Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance

G Model

ARTICLE IN PRESS

ANNPAL-2304; No. of Pages 11

Annales de Paléontologie xxx (2017) xxx–xxx

Disponible en ligne sur

ScienceDirect www.sciencedirect.com

Original article

Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance La faune additionnelle de trilobites du Cambrien Série 3, Étage 5, partie basale de la Formation Kunzam La (=Parahio), vallée Parahio, Spiti (Nord-ouest de l’Himalaya), de l’Inde et son importance biostratigraphique Birendra P. Singh a,∗ , Om N. Bhargava a , Ranveer S. Negi a , Yuanlong Zhao b , Leiming Yin c , Choudhurimayum A. Sharma a a b c

Center of Advanced Study in Geology (CAS), Panjab University, 160014 Chandigarh, India College of Resource and Environment of Guizhou University, 550003 Guiyang, China Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, 210008 Nanjing, China

a r t i c l e

i n f o

Article history: Received 24 November 2016 Accepted 4 September 2017 Available online xxx Keywords: Middle Cambrian Tethyan Himalaya Biostratigraphic correlation Kunzam La (=Parahio) Formation Kaili Formation Oryctocephalus indicus biozone Peronopsis taijiangensis biozone

a b s t r a c t Additional Cambrian Series 3, Stage 5, trilobite fauna comprising Peronopsis sp., Eosoptychoparia cf. Spinosa Gaotanaspis cf. pingzhaiensis and Gaotanaspis cf. transversa have been recorded just immediately above the known Oryctocephalus indicus biozone (Cambrian Series 3, Stage 5) in the Parahio valley section (Spiti region). The FAD of Peronopsis and LAD of Gaotanaspis are used to establish a Peronopsis–Gaotanaspis concurrent biozone immediately above the Oryctocephalus indicus biozone. The first records of Gaotanaspis cf. pingzhaiensis and G. transversa from the Cambrian of Spiti region and the other faunal elements are correlated with the Peronopsis taijiangensis biozone of the Kaili Formation (South China). The stratigraphic thickness from the base of the O. indicus biozone to the top of the Peronopsis–Gaotanaspis concurrent biozone in the Kunzam La (=Parahio) Formation and its comparison to the Kaili Formation (South China) indicate a possible stratigraphic condensation in the basal part of the Cambrian Series 3, Stage 5 of the Parahio valley (Spiti). Sedimentological and sequence stratigraphic analysis supports this contention. © 2017 Elsevier Masson SAS. All rights reserved.

r é s u m é Mots clés : Cambrien moyen Himalaya téthysien Corrélation biostratigraphique Formation Kunzam La (=Parahio) Formation Kaili Zone à Oryctocephalus indicus Zone à Peronopsis taijiangensis

La faune additionnelle de trilobites du Cambrien Série 3, Étage 5, comprenant Peronopsis sp., Eosoptychoparia cf. spinosa, Gaotanaspis cf. pingzhaiensis et Gaotanaspis cf. transversa a été reportée immédiatement au-dessus de la biozone à Oryctocephalus indicus (Cambrien Série 3, Étage 5) dans la coupe de la vallée Parahio (région de Spiti). La FAD de Peronopsis et la LAD de Gaotanaspis sont utilisées pour établir la biozone à Peronopsis–Gaotanaspis, immédiatement au-dessus de la biozone à Oryctocephalus indicus. Le premier enregistrement de Gaotanaspis cf. pingzhaiensis et G. Transversa dans cette région et la faune associée sont corrélés avec la biozone à Peronopsis taijiangensis de la Formation Kaili en Chine du Sud. L’épaisseur stratigraphique depuis la base de la biozone à O. Indicus jusqu’au sommet de la biozone à Peronopsis–Gaotanaspis au sein de la Formation Kunzam La (Parahio) et sa comparaison avec la Formation Kaili (Chine du Sud) indiquent une possible condensation stratigraphique dans la partie basale du Cambrien Série 3, Étage 5 de la vallée Parahio (région de Spiti). L’analyse sédimentologique et la stratigraphie séquentielle appuient cette affirmation. ´ ´ es. © 2017 Elsevier Masson SAS. Tous droits reserv

∗ Corresponding author. E-mail address: v [email protected] (B.P. Singh). http://dx.doi.org/10.1016/j.annpal.2017.09.001 0753-3969/© 2017 Elsevier Masson SAS. All rights reserved.

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

2

1. Introduction The Cambrian deposits of the Himalaya, particularly from the Spiti region, were recently subjected to detailed biostratigraphic zonation (Jell and Hughes, 1997; Peng et al., 2009; Singh et al., 2014; 2015a, 2015b, 2016a, 2016b, 2016c; Popov et al., 2015; Gilbert et al., 2016; Hughes, 2016; Yin et al., 2017) including identification of the Oryctocephalus indicus biozone or the basal part of the Cambrian Series 3, Stage 5 (Singh et al., 2015a, 2015b, 2016a, 2016b, 2016c). The studied Parahio valley of the Spiti region (Tethyan Himalayan Zone) is a subsidiary valley to the major Pin valley and lies in the Lahaul-Spiti district, Himachal Pradesh, India (Fig. 1). The Parahio valley preserves uppermost part of the traditional Kunzam La Formation (Srikantia, 1981), which was recently renamed as Parahio Formation and interpreted to be deposited in a deltaic setting under high rate of sedimentation (Myrow et al., 2006a, 2006b) or wave-dominated shoreface (Virmani et al., 2015). The Kunzam La (=Parahio) Formation in the Parahio Valley yielded trilobites ranging in age from the late part of the Cambrian Series 2, Stage 4 to upper-middle part of the Cambrian Series 3, Stage 5 (Hayden, 1904; Reed, 1910; Jell and Hughes, 1997; Peng et al., 2009; Singh et al., 2014, 2015a, 2015b, 2016a, 2016c). More recently, Singh et al. (2015a, 2015b, 2016a) established the Oryctocephalus indicus biozone in the Parahio (Fig. 1, Section D) and Pin valleys (Singh et al., 2016b) and recorded trilobites Oryctocephalid Oryctocephalus indicus, eodiscoid Pagetia significans, Pagetids, ptychoparid

Kunmingaspis pervulgata and Eosoptychoparia (Danzhaina) sp., from the basal part of the Cambrian Series 3 (Stage 5). The present work is an extended work along the Parahio Valley section (Fig. 1, Section D). An additional trilobite fauna has been recorded immediately above the Oryctocephalus indicus biozone. The new record, including the genus Peronopsis and Gaotanaspis, allows us to establish a Peronopsis–Gaotanaspis concurrent biozone based on the FAD of Peronopsis and LAD of Gaotanaspis taxon. This concurrent biozone is correlatable with the Peronopsis taijiangensis biozone of the Kaili Formation (South China). The recorded genus Peronopsis from this stratigraphic interval is significant as it indicates the lowest record of this taxon from the Indian Himalaya. 2. Setting and lithostratigraphy The low grade Neoproterozoic to Eocene sedimentary rocks of the Tethyan Himalayan Fold-thrust belt (Searle, 1986; Steck et al., 1993; Bhargava and Bassi, 1998; Corfield and Searle, 2000; Wiesmayr and Grasemann, 2002), exposed within the Spiti-Zanskar region, are bounded to the south by the high grade gneisses of the Greater Himalaya across the “South Tibetan Detachment System” (Vannay and Grasemann, 1998; Wyss et al., 1999; Vannay et al., 2004). The northern boundary of this belt is the south-dipping Cenozoic Greater counter Thrust, which marks the Indus-Tsangpo Suture Zone (ITSZ), separating rocks of the Indian and Eurasian

Fig. 1. Geological map of the Parahio valley (Spiti, Northwest Himalaya, India) and location of the studied section (Section: D). The Cambrian rocks of the Parahio valley are grouped under the Haimanta Group (after Srikantia, 1981; Bhargava and Bassi, 1998). Carte géologique de la vallée Parahio (Spiti, Nord-Ouest de l’Himalaya, Inde) et localisation de la section étudiée (Section : D). Les roches cambriennes de la vallée Parahio sont rassemblées dans le groupe Haimanta (Srikantia, 1981 ; Bhargava et Bassi, 1998).

