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The Cambrian pre-salt dolomite sequence in the Tarim Basin is a target zone of great strategic significance for hydrocarbon exploration in the basin. Using the results of the interpretation of 3D seismic data from Lunnan and 2D seismic data covering the whole basin, and based on a synthesis of outcrop data, drilling data, well logs, core data, and thin-section data, and the findings from previous studies, this paper studies the characteristics of the facies of the Middle–Lower Cambrian in the platform area in the Tarim Basin, the formation and evolution of platform margins, and the sedimentary characteristics, lithofacies, and paleogeographic characteristics of the Middle–Lower Cambrian series. Based on the types of lithofacies and the seismic facies analysis, the sedimentary facies of the Middle–Lower Cambrian strata can be classified into the five types. From bottom to top, the Middle–Lower Cambrian have experienced several development stages, including the deposition of continental shelf sediments of the Yuertusi Formation, gently sloping non-rimmed platform margin sediments of the Xiaoerbulake Formation, weakly rimmed platform margin sediments of the Wusongger and Shayilike formations, and strongly rimmed platform margin sediments of the Awatage Formation. In each stage, the platform margin shifted further east relative to its location in the previous stage. Based on these results and previous studies, the lithofacies and paleogeography maps of the Middle–Lower Cambrian in the Tarim Basin are modified, and the implications for hydrocarbon exploration in this area are discussed. [ABSTRACT FROM AUTHOR]

The strong tidal currents of the Minas Passage in the Bay of Fundy, Nova Scotia, have made this area an important site for testing and development of tidal power technologies. Understanding sediment processes in this area is essential for determining the impacts that large-scale tidal power extraction would have on the system. Previous estimates of sediment input to the Basin suggest that much more sediment enters the Basin than accumulates within it; therefore, the bottom sediment texture should be in hydrodynamic equilibrium with bottom currents. A recent study, however, showed that sediment texture is generally finer that what was expected based on current speeds. This paper uses geographic information systems methods to provide updated and more highly resolved measurements of the amount of sediment entering the Minas Basin from the dominant source, which is coastal erosion. Volumetric input from coastal erosion is 1.1 × 106 m3·a−1, which is more than two times smaller than previous estimates. This updated value makes input rates comparable to accumulation rates, and agrees with the hypothesis that bottom sediment texture is not in equilibrium with current speeds. Grain-size distributions also support the hypothesis that the Minas Basin acts as a sediment trap. [ABSTRACT FROM AUTHOR]

The holotype of Garudimimus brevipes, discovered from the Upper Cretaceous sediments of Mongolia and named by Barsbold in 1981, is redescribed in detail in this paper. Reexamination of the holotype reveals a great deal of anatomical information, which allows us to revise the original diagnosis of this taxon and make comparisons with other ornithomimosaur taxa to understand the evolution of ornithomimosaurs. This paper suggests that characters used to differentiate this taxon in the original paper (short ilia, short metatarsals, exposure of the proximal end of metatarsal III, presence of pedal digit I, and absence of pleurocoels) are not apomorphies but represent the primitive conditions in ornithomimosaurs and are symplesiomorphies. Revised diagnoses are assigned for G. brevipes (posteriorly positioned jaw articulation, fossae at base of dorsal process of supraoccipital, paired depressions on neural spines of proximal caudal vertebra, and deep groove on lateral surface of pedal phalanges III-1 and III-2). Metatarsals of Garudimimus display a non-arctometatarsalian condition as in an Early Cretaceous form, Harpymimus, but the constriction of metatarsal III in Garudimimus is intermediate between Harpymimus and the arctometatarsalian condition in Gallimimus and other derived ornithomimosaurs (ornithomimids). Garudimimus is the only non-ornithomimid ornithomimosaur with edentulous jaws, which were probably covered by rhamphothecae. The loss of teeth with evolution of rhamphothecae and development of a cutting edge in the dentary of Garudimimus suggest the acquisition of feeding habits that included plucking food at the anterior portion of the jaw and cutting at the middle portion, similar to ornithomimids. [ABSTRACT FROM AUTHOR]

