Dolomite: occurrence, evolution and economically important associations

A primary objective in exploration for and development of fluvial reservoirs is determining the thickness and width of sandstone-conglomerate bodies (mainly channel-belt deposits). Most of the existing techniques for estimating the dimensions of fluvial reservoirs have major drawbacks. A fresh approach to the problem is made using recent theoretical, experimental, and field studies. This new approach involves (1) new models for the lateral and vertical variation of lithofacies and petrophysical-log response of river-channel deposits with explicit recognition of the different superimposed scales of strata, (2) distinction among single and superimposed channel bars, channels, and channel belts, (3) interpretation of maximum paleochannel depth from the thickness of channel bars and the thickness of sets of cross-strata formed by dunes, and (4) evaluation of various methods for estimation of widths of sandstone-conglomerate bodies that represent either single or connected channel belts (outcrop analogs; correlation of sandstone-conglomerate bodies between wells; use of empirical equations relating channel depth, channel width, and channel-belt width; theoretical models; and three-dimensional seismic data).

Interpreting the Dimensions of Ancient Fluvial Channel Bars, Channels, and Channel Belts from Wireline-Logs and Cores

One - Printed Volume.- 1 The Mediterranean Area and the Surrounding Regions: Active Processes, Remnants of Former Tethyan Oceans and Related Thrustbelts.- Abstract.- 1.1 Introduction.- 1.2 Mediterranean Fold-and-thrust Belts.- 1.3 Mediterranean Marine Basins.- 1.4 Geological-geophysical Baseline.- 1.4.1 Heat Flow.- 1.4.2 Crustal and Lithospheric Structure.- 1.4.3 Gravity.- 1.4.4 Magnetic Field.- 1.4.5 Seismicity.- 1.4.6 Geodetic Data.- 1.4.7 Stress Field.- 1.5 Global Dynamics and Active Processes Exemplified in the Mediterranean.- 1.5.1 Subduction of the Eastern Mediterranean Lithosphere beneath the Calabrian and Aegean.- 1.5.2 Rifting and Passive Margin Development in Back-arc Regions and Other MediterranRelated to Tectonic Wedges, Tilted Blocks and Sedimentary Loadingean Domains.- 1.5.3 Mud and Salt Diapirism (Eastern Mediterranean Ridge, Alboran Sea, Nile Delta).- 1.5.4 Sea-level Changes, Salinity Crisis, Flooding (Messinian Mediterranean versus Pleistocene Black Sea).- 1.6 Record of Ancient Dynamics of the Tethyan Oceans, Ophiolitic Sutures, Mantle Tomography versus Paleogeography of the Mediterranean Realm.- 1.6.1 Collisional vs. Intracontinental Thrust Belts and Oceanic Sutures.- 1.6.2 Plate Dynamics and Palinspastic Restorations: Demise of the Concept of a Single Tethys.- 1.6.3 Cenozoic Magmatism in the Mediterranean Region.