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

plates to the south and north, respectively (Thakur, 1981; Srikantia, 1981; Valdiya, 1989; Yin et al., 1999; Yin and Harrison, 2000; Webb et al., 2011). The Cambrian rocks in the Lahaul-Spiti region of the Tethyan Himalayan Fold-thrust belt are exposed in the Chandra Valley, Kunzam Pass-Takche section, and in the Pin-Parahio valleys. The Cambrian rocks of the Spiti region are grouped under the Haimanta Group (Srikantia, 1981; Bhargava and Bassi, 1998), which is divided into the Precambrian-?lower Cambrian Batal

3

Formation and lower-middle Cambrian Kunzam La (Parahio) Formation (Srikantia, 1981; Kumar et al., 1984; Myrow et al., 2006a, 2006b; Bhargava, 2008, 2011; Singh et al., 2014, 2015a, 2015b, 2016a, 2016b, 2016c). The Precambrian–Cambrian boundary in the Spiti region is presumed at the contact of the Batal and Kunzam La (Parahio) formations (Kumar et al., 1984). In the Spiti area, the contact between these two formations is generally gradational and locally tectonic (Hayden, 1904; Fuchs, 1982; Bhargava et al., 1982;

Fig. 2. Detailed lithocolumn of the lowermost part of the Parahio valley section (Fig. 1, section: D) measured on the steep slope along the left bank of the Parahio River, Parahio Valley (Spiti) showing the distribution of the faunal elements of the Oryctocephalus indicus biozone (Singh et al., 2015a, b, 2016a), Peronopsis–Gaotanaspis concurrent biozone (present work) and Bhargavia prakritika level (Singh et al., 2016c). Coupe lithologique détaillée de la partie basale de la série relevée dans la vallée Parahio (Fig. 1, section D), le long d’une pente raide de la rive gauche de la rivière Parahio, vallée Parahio (Spiti), montrant les éléments fauniques de la biozone à Peronopsis–Gaotanaspis (Singh et al., 2015a, b, 2016a), de l’intervalle Peronopsis–Gaotanaspis (présent travail) et du niveau à Bhargavia prakritika (Singh et al., 2016c).

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

4

Myrow et al., 2006a). In the Parahio valley, a faulted contact has been reported (Bhargava et al., 1982; Myrow et al., 2006a, Singh et al., 2014, 2015a, 2015b, 2016a).

3. Studied section The Parahio valley section is exposed along the north bank of the Parahio River along a steep hill near the Maopo encamping ground (Fig. 1, Section: D). This section is biostratigraphically well constrained (Peng et al., 2009, Singh et al., 2016a, 2016c) and it bears the probable Cambrian Series 2–Series 3 boundary interval based on the FAD of the trilobite Oryctocephalus indicus (Singh et al., 2015a, 2016a). The lower part of this Parahio valley section comprises thin-to-thickly bedded sandstones, calcareous sandstones, black-bluish shales, siltstones, interbedded silty-shale, argillaceous limestone and packstone (Fig. 2). Out of the 280 m measured section, the lowermost 35.90 m thick succession (Fig. 2) is highly fossiliferous. It contains the Oryctocephalus indicus biozone from 7.74 m to 14.61 m representing a 6.87 m thick interval (Singh et al., 2016a). The Peronopsis–Gaotanaspis concurrent biozone is 4.89 m thick interval extends from 14.61 m to 19.50 m. The Bhargavia prakritika level starts at 26.4 m (Singh et al., 2016c).

4. Biostratigraphy The Peronopsis–Gaotanaspis concurrent biozone is 4.89 m thick and established based on the first appearance datum (FAD) of Peronopsis sp. at 14.61 m and last appearance datum (LAD) of Gaotanaspis at 19.50 m. This Peronopsis–Gaotanaspis biozone lies immediately above the Oryctocephalus indicus biozone in the Parahio valley section, Spiti, India (Fig. 2). The Peronopsis–Gaotanaspis biozone contains Peronopsis sp., Eosoptychoparia cf. spinosa, Gaotanaspis cf. transversa, Gaotanaspis cf. pingzhaiensis, Kunmingaspis pervulgata and Pagetia significans. The FAD and LAD of Peronopsis sp. (Fig. 3.1–3.3), are recorded at 14.61 m and 18.34 m, respectively from the base of the section. Eosoptychoparia spinosa (Fig. 3.4–3.6), ranges from 14.61 m to 17.50 m. Gaotanaspis cf. pingzhaiensis (Fig. 3.7) and Gaotanaspis cf. transversa (figs. 3.8–3.10) range from 18.20 m to 19.50 m. Pagetia significans in the Parahio valley section ranges from Pagetia-Kunmingaspis level (7.38 m to 7.74 m) to the Peronopsis–Gaotanaspis concurrent biozone (Fig. 2). Peronopsis and Gaotanaspis are characteristic trilobites of the Peronopsis taijiangensis biozone in the Kaili Formation in China. In the Parahio valley section, Peronopsis and Gaotanaspis cooccur only in a 14 cm thick interval (from 18.20 m to 18.34 m; Fig. 2). The FAD of Peronopsis taijiangensis in the Kaili Formation (China) defines the base of the Peronopsis taijiangensis biozone (Zhao et al., 2001; Zhao et al., 2011, 2012). We also use the FAD of Peronopsis sp. in the Parahio valley section (Spiti) to demarcate the base of the Peronopsis–Gaotanaspis concurrent biozone from the underlying Oryctocephalus indicus biozone.

5. Systematic Paleontology Class Trilobita Walch, 1771 Order Agnostids Salter, 1864 Family Peronopsidae Westergard, 1936 Genus Peronopsis Hawle and Corda, 1847 Peronopsis sp. (figs. 3.1–3.3) Material: Three disarticulated cephalons (CAS/T-2015901a; CAS/T-2015908a; CAS/T-2015906), two from silty shale horizon and one from fine-grained silty-sandstone horizon, Parahio valley Section (Spiti, India).

