Stratigraphy

The Ernst Member of the Boquillas Formation of West Texas was deposited in shallow waters (above storm wave base) near the Tethyan aperture of the Cretaceous Western Interior Seaway (KWIS) immediately following regionwide subaerial exposure of the Buda Limestone, and has partial lateral equivalence to both the Eagle Ford Group and overlying Austin Chalk of south and central Texas (where the Eagle Ford Group is a prolific, unconventional shale play). The Ernst Member type section at Ernst Tinaja, Big Bend National Park (BBNP), Texas is an important reference section for understanding stratigraphic relations between Eagle Ford Group- and Austin Chalk-equivalent strata in West Texas and northern Mexico.

A new chronostratigraphic framework integrating four U-Pb Chemical Abrasion-Isotope Dilution Thermal Ionization Mass Spectrometry (CA-IDTIMS) bentonite ages from the Ernst Member and six bentonite ages from the Eagle Ford Group at Lozier Canyon with biostratigraphic proxies (ammonites, inoceramids, foraminifera and calcareous nannofossils), hand-held spectral gamma ray (HHSGR), hand-held X-Ray Fluorescence (HHXRF) and δ13Ccarb measurements constraining (spatially and temporally) stratal surfaces, isotopic events and biozones in West Texas is presented. In BBNP, the Ernst Member preserves neither the OAE2 positive carbon isotope excursion nor the Cenomanian/Turonian boundary. Chemostratigraphic analysis of U, Mo, V, Zr, Ti, Ca, Sr, K, Al and Si/Ti identify carbonate and TOC-rich intervals whereas biostratigraphic proxies and CA-IDTIMS bentonite ages, in conjunction with lithostratigraphic data, delineate a Late Turonian Austin Chalk-equivalent section (52.7-84.6 m; 173-277.5 ft) at Ernst Tinaja, BBNP.

Principes de la Stratigraphie - HARRIS en VF !  La version Française du célèbre ouvrage de E.C. HARRIS "Principles of Archaeological Stratigraphy"  publiée en 1979 vient de paraître.

  Elle sera prochainement disponible en téléchargement gratuit sur le site de l'auteur :

http://harrismatrix.com/

Much of the enigma in the geology of Ilocos Norte originates from the tectonic zone of the Philippine archipelago in the Western Pacific. Even the basement rock of Ilocos Norte is also less documented in literatures, in which an 'ophiolite' or 'melange' is loosely used to describe the 'chaotic assemblage of ultramafics' found in northwest Luzon. In this study, Ilocos Norte is composed of the basement Cretaceous Dos Hermanos Melange characterized by highly sheared, serpentinized ultramafics and metamorphics, which formed at the southeastern margin of Mainland Asia that eventually thrusted over northwestern Luzon during the Middle Miocene. The volcanic-clastics and intrusive sequences attributed to the Bangui Formation, Bojeador Formation, and Pasaleng Quartz Diorite are mainly formed by subduction-related magmatism associated to the regional geodynamic setting of southeast Asia during Eocene to Miocene times. Lastly, marine clastic-carbonate sequences, comprised by the Batac Formation, Laoag Formation, Dagot Limestone, and Pasuquin Limestone, are formed by southeast Asian regional sea level fluctuations caused by the opening of the South China Sea Basin since mid-Oligocene. Deformational features such as a slump deposit and folding of the Batac Formation are attributed to post-depositional ductile compressive deformation associated to the Plio-Quaternary Vigan-Aggao Fault and Abra River Fault activity. Furthermore, this study presents new extensive exposures of the Pasaleng Quartz Diorite along the eastern margin of Ilocos Norte in Solsona as well as recent findings on the ages of Batac Formation, Pasuquin Limestone, and Laoag Formation based on paleontological analysis of calcareous nannofossils.