- 1.7 Conclusions.- Acknowledgements.- 2 A Tomographic View on Western Mediterranean Geodynamics.- Abstract.- 2.1 Introduction.- 2.2 The Global Tomography Model BS2000.- 2.3 Interpretation of Model BS2000 for the Western Mediterranean Mantle.- 2.3.1 Alps, Apennines, and the Western Mediterranean.- 2.3.2 The Betic-Rif and Alboran Region.- 2.4 Analysis: the Geodynamic Evolution of the Western Mediterranean.- 2.4.1 Tomographic Evidence for Slab Roll-back.- 2.4.2 Northern Apennines and Alpine-Tethys Subduction.- 2.4.3 Slab Detachment beneath the Central-southern Apennines.- 2.4.4 Calabria Subduction.- 2.4.5 The North African Margin.- 2.4.6 Betic-Rif and Alboran Region: I. Subduction and Roll-back of Predominantly Oceanic Lithosphere.- 2.4.7 Betic-Rif and Alboran Region: II. Development of Arc Geometry and Subduction Roll-back.- 2.4.8 Synthesis of Tomographic Constraints on the Geodynamic Evolution of the Western Mediterranean Region.- 2.5 Summary.- Acknowledgements.- Appendix 1 (CD-ROM).- Appendix 2 (CD-ROM).- 3 The TRANSMED Transects in Space and Time: Constraints on the Paleotectonic Evolution of the Mediterranean Domain.- Abstract.- 3.1 Introduction.- 3.2 The Western Tethys Main Plate Tectonic Constraints.- 3.2.1 The East Mediterranean-Neotethys Connection.- 3.2.2 The Apulia-Adria Problem.- 3.3 The Geodynamic Evolution of Greater Apulia and Surrounding Regions.- 3.3.1 Paleotethys Evolution (Figs. 3.2-3.6).- 3.3.2 Cimmerian Events and Triassic Marginal Oceans (Figs. 3.6-3.9).- 3.3.3 The Jurassic Oceans: Alpine Tethys, Central Atlantic and Vardar (Figs. 3.8-3.11).- 3.3.4 The Cretaceous Oceans: North Atlantic and the Pyrenean Domain (Figs. 3.10-3.14).- 3.4 The TRANSMED Transects in Space and Time.- 3.4.1 Transects I-II-III West.- 3.4.2 Transects IV-V-VI.- 3.4.3 Transects III East, VII and VIII.- 3.5 Conclusions.- Acknowledgements.- Appendix 3 (CD-ROM).- References: Preface, Chapters 1, 2 and 3.- References: CD-ROM.- Transect I: Iberian Meseta - Guadalquivir Basin - Betic Cordillera - Alboran Sea - Rif - Moroccan Meseta - High Atlas - Sahara Domain.- Transect II: Aquitaine Basin - Pyrenees - Ebro Basin - Catalan Coastal Ranges - Valencia Trough - Balearic Promontory - Algerian Basin - Kabylies - Atlas - Saharan Domain.- Transect III: Massif Central - Provence - Gulf of Lion - Provencal Basin - Sardinia - Tyrrhenian Basin - Southern Apennines - Apulia - Adriatic Sea - Albanian Dinarides - Balkans - Moesian Platform.- Transects IV, V and VI: The Alps and Their Forelands.- Transect VII: East European Craton - Scythian Platform - Dobrogea - Balkanides - Rhodope Massif - Hellenides - East Mediterranean - Cyrenaica.- Transect VIII: Eastern European Craton - Crimea - Black Sea - Anatolia C2014 Cyprus - Levant Sea - Sinai - Red Sea.

