI )

Fossils and age to Pragian, sulcatus Zone, probably late sulcatus Zone (see: Taxonomic comments). Due to incipient metamorphism, the fossil content, The c. 200 m of sequence between (uppermost even when fairly abundant, is too poorly preserved for litho-interval 4 and litho-interval 5) failed to produce identification. Conodonts, though not in great abun - evidence of late Pragian through Emsian and Eifelian. dance, have been obtained from litho-intervals 3 and 4 Out of the section laterally, we found an isolated out - (samples CK 1019 and CK 1045). CK 1019 produced a crop very rich in corals and brachiopods (CK 1046, Text- single specimen of Pandorinellina steinhornensis miae fig . 7 ), thought to be a lateral equivalent of the thin BULTYNCK (Pl. 1, Fig . 10); it is indicative of an age-range bedded interfingerings observed in litho-horizon 5. of late in the sulcatus Zone to dehiscens Zone (Pragian- SCHRÖDER (2004) described from this sample the coral early Emsian). Conodonts from CK 1045 include Spongophyllum cf. sedgwicki (MILNE -E DWARDS & Ozarkodina excavata excavata (B RANSON &MEHL ) HAIME ), assuming a Givetian age for the top of the Van - (Pl. 1, Fig . 4), Oz. remscheidensis remscheidensis danil Formation . But caution is here called for; the genus (Z IEGLER )(Pl. 1 , Fig . 1) , an Sc element of Oulodus sp. Spongophyllum is long-ranging ( to Middle De - (Pl. 1 , Fig . 5), reminiscent of one published by PICKETT vonian) and the type species, S. sedgwicki , was based on (1980, fig. 12H) from a fauna now considered to be no material from a “pebble in a river bed”. Though a posi - older than sulcatus Zone, Pandorinellina steinhornen - tive indentification at species-level is not possible, the as - sis miae (Pl. 1, Fig. 2), an M element of Amydrotaxis sociated brachiopod faunule ( CHEN XIUQIN , pers. comm.) druceana (P ICKETT )(Pl. 1 , Fig . 3) , and Amydrotaxis n. of “ Spinatrypa ” spinosa chitralensis (R EED ) and species sp. (Pl. 1 , Figs 6, 7), a form identified from the Darling of Gypidula (Devonogypa ), Uncinulus , Nalivkinaria , and Basin, western New South Wales ( MATHIESON & al ., in Waiotrypa accords with an age close to the Givetian- prep.). The age-range indicated for this fauna is Early Frasnian boundary. Because this brachiopod faunule is Devonian; the last three conodont taxa refining the age characteristic for low in the Shogrām Formation, we are THE DEVONIAN OF WESTERN KARAKORUM 267

thus suggesting this isolated outcrop may be a slab of Shogrām Formation displaced by the glacier.

Chilmarabad Formation (GAETANI & al . 1996)

The unit is ubiquitous in all thrust sheets in which Devonian rocks are present. The type section, here de - scribed, was measured upwards on the slopes on the left side of the Yarkhun River from the locality known as Barboon (Text-fig. 9).

Fig. 9. Stratigraphic log of the type-section of the Chilmarabad Fig. 8. Stratigraphic log of the type-section of the Vandanil Formation Formation 268 MAURIZIO GAETANI & al.

Fig. 10. Package of tabulates, gastropods and bivalves in the dolostone member of the Chilmarabad Formation on the plateau east of Darwaz An at about 4400 m altitude (hammer for scale). (Photo courtesy P. L E FORT 1992)

Two members may be identified: light grey dolostone in thick, poorly-defined beds. At The lower dolo-arenitic member is characterized the top, the stromatolitic laminae are locally de - by significant terrigenous content, mostly arenitic but formed by tepee structures (Text-fig . 11). This mem - also microconglomeratic, interfingering with light ber is present in all thrust sheets; the dolostones of grey dolostone. This member may be present in all the Tash Kupruk Zone are similar to it. The thickness thrust sheets, including the Chillinji Thrust Sheet, but is 100 to 300 m. This last figure was estimated, not has not been encountered in the Karambar Thrust measured. Sheet. The terrigenous content occurs as grey to light brown, fine to coarse sandstone with dolomitic matrix in 10-100 cm beds, mostly with parallel laminations or gentle, low-angle cross-laminations. Siltstone interca - lations are thin. The lower part of this unit is about 80 m thick on Vidiakot Ridge where it consists of metre- scale packages of coarser conglomerate with angular to poorly rounded clasts of black chert up to 5-6 cm, and quartzose sandstone layers interbedded with grey (yellow when weathered) dolostone. These mostly lack obvious structures, occur in 20-40 cm beds, and are usually subordinate to the arenites and hybrid aren - ites. Total thickness of the member: 90-130 m. The upper dolostone member is monotonously dominated by light grey dolostone, usually in 20-50 Fig. 11 . The stromatolitic layers deformed by tepee structures, at the cm beds with parallel lamination, stromatolitic lam - top of the Chilmarabad Formation, are unconformably overlain by the inae, and local enrichments of tabulates, bivalves, coarse arenites and microcoglomerates of the Shogrām Formation. and gastropods (Text-fig. 10 ). Subordinate are coarse Ribat section. Ski stick for scale THE DEVONIAN OF WESTERN KARAKORUM 269

Fig. 12. Correlations and petrofacies through the measured sections of the Shogrām Formation. Extension of the coral bafflestone lithohorizon in indicated in grey 270 MAURIZIO GAETANI & al.

Sandstone petrography 2. The second litho-interval consists of fine arenites in thin to medium layers with faint parallel lamina - A single sandstone sample from the lower mem - tions, burrowed and containing rare bioclasts, cycli - ber (Chillinji section: CK 534) is a coarse-grained, cally overlain by bioclastic calcarenites (mostly moderately to poorly-sorted sublitharenite with little packstone) with parallel and high angle cross-lamina - plagioclase; volcanic, subvolcanic and cherty lithics tion. The cycles are several metres thick. The bioclas - represent over 7% of the sandstone framework. Phyl - tic layers may be very rich in fossils, especially losilicate pseudomatrix ( DICKINSON 1970) may repre - brachiopods and crinoids, but also coelenterates may sent the remnant of further, deeply-diagenized occur locally. Conodonts are extremely rare . Thick - sedimentary rock fragments ( to slate). ness: 90 to 120 or 130 m.

