Satish J. Patel

Trace fossil assemblages in mixed siliciclastic-carbonate sediments of the Kaladongar Formation (Middle Jurassic), Patcham Island, Kachchh, Western India

The Middle Jurassic rocks of the Kaladongar Formation well exposed in the Kaladongar Hill range of the Patcham Island and Kuar Bet of the Northern Kachchh comprises of ∼450 m thick sequence of mixed siliciclasticcarbonate sediments intercalated with shales. These Mixed siliciclastic-carbonate sediments show wide variation in textural and mineralogical composition and represent genetically related six rock types: micritic sandstone, allochemic sandstone, sandy allochemic limestone, micrtic mudrock, sandy micrite and muddy micrite; which are highly bioturbated and show behaviourally diverse groups of trace fossils. Total 34 ichnogenera are identified, which includes, Arenicolites, Asterosoma, Beaconites, Bergaueria, Chondrites, Cochlichnus, Dactylophycus, Daedalus, Didymaulichnus, Diplocraterion, Gordia, Gyrochorte, Gyrolithes, Ichnocumulus, Laevicyclus, Lockeia, Margaritichnus, Monocraterion, Nereites, Ophiomorpha, Palaeophycus, Phoebichnus, Phycodes, Pilichnus, Planolites, Plug Shaped Form, Protovirgularia, Rhizocorallium, Scolicia, Skolithos, Taenidium, Teichichnus, Thalassinoides and Walcottia. These trace fossils are classified into six morphological groups namely, circular and elliptical structures; simple structures; branched structures; rosette structures; spreiten structures; and winding and meandering structures. These trace fossils are further group into eight assemblages which occurred together into mixed siliciclastic-carbonate sediments, include, Asterosoma assemblage, Gyrochorte assemblage, Rhizocorallium assemblage, Thalassinoides assemblage, Planolites-Palaeophycus assemblage, Phycodes assemblage, Ophiomorpha assemblage and Skolithos assemblage. The recurring pattern of these assemblages through the sequence displays the development of Skolithos and Cruziana ichnofacies and at places the mixed Skolithos-Cruziana ichnofacies which suggest a low wave and current energy conditions with intervening period of high wave and current energy conditions and an intermediate period of stressful environments, respectively. Sedimentological and ichnological data suggest that the deposition of the mixed siliciclastic-carbonate sediments of the Kaladongar Formation took place in the foreshore to offshore environment under fluctuating wave and current energy condition.

Ichnology of the Goradongar Formation, Goradongar hill range, Patcham island, Kachchh, Western India

The middle Jurassic Goradongar Formation exposed in Goradongar hill represents a mixed siliciclasticcarbonate succession with shales and limestones. They contain a large number of well preserved trace fossils. Total 44 ichnospecies of 31 ichnogenera; representing diverse ethology, were grouped in five ichnoassemblages (Planolites, Palaeophycus, Gyrochorte, Rhizocorallium and Arenicolites assemblage). These recurring ichnoassemblages represent the Cruziana ichnofacies and occasionally a mixed Skolithos-Cruziana ichnofacies. Patterns of diversity and density of the trace fossils reveal changes in bathymetry, oxygen level, trophic level and the sub-strate conditions at the time of deposition. These paleoenvironment and palaeo-oceanography changes are co-relatable to world-wide Bathonian-Callovian (middle Jurassic) deposits.

