Autochthonous Formations Research Articles

The Structure of the Late Bronze Age Population of Western Siberia: Craniometric Evidence

To assess the sources of population differentiation in Late Bronze Age Western Siberia, measurements of 68 cranial samples of this and earlier periods were processed with multivariate statistical methods. Results support the idea of at least two post-Afanasyevo migrations to Siberia from the west—pre-Andronovo and Andronovo. The former was represented by Chaa-Khol, Yelunino, and Samus people. Those associated with Karakol culture partly resemble the above and partly both autochthonous populations—that of Baraba (“Northern Eurasian formation”) and that of Okunev culture (“Southern Eurasian formation”), which appear to be two extremes of a single continuum. Differences between the two Andronovo traditions, Fedorovka and Alakul, are likely due to the local substratum in the former rather than to various origins. The Karasuk group arose through admixture between Okunev and Andronovo. People associated with the classic Karasuk culture are closer to the former, while those of the Kamenny Log stage tend toward the latter. People of the Upper Irtysh and the Mongun-Taiga people from Baidag III resemble those of Karasuk. Two pooled groups, Irmen and Mongun-Taiga, and the Pakhomovskaya sample indicate a possible admixture between both autochthonous formations, Northern and Southern, as well as Andronovo and Karasuk. Among the so-called Andronoid groups, only Yelovka and Pakhomovskaya, as well as a sample from Yelovka I, suggest admixture between Andronovans and Western Siberian natives, while Cherkaskul and Korchazhka, like the Late Krotovo groups from Sopka and Cherno-Ozerye and the Begazy-Dandybai group of Baraba, deviate from the Northern Eurasian formation toward Okunev rather than Andronovo. Among the two Eurasian formations, the Southern one (i.e., Okunev) was more affected by admixture between the autochthones and the immigrants.

Assessment of Landslide Risks Through a Multi-Disciplinary Approach: A Case Study of Al Hoceima, Northern Morocco

Landslides are very dangerous phenomena dependent upon several parameters and criteria widespread in Northern Morocco. Their management is complex because of the dangers posed to the population and by the habitat, but also due to the difficulty of remedial actions. To address this, a methodology is needed based on the analysis of land movements through a multidisciplinary approach combining geology, hydrogeochemistry, and geotechnics. This perspective was adopted in this study of landslides in the city of Al Hoceima (Northern Morocco), and in particular on the slope located in front of the Al Hoceima port, which shows a morphology of old landslides, and more recent ones subject to factors of instability or landslides that activate after periods of intense rain. The analysis and interpretation of satellite images reveals a complex morphology, shaped by a geology characterized by tectonic activity and often-altered lithology. From a geotechnical point of view, the latter induces low to medium mechanical characteristics. Inclinometric measurements situate the average depths of the sliding planes at between 15 m and 25 m. The chemical facies of the groundwater is sodium sulphate, sometimes tilting toward chloride-sodium, proof of a leaching of the autochthonous formations (Trias-Lias and Jurassic), to which is added the action of the rising water table. All these factors intervene directly in the destabilization of the slope. These results allow us to establish concrete actions for the stabilization of the slope.

High‐Velocity Slip and Thermal Decomposition of Carbonates: Example From the Heart Mountain Slide Ultracataclasites, Wyoming

AbstractThe Heart Mountain Slide in Wyoming is one of the largest known terrestrial gravity slides (3,500 km2) formed ∼49 Ma ago by the nearly horizontal detachment of Paleozoic‐Eocene cover sliding on top of autochthonous formations. At the White Mountain locality, exposures offer an exceptional opportunity to investigate high strain rate/high velocity processes in carbonates. Here we use the anisotropy of magnetic susceptibility (AMS) of 274 samples to shed light on ultracataclastic deformation along this detachment. Contrary to predictions, the carbonate ultracataclasite displays a consistent AMS fabric, particularly in the upper ultracataclasite. The AMS in this unit is controlled primarily by magnetite formed through the breakdown of iron sulfides caused by frictional heating. Additional thermomagnetic experiments reveal that the new magnetic fabric began forming ∼250ºC and continued up to ∼400ºC when calcination of carbonate minerals caused a major drop in friction. The main cataclastic slip direction inferred from AMS is ∼N033°, at odds with the previously accepted NNW‐SSE direction. We validate these AMS fabrics through 3D shape preferred orientation analysis and micro X‐ray scanning of the same specimens. These results, however, may only represent cataclastic flow directions at the local scale as a result of synkinematic rotation of the White Mountain block. Alternatively, these results may call for a re‐evaluation of the large scale movement of the slide. Finally, this study demonstrates the usefulness of a magnetic approach in deciphering deformation processes in carbonates, particularly in high strain rate cases such as seismic faults.