Fossil and age 3. Coral bafflestones usually form a single ridge in the landscape, rarely two as in the Border Ridge section. Fossils are rare in the peritidal dolostones and very They are commonly crowded with colonial rugosans, poorly preserved; only algae and tabulates have been tabulates, bryozoans and, in a minor way in the lower recognized in this unit ( HUBMANN &GAETANI 2007). part, also brachiopods. Coral colonies , up to 50 cm They are Pseudopalaeoporella ? sp., Thamnopora cf. high , may be preserved in life position. Unfortunately, longdongshuiensis DENG , Pachycanalicula ? sp., especially in the Ribat section, the pronounced re - “Caunopora” sp. They are consistent with a Middle crystallization prevents useful collections. Local in - Devonian age. terruption of sedimentation with lithified surfaces may It should be noted that on the Wakhan side in the be present. Thickness: from less than 10 up to 34 m. Darya-i-Baroghil catchment area, KAFARSKIY & al. (1974) and KAFARSKIY &ABDULLAH (1976) quote sev - 4. Nodular grey limestone in medium to thin beds, eral species of Rugosa and Tabulata of Early Devon - with increasing shaly intercalations and siltstone. Are - ian age. Further research should focus particularly on naceous limestone and bioclastic calcarenite with bra - the area around the Baroghil Pass on both sides of the chiopods also occur. Thickness: from 5 to 20 m. watershed, because that area seems to have better preservation of fossils than the Devonian carbonate 5. The uppermost litho-interval consists mostly of very rocks on the southern side of the watershed. fine terrigenous sediments (fine arenites, siltstones and shales ) with gentle parallel lamination and diffuse bur - Shogrām Formation ( DESIO 1963, 1966) rowing of Rhizocorallium type or with limonitized nod - ules, probably originally pyrite. Cross laminations are The formation is present in all sequences in which De - rarer. Rare occurrence of calcareous siltstone crowded vonian rocks are preserved. It corresponds broadly to with brachiopods (CK 1057). The thickness varies from intervals 10-19 of the Mount Shogrām section origi - less than 20 m up to 45 m. Transition upwards to the nally described by DESIO (1966). A standard succes - Margach Formation is gradual with almost complete sion for the Yarkhun and Karambar river basins disappearance of limestone intercalations following a appears to be as follows, from bottom to top (Text-figs basal package of 45 m of siltstones and fine arenites. 12, 13): Sandstone petrography 1. The unit invariably starts with a terrigenous package of 15 -35 m of conglomerates and coarse Twenty-three sandstone samples of this sand-rich grained arenites. Some sections exhibit only rather unit were quantitatively analysed. They range from homogeneous coarse arenites; others, such as the sublitharenites and subarkose/arkose to almost pure Ribat section, have 1 -2 m conglomerates chan - quartzarenites; grain size of the analysed samples nelling previous conglomeratic or arenitic layers. ranges from very coarse- to very fine-grained sand - High-angle cross-laminations arranged in festoons stone. Monocrystalline quartz is by far the dominant are common. In no case, however, is the base of the grain type. Only exceptionally, it displays resorption formation deeply cut into the dolostone of the embayments, indicating a volcanic origin. Polycry - Chilmarabad Formation . Pebbles, up to 8 cm in stalline quartz (Qp) also occurs, with a highly variable size, consist of white quartzite and angular black abundance that is positively correlated to sandstone chert clasts similar to those in the lower member grain size, although with low coefficients ( PEARSON ’s of the Chilmarabad Formation . r = 0.66, sign. lev. < 0.1%). Especially in fine-grained THE DEVONIAN OF WESTERN KARAKORUM 271 sandstones, however, anomalously high Qp content might represent an overestimate due to subgranulation of monocrystalline quartz ( CARTER & al . 1964) at grain boundaries under deep diagenetic conditions. Feldspars consist of plagioclase, commonly un - twinned (probably as an effect of diagenetic albitisa - tion) and alkali feldspar. A single occurrence of chessboard-albite was noted, pointing to diagenetic destabilisation of high-temperature alkali feldspar. Volcanic rock fragments (VRF) display felsitic and vitric structures; subvolcanic and plutonic rock frag - ments are comparatively rare. Sedimentary rock frag - ments are represented mainly by chert, occurring in low numbers throughout the unit, and by less common shale and siltstone fragments (TRF). Not a single car - bonate lithic (CE of ZUFFA 1980) was detected. Low- grade metamorphic grains are minor. Heavy minerals are restricted to an ultrastable zir - con-tourmaline (ZTR) suite, with minor rutile and very little detrital mica. Pseudomatrix ( DICKINSON 1970) and phyllosilicate to tectosilicate pseudomorphs are com - mon; they were partitioned between lithic grains (VRF or TRF) and feldspars depending on mineral associa - tion, apparent hardness (deduced from the degree of de - formation at grain boundaries) and relict crystal shape. Intrabasinal grains are restricted to rip-up clasts and “ghosts” of allochems, locally recognised as bioclasts (mostly represented by echinoderms, brachiopods and less commonly bivalves ). Despite pervasive diagenetic dolomitization, such carbonate intrabasinal grains (CI sensu ZUFFA 1980) retain their original calcite compo - sition in samples where their abundance is maximal (CK 546, CK 547, CK 554, CK 653). Primary pores were filled by epimatrix and syn - taxial cements, mostly quartzose, whereas secondary pores were filled by authigenic carbonates, ferroan carbonates and opaques. The sum of interstitial com - ponents in samples CK 556, 662, and 1041 exceeds the theoretically expected maximum for grain-sup - ported sands (48.8%); in the same samples, interstitial carbonates represent at least 9% of rock volume. This indicates partial diagenetic dissolution of framework grains and growth of authigenic carbonates in sec - ondary pores ( SCHMIDT &MCDONALD 1979). In those samples, quartz content in the QFL mode is probably overestimated, as sandstone composition tends to - wards “diagenetic quartzarenite” ( HARRIS 1989) due to higher mineralogical stability of quartz compared to feldspar and most lithic grains.

Fig. 13. View of the Yarkhun River section measured in the Shogrām Formation. The position of the problematic CK 718 sample is indicated 272 MAURIZIO GAETANI & al.

Fossils and age about the published identifications or the age inference (TALENT & al . 1999, p. 212 and fig. 4). Sample CK 374 The Shogrām Formation is the most fossiliferous from 1 m below CK 718 contains fragments of the unit of the Karakorum Devonian. icriodid forms also identified from CK 718; accord - The tabulate, rugosan, and brachiopod horizon at ingly it too is considered to be early Famennian in age. the base of the second litho-interval, contains Cyatho - The icriodid faunas from the Yarkhun River can be cor - phyllum afghanense (BRICE ), identified by SCHRÖDER related with the Kurāgh section samples KUR 21 to (2004), and the tabulates Alveolites hudlestoni REED KUR 24 ( TALENT & al. 1999). In these horizons, two and Heliolites ? sp. identified by HUBMANN in HUBMANN Famennian species make their first appearance: Icrio - & G AETANI (2007); these are consistent with a Givetian dus iowaensis iowaensis and I. alternatus mawsonae. age. Amongst brachiopods (CK 1013 , CK 1031, CK Associated with them are other species that cross the 1032, CK 1034) were identified : Schuchertella sp., Frasnian–Famennian boundary, principally I. alterna - Schizophoria striatula (S CHLOTHEIM ), Cupularostrum tus alternatus morph 1, I. homeomorphus , Polygnathus koraghensis transiens (R EED ), Nymphorhynchia sp. brevilaminus OVNATANOVA , P. politus OVNATANOVA (= nov., Athyris asiatica REED , Athyris triplesioides P. pacificus ) and P. webbi STAUFFER . This interval, iso - OEHLERT , Douvillina dutertrei (M URCHISON ), Ambo - lated by debris from other parts of the Yarkhun River coelia asiatica REED , Rugosatrypa sp. section (Text-fig. 13 ), is biostratigraphically anom - In the second litho-interval, several layers are rich alous, raising the question of a possible fault-slice. in brachiopods and also contain rugosans such as Coral bafflestones of the third litho-interval have Siphonophrentis sp. A, Siphonophrentis sp. B, Enal - produced rugose and tabulate faunas of broadly Frasn - lophrentis ? sp., Endophyllum sp., Spinophyllum sp. cf. ian aspect: Pseudopexiphyllum occultum SCHRÖDER , varioseptatum (SPASSKY ), Spinophyllum ? shogra - Hexagonaria sp., Argutastrea sp., Tryplasma ? sp., mense SCHRÖDER , Spinophyllum sp., Keriophyllum Disphyllum cf. caespitosum caespitosum (GOLDFUSS ), sp., Stringophyllum acanthicum FRECH , Macgeea cf. and Disphyllum sp. described by SCHRÖDER (2004). gallica gigantea BRICE & R OHART , Phillipsastrea cf. HUBMANN in HUBMANN &GAETANI (2007) described orientalis SMITH , Pseudozaphrentis sirius SCHRÖDER , Thamnopora grandis DUBATOLOV , Thamnopora cf. Macgeea cf. multizonata (REED ), Macgeea ? sp., Dis - reticulata (BLAINVILLE ) and Alveolites hudlestoni phyllum caespitosum lazutkini (IVANIJA ), Hexagonaria REED . Amongst brachiopods are identified (CK 377, cf. sanctacrucensis MOENKE , Hexagonaria sp. B, CK 1051, CK 1052 ) Schizophoria striatula , Schucher- Hexagonaria sp. C. or tabulates such as Pachy - tella sp., “Spinatrypa” spinosa chitralensis , Spina - favosites polymorphus (GOLDFUSS ). Amongst bra - trypa sp., Waioatrypa sp. , Nymphorhynchia sp. nov., chiopods (CK 1040, CK 1041, CK 1044, CK 1046, Tabarhynchus ? pamirica (R EED ), Tenticospirifer CK 1048, CK 1049 , Text-fig. 14 ) are Schizophoria triplisinosus , and Ambocoelia asiatica . striatula , Costatrypa sp., Rugosatrypa sp., “Spina - The fourth litho-interval is still Frasnian in the trypa” spinosa chitralensis , Waiotrypa sp., Gypidula lower part with conodonts Icriodus alternatus alter - (Devonogypa) sp. , Sinotectirostrum ? sp. , Uncinulus natus , morph 2 and Polygnathus decorosus STAUFFER sp. nov. , Nalivkinaria sp. nov. , Athyris triplesioides , (Yarkhun River section, sample CK 1012). According Ambocoelia asiatica , Cyrtospirifer verneuili (G OSSE - to ZIEGLER &SANDBERG (1990), I. a. alternatus first LET ), Tenticospirifer triplisinosus (G RABAU ). occurs at or just above the start of the Late rhenana In the Yarkhun River section (Text-fig. 13) , TAL - Zone. The range for P. decorosus given by JI & ENT & al . (1999) identified Icriodus conodont faunas of ZIEGLER (1993) is from within the disparilis Zone early Famennian age from samples CK 374 and CK through to the linguiformis Zone; BARSKOV & al. 718. Sample CK 718, collected 104 m above the base (1991) suggest the range, in recent zonal terminology, of the Shogrām Formation, was dated as being early to be from the triangularis to rhenana zones. Co-oc - Famennian (from mid triangularis Zone to mid crep - currence of the two forms in question indicates prob - ida Zone) on the basis of co-occurrence of I. a. alter - able Late rhenana Zone. The presence of atrypid natus BRANSON &MEHL morph 1, Icriodus alternatus brachiopods above this sample (Text-fig. 13 ) is con - alternatus BRANSON &MEHL , morph 2 , I. a. mawsonae sistent with this allocation. The following brachiopods YAZDI , I. homeomorphus MAWSON , I. iowaensis were identified (CK 1022, CK 1023, CK 1026, CK iowaensis YOUNGQUIST &PETERSON , and I. i. ancylus 1057, CK 10 62): Douvillina dutertrei, Rhipidomella ? SANDBERG &DREESEN . These identifications and the sp., Exatrypa sp., Planatrypa sp. nov., “Spinatrypa ” inferred age were confirmed by colleagues Gilbert spinosa chitralensis , Spinatrypa sp., Radiatrypa sp. , KLAPPER and Charles SANDBERG ; we have no doubt Gypidula (Gypidula ) sp. nov., and Athyris asiatica . THE DEVONIAN OF WESTERN KARAKORUM 273