Frequent inoculations with radiation attenuated sporozoite is essential for inducing sterile protection that correlates with a threshold level of Plasmodia liver-stage specific CD8+ T cells

Whole sporozoite vaccine (WSV) is shown to induce sterile protection that targets Plasmodium liver-stage infection. There are many underlying issues associated with induction of effective sterile protracted protection. In this study, we have addressed how the alterations in successive vaccine regimen could possibly affect the induction of sterile protection. We have demonstrated that the pattern of vaccination with RAS (radiation attenuated sporozoites) induces varying degrees of protection among B6 mice. Animals receiving four successive doses generated 100% sterile protection. However, three successive doses, though with the same parasite inoculum as four doses, could induce sterile protection in ∼50% mice. Interestingly, mice immunized with the same 3 doses, but with longer gap, could not survive the challenge. We demonstrate that degree of protection correlates with the frequencies of IFN-γ+ and multifunctional (IFN-γ+ CD107a+) CD8+ TEM cells present in liver. The failure to achieve protective threshold frequency of these cells in liver might make the host more vulnerable to parasite infection during infectious sporozoite challenge.

Facies controlled synaeresis cracks in mixed siliciclastic-carbonate sediments of Middle Jurassic of Patcham Island, Kachchh, Western India

Synaeresis cracks are observed at different stratigraphic levels in shallow marine mixed siliciclastic-carbonate sediments of the Middle Jurassic rocks of the Patcham Island, Kachchh, Western India. Cracks are preserved as cast or grooves in micritic sandstone of the Kuar bet member of Kaladongar Formation and sandy allochem limestone of the Raimalro Limestone member of Goradongar Formation. It bear distinct morphology of simple, straight to gently curved, spindle-shaped, irregular, unbranched to branched at acute angle; interconnected curlicue forms of non-orthogonal pattern. The X-radiography shows sharp margin and tapering twigs which support to nullify the possible biogenic origin. These cracks are developed at sediment-water interface and sediment-sediment interface in aqueous conditions, where partial dewatering of sediments causes reduction of sediment volume and loss of plasticity. Formation of cracks are also post-depositional phenomenon operated during initial phase of diagenesis where induced stress is generated due to compaction of sediments and neomorphism/recrystallisation of the susceptible carbonate grains.

Funalichnus bhubani isp. nov. from Bhuban Formation, Surma Group (Lower -Middle Miocene) of Aizawl, Mizoram, India.

A new ichnospecies of the ichnogenus Funalichnus Pokorný is described from the Middle Bhuban Unit, Bhuban Formation, Surma Group (Lower - Middle Miocene) of Aizawl, Mizoram, India. Funalichnus bhubani isp. Nov. Is a large burrow displaying cylindrical segments that are oriented nearly perpendicular to the bedding plane. The new ichnospecies can be identified on the basis of general form, size, unlined passive filling and twisted rod-like structure. The association of Funalichnus bhubani isp. Nov. With Arenicolites, Diplocraterion, Ophiomorpha Psilonichnus Skolithos and Thalassinoides points to its bathymetric restriction. The deep extension of the burrow in clastic sediments provides a favourable condition for preservation in the shoreface environment and occurrence in fine- to medium-grained clastic sediments may be a preservational preference.

Plug shaped burrows Conichnus - Conostichus from the Late Cretaceous of Bagh Group, Gujarat, western India

Plug-shaped ichnofossils Conichnus conicus, Conostichus broadheadi and C. stouti are found in the intercalated micritic sandstone and sandy allochemic limestone shale sequence of Bagh Group, Narmada district, Gujarat. These ichnospecies occur at two stratigraphic levels and shows distinct morphological features interpreted as resting/dwelling structures of sea anemone. The occurrence of these ichnospecies along with oyster fossils genera like Bosostrea and Indostrea indicate shallow marine environment.