Non‐metamorphosed autochthonous Kuncha‐Naudanda‐Heklang Formations and their differences from those of the Kuncha nappe: A multichronological approach

AbstractNon‐metamorphosed, autochthonous Lesser Himalayan sediments (LHS), which are correlated to the Kuncha and Naudanda Formations, were found in a narrow belt between the Main Boundary Thrust and the Lesser Himalayan Thrust at the base of the Kuncha nappe in southeastern Nepal. The autochthonous Naudanda Formation is comprised of cross‐bedded and rippled orthoquartzite and yielded a maximum depositional age of 1795.1 Ma ±5.1 Ma using detrital zircons. Low‐grade metamorphosed quartzite in the Kuncha nappe yielded a maximum depositional age of 1867.4 Ma ±3.4 Ma, although it is totally recrystallized. These ages and age distribution patterns of detrital zircon grains indicate that the meta‐quartzite of the nappe is originally Naudanda Formation. A zircon fission‐track age of the autochthonous Naudanda Formation shows partially annealed age of 864 Ma ±56 Ma, in contrast, that of the Kuncha nappe shows a totally annealed age of 11.9 Ma ±1.6 Ma. These results suggest that the autochthonous LHS have never undergone metamorphism during the Himalayan orogeny. We also discovered a non‐metamorphosed Heklang Formation that rests on the Naudanda Formation, and designated it as a sub‐type section on the basis of detailed lithostratigraphic study. It is characterized by black and light green slate with dolerite sills and ill‐sorted quartzose sandstone, and correlated to the metamorphosed Dandagaon Phyllites in the Kathmandu area. Non‐metamorphosed autochthonous formations distributed to the south of the nappe front suggest that they escaped from thermal metamorphism by hot nappe.

Geology of the ‘Coltre della Val Marecchia’ (Romagna-Marche Northern Apennines, Italy)

ABSTRACTA detailed geological map at 1:50,000 scale of the Marecchia Valley and adjoining areas (Northern Apennines, NA, Italy) is presented here. The Marecchia Valley represents a geological ‘unicum’ for the NA and it has been the focus of scientific debate for a long time, due to the occurrence in the area of the ‘Coltre della Val Marecchia (CVM)’, a complex stack of allochthonous and semi-allochthonous units emplaced in a foredeep basin during the Late Miocene to Early Pliocene. In order to clarify the geological evolution for this area, the lithostratigraphic relationships and the tectonic framework have been studied, allowing better understanding of the complex relationships between tectonics and sedimentation. The main result has been a new evolutionary framework for this sector of the orogen during the Late Miocene-Early Pliocene. Several new findings about the geological-structural setting and stratigraphy, result from the geological map presented here. These are overall supported by stratigraphic and tectonic evidence, which suggest time and modes of the CVM allochthonous emplacement within the Messinian-early Pliocene foredeep successions. Relationships between the allochthonous and autochthonous formations allowed recognition of two different bodies in the CVM, gravitationally emplaced following different trajectories and timing.

The Jabal Akhdar dome in the Oman Mountains: Evolution of a dynamic fracture system

The Mesozoic succession of the Jabal Akhdar dome in the Oman Mountains hosts complex networks of fractures and veins in carbonates, which are a clear example of dynamic fracture opening and sealing in a highly overpressured system. The area underwent several tectonic events during the Late Cretaceous and Cenozoic, including the obduction of the Samail ophiolite and Hawasina nappes, followed by uplift and compression due to the Arabia-Eurasia convergence. This study presents the results of an extensive tectonic survey, and correlates subseismic-scale structures in Jabal Akhdar (faults, fractures, veins and stylolites) with the main tectonic events in the Northeastern Arabian plate. As some of the studied formations host large oil reserves in neighboring areas, determining the relative timing of these events in the exhumed rocks is important to understand hydrocarbon distribution and fracture patterns in these reservoirs. The formation of early veins and stylolites in the Oman Mountains is followed by top-to-the- South layer-parallel shearing that may be associated with the obduction of the Samail and Hawasina nappes. This compressional tectonic event is followed by normal (dip-slip) to oblique-slip faults and veins. Top-to-the-Northeast layer-parallel shearing, which corresponds to the first stage of exhumation of the autochthonous rocks offsets these structures. Our new data indicate that this first phase of events is overprinted by complex strike-slip networks of veins and fractures, as well as by the reactivation and onset of seismic-scale faults. Strike slip structures belong to three distinct events. The first one (NW-SE-oriented compression) is probably associated with the oblique collision of the Indian plate against the Arabian platform during the Late Campanian to the Mid Eocene. The second event (E-W-oriented compression) is likely to have been formed during the Late Oligocene-Middle Miocene during uplift. The last event (NE-SW-oriented compression) probably took place during the Miocene-Pliocene. Structures of the first two strike-slip events have the same orientation as seismic-scale faults observed in the subsurface of Oman and Abu Dhabi. In addition, increasing vein intensity towards the top of the autochthonous formations in the Oman mountains, as well as the small angle between conjugate vein sets, indicate that high fluid pressures that are thought to be present during strike-slip deformation.