Margach Formation (GAETANI & al . 2004a) 2. Dark grey to black splintery siltstones and slates with bioturbated horizons and rare arenitic intercalations This recently described unit is briefly summarized. with dish-and-pillar structures. Thickness: 118 m. Three litho-intervals were discriminated in the type- section in the Ribat valley, from bottom to top : 3. Fine- to very fine-grained arenites in 20-40 cm beds, locally displaying parallel lamination, dominate 1. Dark grey to dark green splintery siltstones inter - in the lower part. Coarser arenites, also displaying mi - calated with thin-bedded arenites, rarely with parallel croconglomerate lags and erosional channels, tend to laminations; intercalations of bioclastic limestones predominate upwards. Asymmetric ripple marks indi - bearing brachiopods and crinoid fragments are rare; cate progradation from S to N. Bioturbation is more the sequence includes a single 0.5 m bed with Recep - common in the thinner bedded arenites; hybrid bio - taculites cf. chardini . Thickness: 92 m. calcarenites and biocalcirudites are also present. Thickness: 84 m.

Sandstone petrography

Two samples from the Chillinji section (CK 564- 565) are coarse to very coarse-grained, moderately to poorly-sorted quartzarenites with very few feldspars (both plagioclase and K-feldspar) and felsitic volcanic, cherty and silty lithics. Heavy minerals are restricted to an ultrastable ZTR suite, while interstitial con - stituents are epimatrix, syntaxial quartz cement and authigenic dolomite in variable proportions.

Fossils and age

Receptaculites cf. chardini NITECKI & L APPARENT , a form of a group of green algae which appeared in the Early Ordovician and disappeared in the Permian was collected in the Ribat section (CK 1066) ( HUB - MANN &GAETANI 2007). No fossils were discovered in the second litho-interval, but in the third litho-interval a small brachiopod assemblage with Parallelora aff. subsuavis (PLODOWSKI ), Rhipidomella sp., and Rhyn - chopora sp. accords with an early middle Tournaisian age ( GAETANI & al . 2004a).

Tash Kupruk Zone ( KAFARSKIY & al . 1974)

The only comprehensive geological study of the Wakhan corridor is an internal report by KAFARSKIY & al . (1974) undertaken during the Soviet–Afghan coop - eration programme. Their data were summarized by KAFARSKIY &ABDULLAH (1976) and by ABDULLAH & CHMYRIOV (1980) in their comprehensive books and maps on the geology of Afghanistan. KAFARSKIY con - sidered all sedimentary rocks cropping out south of the Wakhan slates and crystalline rocks to belong to his Tash Kupruk Zone which, in fact, includes the entire Northern Karakorum Terrain. GAETANI & al . (1996) adopted this term, restricting its meaning to the belt Fig. 1 4. Range of brachiopods in the Ribat section with dolostones and volcanics outcropping extensively 274 MAURIZIO GAETANI & al. a few km north of the Baroghil Pass. We did not have to thorough greenschist-facies recrystallisation. Sam - access to this area but from the Pakistan–Afghan bor - ples analysed plot in an alkaline to peralkaline field of der we could identify the succession illustrated in Text- basalts to latibasalts ( DEBON &LE FORT 1988). Trace fig. 7 of KAFARSKIY ’s report (1974). Our Tash Kupruk elements and REE support these alkaline features. The Zone is thus only part of the complex of thrust sheets high Zr, Nb and La ( LE FORT in GAETANI & al. 1996) that forms the Northern Karakorum Terrain. This compare well with oceanic island basalts (OIB, e.g. tectonostratigraphic unit contains the following prin - PEARCE & NORRY 1979) and other alkali basalts from cipal rock units on the Pakistan side of the border: continental rifting situations (e.g. BARBIERI & al . 1975). Very high Cr and Ni contents testify to a man - 1. Grey yellow dolostone in thick to massive beds, tle source. usually heavily dolomitized (with boudinage “fishes”), aggregating about 100 m in thickness. Lo - cally and especially in the area north of Inkip on the SANDSTONE PETROFACIES AND PROVENANCE: eastern flank of the Kushrao valley, and to a lesser de - PALAEOTECTONIC IMPLICATIONS gree along Khan Kun Gol at an altitude about 4000- 4100 m, ooidal dolostones, with stromatolitic laminae , Although the studied sandstones from the sparse tabulates and bryozoans were collected. B. Chilmarabad, Shogrām and Margach formations are HUBMANN in HUBMANN &GAETANI (2007) identified invariably quartz-rich, vertical trends of sand miner - Celechopora devonica (SCHLÜTER ) suggesting a alogy allowed us to recognise three distinct petrofa - Givetian age. The dolostones on the Pakistan side are cies in the studied population of 26 samples, based on intimately associated with dark green tuffs and lavas, standard QFL modes ( DICKINSON 1970; Text-fig. 15 ). but contacts are sheared in the area we studied. The three petrofacies characterise regularly super - posed petrologic intervals as originally defined by 2. Other rock units are represented by volcanics DICKINSON & R ICH (1972). (spilites) which, petrographically, are extremely al - tered with a dirty assemblage of quartz-albite- The Quartzo-lithic Petrofacies Dv1 (n = 12) is de - chlorite-amphibole-epidote-sphene and opaques, due fined by detrital modes Q = 93.5±5.5, F = 2.5±2.4, L