Stratigraphy and Sedimentology of Middle Jurassic Sequence of Chorar Island, Patan District, Kachchh Basin, Gujarat

Chorar Island exposes ∼109 m thick middle Jurassic (Bathonian-Callovian) succession in the eastern most part of the Kachchh Basin, Patan District, Gujarat and is divided into two, Khadir and Gadhada formations. It mainly comprises of mixed siliciclastic-carbonate sediments and limestones; the shales dominate the lower part of the succession while the top of the succession is marked by ferruginous sandstone which also forms the vast, prominent peripheral zone of the Chorar dome. The field and laboratory analysis of the succession reveals nine lithofacies which includes ferruginous sandstone, cross bedded white sandstone, micritic sandstone, allochemic sandstone, sandy micrite, mudstone, sandy allochemic limestone, coralline limestone and shale. The mix siliciclastic-carbonate sediments and ferruginous facies are fossiliferous in nature and display sedimentary structures, like ripple marks, cross- and planar- lamination with biogenic sedimentary structures. Coralline limestone facies comprise of large size (>1m diameter) corals, which are diagenetically modified severely and have lost its original internal structures. The sediment characteristics and associated bioclasts indicates low to moderate wave and current energy in shoreface-offshore subsequently changing to wave dominated shoreface during the deposition of the middle Jurassic sediments of the Chorar Island.

Facies characterisation of a shallow-water deltaic succession: the Upper Jurassic Wagad Sandstone Formation of Kachchh, western India

Abstract Ancient deltaic facies are difficult to differentiate from tidally influenced shallow-marine facies. The Wagad Sandstone Formation of the Wagad Highland (eastern Kachchh Basin) is typified by offshore and deltaic facies with sedimentary characteristics that represent different conditions of hydrodynamics and related depositional processes. The study area, the Adhoi Anticline, constitutes a ~154-m-thick, shale-dominated sequence with progressive upward intercalations of bioturbated micritic sandstone and quartz arenite. Two thick Astarte beds (sandy allochemic limestone), with an erosional base and gravel blanketing, illustrate tidal amplification and high-energy stochastic events such as storms. Sedimentological characteristics document three depositional facies: an offshore, shale-dominated sequence prograding to proximal prodeltaic micritic sandstone and quartz arenite with sandy allochemic limestones, further prograding to mouth bars and abandoned channel deposits. The Wagad Sandstone Formation displays depositional environmental conditions that are dissimilar from those of coeval deposits in Kachchh sub-basins as well as on regional and global scales. This is attributed to a reactivation of the Kachchh Mainland and South Wagad faults which resulted in detachment and uplift of the Wagad block which then experienced prograding deltaic conditions.

Ichnology of the Callovian-Oxfordian rocks of the Katrol hill range, Kachchh, western India

On the basis of distinct lithologic features such as composition, grain size, bedding characteristics and sedimentary structures, six facies were identified in Callovian to Oxfordian rocks exposed southwest of Bhuj, Kachchh. They are interbedded calcareous shale-siltstone (ICSSF), limestone (LF), ferruginous sandstone (FerSF), felspathic sandstone (FelSF), grey shale (GSF) and oolitic limestone (OLF) facies. The rich and highly diversified trace fossils reveal a wide range of animal behaviours represented by dwelling, feeding, crawling and resting structures. Horizontal feeding structures are found abundantly in all lithofacies indicating low wave and current energy and deposition of poorly sorted muddy to sandy sediments. A few coarse layers containing Arenicolites, Ophiomorpha and Skolithos indicate the presence of opportunistic animals (due to their first appearance under harsh conditions) under -intermittently moderate wave and current energy or storm wave conditions (due to coarse grain size and dominance/presence of only vertical trace fossils) in the shoreface zone. Taenidium occurs mainly in the lower shoreface to transitional zone suggesting low to moderate energy conditions. Thalassinoides occurs in middle to lower shoreface settings under relatively low-energy conditions. Zoophycos represents offshore environment, where it occupies the deepest bioturbation levels.The characteristic lithofacies and assemblages of trace fossils in the rocks of the Chari/Jumara Formation indicate a depositional environment fluctuating from the upper shoreface to offshore zone.