The Frenchman and Ravenscrag formations of southwestern Saskatchewan, Canada, record an apparently continuous sequence of nonmarine clastic sediments across the Cretaceous-Paleogene (K-Pg) boundary. Extensive exposures of these fossil-rich sediments occur in the Frenchman River Valley, near the towns of Ravenscrag, Eastend, and Shaunavon, and have been a focus of study since the 1970s. Despite this long history of investigation, a comprehensive account of the geographic and stratigraphic positions of many of the significant fossil localities has yet to be published. Given this state of affairs, the goals of this paper are to ( i) document the geographic locations, stratigraphic positions, and lithologies of 11 key vertebrate microfossil localities, including several new localities that have been recently discovered, and ( ii) provide an update on the status of these fossil localities, the majority of which have not been sampled in the last 20 years. Four fossil localities are known from the lower Paleocene Ravenscrag Formation, all of which are Puercan in age: Rav W-1 (Pu2), French Fry (Pu1), Croc Pot (?Pu2), and Pine Cree (?Pu2). With the exception of Rav W-1, which has since been lost as a consequence of quarry reclamation, all of the Ravenscrag Formation localities remain accessible and continue to be productive. Seven vertebrate microfossil localities from the upper Maastrichtian Frenchman Formation are reported here, all of which are Lancian in age: Long Fall, Fr-1, By Gar Gap, Hairpin, Wounded Knee, Wounded C, and Gryde. With the exception of Long Fall and Wounded Knee, which have been lost through reclamation or construction, all of the Frenchman Formation localities are accessible and remain productive. [ABSTRACT FROM AUTHOR]

The exposures at the St. Marys Cement Inc. quarry at St. Marys, Ontario, have been studied by geologists since the mid-1950s. This paper summarizes previous and new information collected in 2009, 2010, and 2012 and discusses the record of sediments resting on the bedrock surface that have been exposed during quarry operations. The exposed sediments illustrate the dynamic behavior of the Laurentide Ice Sheet in this area during the Late Wisconsin. Evidence for subglacial meltwater activity, shifting ice-flow directions during till deposition, a local or regional erosion event, possible subaerial exposure, and ice-marginal sedimentation is observed in the sequence of tills and stratified sediments exposed in the quarries. It also highlights how rapid lateral facies changes, complex contact relationships, and steep erosional contacts can prove to be challenging for correlation and extrapolation of subsurface units into three-dimensional stratigraphic models. Fourteen units were identified of which the lower six were deposited during the Nissouri age (Catfish Creek Drift). This included five layers of till deposited by a glacier that alternated from flowing out of the Lake Huron basin to that of a regional flow to the south-southwest. An angular unconformity cuts into these sediments and separates them from a finer-grained sediment sequence (primarily of Port Bruce age) consisting of glaciofluvial gravel, two fine-textured till layers, and rhythmically bedded glaciolacustrine sediments, all overlain by the uppermost till, the Rannoch Till, and Mitchell Moraine ice-marginal fan sediments. [ABSTRACT FROM AUTHOR]

This paper presents results of a passive-source seismic mapping study in the Nechako-Chilcotin plateau of central British Columbia, with the ultimate goal of contributing to assessments of hydrocarbon and mineral potential of the region. For the present study, an array of nine seismic stations was deployed in 2006-2007 to sample a wide area of the Nechako-Chilcotin plateau. The specific goal was to map the thickness of the sediments and volcanic cover, and the overall crustal thickness and structural geometry beneath the study area. This study utilizes recordings of about 40 distant earthquakes from 2006 to 2008 to calculate receiver functions, and constructs S-wave velocity models for each station using the Neighbourhood Algorithm inversion. The surface sediments are found to range in thickness from about 0.8 to 2.7 km, and the underlying volcanic layer from 1.8 to 4.7 km. Both sediments and volcanic cover are thickest in the central portion of the study area. The crustal thickness ranges from 22 to 36 km, with an average crustal thickness of about 30-34 km. A consistent feature observed in this study is a low-velocity zone at the base of the crust. This study complements other recent studies in this area, including active-source seismic studies and magnetotelluric measurements, by providing site-specific images of the crustal structure down to the Moho and detailed constraints on the S-wave velocity structure. [ABSTRACT FROM AUTHOR]

A giant short-faced bear (Arctodus simus) ulna fragment was found at the base of exposed Quaternary sediments at Cowichan Head, southern Vancouver Island, British Columbia. In this paper, the ulna fragment and its geological context are described and a reasonable taphonomic trajectory is presented. The radiocarbon age of 22 750 ±140 BP on the bone indicates that these bears were on Vancouver Island during the late Wisconsinan. A likely source for the Cowichan Head A. simus was from the mainland to the southeast. [ABSTRACT FROM AUTHOR]

Recent archaeological excavations at a deeply stratified site in northwest Calgary, Alberta have uncovered four occupation layers spanning the interval from 8000 to 2000 BP. Depending on the dating one accepts for the Holocene thermal maximum, two or more of these occupations occurred during this interval of aridity. This site thus provides a record of human occupation during the Archaic (Middle Prehistoric I) period in the Calgary area. More importantly, the site occurs in an upland setting, apparently far removed from reliable sources of water and normal environments of deposition. Yet, the cultural deposits occur in sediments which extend 2 m below surface and include five sedimentary units as well as a minimum of three pedogenic units. This paper presents the results of geoarchaeological research on the changing landscape for the site and notes the implications of these changes for the study of Archaic manifestations on the northern Plains. [ABSTRACT FROM AUTHOR]