Fig. 15. Provenance fields and petrofacies distribution in the Devonian sandstones of the Western Karakorum. Due to consistently quartz-rich composition of sandstones, only the upper part of the QFL triangle ( DICKINSON 1985) is displayed (baseline at Q = 65) THE DEVONIAN OF WESTERN KARAKORUM 275

= 4.0±3.7; sublitharenites are the dominant sandstone sensu FOLK 1974). Alternative explanations are less type. Quartz is mostly monocrystalline (C/Q = 10 ± viable: control by grain size on feldspar abundance, 10%), whereas feldspar is mostly represented by pla - although expected theoretically ( ODOM & al . 1976), is gioclase (P/F = 90 ± 20%); volcanic rock fragments not significant (r = – 0.46); rather, feldspar concentra - are widespread, but subordinate relative to other sed - tion might be due to hydraulic selection of feldspar in imentary lithic types (V/L = 30 ± 30%). Carbonate in - shelf settings ( IBBEKEN & S CHLEYER 1991). However, trabasinal grains (CI; in the present case study, the abundance of lithic grains is not correlated with bioclasts from benthic communities) are abundant grain size (r = – 0.13), so the concurrent increase of only at definite stratigraphic intervals. Petrofacies Dv1 feldspars and lithics in Petrofacies Dv2 can be re - characterizes a petrologic interval including the garded as a true provenance signal. Chilmarabad Formation and the first (basal) litho-in - The story that sandstones tell us is intriguing. After terval of the Shogrām Formation as described above. the initial stage of block-faulting that caused recycling The Litho-feldspathic Petrofacies Dv2 (n = 5) is de - of Early Palaeozoic to sedimentary rocks fined by detrital modes Q = 83.0±9.0, F = 11.2±8.9, L = (seemingly associated with some volcanic activity ) a 5.8±2.5; subarkoses are the dominant sandstone type. second stage of block-faulting during the Givetian in - Quartz is mostly monocrystalline (C/Q = 10±0%), while volved the newly-emplaced volcanic successions. feldspar is represented by both plagioclase and K-feldspar Topographic trends towards more subdued relief char - (P/F = 60±30%); volcanic rock fragments are more abun - acterised sand accumulation during the Frasnian-Fa - dant than other sedimentary lithic types (V/L = 60±50%). mennian, resulted in mineralogically stable and CI’s are abundant only at definite stratigraphic intervals. texturally submature sediments. Such a trend was in - Petrofacies Dv2 characterizes a petrologic interval terrupted by a major rift unconformity within the Tour - roughly corresponding to the second litho-interval of the naisian part of the Margach Formation (when Shogrām Formation as described above. micaceous subarkoses were deposited ), pointing to first-cycle contributions from uplifted crystalline The Quartzose Petrofacies Dv3 (n = 9) is defined by rocks and thus to a deeper level of rift-related crustal detrital modes Q = 95.6±5.0, F = 2.5±3.2, L = 1.9±2.2; dissection ( GAETANI & al . 2004a). A locally deep dia - quartzarenites are the dominant sandstone type. Quartz genetic overprint partially obscured the already de - is mostly monocrystalline (C/Q = 10±0%); feldspar is scribed petrographic signals. mostly represented by plagioclase (P/F = 90±30%); vol - canic rock fragments are widespread, but subordinate relative to other sedimentary lithic types (V/L = PALEOENVIRONMENTAL EVOLUTION 30±40%). Both carbonate and non-carbonate intrabasi - nal grains are rare. Petrofacies Dv3 characterizes a petro - The palaeogeographic scenario for the Devonian logic interval including the upper two litho-intervals of of the NW Karakorum is that of a marine coastal shelf the Shogrām Formation as described above, plus the on which carbonate sedimentation gradually became lower member of the overlying Margach Formation dominant over the poorly oxygenated muddy flats of Since Petrofacies Dv1 and Dv3 are defined by the Vidiakot Formation (Baroghil Group). There was similar detrital modes, the corresponding petrologic not complete cessation of terrigenous input. This, intervals can be distinguished with confidence mostly episodically, became coarser, reaching microcon - due to the interposition of sandstones characterised by glomerate-scale. The occurrence of terrigenous com - Petrofacies Dv2. pared with carbonate sedimentation also varies In terms of provenance, the studied sandstones between the different thrust sheets, being generally consistently point to a scenario of limited tectonic in - more abundant and coarser in the most southern and version and shallow dissection of older sedimentary western sheets, but rarer and finer in the Karambar basins filled up by terrigenous and cherty sediments, Sheet, one of the higher structural elements. Accurate as well as of volcanic successions that might be age identifications are scanty and therefore correla - penecontemporaneous with the sedimentation. From tions between sheets are tentative. Also it should be the stratigraphic reconstruction here proposed, such kept in mind that, south of the Reshun Fault, Devon - volcanic successions might be found in the Tash ian rocks are exposed expecially in the Chillinji Anti - Kupruk Zone. Relative abundance of feldspar, char - cline. Along the Axial Unit , usually the Permian acterising the Litho-feldspathic Petrofacies Dv2, Gircha Formation unconformably overlies the might be interpreted as the result of more pronounced Baroghil Group and only few sparse outcrops of block-faulting in the drainage basin (“tectonic arkose” Shogrām Formation are preserved . 276 MAURIZIO GAETANI & al.

The Early Devonian saw the onset of very shallow- at least in part under alluvial conditions, with chan - water carbonate factory environments over most of the nels and cross-laminated festoons. The Tash Kupruk area. Occasional intervals of submature terrigenous volcanics might be linked to this early rifting episode. clastics (quartz and black cherts) interfinger with the The sea gradually transgressed once more, initially carbonates; the latter were often later transformed into with marginal mixed carbonate–clastic facies, then with dolostones. Noteworthy is the well-sorted nature of the prevailing packstone; grainstone sediments rich in bio - clastic bars and the absence of mud. Apparently the clasts were rare. The benthic invertebrate community coastal flats were not favourable for benthic inverte - was dominated by brachiopods, sometimes in gregari - brates; stromatolitic laminae occur occasionally. Only ous patches or accumulated by bottom currents in lenses in the Karambar Sheet is more diversified life present: along the shelf. On well-washed, clean bottoms during solitary and colonial corals, brachiopods, and crinoids. the Frasnian, corals and bryozoans flourished, building In this structural unit, clastics are much reduced with a thick bindstones and bafflestones. Fine terrigenous few metres richer in quartz grains and some shaly in - input gradually recovered during the Frasnian. During tercalations in litho-intervals 3 and 4 of the Vandanil the Famennian, the area received coarser inputs of aren - Formation. It is difficult to discriminate if the clastic ites, mostly litharenites, with carbonate sedimentation input was linked to erosional pulses connected with eu - becoming subordinate. Age-control for the Famennian static cycles or to incipient tectonic activity along the is poor. Around the Devonian– boundary, passive margin of the Northern Karakorum. the Margach Formation records sedimentation on a The terrigenous inputs gradually diminished or muddy shallow-marine flat, with significant terrigenous even disappeared during the Middle Devonian; a wide input under low-energy conditions, mainly sheltered peritidal carbonate platform spread over the area, with from waves. No significant emersion was detected. No local ponds and shoals. Small and patchy tabulate ironstones were noted, though these are present in the mounds (Text-fig. 12 – Chilmarabad Formation in the Kurāgh Spur and Mt. Shogrām sections in Chitral ( TAL - Lashkargaz Sheet) and a larger rugose/tabulate mound ENT & al . 1982, 1999; KLOOTWIJK &CONAGHAN 1979). (litho-interval 5 of the Vandanil Formation) devel - A general increase in energy was observed at the be - oped. Age-control at this level is difficult; the correla - ginning of the Carboniferous ( GAETANI & al . 2004a) tions are very tentative. with traction currents, erosional channels and coarser- During the Givetian a very important rifting event grained detritus documenting a general forestepping of occurred over a wide area. The carbonate platform more proximal facies. [homogeneous under peritidal conditions (bedded stromatolitic dolostones) ] rifted and emerged. On the shoulder of the rift, quartzitic rocks (like the pre-Or - PALAEOGEOGRAPHY AND REGIONAL dovician Chikar Quartzite) and again dark cherts from CORRELATION an unknown, possibly Pre-Cambrian sedimentary unit, were vigorously eroded. This early stage of block- Wakhan faulting did not, however, exhume micaceous crys - talline basement units; these were unroofed during The Devonian succession on the northern side of the deposition of the upper member of the Margach For - Baroghil Pass was described by KAFARSKIY & al . (1974) mation , already well into the Carboniferous ( GAETANI and KAFARSKIY &ABDULLAH (1976); their data are sum - & al . 2004a). A blanket of terrigenous sediments, 10 marized in ABDULLAH &CHMYRIOV (1980). At least part to 30 m thick, spread over the entire area, deposited of that area is to be included in our Lashkargaz-Baroghil