Regolith map of France

Regolith formations are surficial fragmental and unconsolidated rocks whose genesis and properties result from successive periods of surface processes. They comprise:– autochthonous formations resulting directly from successive periods of surface weathering in the upper 200 metres of the Earth’s crust;– allochthonous formations in which the unconsolidated deposits result from weathering and transport and have not yet been affected by burial diagenesis.Regolith studies are currently at the crossroads of new scientific challenges and new environmental needs. Not only do regolith formations support a full spectrum of biological activity, including human activities, they also provide a source of extractable materials and form the substratum of soils. As such, they should be considered as a capital to be managed and protected. Historically, geological maps have focused mainly on substratum geology. Although the inclusion of regolith formations in the 1:50,000-scale geological map series of France since the 1980s has considerably increased our knowledge of France’s regolith, this is still is patchy and generally insufficient for applied uses despite increasing societal pressures demanding up-to-date regolith maps. To produce an updated map at the scale of France is an ambitious project that must necessarily begin with an inventory of existing geological cartographic data relating to regolith formations. A digital two-layered regolith map of France, representing both the allochthonous and autochthonous formations, was produced in 2009 at a scale of 1:1,000,000. Each layer is accompanied by a confidence index map, and a brief descriptive note of the mapped formations (in French) is also available. A critical analysis of the two map layers reveals not only the very uneven nature of our current knowledge in terms of data quantity and quality, but also its deficiency as regards the expectations of the public authorities. Today, therefore, we require surface studies combining geology, geophysics and geochemistry in order to enhance our understanding of the natural processes governing the distribution and evolution of subsoil formations. This approach is critical for developing appropriate guidance in the use and management of natural and groundwater resources. The 2009 map can be viewed and interrogated at http://infoterre.brgm.fr, and a “pdf” of the map and corresponding project report can be downloaded from http://www.brgm.fr/brgm/GEO/rego.htm.

European provenance of the Numidian Flysch in northern Tunisia

Terra Nova, 00, 1–9, 2010 Abstract The ultimate source of the deepwater Numidian Flysch sediments has long been a matter of controversy. Did the sediments of this late Cenozoic orogenic belt in the western Mediterranean derive from a European or African source, or from a combination of the two? New data presented here strongly favour a European provenance. Zircon ages of 514 ± 19 Ma from Tunisia and 550 ± 28 Ma from Sicily can only have derived from rocks of European affinity. These zircons have been separated from quartz-rich sandstones with a distinctive, highly mature heavy mineral assemblage that is different from those of North African autochthonous formations. The mature petrography and dominance of euhedral prismatic zircon grains indicate a medium to high-grade metamorphic source. Most palaeocurrent data are indicative of flow from the N and NW. The original European provenance is most likely now represented by predominantly metamorphic rocks of the Kabylie belt in northern Algeria, as a result of microplate movement and thrust emplacement.

Historicizing State Sovereignty: Inequality and the Form of Equivalence

The overarching argument of this paper is not a new one; others have made it in various forms. The argument suggests, in Bernard Cohn's simple formulation, that metropole and colony should be treated in a unified field of analysis. Reconstituting the analytical frame in the manner Cohn suggests has a range of implications not only for the study of colonialism but also, and perhaps more importantly, for understanding current geopolitical conjunctures. The suggestion diverges from the conventional analytical approach that divides and demarcates the world into separable entities—whether they be described as the mutually exclusive categories of metropole and colony, Europe and its Others, a set of distinct nations, first and third world, or indeed of areas and regions—and studies these distinct entities in isolation from, or in comparison with, each other. In contrast, Cohn's proposition asks for an analysis of how such demarcations are produced and of how, rather than being discrete entities with autochthonous formations, they are co-produced through a complex array of related and relational historical events. It is a call, in other words, to shift the analytical framework from one that functions, implicitly or explicitly, on the basis of comparison, to one that operates on the basis of co-production. Such an approach, this essay demonstrates, is especially necessary for a thoroughly historicized understanding of nation-state formation, particularly since the nation-state constitutes a preeminent category of and for comparative analysis.