The transmed atlas : the mediterranean region from crust to mantle : geological and geophysical framework of the mediterranean and the surrounding areas

Geodynamic evolution of the central and western Mediterranean: Tectonics vs. igneous petrology constraints

An efficient inverse kinematics solver is a key element in applications targeting the on-line or off-line postural control of complex articulated figures. In the present paper we progressively describe the strategic components of a very general and robust inverse kinematics architecture. We then present an efficient recursive algorithm enforcing an arbitrary number of strict priorities to arbitrate the fulfillment of conflicting constraints. Due to its local nature, the moderate cost of the solution allows this architecture to run within an interactive environment. The algorithm is illustrated on the postural control of complex articulated figures.

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An inverse kinematics architecture enforcing an arbitrary number of strict priority levels

La chaine iberique et la chaine cotiere catalane se sont developpees durant le Paleogene par l'inversion des rifts mesozoiques. Ces rifts appartiennent au systeme de bassins de la plate-forme peri-tethysienne nord-occidentale. Celle-ci a evolue pendant l'ouverture de la Tethys alpine et de l'Atlantique nord, a la suite de la rupture de la Pangee. Le bassin iberique s'est developpe durant le cycle de rifting du Permien superieur-Trias en meme temps que l'ouverture des systemes de rift de la Tethys et de l'Arctique-Atlantique nord vers l'ouest et le sud, respectivement. Pendant le Jurassique superieur et moyen, l'evolution du bassin iberique a ete controlee par une subsidence thermique post-rift. Le magmatisme alcalin, Trias superieur a Jurassique moyen, qui est evident dans le sud-est du bassin iberique, s'est produit probablement en relation avec la plume magmatique de l'Atlantique central. Le rifting a recommence pendant l'Oxfordien superieur et a persiste jusqu'au debut de l'Albien superieur. Ce cycle de rifting peut etre subdivise en trois pulsations qui ont controle le developpement des bassins de Cameros, Maestrat, Columbrets et iberique sud-occidental. Il n'existe pas de preuves de magmatisme syn-rift au Cretace inferieur. Ce deuxieme cycle de rifting coincide avec une activite similaire dans le domaine de l'Atlantique nord et culmine durant l'Aptien moyen avec la separation entre l'Iberie, l'Amerique du Nord et l'Europe. L'ouverture des bassins oceaniques de l'Atlantique nord et du Golfe de Gascogne ont eu lieu aussi durant cette etape. De l'Albien superieur au Maastrichtien, le bassin iberique a subside en reponse a la re-equilibration thermique post-rift de la lithosphere. La contraction intraplaque s'est produite en Iberie cratonique a la suite de la collision pyreneenne et des premieres phases de l'orogenese Betique. Ceci a controle ensuite le developpement des chaines iberique et cotiere catalane durant l'Eocene et l'Oligocene moyen. Le raccourcissement total de l'ecorce durant le Paleogene en chaine iberique est estime d'environ 75 km soit environ 20%, et a ete responsable de la formation d'une racine de 43 km de profondeur. Cette etude est basee sur une analyse pluridisciplinaire qui integre des donnees de sismique reflexion et de sondage, la biostratigraphie, la sedimentologie, la stratigraphie sequencielle, l'analyse de subsidence, la geologie structurale, ainsi que des donnees de gravite, magnetiques, et de sismique refraction.

Evolution of the Mesozoic Central Iberian Rift System and its Cainozoic inversion (Iberian chain)

The Iberian Chain developed within the Iberian plate during the Palaeogene and Early Miocene as a result of convergence between the African and Eurasian plates. It is a fold-and-thrust belt, which involves the Hercynian basement and the Mesozoic and Cenozoic cover. A generalized cross-section of the NW part of the Chain, of 195 km length, is presented. Mesozoic basins, developed on the Hercynian basement, display thickness variations across normal faults that bounded them and that can be recognized in the field. The Tertiary contraction deformed and inverted the Mesozoic basins, and it is inferred to have produced a thrust sheet about 5 km thick in its frontal (northeastern) part, which thickens to the SW. The total Tertiary shortening in the section is 66.6 km (26%). The structure and the crustal shortening and thickening of the Iberian Chain are explained by a major upper-crustal thrust system with simple flat-and-ramp geometry, which may branch to the Pyrenees or the Betics. This is combined with internal deformation of the thrust sheet. The contribution of the Iberian Chain shortening to the convergence of the African and Eurasian plates during the Tertiary is about one-half of that of the Pyrenees, and should be taken into account in any reconstruction of the kinematics of these plates.

Intraplate deformation in the NW Iberian Chain: Mesozoic extension and Tertiary contractional inversion