Fig. 16. Palaeogeographic cartoon for the Early–Middle Devonian in Western Karakorum. Outpouring of the Tash Kupruk volcanics is inter - preted as linked to Givetian rifting. The Charun Quartzite was not discriminated in the Upper Yarkhun area, but the doloarenitic member of the Chilmarabad Formation and especially the basal beds of the Shogrām Formation could be its distal equivalents THE DEVONIAN OF WESTERN KARAKORUM 277

Thrust Sheet. The lower part of the section, up to 800 m was from this section that KLOOTWIJK & CONAGHAN thick, consists of massive limestone with rugosan and (1979) and KLOOTWIJK & al . (1994) endeavoured to tabulate corals of Early Devonian age, overlain by alter - obtain palaeomagnetic data. nating fine terrigenous sediments and limestones, tenta - tively regarded as Middle Devonian. The Frasnian part of Peshawar area the section consists mostly of limestones, c. 360 m thick with two coral horizons. The Devonian rocks are overlain In the Khyber region, MOLLOY & al . (1997) docu - by Lower Carboniferous rocks with an erosional contact. mented a section with a quartzarenitic unit at the base It should be noted that the faults we trace on the Pakistan overlain by a siliciclastic-carbonate sequence. The side are not recognized on their map and sections, and base of the latter is thought to be Givetian (with abun - what is mapped by them as a granitoid of Late dant colonies of the rugose coral Phillipsastraea ) age, on the Pakistan border corresponds to a light massive passing upwards through Frasnian and Famennian limestone of Permian–Triassic age (LEVEN & al . 2007) . horizons into the early Tournaisian. An even better se - Looking from the border, part of the Devonian-Car - quence occurs at Ghundai Sar on the eastern margin of boniferous section belongs to our Tash Kupruk Zone. the Khyber ranges overlooking the Peshawar Basin; Reinvestigation of this section is very important. only one horizon has been acid-leached, producing ex - pansa Zone Famennian conodonts. The Devonian se - Chitral quence (Nowshera Limestone) at Nowshera within the Peshawar Basin has been shown to span the Silurian– Though Devonian rocks are not particularly well Devonian boundary and extend up to within the Em - preserved around the Karakorum, correlation of se - sian ( MAWSON & al . 2003) before giving way to quences in the Upper Yarkhun area with the classic quartzites that bring to mind the Charun Quartzite of succession in Chitral is obvious ( HAYDEN 1915; DESIO Chitral. Sampling a scatter of localities from carbon - 1966; STAUFFER 1967, 1975; TALENT & al . 1982, ates in siliciclastic-carbonate sequences in the Pan - 1999). Two sections are most interesting: Mt. jpir–Swabi–Jafar Kandao–Rustam area on the NE Shogrām and the especially fossiliferous Kurāgh Spur. margin of the basin has indicated a broad spectrum of The first was briefly described by DESIO (1966), the ages extending through the Devonian into younger last by HAYDEN (1915) and described in detail by TAL - horizons ( POGUE & al . 1992; AHMAD & al . 2001). ENT & al. (1999). The base of both sections has not been described in detail, but the lower part consists of Afghanistan alternating dolostones and quartzarenites named the Charun Quartzite by STAUFFER (1967, 1975). Devonian rocks are present in several tectonic The Charun Quartzite may be compared with the zones of Afghanistan; two of them are relevant for the lower doloarenitic member of the Chilmarabad Forma - present paper: tion with which it shares similar sandstone composition of the interbedded arenites, but the environments of Central Badakshan (ABDULLAH & C HMYRIOV 1980) deposition appear to be different. P. C ONAGHAN (pers. comm. 2005) believes that at least the lower part of the The Early and Middle Devonian are characterized Charun Quartzite was deposited by turbidity currents by about 600-700 m consisting of massive limestones and therefore represents a deeper environment. We have and dolostones; some arenitic and shaly intercalations not found evidence of deposition of the Chilmarabad occur in its lower part. This succession is uncon - Formation under deep conditions in the Upper Yarkhun formably overlain by a Frasnian complex up to 400 m area. In the Mt. Shogrām section, DESIO (1966) de - thick of dolostones, platy limestones, shales and silt - scribed up to 160 m of limestone below the stones. A distinctive horizon of quartzarenites occurs quartzarenitic and microconglomeratic beds (Charun at their base. The overlying Famennian is represented Quartzite) that could be tentatively aligned with the by up to 350 m of a mixed succession of sandy–shaly Vandanil limestones. This warrants closer investigation. sediments and limestones with abundant brachiopods. The base of the Shogrām Formation is Givetian The succession is similar to that of the Central Pamir. (varcus conodont zone) on the Kurāgh Spur section (TALENT & al . 1999) as well as in our study area. How - Helmand ever, the arenitic and microconglomeratic basal litho- interval is absent in the Kurāgh section and the coral The Helmand Block (Montagnes Centrales of assemblage is somewhat different ( SCHRÖDER 2004). It French authors; South Afghan Middle Massif of So - 278 MAURIZIO GAETANI & al. viet authors) was studied extensively by French and tered in the Central Pamir ( KARAPETOV 1963, 1971; German missions to Afghanistan ( BLAISE & al . 1977; BARDASHEV &BARDASHEVA 1999; SCHRÖDER & DÜRKOOP 1970; PLODOWSKI 1970, and references LELESHUS 2002). Succeeding the Upper Silurian, repre - therein) and under the Soviet–Afghan Cooperation sented by dark limestones, the Devonian is mostly cal - Programme ( ABDULLAH &CHMYRIOV 1980). The De - careous with spectacular Middle Devonian reefoidal vonian crops out extensively and was subsequently de - facies up to 1300 m thick. From the late Givetian up - scribed by MISTIAEN (1985) , who grouped it in the wards, terrigenous input recurs sporadically, becoming “Zone de Tezak-Nawar”. ABDULLAH &CHMYRIOV significant in the late Famennian. In the thrust sheets (1980) instead discriminated three zones : Tirin, Logar along the Ak Baital zone, KARAPETOV (1963, 1971) de - and Argandab zones respectively. scribed more than 200 m of dolostones of Frasnian age In the Tirin Zone (equivalent to the “bordure nord overlain by limestones passing into marly limestones et nord-ouest du bassin” of BLAISE & al . 1977) only and marls in the Famennian, separated by an unconfor - the Upper Devonian is present, with the Frasnian mity from the overlying red platy limestone of Tour - transgressive onto various Silurian, Ordovician or naisian age. There are significant analogies with the even Precambrian sequences. The rocks are mostly Northern Karakorum Terrain, especially with the calcareous with quartzarenitic intercalations. Karambar unit, with dark limestones in the Early De - The Logar Zone corresponds to the area of Toyka- vonian, thick reefoidal dolomitized Middle Devonian Dewal of MISTIAEN (1985), and contains the most com - and an unconformity in the Givetian. plete successions. The entire Lower and part of the Middle Devonian are mostly terrigenous, with the “For - NW Himalaya mation quartzo-dolomitique de Ghujurak ” recalling the doloarenitic member of the Chilmarabad Formation of The classical Devonian succession of the NW Karakorum. These Afghan successions are overlain by a Himalaya, i.e. Muth Quartzite overlain by the Lipak widespread calcareous succession, several hundred me - Formation, has been recently recalibrated in age by tres thick, the “ Formation des calcaires massifs de DRAGANITS & al . (2002). It is interpreted as a coastal Bokan ” which recalls the ubiquitous dolostone member shelf with barrier island quartzarenites (Muth of the Chilmarabad Formation of Karakorum. Mixed Quartzite), gradually ingressed by a shallow sea carbonate–terrigenous successions overlie the Bokan with mixed calcareous/fine terrigenous sedimenta - Formation, recalling the Shogrām Formation of Karako - tion (Lipak Formation). The Lipak transgression oc - rum–Chitral, but several different erosional surfaces are curred during the Givetian at approximately the present in the Givetian and Frasnian of Helmand, and same time as the similar transgression in the Karako - not a single more pronounced Givetian unconformity, rum/Chitral. DRAGANITS & al. (2002) documented a as in Karakorum. The reappraisal of the prevailing ter - gap in the Frasnian of the Himalaya, an interval that rigenous sedimentation occurs in the middle Frasnian has instead a sedimentary record in the Karakorum. and extends to the Famennian with the “ Formation des encrinites ferrougineuses de Ko-e-Giru ”, rich in Recep - taculites . A correlation to the Margach Formation of PALAEOGEOGRAPHIC INTERPRETATION Karakorum is suggested ( MISTIAEN 2008, pers. comm.). However, the onset of the Margach Formation is grad - The North Karakorum Terrain during the Devon - ual and not abrupt as in the Dasht-e-Nawar area. ian was apparently linked to neighbouring, though The Argandab Zone is characterized by a thinner now-dispersed, blocks forming a wide, gently subsid - thickness of mostly terrigenous sediments with fre - ing platform. During a time span (roughly Early De - quent calcareous intercalations in the Middle Devon - vonian to Givetian) a wide shallow carbonate platform ian. A significant unconformity lies between the lower dominated in Central Badakshan, Central Pamir, and upper Frasnian, with an overlying succession of Karakorum and Chitral. Add to these the NW Hi - up to 800 m of conglomerates and arenites with spo - malaya, interpreting the Karakorum and NW Hi - radic calcareous intercalations. malaya as parts of the same passive margin, with a more external, salient and subsiding section in the Central Pamir Karakorum and a more inner-shelf section in the NW Himalaya, more prone to intermittent emersion and Devonian rocks are not known from the eastern sedimentary gaps. The platform periodically received Hindu Kush, southeast Pamir and its extension to the SE inputs of ultra stable clastics, increasing towards Chi - in Shaksgam Valley. Instead Devonian rocks are scat - tral. Central Afghanistan (the Helmand/Dasht-e- THE DEVONIAN OF WESTERN KARAKORUM 279