Restoration of Open Pit Lignite Mining in the Former GDR: Lessons to Belearnt from Zwenkau

The interactions have been investigated between the near-surface sediments of the sediment dumping at the Zwenkau open pit (used for extraction of lignite) and the produced mining water. These environmental impacts are the legacy of the energy policy of the former GDR. The pyrite oxidation that takes place in the overburden sediments causes the formation of an oxidation front and the pH-value of sediments falls to about 2 to 3 very soon after deposition. The primary mineral contents are destroyed and a considerable number of elements are mobilized that remain locally in the sediment pores. Because of the very weak seepage, rainfall remains in the alluvial areas as dump lakes. The dump lakes are very acidic because the rainwater transports the mobilized elements from the surface. Autochthonous and allochthonous formations of secondary minerals have been observed and analysed. A continuously ongoing interaction of exogenous and endogenous effects hinders the hydrological and geochemical equilibrium stabilisation. What to do with such a “moonscape” is considered in the conclusions.

Stratigraphy, structure and syntectonic sedimentation of the Campanian 'Belly River' clastic wedge in the southern Canadian Cordillera

The parautochthonous, subproximal segment of the 'Belly River' clastic wedge is subdivided into five new formations, listed here from oldest to youngest: Lees Lake, Burmis, Connelly Creek, Lundbreck and Drywood Creek. The Pakowki Formation divides the 'Belly River' clastic wedge into a lower succession consisting of predominantly marine sediments (the Lees Lake and Burmis Formations) and an upper succession (the Connelly Creek, Lundbreck and Drywood Creek Formations). The lower succession including the Pakowki Formation belongs to the Alberta Group and the upper succession represents the Belly River Group. The formations have been mapped in the Foreland Thrust and Fold Belt west of Lundbreck, Alberta, and correlated with the subsurface distal, autochthonous formations of the Interior Platform. Early indications of Laramide tectonic activity in the source area are recorded by the turbidites of the Lees Lake Formation. An increase in the supply of sand during deposition of the Lees Lake Formation produced thick sandstone layers which were syndepositionally deformed and partly eroded by sediment-laden density currents. The contact between the Lees Lake Formation and the overlying Burmis Formation is unconformable because of submarine erosion. The Burmis Formation is recognized as a deltaic sequence containing a lateral transition from fluviatile through distributary channel-fill to distributary mouth-bar facies. The next phase of the Laramide Orogeny is recorded by the upper delta plain facies of the Connelly Creek Formation and the alluvial fan facies of the Lundbreck Formation. The fan-shape geometry and sedimentological features of the Lundbreck Formation, especially the ephemeral, high-energy channels, semi-arid paleosols and playa deposits indicate sedimentation on a semi-arid alluvial fan bordering the upper delta plain environment. Flash-flood deposition within the ephemeral channels and deep erosion of the alluvial plain during sedimentation of the Lundbreck Formation suggest significant syndepositional topography. The semi-arid alluvial fan environment suggested for the Lundbreck Formation implies an uplifted mountain front during its formation. Basinward progradation of the Connelly Creek/Lundbreck delta was caused by easterly propagation of the tectonic deformation that forced the Pakowki Sea to retreat from the Crowsnest Embayment.

A clockwise rotation of southern Apulia?

New paleomagnetic results from 13 sites sampled in Eo‐Oligocene autochthonous formations in the extreme South of the Apulian platform in southeastern Italy are presented. They suggest that this region has undergone a clockwise rotation of about 25° since the Eo‐Oligocene. This rotation is opposite in sense to that obtained from the Cretaceous formations in the Gargano, which has generally been assumed to affect the entire foreland. These new data suggest that the Tertiary structural evolution of this region may be distinct from that of central peninsular Italy and related to that of northwestern Greece on the other side of the Southern Adriatic Sea.