Description: Cephalon moderately convex; lateral sides of the glabella parallel to subparallel; transglabellar furrow straight (Fig. 3.1) in less deformed specimen; median preglabellar furrow absent; anteroglabellar lobe rounded to sub-rounded; frontal sulcus not visible; posteroglabellar lobe elongated with rounded base; basal lobe not visible; axial node poorly preserved. Discussion Though the specimens from the Parahio valley (Spiti) are poorly preserved, yet the preserved and observed features like poorly developed node and the parallel lateral sides of the glabellar axis, are quite diagnostic and warrant an assignment to the genus Peronopsis. The presently recorded specimen of Peronopsis differs from Peronopsis spitiensis (Reed, 1910) in cranidial characters. Our specimens show moderately convex cephalon, poorly developed node and the parallel lateral sides of the glabellar axis. However, Peronopsis spitiensis is characterized by a strongly convex cephalon, posteriorly placed node and small basal lobes. Our specimens also differ from Peronopsis acadica (Peng et al., 2009), which characterized by the presence of a straight or slightly rearwardbowed transglabellar furrow (T3) and subcyclindrical posterior part of glabella with a rounded posterior end and simple basal lobes. Our specimens also differ from Peronopsis recta (Kounamkites biozone, Siberia, Shabanov et al., 2008) characterized by a slightly curved transglabellar furrow. Our specimens resemble to Peronopsis taijiangensis (Huang and Yuan, 1994) recorded from the Peronopsis taijiangensis biozone of the Kaili Formation (Yuan et al., 2002, Zhao et al., 2012) and shows poorly developed node and the lateral sides of the glabellar axis are parallel, which are the most primitive characters of agnostids, and underscore its low stratigraphic position. Occurrences: From Peronopsis–Gaotanaspis concurrent biozone, Parahio valley section, Spiti Himalaya (India). In the Kaili Formation at Wuliu-Zengjiayan section (China) the taxon Peronopsis is known from the Peronopsis taijiangensis biozone. Order Ptychoparrida Swinnerton, 1915 Genus Eosoptychoparia Chang, 1963 Eosoptychoparia spinosa Yuan in Zhang et al., 1980 (figs. 3.4–3.6) Material: Three poorly preserved cranidia (CAS/T-2015908c; CAS/T-2015908d; CAS/T-2015901b), from silty shale horizon, Parahio valley Section (Spiti, India). Description: Cranidium subtrapezoidal in outline; glabella rapidly tapering forward; glabellar furrow weakly preserved; preglabellar field wide, gently sloping to anterior border; anterior border raised and rapidly narrowing laterally; eye ridge prominent and horizontal; palpebral lobe short, one third of glabella length, located middle to anterior of glabella. Discussion: In Cambrian deposits of the Himalaya till so far this genus is known from the Cambrian Series 3 of the Spiti and Zanskar region. In Zanskar, Peng et al. (2009) recorded Eosoptychoparia sp., from the Sudanomocarina sinindica biozone. In Spiti, Singh et al. (2016) recorded Eosoptychoparia (Danzhaina) sp. from the Oryctocephalus indicus biozone along the Parahio valley section. Presently recorded Eosoptychoparia spinosa immediately above the Oryctocephalus indicus biozone in the Parahio valley section closely resembles with the Eosoptychoparia sp., (Peng et al., 2009, fig. 30.5) but differs in shape and size of glabella. Present species also differs from the Eosoptychoparia (Danzhaina) sp. (Sing et al., 2016, fig. 8) in rapidly tapering conical glabella. Occurrences: From Peronopsis–Gaotanaspis concurrent biozone, Parahio valley section, Spiti Himalaya (India). In Kaili Formation at Wuliu-Zengjiayan section (China) Gaotanaspis pingzhaiensis ranges from Oryctocephalus indicus biozone to the Peronopsis taijiangensis biozone. Genus Gaotanaspis Zhang and Li, 1984

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

5

Fig. 3. Trilobites from the Peronopsis–Gaotanaspis concurrent biozone in the Parahio Valley section (Spiti, India). A–C: Peronopsis sp.; A - poorly preserved cephalon, × 30, CAS/T-2015901a; B - poorly preserved cephalon, × 22, CAS/T-2015908a; C - poorly preserved cephalon, × 20, CAS/T-2015906; D–F: Eosoptychoparia cf. spinosa (Yuan et al., 2002); D - partially preserved cranidium, × 11, CAS/T-2015908c; E - poorly preserved cranidium, × 14, CAS/T-2015908d; F - poorly preserved specimen, inset showing the association with Peronopsis (1) × 7, CAS/T-2015901b; G - partially preserved exoskeleton of Gaotanaspis cf. pingzhaiensis (Yuan et al., 2002), × 7, CAS/T-2015904; H–J: Gaotanaspis cf. transversa, H - inset showing figures (I, J), × 8, CAS/T-2015910; I - enlarge view showing broken cranidium, × 20, CAS/T-2015910a; J - partially preserved cranidium, × 20, CAS/T-2015910b. Trilobites de la biozone à Peronopsis–Gaotanaspis dans la section Parahio Valley (Spiti, Inde). A–C : Peronopsis sp. ; A - céphalon mal conservé, × 30, CAS/T-2015901a ; B - céphalon mal conservé, × 22, CAS/T-2015908a ; C - céphalon mal conservé, × 20, CAS/T-2015906 ; D–F : Eosoptychoparia cf. spinosa (Yuan et al., 2002) ; D - cranidium partiellement conservé, × 11, CAS/T-2015908c ; E - cranidium mal conservé, × 14, CAS/T-2015908d ; F - spécimen mal conservé ; encart montrant l’association avec Peronopsis (1) × 7, CAS/T-2015901b ; G : exosquelette partiellement préservé de Gaotanaspis cf. pingzhaiensis (Yuan et al., 2002), × 7, CAS/T-2015904 ; H–J : Gaotanaspis cf. transversa ; H - encart montrant les images I et J, × 8, CAS/T-2015910 ; I - vue agrandie montrant un cranidium cassé, × 20, CAS/T-2015910a ; J - cranidium partiellement préservé, × 20, CAS/T-2015910b.

Gaotanaspis pingzhaiensis Yuan and Zhao in Yuan et al., 2002 (Fig. 3.7) Material: Incomplete exoskeleton (CAS/T-2015904), from very fine-grained silty-sandstone, Parahio valley Section (Spiti, India). Description: Partially preserved exoskeleton, elongated and gently convex; glabella conical, rounded at front, poorly preserved; preglabellar field wide; anterior border and preglabellar field convex; eye ridges poorly preserved, slightly bending forward; palpebral lobes short and located anteriorly to mid glabellar length; thorax with 14 thoracic segments; axis narrower than pleurae (tr.); pleurae with acute angle and without pleural spine; pygidium is poorly preserved. Discussion: Gaotanaspis pingzhaiensis differ from the type species Gaotanaspis tianbeinsis (Zhang and Li, 1984) in longer and slimer glabella with deep glabellar furrows and eye ridges slightly bending forward. In South China, G. Pingzhaiensis is known from the lower-middle part of the Kaili Formation (Yuan et al., 2002). Occurrences: From Peronopsis–Gaotanaspis concurrent biozone, Parahio valley section, Spiti Himalaya (India). In Kaili Formation at Wuliu-Zengjiayan section (China) Gaotanaspis pingzhaiensis occurs in the Peronopsis taijiangensis biozone.

