Pharaonic necrostratigraphy : a review of geological and archaeological studies in the Theban Necropolis, Luxor, West Bank, Egypt

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Terra Nova 21 (2009): 237-256, doi:10.1111/j.1365-3121.2009.00872.x.We present a review of archeological and geological studies on the West Bank as a basis for discussing the geological setting of the tombs and geologically related problems with a view to providing archeologists with a framework in which to conduct their investigations on the restoration, preservation and management of the antique monuments. Whereas the geology of the Upper Nile Valley appears to be deceptively simple, the lithologic succession is vertically variable, and we have recognized and defined several new lithologic units within the upper Esna Shale Formation. We have been able to delineate lithologic (shale/limestone) contacts in several tombs and observed that the main chambers in some were excavated below the Esna Shale in the Tarawan Chalk Formation. We have been able to document changing dip in the strata (warping) in several tombs, and to delineate two major orientations of fractures in the field. Investigations behind the Temple of Hatshepsut, in the Valley of the Kings and around Deir El Medina, have revealed four broad regional structures. We confirm that the hills located near the Nile Valley, such as Sheik Abel Qurna, do not belong to the tabular structure of the Theban Mountain, but are discrete displaced blocks of the Thebes Limestone and overlying El Miniya, as supported by Google Earth photographs

The role of geoarchaeology in the preservation and management of the Theban Necropolis, West Bank, Egypt

A World Heritage Site since 1979, the Theban Necropolis was built by the Pharaohs of the 18th to 20th Dynasties (c. 1539 – 1075 BCE). A variety of pharaonic (and lesser nobles') tombs, funerary temples and sanctuaries were located/excavated in the lower part of the c. 400 m high pyramidal El Qurn in a variety of lithofacies (predominantly marine limestones and shales). These monuments are located in regionally persistent structural entities as well as gravitational collapse structures (GCS) whose probable origin and timing are reviewed and updated here, based on information that was unavailable to us at the time of writing a complementary paper in 2008 (but only published in 2015). We review here the historical development of the Theban Necropolis in the framework of the geological and geomorphological landscape and the first geological map of the region prepared by our Working Group for the Theban International Geoarcheological Project (TIGA) in 2011. We conclude with a preferential prioritizing of the perceived short- and long-term threats to the preservation of the Theban Necropolis and its monuments: least vulnerable to destabilization are the Valley of the Kings, Valley of the Queens, Block of Sheik Abdel Qurnah – El Khokkah; more vulnerable are Deir El Medina, Qunet Mura'I and El Assasif; most vulnerable are the Village of the Workers, Deir El Bahari and the Valley of the Colors. Accordingly it will be necessary to devise geotechnical solutions to prevent the destruction of (at least) some of the monuments under consideration here

The Dababiya corehole, Upper Nile Valley, Egypt : preliminary results

Author Posting. © Austrian Geological Society, 2012. This article is posted here by permission of Austrian Geological Society for personal use, not for redistribution. The definitive version was published in Austrian Journal of Earth Sciences 105, no. 1 (2012): 161-168.The Dababiya corehole was drilled in the Dababiya Quarry (Upper Nile Valley, Egypt), adjacent to the GSSP for the Paleocene/ Eocene boundary, to a total depth of 140 m and bottomed in the lower Maastrichtian Globotruncana aegyptiaca Zone of the Dakhla Shale Formation. Preliminary integrated studies on calcareous plankton (foraminifera, nannoplankton), benthic foraminifera, dinoflagellates, ammonites, geochemistry, clay mineralogy and geophysical logging indicate that: 1) The K/P boundary lies between 80.4 and 80.2 m, the Danian/Selandian boundary between ~ 41 and 43 m, the Selandian/Thanetian boundary at ~ 30 m (within the mid-part of the Tarawan Chalk) and the Paleocene/Eocene boundary at 11.75 m (base [planktonic foraminifera] Zone E1 and [calcareous nannoplankton] Zone NP9b); 2) the Dababiya Quarry Member (=Paleocene/Eocene Thermal Maximum interval) extends from 11.75 to 9.5 m, which is ~1 m less than in the adjacent GSSP outcrop.; 3) the Late Cretaceous (Maastrichtian) depositional environment was nearshore, tropical-sub tropical and nutrient rich; the latest Maastrichtian somewhat more restricted (coastal); and the early Danian cooler, low(er) salinity with increasing warmth and depth of water (i.e., more open water); 4) the Paleocene is further characterized by outer shelf (~ 200 m), warm water environments as supported by foraminifera P/B ratios > 85% (~79-28 m), whereas benthic foraminifera dominate (>70%) from ~27-12 m (Tarawan Chalk and Hanadi Member) due, perhaps, in part to increased dissolution (as observed in nearby outcrop samples over this interval); 5) during the PETM, enhanced hydrodynamic conditions are inferred to have occurred on the sea-floor with increased river discharge (in agreement with sedimentologic evidence), itself a likely cause for very high enhanced biological productivity on the epicontinental shelf of Egypt; 6) correlation of in situ measured geophysical logs of Natural Gamma Ray (GR), Single-Point Resistance (PR), Self-Potential (SP), magnetic susceptibility (MS), and Resistivity, and Short Normal (SN) and Long Normal (LN) showed correspondence to the lithologic units. The Dababiya Quarry Member, in particular, is characterized by very high Gamma Ray and Resistivity Short Normal values.The Dababiya corehole was made possible by the financial support of the National Geographic Society