This is part of a collection of files for my paper on the structure of the Clark, Mescal and Ivanpah mountains of San Bernardino County, California. On Academia.com I have posted the following sections:

Abstract
Structure (Text)
Comparative Stratigraphic Table
Generalized Geologic Map
Detailed Geologic Mosaic
Geologic Mosaic Index
References

These parts are linked at

http://www.greggwilkerson.com/ivanpah-mescal-and-clark-mountains.html

The upper Campanian Dinosaur Park Formation (DPF) is a south- and eastward-thinning fluvial to marginal-marine clastic wedge in the Western Canadian Sedimentary Basin. The DPF is overlain by the Bearpaw Formation (BF), a fully marine clastic succession representing the final major transgression of this epicontinental sea across western North America. In southwestern Saskatchewan, the DPF is comprised of marginal-marine coal, carbonaceous shale, and heterolithic siltstone and sandstone grading vertically into marine sandstone and shale of the BF. Historically these deposits have been interpreted as the record of fluvial delta systems along a paleocoastline. This study revisits this interpretation using integration of ichnologic, sedimentologic, and sequence stratigraphic concepts.

Detailed facies analysis indicates the upper DPF does not record sedimentation in a delta system, but rather was deposited in a low-relief coastal plain with a wave-dominated, tidally influenced, fluvially modified shoreline. Marginal-marine facies, interpreted as lagoons, tidal flats and estuaries, are bioturbated, showing a typical brackish-water trace-fossil assemblage, including Asterosoma isp., Chondrites isp., Cylindrichnus concentricus, Teichichnus rectus, and Skolithos isp. Fine-grained sandstone was deposited in an estuarine mouth-bar and barrier-island complex that protected the coast from wave reworking. As the seaway transgressed across the coast, fully marine wave-dominated parasequences replaced those of the coastal plain. Typical trace fossils include Asterosoma isp., Chondrites isp., Diplocraterion isp., Nereites missouriensis, Phycosiphon incertum, Planolites isp., Rhizocorallium isp., and Zoophycos isp., reflecting open, fully marine conditions. This study provides new insights into the evolution of depositional environments in the Late Cretaceous of southwestern Saskatchewan, and provides a framework for further geological and paleontological studies ongoing in the region.

It's concluded that the succession of lava rocks of "Basalto Montero", besides being studied from geochemical diagrams of tectonic environment discrimination (Pearce, 1982; Shervais, 1982; Pearce, 1983) as in field work, also shows the influence of a Jurassic Volcanic Arc related to subduction (apart from the influence of intraplate, said by Rosas et al, 1996), mentioned its existence by others authors (Wilson, 1984; Romeuf et al, 1995; Jaillard et al, 2000 ; Stern, 2004; Mamani et al, 2010; Bellido et al, 2011).

Археолошким ископавањима 1954. године и 2008–2010. године на источном делу налазишта Бубањ у Новом Селу код Ниша констатовани су остаци насеља Чернавода III културе. Најновијим истраживањима испитане су насеобинске структуре у којима је проналажен археолошки материјал, првенствено керамички, који  се на основу технолошких, морфолошких и орнаменталних карактеристика oпредељује керамичком стилу те културе. Поменути слој налази се непосредно испод беличастосиве пепељасте земље и танког слоја компактне земље сиве боје, који потичу из развијених фаза касног енеолита, и изнад раноенеолитских слојева. Досадашња истраживања праисторијског насељавања локалитета Бубањ доказују да су области јужног Поморавља и Понишавља укључене у културни комплекс Чернавода III-Болераз који захвата већи део југоисточне  и централне Европе.

Two new gray hematite-rich units have been found in Aureum and Iani Chaos, Mars, using data acquired by the Mars Global Surveyor Thermal Emission Spectrometer. These regions correspond with light-toned sulfate-rich deposits identified by the European Space Agency's OMEGA visible/near-IR spectrometer. Much of the light-toned material in Aureum and Iani Chaos is in the form of a capping unit similar

This paper aims to present the results of experiments which
allowed us to propose up-to-date method of 3D visual representation
of explored archaeological layers. Considering the destructive nature
of excavations, the correct documentation of an exploration, which offers an insight both into the decision-making process taking place on site, and into the most faithful representation of the examined material, presents a fundamental challenge for a field archaeologist. The aim of the experiments presented here was to test three methods of creating 3D models of successive archaeological layers (contexts) recorded during an exploration. The presented findings show that the method of editing point clouds using open-source software prior to importing the model of the reconstruction of the explored layer into GIS software, is the best solution from the point of view of both the effort and time required, and it can definitely be suggested as the standard procedure of creating the graphical bases for an archaeological database.