Ichnology of mixed siliciclastic-carbonate sedimentary cycles and their sequence stratigraphic context: Kaladongar Formation (Middle Jurassic) of Kachchh, western India

The bromalite record of the western United States is quite limited, especially in contrast to the Triassic and Cretaceous records of the same region. Indeed, there are only a handful of well documented vertebrate bromalites from the Jurassic strata of the western USA, including: (1) coprolites from the nonmarine Early Jurassic Glen Canyon Group; (2) consumulites and evisceralites from the Middle Jurassic Todilto and Sundance formations; and (3) consumulites, putative coprolites and pseudobromalites from the nonmarine Upper Jurassic Morrison Formation. Early Jurassic red beds are notably less fossiliferous than those of the Triassic (e.g., contrast the fossil record of the Chinle and Glen Canyon groups). The Middle Jurassic of the region includes several eolianites and sabkha-like deposits representing environments that preserve few bromalites. The Upper Jurassic Morrison Formation contains abundant vertebrate body fossils and many tracks but very few bromalites in contrast to many broadly similar fluvial deposits of Triassic and Cretaceous age in the same region. The global bromalite record also appears to be depauperate in the Jurassic, with a few exceptions such as marine shales and lithographic limestones in Europe (e.g., Lower Jurassic of England, Upper Jurassic Solnhofen Limestone of Bavaria). This relative lack of a global Jurassic bromalite record may in part be more a result of a lack of collection and study. However, the relative lack of nonmarine bromalites is clearly influenced by high sea levels in the Early Jurassic, a paucity of Middle Jurassic nonmarine vertebrate-bearing units and a lack, or lack of recognition of, bromalites in major Upper Jurassic nonmarine vertebrate faunas (e.g., China, Tanzania, Portugal, etc.). In the Western United States there is clearly a need for more detailed examination of known specimens (e.g., putative Morrison coprolites) and a focus on collecting more examples. 1 Flying Heritage Collection, 3407 109thSt SW, Everett, WA 98204; e-mail: adrianhu@flyingheritage.com 2 New Mexico Museum of Natural History and Science, 1801 Mountain Road NW, Albuquerque, NM 87104; e-mail: spencer.lucas@state.nm.us JURASSIC BROMALITES IN THE WESTERN UNITED STATESThe Springdale Sandstone records a large number of reversals of the geomagnetic field. Forty-three percent of the 60 m section investigated showed 25 polarity intervals. These frequent reversals follow the nearly constant normal polarity of the underlying Whitmore Point strata. Comparison of the reversal sequence of the Springdale Sandstone with a core from the Paris Basin suggests that the Springdale Sandstone spans an interval extending possibly from as early as late Hettangian to early-mid Sinemurian time. The paleomagnetic pole calculated from Springdale paleomagnetic directions is statistically identical to that of the underlying Whitmore Point Member of the Moenave Formation, and considerably different from that of the overlying Kayenta Formation. This similarity suggests that the Springdale Sandstone should be retained as a member of the Moenave Formation, not considered part of the Kayenta Formation.Two partial skeletons of allosaurid theropods belonging to an adult and a juvenile from the Upper Jurassic (Tithonian) Morrison Formation of McElmo Canyon in Montezuma County, southwestern Colorado, were discovered in 1953 by the late Joseph T. Gregory and David Techter. The adult specimen consists of several isolated cranial and postcranial skeletal elements that are exceptionally well-preserved and include the left premaxilla, maxilla, dentary, teeth, quadratojugal, two caudal vertebrae, pubic peduncle, ischium, proximal tibia, a nearly complete left foot, and several isolated teeth, whereas the juvenile specimen is represented by the distal portion of the right dentary and a fragmentary splenial. The specimens represent a new species of Allosaurus , here named Allosaurus lucasi , which differs from Allosaurus fragilis by having a relatively short premaxilla and robust quadratojugal with short jugal process and a short quadrate process of the quadratojugal that is at the same level as the rostral quadratojugal ramus. The presence of a new species of Allosaurus in