Gaotanaspis transversa Yuan and Zhao in Yuan et al., 2002 (figs. 3.8–3.10) Material: Three poorly preserved specimens from very fine-grained silty-sandstone horizon, described specimen is CAS/T2015910, Parahio valley Section (Spiti, India). Description: Cranidium wide, strongly bending forwards; glabella short and subtrapezoidal, rounded anteriorly, poorly preserved 3 to 4 pairs of glabellar furrows; S1 and S2 deep and long, inclined inward and backward, S3 deep and short and horizontal, S4 faintly developed (Fig. 3.10); anterior border furrow deep and arched; fixed cheeks broad, more or less equal to glabellar width between palpebral lobes; prominent eye ridges, slightly bending forward near the glabellar margin; palpebral lobes short and located mid length of glabella; posterolateral limbs wide and long (exsag. and tr.), wider than glabella at base (tr.); anterior branch of facial suture slightly divergent forward, posterior branch slanting backward; occipital furrow deep; occipital ring convex, wider at center and narrowing laterally; occipital node at centre (Fig. 3.9). Discussion: G. Transversa differs from the type species Gaotanaspis tianbeinsis (Zhang and Li, 1984) mainly in wider

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

6

cranidium strongly bending forwards, glabella with deep glabellar furrows and wider posterolateral limbs. In South China, G. Transversa is known from the middle-upper part of the Kaili Formation (Yuan et al., 2002). Occurrences: From Peronopsis–Gaotanaspis concurrent biozone, Parahio valley section, Spiti Himalaya (India). In Kaili Formation at Wuliu-Zengjiayan section (China) Gaotanaspis pingzhaiensis occurs in the Peronopsis taijiangensis biozone. 6. Discussion A similar faunal assemblage including Pagetia, Gaotanaspis and Peronopsis occurs within the Peronopsis taijiangensis biozone in the Kaili Formation, South China (Yuan et al., 2002; Lin and Yuan, 2009; Gaines et al., 2011, Zhao et al., 2012) (Fig. 4). The Kaili Formation in Guizhou province of South China contains three biozones in ascending order i.e. Bathynotus kueichouensis–Ovatoryctocara

sinensis biozone (Cambrian Series 2, Stage 4), Oryctocephalus indicus biozone, and Peronopsis taijiangensis biozone both of Series 3, Stage 5 (Zhao et al., 2001, 2012, 2015; Esteve et al., 2015). Peronopsis and Gaotanaspis are well known from the Kaili Formation (South China) from the Peronopsis taijiangensis biozone (Yuan et al., 2002; Zhao et al., 2001, 2011, 2012). The stratigraphical thickness between the base of the O. Indicus biozone to the top of the P. Taijiangensis biozone in the Kaili Formation is nearly 161.4 m (Zhao et al., 2001, 2007, 2008, 2012, 2015; Yuan et al., 2002; Guo et al., 2005). However, in the Parahio valley the thickness from the base of the Oryctocephalus indicus biozone to the top of the Peronopsis–Gaotanaspis concurrent biozone is only 11.76 m, which suggests stratigraphic condensation of the section. This condensation indicates the interval from base of Oryctocephalus indicus to top of Peronopsis–Gaotanaspis concurrent biozones was deposited under the low sedimentation rate in a transgressive system tract (TST) to early highstand systems tract (HST) (cf. Baum and Vail,

Fig. 4. Comparative account of trilobite fauna and their respective FAD and LAD in Oryctocephalus indicus and Peronopsis taijiangensis biozones of South China and the Oryctocephalus indicus and Peronopsis–Gaotonaspis concurrent biozones of Spiti Himalaya India. Comparaison des faunes de trilobites et de leurs FAD et LAD respectifs dans les biozones à Oryctocephalus indicus et Peronopsis taijiangensis du sud de la Chine et dans les biozones à Oryctocephalus indicus et Peronopsis–Gaotonaspis de Spiti, Himalaya, en Inde.

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

7

Fig. 5. Sequence stratigraphy along the basal part of the Cambrian Series 3 in the Parahio valley section showing retrogradational and progradational parasequences; (a) medium-grained ferruginous matrix supported sandstone, (b) highly fossiliferous packstone containing small shelly fauna and trilobite fragment, (c) Oryctocephalus indicus rich blackish-shale (offshore) with enriched authigenic mineral pyrite and siderite, (d) tidal lamination, (e) fine-grained sandstone showing storm generated shallower rolling structures, (f) coarse-grained sandstone. Stratigraphie séquentielle de la partie basale de la Série 3 du Cambrien dans la section de la vallée de Parahio, montrant des paraséquences rétrogradantes et progradantes ; (a) grès à matrice ferrugineuse à grain moyen, (b) packstone hautement fossilifère contenant des microfossiles à squelette minéralisé et un fragment de trilobite, (c) schiste noirâtre riche en Oryctocephalus indicus (offshore) enrichi en pyrite et sidérite authigéniques, (d) laminations tidales, (e) grès à grain fin montrant des structures de remaniement générées par des tempêtes proximales, (f) grès à grain grossier.

1988; Van Wagoner et al., 1990; Amorosi, 1995; Li et al., 2012) under limited supply of mixed siliciclastic carbonate sediments due to the action of flood-ebb currents (cf. Zaitsev and Baraboshkin, 2006; Baraboshkin, 2009). This interpretation is support by the sequence stratigraphic analysis along the studied part of the Kunzam La (=Parahio) Formation (Fig. 5). The studied part of the Kunzam La (Parahio) Formation shows retrogradationalprogradational parasequences. The medium-grained ferruginous matrix supported sandstone at the base of the studied part is a nearshore to upper shoreface deposit (Fig. 5a) and its uppermost surface bears fucoid-type burrows. Upward it is followed by a retrogradational parasequence represented by thin packstone bed and

overlying black shale succession, signifying a rapid sea-level rise as part of transgressive systems tract (TST). Packstone is highly fossiliferous and contains small shelly fauna and trilobites (Fig. 5b). The base of the packstone is denoted by a transgressive erosional ravinement surface, which also represent the sequence boundary (SB), and commencement of a condensed section (cf. Jenkyns, 1971; Vail et al., 1984, Loutit et al., 1988; Liu and Gastaldo, 1992; Gomez and Fernandes-Lopez, 1994; Baraboshkin et al., 2002). The rapid sea-level rise is probably related to eustatic sea-level change during the basal part of the Stage 5 (cf. Zhu et al., 1999; Wang et al., 2006; Gaines et al., 2011). It results in the deposition of the Oryctocephalus indicus rich blackish-shale (offshore) (Fig. 5c), over the thin

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11 8

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

Fig. 6. Stratigraphic range of trilobites known from the Spiti and Zanskar regions (Northwest Himalaya) and comparative position of Peronopsis spitiensis (Reed, 1910), Peronopsis acadica (Peng et al., 2009), and Peronopsis sp., (present work). Répartition stratigraphique des trilobites connus dans les régions Spiti et Zanskar (nord-ouest de l’Himalaya) et comparaison entre Peronopsis spitiensis (Reed, 1910), Peronopsis acadica (Peng et al., 2009) et Peronopsis sp., (présent travail).

packstone bed consequent to the maximum flooding surface (MFS). The MFS is delineated at the change in stacking pattern from retrogradational to progradational parasequences. During the TST phase the basin became undersupplied with onset of retrogradational facies. The slow rate of accumulation, reworking of sediments, landward advancement of shoreline, and period of sediment starvation together with enriched authigenic mineral pyrite and siderite bear testimony to stratigraphic condensation (Fig. 5c). Siderite also occurs in the silty-shale succession lying above the offshore shale and contains fragmented specimens of Oryctocephalus indicus. The progradational parasequence commences above the retrogradational parasequence facies. This demarcation is also supported by low faunal diversity and decrease in abundance of individual taxon. The siderite silty-shale may indicate increase in freshwater pulses or discharge due to flood ebb-currents (cf. Zaitsev and Baraboshkin, 2006; Baraboshkin, 2009). This conclusion is further supported by the study of acritarchs in a section containing Oryctocephalus indicus biozone (1.8 km NW of the Parahio valley section), where the silty shale facies records the incoming of cryptospore-like microfossils, which are interpreted to have been transported into the basin from the coastal areas (Yin et al.,