Nawar region) had a more diversified pattern with the Gondwana Supercontinent. It represents the gradual more intense erosion and subsidence, but also there onset of carbonate sedimentation over a wide structural the massive carbonates spread during the late Early platform in shallow to very shallow conditions. Peritidal and Middle Devonian . carbonates, early transformed into dolostone, were lo - During the Givetian the structural platform under - cally interrupted by mounds and reefs built by stroma - went emersions and gentle tectonics interpreted as the tolites, rugose and tabulate corals. The more complete initial episode of rifting, disrupting the wide platform. and thicker successions accord with an increase in area The volcanic episode of the Tash Kupruk Zone should and subsidence (approximately northwards according to be linked to this extensional activity, even though its pre - present coordinates ) extending to higher structural ele - cise timing is not yet determined. The age of the uncon - ments. During the Givetian mild tectonic activity led to formity is apparently slightly younger in the Central emersion and erosion of the carbonate platform, with Pamir. The arenitic composition also shows a shift from fluviatile sedimentation and clastic input from the rift stable sublitharenites to ultrastable quartzarenites within shoulders. The lava flows and tuffaceous intervals of the Petrofacies Dv1, deriving lithics from a shallow-crustal Tash Kupruk Zone are interpreted as reflecting accu - section (older sedimentary successions to low-grade mulation in a graben of the rift system. Gradual spread - metamorphic basement) including some volcanics. ing of marine conditions connected with an increased Erosion of the rift shoulders during the Frasnian rate of subsidence occurred during the Givetian, though generated an influx of litho-feldspathic material to the with intermittent terrigenous inputs continuing during passive margin where it mixed with the important car - the Frasnian with development of coral bafflestones. The bonate production, with coral boundstones and shelly reduced carbonate productivity in the Famennian, cou - accumulations with brachiopods. A crisis in the car - pled with more intense erosion, produced fine to very bonate factory during the Famennian reduced the im - fine terrigenous sedimentation on the marine shelf. portance of the carbonate accumulations. Gaps, About the Devonian–Carboniferous boundary, poorly ironstone horizons and/or more shaly input due to the oxygenated muddier conditions prevailed. demise of the initial rift shoulders, characterized the final stage of the Devonian. The subsequent rifting and spreading during the Car - TAXONOMIC COMMENTS ON CHRONOLOGI - boniferous–earliest Permian, leading to the opening of CALLY SIGNIFICANT CONODONTS FROM THE Neo-Tethys separated these previously closely-juxta - WESTERN KARAKORUM (by Ruth MAWSON ) posed areas, driving the Peri-Gondwanan Fringe towards the Asian margin, away from the remnant Devonian se - quences on the Gondwana side of the NW Himalaya. Order Ozarkodina DZIK , 1976 The meaning of the Givetian unconformity and Family Icriodontidae MÜLLER &MÜLLER , 1957 onset of erosion on the rift shoulder during the Frasnian Genus Icriodus BRANSON &MEHL , 1938 should be interpreted as echoing opening of a sea-way (Palaeo-Tethys in METCALFE ’s 1996 and 1999 termi - TYPE SPECIES : Icriodus expansus BRANSON & nology) far to the east. It should be noted that this ex - MEHL , 1938. tensional activity took place on blocks that drifted away subsequently, during the Permian, such as the Karako - rum and Central Pamir, both lying to the north of the Icriodus alternatus alternatus BRANSON &MEHL , 1934 future passive margin of the Indian Plate in the NW Hi - (Pl. 1 Fig. 9) malaya. This indicates that the opening of Neo-Tethys occurred to the south of Karakorum (in present coordi - REMARKS : In their study of Late Devonian icriodon - nates) . According to the STAMPFLI & al. (1991) model, tid biofacies, SANDBERG &DREESEN (1984, p. 158) Karakorum was therefore situated on the lower plate or designated two morphs of this subspecies, Morpho - at the extreme boundary of the upper plate, later drift - type 1 with laterally compressed medial-row denticles, ing away on the lower plate . and Morphotype 2 with rounded medial row denticles. The specimen from CK 718 illustrated herein has rounded medial-row denticles that, in line with SAND - CONCLUSIONS BERG &DREESEN ’s (1984) argument is an example of Morphotype 2. According to ZIEGLER &SANDBERG The Devonian succession of the Western Karakorum (1990), I. a. alternatus first occurs at or just above the represents a fragment of the former passive margin of beginning of the Late rhenana Zone. 280 MAURIZIO GAETANI & al.