the Tithonian of North America provides further evidence of the taxonomic and morphological diversity of the Allosauridae clade and their continuous evolutionary success, which extended to the Cretaceous.To evaluate the utility of high-resolution micro-computed tomography (micro-CT) in observing radiolarian fossils, we examined the skeleton of the Jurassic radiolarian fossil Protunuma ? ochiensis Matsuoka using a micro-CT device. Although this species is a closed Nassellarian with a thick exterior wall, important taxonomic characters on the interior and exterior of the shell were represented almost perfectly in the acquired three-dimensional computer graphic images. These characters include those documented in the original description, such as the height and width of the skeleton, the outline, the number of segments, the pore arrangement and other features. In addition, the structure of the initial spicule of this species was revealed newly. An enlarged plaster radiolarian model printed using the laminated modelling method was useful for detailed observation. Nondestructive omnidirectional observation is an advantage of this method, which is not possible with scanning electron microscopy or optical microscopic investigations. Micro-CT technology would become an effective observational tool for radiolarian studies in the near future. method of visualising and measuring the internal geometries of opaque objects. Micro-CT is specialised for visualising the structures of micrometreto centimetre-sized objects with greatly increased resolution. This developing technoloINTRODUCTION X-ray computed tomography (CT), which is commonly used for medical and industrial purposes, is a nondestructive 1 Gas Hydrate Research Laboratory, Meiji University, Kanda-Surugadai 1-1, Chiyoda-ku, Tokyo, 101-8301, Japan; phone and fax: +81-3-3296-4582; e-mail: nao.ishida21@mbn.nifty.com. 2 Department of Mechanical Engineering, Faculty of Science and Engineering, Setsunan University, Neyagawa 572-8508, Japan; phone: +81-72-839-9165; e-mail: kishimoto@mec.setsunan.ac.jp. 3 Department of Geology, Faculty of Science, Niigata University, Niigata 950-2181, Japan; phone and fax: +81-25-262-6376; e-mail: amatsuoka@geo.sc.niigata-u.ac.jp. 4 Research and Development Center for Global Change (RCGC), JAMSTEC, Yokosuka, Kanagawa 237-0061, Japan; phone: +81-46-867-9436; e-mail: kimopy@jamstec.go.jp. 5 Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan; phone and fax: +81-25-262-7640; e-mail: kurihara@geo.sc.niigata-u.ac.jp. 6 Department of Mechanical Engineering, Faculty of Science and Engineering, Toyo University, Kawagoe, Saitama 350-8585, Japan; phone: +81-49-239-1396; e-mail: tyoshino@toyo.jp. 78 Naoto Ishida et al. gy is being applied to a wide range of geological and palaeontological investigations (e.g. Ketcham, Carlson, 2001). To evaluate the potential of micro-CT imaging technology in investigating microfossils, the authors have experimentally examined the skeletons of foraminifers, ostracodes, diatoms and radiolarians. For example, Matsuoka et al. (2012) reported the exact pore number of a specimen of the genus Pantanellium and represented its pore distribution on a spherical shell based on three-dimensional (3D) scanning data. Furthermore, Yoshino et al. (2014) presented a method that uses 3D information to automatically determine the pore numbers of spherical radiolarian skeletons. In this study, we present the results of 3D scanning of the Jurassic radiolarian Protunuma ? ochiensis Matsuoka using a high-resolution micro-CT scanner. Although closed Nassellarians, including this species, are commonly recovered from Jurassic sediments, conventional methods cannot be used for nondestructive observation of a combination of both their surface textures and their internal structures. Observation using high-resolution micro-CT overcomes this difficulty. This study introduces the observation of radiolarian fossils using 3D imaging methods and emphasises the utility of high-resolution micro-CT for palaeontological investigations. METHODS AND MATERIALSThe thick and relatively complete Jurassic succession of eastern Greenland provides a unique biostratigraphic record for the North Atlantic region. The main biostratigraphic control for the succession has been provided by molluscs, especially ammonites and to a lesser extent by bivalves and belemnites. The late John Callomon and colleagues recognised 93 Boreal ammonite-bearing horizons in the Mid to Late Jurassic. This provides a reliable backbone to the biostratigraphy of these strata, prompting a palynological colleague to comment that they are the “Policemen of Jurassic Stratigraphy”. Other biostratigraphically significant microfossil and palynological groups, can be calibrated against this standard, but on their own cannot achieve the same precision.