2017). The silty-shale succession locally also exhibits tidal lamination (Fig. 5d; cf. Baraboshkin, 2009). The silty-shale succession upward is followed by a thin succession of fine-grained sandstone which exhibits shallower storm generated rolling structures (Fig. 5e). This in turn is followed by the coarse-grained thin to-thickly bedded sandstone (Fig. 5f) containing the Bhargavia prakritika level trilobite fauna in top part of the section. Change in facies from fine-grained silty-shale succession (HST) to thin-tothickly coarse-grained bedded sandstone of the lowstand systems tract (LST) indicates basinward shift of facies. A sequence boundary (SB) is formed at the base of the LST deposits. The lowstand system tract deposits are coarse-grained and dominated by the trilobite Bhargavia prakritika, which bore unusually robust thick exoskeleton, indicative of very shallow water condition (Peng et al., 2009). To summaries, the studied part of the Kunzam La (=Parahio) Formation incorporates thin and mud-rich transgressive and HST upward followed by thick sandy facies of LST. Much of the highstand systems tract (HST) and falling stage systems tract (FSST) are missing, probably due to erosion or sediment bypassing indicating condensation with concomitant loss of stratigraphic data.

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

The genus Peronopsis from this stratigraphic interval is significant as it indicates the lowest record of this taxon from the Indian Himalaya (Fig. 6). In the Himalaya, Peronopsis is known from the Kashmir, Zanskar and Spiti regions of the Tethyan Himalaya (Reed, 1910; Shah and Sudan, 1987; Shah et al., 1996; Sahni and Sudan, 1996; Jell and Hughes, 1997; Peng et al., 2009). Jell and Hughes (1997) revised all known species of Peronopsis from Himalaya, except Peronopsis amplaxis from the Parahio valley (Sahni and Sudan, 1996), assigned under the Baltagnostus cf. rakuroensis. Later these were reassigned to Peronopsis acadica belonging to Sudanomocarina sinindica biozone of Drumian Stage (Peng et al., 2009). The Spiti material of Hayden (1904), described by Reed (1910, pl. 1, figs. 1–3) as Agnostus spitiensis, was collected from a block of limestone in a thick conglomerate, probably of the Ordovician Thango Formation (Peng et al., 2009). Kobayashi (1943, p. 297) compared the Spiti agnostids with those of Kashmir; however, Jell and Hughes (1997) rejected this comparison based on preservation mode and associated trilobite fauna. Whitehouse (1936) compared Agnostus spitiensis to Diplorrhina sp. However, Naimark (2012) considered that the Spiti material differs from the type species Diplorrhina triplicate and reassigned it to Peronopsis spitiensis under the morphogroup-IX (with typical species egenus). The stratigraphic range of the morphogroup-IX is from Ptychagnostus atavus (=T. Fissus) to Goniagnostus nathorsti biozones of Cambrian Series 3, Stage 5 (Naimark, 2012, fig. 19, p. 987). Fig. 6 in text indicates the range of known trilobite fauna (including various zones and levels) from the Spiti and Zanskar regions. The plotted occurrences of Peronopsis spitiensis in Fig. 6 ranges from Ptychagnostus atavus biozone to the Goniagnostus nathorsti biozone of the Drumian of the Cambrian system (Naimark, 2012, fig. 19, p. 987), which is stratigraphically equivalent to the Sudanomocarina sinindica biozone (Peng et al., 2009). The stratigraphic position of Peronopsis acadica known from the Zanskar and Kashmir regions is in Sudanomocarina sinindica biozone (= P. Gibuss biozone), uppermost part of the informal global Stage 5 of the Cambrian System (Peng et al., 2009). Sahni and Sudan (1996) described Peronopsis amplaxis and Peronopsis sp., from the Parahio valley section. Reevaluation of the Spiti material, described as Peronopsis amplaxis (Sahni and Sudan, 1996, Pl-II, figs. g–r, p. 658) indicates that these specimens closely resemble in morphology with Peronopsis acadica. Hence, we interpret that these specimens were collected from Hayden level 9/Oryctocephalus salteri biozone as interpreted by Peng et al. (2009) in the Parahio valley. However, a close sampling and more collection of specimens from the Oryctoepahlus salteri biozone is required to consolidate this interpretation. Shah and Sudan (1987) mentioned that all known species of Peronopsis from Kashmir are from the middle and upper part of Solenopleura–Tonkinella biozone. Jell and Hughes (1997, text fig. 4) and Peng et al. (2009, p. 12) suggested that Tonkinella bearing beds are possibly correlatable with the Oryctocephalus salteri biozone or Iranoleesia butes level in the upper part of the Kunzam La (=Parahio) Formation of the Spiti. The genus Tonkinella is yet not been recorded from the Spiti region. Moreover, the biostratigraphic zonation of the Indian Himalaya indicates that Cambrian trilobites so far known from the Zanskar region are slightly younger (late Age 5 to early Guzhangian) than all the known Cambrian trilobites of the Spiti region (late Age 4 to early Age 5; Peng et al., 2009). Peronopsis spitiensis is stratigraphically younger than the Peronopsis acadica, which belongs to XIVb (Naimark, 2012). We suggest collection and study of additional in situ material of Peronopsis spitiensis or the revision of the morphogroup of Peronopsis spitiensis to resolve this problem. The recorded trilobites i.e. Peronopsis sp, Gaotanaspis pingzhaiensis, G. Transversa and Eosoptychoparia spinosa from the Parahio valley section in Spiti region (India) is highly correlatable with the Peronopsis taijiangensis biozone of the Kaili Formation (South China). The contemporaneous reports of outer shelf, open-ocean