Unravelling the PETM record in the Sparnacian facies of NW Europe: new data from the north-eastern Paris Basin

The geological archives record "hyperthermic" crises, along with their consequences on the biota and physical environment. Among these, the PETM (Paleocene-Eocene Thermal Maximum) is considered as the closest analogue to the current climate crisis due to its global character and the speeds at which the CO2 rate and average temperatures increased. Some 55.8 Ma ago (Aubry et al., 2007), it affected the Earth for a period of almost 200,000 years; the terrestrial and marine paleoenvironments were marked by a negative δ13C anomaly (or Carbon Isotopic Excursion, CIE) coinciding with a negative δ18O anomaly indicative of a drastic temperature rise (+ 3 to + 8 °C). The causes envisaged to explain the major global disturbances of the atmosphere and oceans are linked with the massive emission of 12C-enriched greenhouse gases whose origins are still debated and probably multiple. Moreover the PETM left a deep and long-lasting imprint on the living animal and plant world, both terrestrial and marine. The preserved paleoenvironments of the sedimentary record also show a recrudescence of clastic influx or are distinguished by specific sediments such as coal and lignite, phosphates, black shales, diatomites, etc. The shallow to deep marine environments from all the paleolatitudes have been studied intensively, the data collected allowing to refine climate models and ocean/atmosphere responses. However, the terrestrial record was seldom examined and very few studies aimed at checking if the drastic rises of greenhouse gases and temperature had a real impact on the fluvial, lacustrine, palustrine sediments and on the paleosols and weathering profiles development during the PETM. Apart notable paleontological studies, its impact on the terrestrial realm at a regional scale and on different interconnected contemporary paleoenvironments has probably not been studied and integrated enough (Zachos et al., 2008). We propose such a regional study in the Sparnacian facies of the Paris Basin. To ensure correlation of the events and processes identified with a confidence level as precise as possible, high resolution temporal framework is essential. Historically, the Paris and adjacent basins are the cradle of stratigraphy, where the notion of "Sparnacian" took shape (Dollfus 1880), pointing terrestrial to brackish deposits with particular facies and faunas, interstratified between two easily distinguishable Late Paleocene (Thanetian) and Early Eocene (Ypresian) mainly sandy and marine formations. Since that time stratigraphy has evolved, especially regarding the Paleocene and Eocene epochs, and we refer to the lithostratigraphies of Aubry et al. (2005) and Steurbaut (1998) for the Paris and Belgian Basins. In Avesnois, close to Belgium, the Paleocene and Eocene lithostratigraphy has been revised thanks to a geological mapping project supported by drillings (Quesnel, 2006). Detailed sampling and various analyses have been performed: granulometry and XRD mineralogy, heavy mineral assemblages, carbonate and organic carbon contents, biostratigraphy, palynofacies, pyrolyse rock-eval, and chemostratigraphy (d13C of the dispersed organic matter). In the AVE 007 drilling (Mormal Forest), the CIE has been identified in a lignitic clay. The clay content is dominated by the illite-smectite mixed layers, with 10 to 20 % of illite and kaolinite. The palynological study of the pollen and spores assemblages confirms the Early Eocene age. The Paleocene markers are absent and using the palynozonation of Roche et al. (2009), the lignitic clay can be correlated to the lower part of the Tienen Fm and to the SP3 to SP4 units of the Cap d'Ailly section. The depositional environment is palustrine-lacustrine, with sporo-pollen fluvial inputs from the hinterland in a humid subtropical climate. The lignitic clay overlies fluvial flint gravels and sands, above the Coniacian chalk. Those clastic deposits contain mainly illite-smectite mixed layers, a few kaolinite and illite and are richer in pyrite downwards. Paleocene pollens and dinocysts are present. The onset of the CIE is recorded at the top of this sandy unit, below the lignitic clay. Those fluvial flint gravels and sands are widespread in Avesnois, and named “Cailloutis à silex de Mormal” (new name) and “Sables et Grès du Quesnoy”. The lignitic clay corresponds to a palustrine deposit, filling the fluvial channel after the river bed migration. Similar units are well known in northern France and Belgium, they belong to the Upper Landenian fluvial sands, often display cross stratification, paleoweathering (oxidation and/or silcrete), lignite or marl lenses, vertebrate fauna and sometimes a rich flora in silicified slabs or beds. They can be attributed to the Tienen Fm. Similar sandy, clayey and lignitic units are also recognized southwards in the Paris Basin, in the first clastic units of the Mortemer Fm. In Northern France and Belgium those terrestrial units often cap or incise Upper Thanetian marine sands. In Avesnois the latter are named “Sables verts de l'Avesnois” and correlated to the “Sables de Grandglise” (NP8) and “Sables de Bois Gilles” (NP9). In the western part of the Avesnois, the AVE 31 drilling has yielded a shallow marine shelly sand (“Falun de Viesly”), with Upper Thanetian benthic foraminifera (P4c to P5), and a shelly clay (“Argile de Louvil”), containing Thanetian benthic foraminifera (P4). They are overlain by a sandy laminated clay (“Tuffeau de Valenciennes”), then a laminated silt at the top. In the AVE007 drilling, the lignitic clay is also overlain by a silty laminated unit, containing the same clay minerals as the clay plus chlorite and vermiculite at the top. Lower Ypresian dinocysts (Wetzeliella sp.), phytoliths, rootlets moulds and agglutinated foraminifera similar to those contained in the Orchies Clay (NP10 – NP 11?) are present. That silty unit is widespread in Avesnois and Valenciennois. We name it “Silt et Sablon de l'Avesnois” and we correlate it to a part of the Kortrijk Clay Fm in the Ieper Gp. The new units described around the Paleocene-Eocene boundary in Avesnois allow correlation between the Belgian and Paris Basins and help to precise the landscape evolution during this critical interval. The PETM record has also been recently identified around 80km southwestwards, at Sinceny (Aisne), a key locality for the Sparnacian facies. The data obtained in this drilling will be presented and compared to those obtained in Avesnois and integrated in the Paris Basin stratigraphic framework