The Cameros Basin in Central Spain is an intraplate rift
basin that developed from Late Jurassic to Middle Albian time along
NW–SE trending troughs. The sedimentary basin fill was deposited
predominantly in continental environments and comprises several depositional
sequences. These sequences consist of fluvial sandstones that
commonly pass upward into lacustrine deposits at the top, producing
considerable repetition of facies. This study focused on the western
sector of the basin, where a total of seven depositional sequences (DS-
1 to DS-7) have been identified.
The composition of sandstones permits the characterization of each
sequence in terms of both clastic constituents and provenance. In addition,
four main petrofacies are identified. Petrofacies A is quartzosedimentolithic
(mean of Qm85F2Lt13) and records erosion of marine
Jurassic pre-rift cover during deposition of fluvial deposits of DS-1
(Brezales Formation). Petrofacies B is quartzofeldspathic (mean of
Qm81F14Lt5) with P/F > 1 at the base. This petrofacies was derived
from the erosion of low- to medium-grade metamorphic terranes of
the West Asturian–Leonese Zone of the Hesperian Massif during deposition
of DS-2 (Jaramillo Formation) and DS-3 (Salcedal Formation).
Quartzose sandstones characterize the top of DS-3 (mean of
Qm92F4Lt4). Petrofacies C is quartzarenitic (mean of Qm95F3Lt2) with
P/F > 1 and was produced by recycling of sedimentary cover (Triassic
arkoses and carbonate rocks) in the SW part of the basin (DS-4, Pen˜ -
acoba Formation). Finally, depositional sequences 5, 6, and 7 (Pinilla
de los Moros–Hortiguela, Pantano, and Abejar–Castrillo de la Reina
formations, respectively) contain petrofacies D. This petrofacies is
quartzofeldspathic with P/F near zero and a very low concentration of
metamorphic rock fragments (from Qm85F11Lt4 in Pantano Formation
to Qm73F26Lt1 in Castrillo de la Reina Formation). Petrofacies D was
generated by erosion of coarse crystalline plutonics located in the Central
Iberian Zone of the Hesperian Massif. In addition to sandstone
petrography, these provenance interpretations are supported by clay
mineralogy of interbedded shales. Thus, shales related to petrofacies
A and C have a variegated composition (illite, kaolinite, and randomly
interlayered illite–smectite mixed-layer clays); the presence of chlorite
characterizes interbedded shales from petrofacies B; and Illite and kaolinite
are the dominant clays associated with petrofacies D.
These petrofacies are consistent with the depositional sequences and
their hierarchy. An early megacycle, consisting of petrofacies A and B
(DS-1 to DS-3) was deposited during the initial stage of rifting, when
troughs developed in the West Asturian–Leonese Zone. A second stage
of rifting resulted in propagation of trough-bounding faults to the SW,
involving the Central Iberian Zone as a source terrane and producing
a second megacycle consisting of petrofacies C and D (DS-4, DS-5, DS-6, and DS-7). Sandstone composition has proven to be a powerful tool
in basin analysis and related tectonic inferences on intraplate rift basins
because of the close correlation that exists between depositional
sequences and petrofacies.

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Sandstone petrography of continental depositional sequences of an intraplate rift basin: western Cameros Basin (North Spain)

A robust approach for the control of the center of mass with inverse kinetics

Three duricrust types (calcretes, palycretes and silcretes) have been distinguished in the Lower Paleogene arkosic materials from the margins of the Duero and Tajo basins (central Spain). In the calcretes the cements are composed of calcite plus palygorskite, whereas palygorskite is the only cement in the palycretes. In the silcretes, the cement consists chiefly of opal and chalcedony, with minor quartz. The important duricrust development in the Paleogene detrital materials can be correlated with a drastic climatic change towards colder and more arid conditions during this time, as inferred from the sedimentological features and the clay mineral evolution. The origin of calcretes and palycretes is related to the movement of alkaline phreatic waters generated from dolomitic rocks of Cretaceous age cropping out in the near surroundings. Silcretes originated from the vertical transfer of silica from supersaturated groundwaters, from the Hercynian granitic rocks, up to the surface. Silcretes are developed either on unconsolidated arkosic materials or replace previous calcrete or palycrete levels.

Ramón Mas

Papers

Evolution of the Mesozoic Central Iberian Rift System and its Cainozoic inversion (Iberian chain)

Intraplate deformation in the NW Iberian Chain: Mesozoic extension and Tertiary contractional inversion

Sandstone petrography of continental depositional sequences of an intraplate rift basin: western Cameros Basin (North Spain)

A robust approach for the control of the center of mass with inverse kinetics

Calcretes, palycretes and silcretes in the Paleogene detrital sediments of the Duero and Tajo basins, central Spain