Genus Oulodus BRANSON & MEHL , 1933 Amydrotaxis sp. nov. (Pl. 1, Figs 6, 7) TYPE SPECIES : Cordylodus serratus STAUFFER , 1930. REMARKS : A single Pa element of a new species of Amydrotaxis occurs in the fauna from CK 1045. It is Oulodus sp . distinguished by having a single row of low, stubby (Pl. 1, Fig . 5) denticles with those posterior to the basal cavity being lower than those above and anterior to the restricted REMARKS : From faunas, now recognised as re - basal cavity lobes that expand at mid-length and tend ferrable to the sulcatus Zone ( MATHIESON & al ., in to be swept forwards towards the anterior of the unit. prep.), PICKETT (1980, text-fig. 12H) illustrated an The nature and step-like arrangement of the stubby Sc element of Oulodus with a close resemblance to denticles and the deep, clearly defined basal cavity sep - the element illustrated herein as Pl. 1, Fig . 5. As with arate this from other spathognathodontiform elements the specimen illustrated by PICKETT , the main cusp described elsewhere. The new species is presently is situated above a deeply-excavated basal cavity – it being documented ( MATHIESON & al ., in prep.) from is of comparable size – and the lateral peg-like den - faunas from the Cobar Supergroup, of western New ticles appear to be grooved along their leading edge. South Wales dated as late in the sulcatus Zone.

Family Spathognathodontidae HASS , 1959 Genus Ozarkodina BRANSON &MEHL , 1933

Genus Amydrotaxis KLAPPER &MURPHY , 1980 TYPE SPECIES : Ozarkodina typica BRANSON & MEHL , 1933. TYPE SPECIES : Spathognathodus johnsoni (KLAP - PER , 1969). Ozarkodina excavata excavata (BRANSON &MEHL , 1933) Amydrotaxis druceana (PICKETT , 1980) (Pl. 1 Fig. 4) (Pl. 1, Fig. 3) 1933. Prioniodus excavatus n. sp. ; BRANSON &MEHL , p. 45, 1980. Ozarkodina druceana nom. nov. PICKETT , p. 73-77, pl. 3, figs 7 -8. figs 5A-W, 6A-U, 7A-C. [q.v. for earlier synonymy]. 1933. Trichognathus excavata n. sp. ; BRANSON &MEHL , p. 1990. Amydrotaxis druceana (PICKETT ); BISCHOFF &AR- 51, pl. 3, fig. 35. GENT , p. 453-454, pl. 1, figs 1-29. 1933. Ozarkodina simplex n. sp. ; BRANSON &MEHL , p. 52, 1994. Amydrotaxis druceana (PICKETT ); MAWSON &TALENT , pl. 3, figs 46 -47. p. 49, fig. 10 A-P. 1994. Ozarkodina excavata (BRANSON &MEHL ); VALEM - 1995. Amydrotaxis druceana (PICKETT ); WALL & al ., 378, ZUELA -R ÍOS , p. 69-70, pl. 4, fig. 4. pl. 1, figs 1 -17. 1995. Ozarkodina excavata excavata (BRANSON &MEHL ); 1999. Amydrotaxis druceana (PICKETT ); TALENT &MAW - SIMPSON &TALENT , p. 147-152, pl. 8, figs 16 -25; pl. SON , pl. 4, figs 10 -21; pl. 5, text-fig. 10; pl. 8, figs 3, 9, figs 1 -24 [q.v. for extensive synonymy prior to 5, 7, 15; pl. 11, text-fig. 8. 1995]. 2003. Amydrotaxis druceana (PICKETT ); FARRELL , p. 129 - 1995. Ozarkodina excavata excavata (BRANSON &MEHL ); 131, pl. 4, figs 13 -21; pl. 5, figs 1 -9. COLQUHOUN , pl. 1, fig. 16. 1995. Ozarkodina excavata excavata (BRANSON &MEHL ); REMARKS : PICKETT (1980) identified the various ele - DONGOL , fig. 4G-J. ments of the apparatus of Amydrotaxis druceana from 1995. Ozarkodina excavata (BRANSON &MEHL ); MILLER , collections from the Rookery Limestone Member at pl. 1, fig. 8. “The Rookery”, c. 35 km SE of Cobar, NSW, Australia. 1999. Ozarkodina excavata excavata (BRANSON & M EHL ); The M element illustrated here as Pl. 1, Fig. 3 is very TALENT &MAWSON , pl. 4, figs 1, 3 -4; pl. 5, figs 1 -4; similar to that illustrated by PICKETT (1980, p. 72, text- pl. 6, figs 19 -22; pl. 7, text-fig. 14; pl. 9, figs 8 -9; pl. fig. 5D) and to the M element illustrated by WALL & al . 11, figs 12 -14; pl. 12, figs 1 -4. (1995, pl. 1, text-fig. 13) from the Lilydale Limestone, 2001. Ozarkodina excavata excavata (BRANSON & M EHL ); Victoria, Australia. SLAVÍK , pl . 2, figs 11, 15, 19. THE DEVONIAN OF WESTERN KARAKORUM 281

2003. Ozarkodina excavata excavata (BRANSON & M EHL ); 1991. Pandorinellina steinhornensis praeoptima (MA- MAWSON & al. , pl . 3, figs 1 -19; pl. 4, figs 1 -15. SHKOVA ) sensu LANE &ORMISTON 1979; UYENO , pl. 2003. Ozarkodina excavata excavata (BRANSON & M EHL ); 21, text-fig. 19. FARRELL , p. 135 -136, pl. 6, figs 10 -21. 1992. Pandorinellina miae BULTYNCK ;BARDASHEV &ZIE - 2004. Ozarkodina excavata excavata (BRANSON & M EHL ); GLER , pl. 1, figs 41, 47. SLAVÍK &HLADIL , pl. 1, figs 14, 15, 17 -19. 1994. Pandorinellina steinhornensis miae BULTYNCK ;MAW - 2004. Ozarkodina excavata excavata (BRANSON & M EHL ); SON &TALENT , p. 55 -57, text-fig. 11A–G. SLAVÍK , pl. 1, figs 10, 11. 2003. Pandorinellina cf. miae BULTYNCK ; FARRELL , p. 150, pl. 12, figs 5, 6. REMARKS :Ozarkodina excavata excavata is recog - nised as a long-ranging species with its Pa element ex - REMARKS : This form was originally described from hibiting a high degree of variation (e.g. KLAPPER & Spanish collections dated as dehiscens Zone (BULTYNCK MURPHY 1975; JEPPSSON 1975). Other elements, in - 1971). MAWSON &TALENT (1994) obtained 694 speci - cluding the M element illustrated on Pl. 1, fig. 4 from mens from sampled sections of sulcatus–kindlei age at CK 1045, are easily distinguished by their unique ‘ex - Tyers and Boola in east-central Victoria, Australia. The cavated’ basal cavities. specimens from CK 1045 (Pl. 1, Fig.2) and CK 1019 (Pl. 1, Fig. 10) fit within the range of variation of the above as well as within the range of material illustrated Ozarkodina remscheidensis remscheidensis (Z IEGLER , by BULTYNCK (1971, figs 19, 20 a-c; pl. 4, figs 13, 14; pl. 1960) 5, figs 1-14). Specimens from faunas from the sulcatus (Pl . 1, Fig. 1 ) to early kindlei zones from the Hill End Trough of east- central New South Wales ( TALENT &MAWSON 1999, pl. 1960. Spathognathodus remscheidensis n. sp. ; ZIEGLER , p. 5, figs 11, 20-24) show, in lateral view, the posterior up - 194 -196, pl. 13, figs 1 -2, 4-5, 7-8, 10, 14. ward curving of the ventral margin from the anterior end 2001. Ozarkodina remscheidensis remscheidensis ZIEGLER ; of the basal cavity as shown here (Pl. 1, Fig. 2) and, in SLAVÍK , pl. 2, fig. 9. the same publication ( TALENT &MAWSON 1999, p. 5, 2003. Ozarkodina remscheidensis remscheidensis ZIEG - figs 12, 19; text-fig. 12, figs 11-13), show the asymmet - LER ;MAWSON & al ., p. 90 -92, pl. 2, figs 1 -19; pl. 4, ric basal lobes above the basal cavity that are seen with figs 1-6, 17 [q.v. for extensive synonymy prior to specimens from the Western Karakorum (Pl. 1, Fig. 10). 2000]. 2003. Ozarkodina remscheidensis remscheidensis ZIEGLER ; FARRELL , p. 90 -92, pl. 2, figs 1 -19; pl. 4, figs 16, 17. Genus Polygnathus HINDE , 1879