9

faunas containing similar taxa such as Peronopsis, oryctocephalids, Elrathina, Kootenia and Pagetia among others in the Hainan Province in China (Lin and Jago, 1993), Argentine Precordillera (Bordonaro et al., 2008), Newfoundland, Canada (Young and Ludvigsen, 1989) and the United States (Robison, 1976, 1982; Palmer and Halley, 1979) and India (present report) suggest that this distinct biofacies was global in extent during the Cambrian Series 3, Stage 5 (Hally and Paterson, 2014). Disclosure of interest The authors declare that they have no competing interest. Acknowledgements BPS is thankful to the UGC (New Delhi) for providing the financial grant (No. F.20-1/2012 (BSR)/20-8(12)/2012(BSR). ONB acknowledges Indian National Science Academy for financial support. BPS is highly thankful to Profs. Thomas Hegna (WIU) and Jim Jago (Australia) for providing the literatures. Dr. S. S. Guleria (former Deputy Commissioner Lahaul & Spiti), Chawang and Cheering Gatak (our mule man and porters) are acknowledged for logistics support. We are thankful to the editorial board of Annales de Paleontologie and two anonymous reviewers for constructive review of the manuscript. LY and YLZ acknowledges State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology), and Chinese Academy of Sciences (No. Y326150507), and the National Natural Science Foundation of China (Nos. 41473039, 4151101015). References Amorosi, A., 1995. Glaucony and sequence stratigraphy: a conceptual framework of distribution in siliciclastic sequences. Journal of Sedimentary Research 65, 419–425. Baraboshkin, E.Yu., 2009. Condensed sections: terminology, types, and condition of formation. Vestnik Moskovskogo Universiteta. Seriya 3, 13–20. Baraboshkin, E.Yu., Veimarn, A.B., Kopaevich, L.F., Naidin, D.P., 2002. Izuchenie stratigraficheskikh pereryvov priproizvodstve geologicheskoi s”emki. Metodocheskie rekomendatsii (Examination of Stratigraphic Hiatuses at Geologic Mapping: Methodic Recommendations). Vestnik Moskovskogo Universiteta, pp. 1–23. Baum, G.R., Vail, P.R., 1988. Sequence stratigraphic concepts applied to Paleogene outcrops, Gulf and Atlantic basins. In: Wilgus, C.K., Hastings, B.S., Christopher, G., St. Kendall, C., Posamentier, H.W., Ross, C.A., Van Wagoner, J.C. (Eds.), Sea-level changes: an integrated approach, 42. Society of Economic Paleontologists and Mineralogists Special Publication, pp. 309–327. Bhargava, O.N., 2008. An updated introduction to the Spiti geology. Journal Palaeontological Society of India 53, 113–129. Bhargava, O.N., 2011. Early Palaeozoic paleogeography, basin configuration, paleoclimate and tectonics in the Indian Plate. Memoir Geological Society of India 78, 69–99. Bhargava, O.N., Bassi, U.K., 1998. Geology of Spiti-Kinnaur Himachal Himalaya. Memoir Geological Survey of India 124, 1–210. Bhargava, O.N., Kumar, G., Gupta, S.S., 1982. Cambrian trace fossils from the Spiti valley, Himachal Himalaya. Journal of Geological Society of India 23, 183–191. Bordonaro, O.L., Banchig, A.L., Pratt, B.R., Raviolo, M.M., 2008. Trilobite-based biostratigraphic model (biofacies and biozonation) for the Middle Cambrian carbonate platform of the Argentine Precordillera. Geologica Acta 6, 115–129. Corfield, R.I., Searle, M.P., 2000. Crustal shortening estimates across the north Indian continental margin, Ladakh, NW India. In: Khan, M.A., et al. (Eds.), Tectonics of the Nanga Parbat Syntaxis and the Western Himalaya, 170. Special Publication Geological Society of London, pp. 385–410. Chang, W., 1963. A classification of the lower and middle Cambrian trilobites from northern and northeastern China, with descriptions of new families and new genera. Acta Palaeontologica Sinica 11, 447–487. Esteve, J., Zhao, Y.L., Peng, J., Sun, H., 2015. Ontogeny, morphological variability and taphonomy of Oryctocephalus indicus (Reed, 1910) from the Kaili Formation, South China. Band 21, 99. Fuchs, G., 1982. The geology of the Pin Valley in Spiti, H.P., India. Jahrbuch fuer Geowissenschaften. Band 124, 325–359. Gaines, R.R., Mering, J.A., Zhao, Y., Peng, J., 2011. Stratigraphic and microfacies analysis of the Kaili Formation, a candidate GSSP for the Cambrian Series 2–Series 3 boundary. Palaeogeography, Palaeoclimatology, Palaeoecology 311, 171–183.

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11 10

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

Gilbert, I.R., Hughes, N.C., Myrow, P.M., 2016. Cambrian microfossils from the Tethyan Himalaya. Journal of Paleontology 90, 10–30, http://dx.doi.org/10.1017/jpa.2015.74. Gomez, J.J., Fernandes-Lopez, S., 1994. Condensation processes in shallow platforms. Sedimentary Geology 92, 147–159. Guo, Q.J., Strauss, H., Liu, C.Q., 2005. Carbon and Oxygen Isotopic Composition of Lower to Middle Cambrian Sediments at Taijiang, Guizhou Province, China. Geological Magazine 142, 723–733. Hally, L.A., Paterson, J.R., 2014. Biodiversity, biofacies and biogeography of middle Cambrian (Series 3) arthropods (Trilobita and Agnostida) on the East Gondwana margin. Gondwana Research 26, 654–674. Hawle, I., Corda, A.J.C., 1847. Prodrom einer Monographie der bohmischen Trilobiten. Abhandlungen der kongligische bohemischen Gesellschaft der Wissenschaften. V. Golge 5, 1–176. Hayden, H.H., 1904. The Geology of Spiti with parts of Bashahr and Rupshu. Memoirs of the Geological Survey of India 36, 1–121. Huang, Y.Z., Yuan, J., 1994. Peronopsis of Early–Middle Cambrian Kaili Area. Guizhou. Acta Paleontologica Sinica 33 (3), 295–304. Hughes, N.C., 2016. The Cambrian palaeontological record of the Indian subcontinent. Earth-Science Reviews 159, 428–461. Jell, P.A., Hughes, N.C., 1997. Himalayan Cambrian trilobites. Special papers in Palaeontology 58, 1–113. Jenkyns, H.C., 1971. The genesis of condensed sequences in the Tethyan Jurassic. Lethaia 4, 327–352. Kobayashi, T., 1943. Brief notes on the eodiscids 1, their classification with a description of a new species and a new variety. Proceedings of the Imperial Academy, Tokyo 19, 37–42. Kumar, G., Raina, B.K., Bhargava, O.N., Maithy, P.K., Babu, R., 1984. The PrecambrianCambrian boundary problem and its prospects, northwest Himalaya, India. Geological Magazine 121, 211–219. Li, X.F., Ling, J.P., Yin, L.M., 2012. New Material of Organic-Walled Microfossils from the Kaili Formation (Cambrian Series 2-3) of Guizhou. Acta Palaeontologica Sinica 51 (4), 463–474 (in Chinese with English Abstract). Lin, T.-R., Jago, J.B., 1993. Xystridura and other early Middle Cambrian trilobites from Yaxian, Hainan Province, China. Transactions of the Royal Society of South Australia 117, 141–152. Lin, J.-P., Yuan, J.-L., 2009. Reassessment of the mode of life of Pagetia Walcott, 1916 (Trilobita: Eodiscidae) based on a cluster of intact exuviae from the Kaili Formation (Cambrian) of Gizhou, China. Lethaia 42, 67–73. Liu, Y., Gastaldo, R.A., 1992. Characteristics of a Pennsylvanian ravinement surface. Sedimentary Geology 77, 197–214. Loutit, T.S., Hardenbol, J., Vail, P.R., Baum, G.R., 1988. Condensed sections: the key to age determination and correlation of continental margin sequences. Society of Economic and Paleontology Mineral Special Publication 42, 183–213. Myrow, P.M., Snell, K.E., Hughes, N.C., Paulsen, T.S., Heim, N.A., Parcha, S.K., 2006b. Cambrian depositional history of the Zanskar Valley region of the Indian Himalaya; tectonic implications. Journal of Sedimentary Research 76, 364–381. Myrow, P.M., Thompson, K.R., Hughes, N.C., Paulsen, T.S., Sell, B.K., Parcha, S.K., 2006a. Cambrian stratigraphy and depositional history of the northern Indian Himalaya, Spiti Valley, north -central India. Geological Society of America Bulletin 118, 491–510. Naimark, E.B., 2012. Hundred Species of the Genus Peronopsis Hawle et Corda, 1847. Paleontological Journal 46 (9), 945–1057. Palmer, A.R., Halley, R.B., 1979. Physical stratigraphy and trilobite biostratigraphy of the Carrara Formation (Lower and Middle Cambrian) of Southern Great basin. United States Geological Survey Professional Paper 104, 1–131. Peng, S., Hughes, N.C., Heim, N.A., Sell, B.K., Zhu, X., Myrow, P.M., Parcha, S.K., 2009. Cambrian trilobites from the Parahio and Zanskar Valleys, Indian Himalaya. Memoir Paleontological Society 71, 1–95. Popov, L.E., Holmer, L.E., Hughes, N.C., Ghobadi Pour, M., Myrow, 2015. Himalayan Cambrian brachiopods. Palaeontology, P.M., http://dx.doi.org/10.1002/spp2.1017. Reed, F.R.C., 1910. The Cambrian fossils of Spiti. Palaeontologia Indica 15, 1–70. Robison, R.A., 1976. Middle Cambrian trilobite biostratigraphy of the Great Basin. Brigham Young University Geology Studies 23, 93–109. Robison, R.A., 1982. Some Middle Cambrian agnostoid trilobites from western North America. Journal of Paleontology 56, 132–160. Sahni, A.K., Sudan, C.S., 1996. Agnostid Fauna from the Cambrian of Spiti. Journal of the Geological Society of India 48 (6), 653–662. Salter, J.W., 1864. A monograph of British trilobites. Part 1. Palaeontographical Society, London, Monograph 1862, 1–80. Searle, M.P., 1986. Structural evolution and sequence of thrusting in the High Himalayan, Tibetan Tethyan and Indus suture zones of Zanskar and Ladakh, western Himalaya. Journal of Structural Geology 8, 923–936. Shabanov, Yu.Ya., Korovnikov, I.V., Pereladov, V.S., Fefeolov, A.F., 2008. Excursion 1a: the traditional boundary of the Lower and Middle Cambrian in the Kuanam Formation of the Molodo River, in Kembrii Sibirskoi platformy (Cambrian of the Siberian Platform), Moscow–Novosibirsk. Paleontology Institut Rossiiskaia Akademiia Nauk 2, 7–59. Shah, S.K., Sudan, C.S., 1987. Agnostid fauna from the Middle Cambrian of Kashmir. Journal of Geological Society of India 30, 48–60. Shah, S.K., Kumar, A., Sudan, C.S., 1996. Agnostid trilobites from the Cambrian sequence of Zanskar and their stratigraphic significance. Current Science 71, 951–954. Singh, B.P., Bhargava, O.N., Juyal, K.P., Negi, R.S., Virmani, N., Sharma, C.A., Gill, A., 2015b. Skeletal microfauna from the Cambrian Series 2 (Stage 4) Kunzum La