​ The Early Jurassic of eastern Greenland does not have such fine control as later parts of the period. No single biostratigraphic group can be used successfully throughout the interval, and there are only three significant ammonite faunas during this period. Reliance on various different organisms is necessary to cope with the changing range of marine to non-marine environments. CASP field-work from 1990 to 2012 has resulted in the collection of much biostratigraphic material. In this article, published data are summarised together with previously unpublished data in the form of a unified table. The integrated chart shows detailed columns for the whole eastern Greenland Jurassic. It demonstrates the ammonite, palynological and microfossil events/biozones and horizons which are correlated by time. More limited information is available on belemnites, bivalves and macroflora. This is the first time such an integrated biostratigraphic scheme has been assembled for the Jurassic of eastern Greenland. It will be of value to the offshore oil-industry in the northern North Atlantic and on the Barents Shelf as well as to field geologists in Greenland.Measured sections of Jurassic San Rafael Group strata correlated by lithostratigraphy along an ~60 km transect between Bluff and the Abajo Mountains in southeastern Utah indicate that: (1) the Carmel Formation is continuous and disconformable on the Navajo Sandstone (J-2 unconformity); (2) the Entrada Sandstone (Slick Rock Member) is continuous and conformable on the Carmel; (3) the Summerville Formation is continuous and does not intertongue with the Entrada (its base is the J-2 unconformity); (4) the Bluff Sandstone grades northward into the upper Summerville south of the Abajo Mountains; (5) the Recapture Member of the Bluff is physically continuous with at least part of the Tidwell Member of the Summerville; and (5) the base of the Salt Wash Member of the Morrison Fm. is a pervasive unconformity (J-5) with demonstrable local stratigraphic relief of up to 14 m. These observations counter previous claims of extensive Entrada-Summerville intertonguing in southeastern Utah and do not support recognition of depositional sequence boundaries in the Entrada and Summerville lithosomes. Though Entrada deposition may have been by a wet eolian system, its southeastern Utah outcrops are well to the south/ southeast of any marine and paralic facies with which the Entrada intertongues. 1 New Mexico Museum of Natural History, 1801 Mountain Road NW, Albuquerque, NM 87104 USA; e-mail: spencer.lucas@state.nm.us fornia and left eolian sandstone up to 660 m thick called in different regions Navajo Sandstone, Nugget Sandstone or Aztec Sandstone. Later, during the Middle Jurassic (Callovian), the Entrada erg extended from Utah to Oklahoma and from New Mexico to Wyoming. The last Jurassic erg, the Bluff sand sea, accumulated during the Middle-Late Jurassic transition and was primarily located in the Four Corners. The two younger ergs – Entrada and Bluff – accumulated at a time when a Jurassic Cordilleran seaway was present to the northwest, in what is now Idaho and parts of northern and western Utah. The ergs were landward of that seaway and their deposits interfinger to the northwest with its marine and paralic facies. In southeastern Utah, O’Sullivan (1980) INTRODUCTION Jurassic strata of the American Southwest include some of the most intensively studied eolian strata on the planet. These strata document several extensive sand seas (ergs) of Jurassic age that covered many thousands of square kilometers, including the largest of all Phanerozoic ergs, the Navajo erg (e.g., Kocurek, Dott, 1983; Blakey et al., 1988). The Jurassic erg history in the southwestern USA begins with the Wingate erg, which covered the Four Corners during the Triassic-Jurassic boundary interval. Next youngest is the Navajo erg, which extended at least from Wyoming to Cali-