Chronostratigraphic terminology at the Paleocene/Eocene boundary.

Integrated research over the past decade has led to the recognition of a short (150-200 k.y.) interval of Paleogene time within Chron C24r at ~55.5 Ma, formerly termed the late Paleocene Thermal Maximum (LPTM) but more recently the Paleocene-Eocene Thermal Maximum (PETM), that was crucial in the climatic, paleoceanographic, and biotic evolution of our planet. Stable isotope analysis of marine carbonates indicates that there were transient changes in surface and deep-water temperatures. These climatic changes coincided with a negative 3%-4% carbon isotope excursion (CIE), which is recorded in both marine and terrestrial deposits. It was soon realized that the CIE not only constitutes a powerful tool for long distance ("global") isochronous correlation, but even more importantly that it is coeval with notable biotic events in both marine and continental fossil records that have long been taken as criteria for the beginning of the Eocene in North America and more recently in deep sea cores. On the other hand, the conventional Paleocene/Eocene boundary level at the Thanetian/Ypresian boundary in Belgium and the London Basin has been found to be ~1 m.y. younger than the CIE, based on the association of the First Appearance Datum (FAD) of the (calcareous nannoplankton) Tribrachiatus digitalis (at ~54.4 Ma) with the base of the Ypresian in the London Basin. Although the Ypresian definition would take priority under normal circumstances, a consensus has been reached to redefine the Eocene in recognition of the worldwide significance and correlatibility of stratigraphic features associated with the PETM. Redefinition of the Eocene, however desirable, nevertheless cannot proceed in a stratigraphic vacuum, and this paper is concerned with resolving the consequences of this action. To be made coincident with the CIE at ~55.5 Ma, the Ypresian/Thanetian boundary would have to be lowered by ~1 m.y., resulting in the inflation of the span of the Ypresian by 20% and a reduction of the span of the Thanetian by 30%. At the same time, the terminology of the strata in the leapfrogged interval would be thrown into total conflict with the literature, with the substitution of one widely used stage name for the other in the conflicted interval. On the other hand, to relocate the Paleocene/Eocene boundary without moving the stage boundaries would result in the upper third of the Thanetian falling within the Eocene, demolishing a century-old consensus. We propose that the destabilizing effect of the new boundary in the classic chronostratigraphy of western Europe can best be minimized with the introduction of a pre-Ypresian Stage, to encompass the orphaned upper Thanetian interval as the basal unit of the Eocene under a separate name. To this end, we suggest the reintroduction of the Sparnacian Stage, now that its original concept has been shown to correlate essentially with the interval between the CIE and the FAD of T. digitalis