Formation, Parahio valley, Spiti region (Tethyan Himalaya), India. Current Science 109, 2191–2195. Singh, B.P., Chaubey, R.S., Bhargava, O.N., Prasad, S.K., Negi, R.S., 2016b. The Cambrian trilobite fauna from the Shian (Saybang) section, Pin Valley (Spiti) and its biostratigraphic significance. Palaeoworld, http://dx.doi.org/10.1016/ j.palwor.2016.04.002. Singh, B.P., Virmani, N., Bhargava, O.N., Gill, A., 2016c. Revision of diagnostic features of the trilobite genus Bhargavia (Ellipsocephaliodea) from the Parahio valley (Spiti), Northwest Himalaya, India. Journal Palaeontological Society India 61 (1), 9–14. Singh, B.P., Virmani, N., Bhargava, O.N., Kishore, N., Gill, A., 2014. Yuehsienszella (Cambrian Series 2) trilobite from the Parahio Valley, Spiti region (Zanskar-Spiti Sub-basin), India and its biostratigraphic significance. Journal Palaeontological Society India 59, 81–88. Singh, B.P., Virmani, N., Bhargava, O.N., Kishore, N., Gill, A., 2015a. Trilobite fauna of Cambrian Series 2 (Stage 4)-Series 3 (Stage 5) boundary from the Parahio Valley (Spiti), Northwest Himalaya, India. Abstract Himalayan Karakoram Workshop 30, 42–43. Singh, B.P., Virmani, N., Bhargava, O.N., Negi, R.S., Gill, A., Kishore, N., 2016a. Trilobite fauna of basal Cambrian Series 3 (Stage 5) from the Parahio Valley (Spiti), Northwest Himalaya, India and its biostratigraphic significance. Annales de Paléontologie 102, 59–67. Srikantia, S.V., 1981. The lithostratigraphy, sedimentation and structure of Proterozoic-Phanerozoic formations of Spiti basin in the higher Himalaya of Himachal Pradesh, India. In: Sinha, A.K. (Ed.), Contemporary Geoscientific Researches in India, (a commemorative volume in honor of S. P. Nautiyal). Bishen Singh Mahendra Pal Singh, Dehra Dun, pp. 31–48. Steck, A., Spring, L., Vannay, J.C., Masson, H., Stutz, E., Bucher, H., Marchant, R., Tiéche, J.C., 1993. Geological transect across the northwestern Himalaya in eastern Ladakh and Lahul. Eclogae Geologicae Helvetiae 86, 219–263. Swinnerton, H.H., 1915. Suggestions for a revised classification of trilobites. Geological Magazine (New Series) 6 (2), 487–496, 538–545. Thakur, V.C., 1981. Regional framework and geodynamic evolution of the IndusTsangpo suture zone in the Ladakh Himalayas. Royal Society of Edinburgh Transactions. Earth Sciences 72, 89–97. Vail, P.R., Hardenbol, J., Todd, R.G., 1984. Jurassic unconformities, chronostratigraphy, and sea-level changes from seismic stratigraphy and biostratigraphy. Association of American Petroleum Geologists Memoir 36, 129–144. Valdiya, K.S., 1989. Trans-Himadri intracrustal fault and basement upwarps south of the Indus-Tsangpo suture zone. In: Malinconico, L.L., Lillie, R.J. (Eds.), Tectonics of the western Himalayas., 232. Geological Society of America Special Paper, pp. 153–168. Van Wagoner, J.C., Mitchum, R.M., Campion Jr., K.M., Rahmanian, V.D., 1990. Siliciclastic sequence stratigraphy in well logs, core, and outcrops: concepts for high-resolution correlation of time and facies. American Association of Petroleum Geologists Methods in Exploration Series 7, 1–55. Vannay, J.C., Grasemann, B., 1998. Himalaya inverted metamorphism in the High Himalaya of Kinnaur (NW India): Petrography versus thermobarometry. Schweizerische Mineralogische und Petrographische Mitteilungen 78, 107–132. Vannay, J.C., Grasemann, B., Rahn, M., Frank, W., Carter, A., Baudraz, V., Cosca, M., 2004. Miocene to Holocene exhumation of metamorphic crustal wedges in the NW Himalaya: Evidence for tectonic extrusion coupled to fluvial erosion. Tectonics 23, http://dx.doi.org/10.1029/2002TC001429, TC1014. Virmani, N., Singh, Birendra, P., Gill, A., 2015. Integrated Litho-ichnofacies and Ichnofabric Analysis of the Lowermost Part of the Kunzum La Formation along the Khemangar khad and the Parahio Valley Sections, Spiti Region (Zanskar-SpitiKinnaur Basin), Northwest Himalaya, India. Journal of Geological Society of India 85, 557–566. Walch, J.E.I., 1771. Die Naturgeschiche der Versteinerungen Dritter Theil. Paul Jonathan Felstecher, Nuremberg, 235 p. Wang, Y., Yu, Y.Y., Peng, J., Wang, P.L., 2006. Discussion on the sequence stratigraphy and sea-level changes of the Kaili Formation at Balang, Taijiang, Guizhou. Journal of Stratigraphy 30, 34–41. Webb, A.A.G., Yin, A., Harrison, T.M., Célérier, J., Gehrels, G.E., Manning, C.E., Grove, M., 2011. Cenozoic tectonic history of the Himachal Himalaya (northwestern India) and its constraints on the formation mechanism of the Himalayan orogen. Geosphere 7, 1013–1061. Whitehouse, F.W., 1936. The Cambrian faunas of northeastern Australia, Part 1: stratigraphical outline, part 2: Trilobita (Miomera). Memoirs of the Queensland Museum 11, 59–112. Wiesmayr, G., Grasemann, B., 2002. Eohimalayan fold and thrust belt: implications for the geodynamic evolution of the NW Himalaya (India). Tectonics 2, 1058. Wyss, M., Hermann, J., Steck, A., 1999. Structural and metamorphic evolution of the northern Himachal Himalaya, NW India (Spiti-eastern Lahul-Parvati valley traverse). Eclogae Geologicae Helvetiae 92, 3–44. Yin, A., Harrison, T.M., 2000. Geologic evolution of the Himalayan–Tibetan orogen. Annual Review of Earth and Planetary Sciences 28, 211–280. Yin, A., Harrison, T.M., Murphy, M.A., Grove, M., Nie, S., Ryerson, F.J., Wang, X., Chen, Z., 1999. Tertiary deformation history of southeastern and southwestern Tibet during the Indo-Asian collision. Geological Society of America Bulletin 111, 1644–1664. Yin, L.-M., Singh, B.P., Bhargava, O.N., Zhao, Y-, L., Negi, R.S., Meng, F.-W., Sharma, C.A., 2017. Palynomorphs from the Cambrian Series 3, Parahio valley (Spiti), Northwest Himalaya. Paleoworld, http://dx.doi.org/10.1016/j.palwor.2017.05.004.