REMARKS : Oz. r. remscheidensis sensu stricto can be TYPE SPECIES : Polygnathus dubius HINDE , 1879. identified by its irregular denticulation with a large cusp and a group of large denticles along the anterior of the blade with an enlarged denticle about mid-way above a Polygnathus decorosus STAUFFER , 1938 heart-shaped (rather than ear-shaped) basal cavity. (Pl. 1 , Fig. 8)

1938. Polygnathus decorosus n. sp. ; STAUFFER , p. 438, pl. Genus Pandorinellina MÜLLER &MÜLLER , 1933 53, figs 5, 6, 10, 15-16 (non figs 1, 11, 20, 30) . 1973. Polygnathus decorosus STAUFFER ;KLAPPER in TYPE SPECIES : Pandorina insita Stauffer , 1940. ZIEGLER (Ed .), p. 351-352, Polygnathus pl. 1, text-fig. 5 [ q. v. for additional synonymy]. 1980. Polygnathus decorosus STAUFFER ;PERRI & S PAL - Pandorinellina steinhornensis miae BULTYNCK , 1971 LETTA , p. 305, pl. 6, figs 7a-9c. (Pl. 1, Figs 2, 10) 1993. Polygnathus decorosus STAUFFER ;JI & Z IEGLER , p. 77, pl. 40, figs 16-18; text-figs 18, 16-17. [q.v. for addi - 1971. Pandorinellina steinhornensis miae n. sp.; BULTYNCK , tional synonymy]. p. 25 -31, pl. 4, figs 13 -20; pl. 5, figs 1 -14. 1993. Polygnathus decorosus STAUFFER ;MATYJA , pl. 19, fig. 1; 1980. Pandorinellina steinhornensis miae BULTYNCK ;KLAP - pl. 20, fig. 1. PER &JOHNSON , p. 451 [q.v. for additional synonymy prior to 1980]. REMARKS : The Pa element is distinguished by having 282 MAURIZIO GAETANI & al. a narrow, symmetrical, saggitate platform. The free BARDASHEV , I. & ZIEGLER , W . 1992. Conodont biostratigra - blade is normally half the length of the unit; this is not phy of Lower Devonian deposits of the Shishkat Section apparent from the damaged specimen from CK 1012 il - (Southern Tien-Shan, Middle Asia). Courier lustrated in Pl. 1, Fig. 8. Distinct nodes occur along the Forschungsinstitut Senckenberg , 154 , 1-29. margins of the platform. Geniculation points are oppo - BARSKOV , I.S., V ORONTSOVA , T.N., K ONONOVA , L.I. & site and the anterior trough margins are short and curve KUZ ’MIN , A.V . 1991. Opredelitel’ konodontov devona i upwards. The specimen from CK 1012 closely resem - nizhnego karbon (Index conodonts of the Devonian and bles those dated as Early rhenana Zone from western Lower Carboniferous), 183 pp. Moskovskiy Gosu - Pomerania ( MATYJA 1993, pl. 19, fig. 1; pl. 20, fig. 1). darstvennyy Universitet ; Moscow. The range for P. decorosus given by JI &ZIEGLER BISCHOFF , G.C.O. &ARGENT , J.C . 1990. Lower Devonian (1993) is from within the disparilis Zone up to and (Late Lochkovian–Pragian) limestone stratigraphy at [sic] into the linguiformis Zone; BARSKOV & al. (1991) sug - conodont distribution, Waratah Bay, Victoria. Courier For - gest the range to be from triangularis Zone [Late hassi schungsinstitut Senckenberg, 118 , 441-471. Zone to gigas Zone = rhenana Zone]; ZIEGLER & BLAISE , J., B ORDET , P., M ONTENAT , C., D ESPARMET , R. & SANDBERG (1990) mention P. decorosus as an impor - MARIN , P. 1977. Recherches géologiques dans les Mon - tant associated conodont in the Late Devonian from tagnes Centrales de l’Afghanistan (Hazarajat et sa bordure Early falsiovalis to Late rhenana zones . orientale). Mémoires hors serie Societé Géologique de France , 8, 117-143. BRANSON , E.B. & MEHL , M.G. 1933. Conodont studies No. 1: Acknowledgements Conodonts from the Bainbridge (Silurian) of Missouri. University of Missouri Studies , 8, 39-52. The Geoscience Laboratory Directors of the Geological — & — 1934. Conodonts from the Grassy Creek shale of Mis - Survey of Pakistan permitted and supported our field activity; souri. University of Missouri Studies , 8, 171-259. this was logistically managed by Adventure Tour Pakistan and BRICE , D. 1970. Etude paléontologique et stratigraphique du Himalayan Travels, Italy. L. ANGIOLINI , A. NICORA , and A. Dévonien de l’Afghanistan. Contribution à la connais - ZANCHI participated in part of the field activity. P. LEFORT col - sance des brachiopodes et des polypiers rugueux. Notes et lected some of the fossils. R.A.K. TAKIRKHELI , Peshawar sup - Mémoires sur le Moyen-Orient , 11 , 364 pp. ported the field activity in Chitral of J.A. TALENT . E.YA. LEVEN BULTYNCK , P . 1971. Le Silurian supérieur et le Devonian infé - provided Soviet literature on Pamir and Afghanistan. P. CON - rieur de la Sierra de Guadarrama (Espagne centrale): SGHAN kindly showed thin sections of arenites of the Charun Deuxieme partie: assemblages de conodontes à Spatho - Quartzite at Kurāgh Spur, Chitral. CHEN XIUQUIN generously gnathodus . Institut Royal des Sciences naturelles de Bel - provided data on the brachiopods; some photographs are cour - gique Bulletin , 47 (3), 1-43. tesy of A. ZANCHI and P. LEFORT . The reviewers J. WENDT , CARTER , N.L., C HRISTIE , J.M. &GRIGGS , D.T . 1964. Experi- Tübingen and B. MISTIAEN , Lille, are warmly acknowledged mental deformation and recrystallization of quartz. 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Manuscript submitted: 28 th February 2008 Revised version accepted: 28 th August 2008 ACTA GFOLOGICA POLONICA, VOL. 58 M. GAETANI & al. , PL. 1

PLATE 1

Chronologically significant conodonts from Devonian carbonates of the Western Karakorum. (All specimens housed in the Department of Earth and Planetary Sciences, Macquarie University, with numbers prefixed by MU; scale bar = 0.1 mm)

1 – Ozarkodina remscheidensis remscheidensis (ZIEGLER , 1960), lateral view of Pa element, CK 1045, MU61781; 2, 10 – Pandorinellina steinhornensis miae BULTYNCK , 1971, lateral view of Pa ele - ment, CK 1045, MU61782; and upper view of Pa element, CK1019, MU61783, respectively; 3 – Amydrotaxis druceana (PICKETT , 1980), anterior-lateral view of M element, CK 1045, MU61784; 4 – Ozarkodina excavata excavata (BRANSON &MEHL , 1933), lateral view of M ele - ment, CK 1045, MU61785; 5 – Oulodus sp., lateral view of M element, CK 1045, MU61786; 6, 7 – Amydrotaxis n. sp., upper and lateral views respectively of Pa element, CK 1045, MU61787; 8 – Polygnathus decorosus STAUFFER , 1938, upper view of Pa element, CK 1012, MU61788; 9 – Icriodus alternatus alternatus BRANSON & M EHL , 1934 , Monotype 2 upper view of I element, CK 1012, MU61789. ACTA GFOLOGICA POLONICA, VOL. 58 M. GAETANI & al. , PL. 1