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001

G Model ANNPAL-2304; No. of Pages 11

ARTICLE IN PRESS B.P. Singh et al. / Annales de Paléontologie xxx (2017) xxx–xxx

Young, G.A., Ludvigsen, R., 1989. Mid-Cambrian trilobites from the lowest part of the Cow Head Group, western Newfoundland. Geological Survey of Canada Bulletin 392, 1–49. Yuan, J.L., Zhao, Y.L., Li, Y., Huang, Y.Z., 2002. Trilobite fauna of the Kaili Formation (uppermost Lower Cambrian-lower Middle Cambrian) from southeastern Guizhou, South China. Earth, Shanghai Scientific and Technical Publisher, Shanghai, 422 p. (in Chinese). Zaitsev, A.V., Baraboshkin, E.Yu., 2006. Stratigraphic hiatuses in the BillingenianKundan sediments (Lower-Middle Ordovician) in the central and eastern parts of the Baltic-Ladoga Klint. Moscow University Geological Bulletin 3, 11–30. Zhang, W., Lu, Y., Chu, C.-L., Qian, Y.-Y., Lin, H.-J., Zhaou, Z., Zhang, S.-G., Yuan, J.-L., 1980. Cambrian trilobite faunas of southwestern China. Palaeontologia Sinica, New Series B 16, 1–497. Zhao, Y.L., Peng, J., Yuan, J.L., Guo, Q.G., Tai, T.S., Yin, L.M., Parsley, L.R., Yang, Y., Yang, X.L., Zhang, P.X., 2012. The Kaili Formation and Kaili Biota at the WuliuZengjiayan section Guizhou Province, China and proposed Global Standard Stratotype - section and Point (GSSP) of the unnamed Cambrian Series 3, Stage 5. In: Zhao, Y.L., Zhu, M., Peng, J., Gaines, R.R., Parsley, R.L. (Eds.), CryogenianEdiacaran to Cambrian Stratigraphy and Paleontology of Guizhou, China. Journal of Guizhou University Natural Science 29, Suppl. 1. , pp. 108–124. Zhao, Y.L., Ruidong, Y., Yuan, J.L., Zhu, M., Guo, Q., Yang, X., Tai, T., 2001. Cambrian stratigraphy at Balang, Guizhou Provice, China: Candidate section for a global unnamed series and stratotype section for the Taijiangian stage. In: Peng, S.,

11

Babcock, L.E., Zhu, M. (Eds.), Cambrian System of South China, 13. Paleoworld, pp. 1–310. Zhao, Y.L., Yuan, J.L., Peng, S.C., Babcock, L.E., Peng, J., Guo, Q.J., Lin, J.P., Tai, T.S., Yang, R.D., Wang, Y.X., 2008. A new section of Kaili Formation (Cambrian) and a biostratigraphic study of the boundary interval across the undefined Cambrian Series 2 and Series 3 at Jianshan, Jianhe County, China with a discussion of global correlation based on the first appearance datum of Oryctocephalus indicus (Reed, 1910). Progress in Natural Science 18, 1549–1556. Zhao, Y.L., Yuan, J.L., Peng, S.C., Babcock, L.E., Peng, J., Lin, J.P., Guo, Q.J., Wang, Y.X., 2007. New data on the Wuliu-Zengjiayan section (Balang, South China), GSSP candidate for the base of Cambrian Series 3. Memoirs of Association of Australasian Paleontologist 33, 57–65. Zhao, Y., Yuan, J., Peng, J., Yang, X., Esteve, J., 2015. Restudy of Ovatoryctocara Tchernysheva, 1962 from the Kaili Formation, Jianhe County, Guizhou, South China. Annales de Paléontologie 101 (3), 193–198. Zhao, Y.L., Yuan, J.L., Peng, J., Yang, Y.N., 2011. The FADs of trilobite species for the international Cambrian stage 3, stage 4 and stage 5 in Guizhou Province China. In: Hollingworth, J.S., Sundberg, F.A., Foster, J.R. (Eds.), Cambrian Stratigraphy and Paleontology of Northern Arizona and Southern Nevada, 67. Museum of Northern Arizona Bulletin, p. 316. Zhu, M.Y., Erdtmann, B.D., Zhao, Y.-L., 1999. Taphonomy and Paleoecology of the early Middle Cambrian Kaili Lagerstätte in Guizhou, China (in Chinese). Acta Palaeontologica Sinica 38, 28–57.

Please cite this article in press as: Singh, B.P., et al., Additional trilobite fauna from the basal part of the Cambrian Series 3, Stage 5, Kunzam La (=Parahio) Formation, Parahio Valley, Spiti (Northwest Himalaya), India and its biostratigraphic significance. Annales de Paléontologie (2017), http://dx.doi.org/10.1016/j.annpal.2017.09.001