Upper carboniferous to upper permian 13C-enriched primary carbonates in the sverdrup basin, Canadian arctic: Comparisons to coeval Western North American Ocean Margins

Carbon isotopes analyses performed on more than 250 limestone samples from thirteen late Paleozoic autochthonous formations of western and Arctic Canada demonstrate that: (1) For a given locality, the δ 13C-values are uniform and there is no temporal increase in δ 13C during the whole Late Carboniferous (Pennsylvanian), Early Permian and basal Late Permian (latest Permian strata being absent). (2) There is a well-defined latitudinal trend showing that for any specific time interval, extremely high δ 13C-values are encountered in the Sverdrup Basin ( +5 to + 7%), intermediate but still high values in northern Yukon Territory ( +3 to +5%), and low values in east-central and southeastern British Columbia ( +1 to +3%). A model is proposed whereby oceanic stagnation and thermohaline stratification prevailed in the Sverdrup Basin. As a result, large amounts of 12C-enriched organic matter were preserved in central parts of the basin. As the organic matter accumulated, residual dissolved carbonate species became enriched in 13C. Additional enrichment was also promoted by the escape of CO, from evaporating brines following intermittent closures of the Sverdrup Basin early during the Late Carboniferous. Since the Sverdrup sea was connected to the Paleopacific ocean during most of its history, it acted as a source of 13C-enriched surface waters which were then spread southward by wind-driven surficial currents. With this model, the trend of decreasing δ 13C in a southerly direction is explained by increasing dilution with waters of the Paleopacific along the western margin of North America.

Mesozoic volcanics of western sicily

The Mesozoic lavas and minor intrusions in the thrust sheets of western Sicily have the following characteristics: 1. The lavas in the Triassic Mufara Formation in the north were broken into fragments which rotated independently within the incompetent strata that enclose them. This behavior is characteristic of igneous rocks found within the more internal (northerly) thrust units. 2. The Jurassic lavas in the more external (southerly) units have consistent directions which agree with those of the Ammonitico Rosso limestones in the same zone and lie about 30° clockwise from those of coeval autochthonous formations in Tunisia.Schult's presumed Cretaceous directions from Custonaci on the north coast (similar to those found in the Cretaceous Scaglia Rossa at Terrasini to the east byChannel et al., 1980) are rotated still more (140°) with respect to those of the autochthonous Iblean platform of SE Sicily. These differences are believed to reflect rotation of the thrust sheets during tectonic transport in Cenozoic times, the internal units being the most strongly rotated. 3. All the igneous rocks are highly altered: generally the original mineralogy cannot be completely determined. Relative abundances of some of the less mobile elements (Ti, Sr, Y) suggest that they are intraplate basalts.

Ordovician Graptolite Zones of Western Newfoundland in Relation to Paleogeography of the North Atlantic

Research Article| June 01, 1971 Ordovician Graptolite Zones of Western Newfoundland in Relation to Paleogeography of the North Atlantic BERND-DIETRICH ERDTMANN BERND-DIETRICH ERDTMANN Department of Geology, Indiana University at Fort Wayne, Fort Wayne, Indiana 46805 Search for other works by this author on: GSW Google Scholar Author and Article Information BERND-DIETRICH ERDTMANN Department of Geology, Indiana University at Fort Wayne, Fort Wayne, Indiana 46805 Publisher: Geological Society of America Received: 01 Jun 1970 Revision Received: 17 Nov 1970 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1971, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1971) 82 (6): 1509–1528. https://doi.org/10.1130/0016-7606(1971)82[1509:OGZOWN]2.0.CO;2 Article history Received: 01 Jun 1970 Revision Received: 17 Nov 1970 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation BERND-DIETRICH ERDTMANN; Ordovician Graptolite Zones of Western Newfoundland in Relation to Paleogeography of the North Atlantic. GSA Bulletin 1971;; 82 (6): 1509–1528. doi: https://doi.org/10.1130/0016-7606(1971)82[1509:OGZOWN]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Combined paleontological evidence from the western and northern structural units of Newfoundland (the autochthonous St. George, Table Head, and Goose Tickle Groups, and the allochthonous Cow Head and northern klippen sequences) reveals an almost uninterrupted succession of the North American graptolite Zones 1 through 9 (of Berry, 1960). Only Zone 7 has not been verified. In Berry's Zones 1 and 9, the zonal record is extensive enough to justify subdivision into separate zones, whereas some other zones appear to be lithologically condensed.A recently discovered Early Ordovician Dictyonema flabelliforme-Staurograptus fauna from an unknown allochthonous formation at Onion Cove, northern Newfoundland, is provisionally referred to the mobile belt facies and appears to be related to similar occurrences in Nova Scotia and western Europe. Most of the autochthonous and allochthonous sequences contain graptolites with strong Pacific-American affinities, but one graptolite association with Baltic-British affinities has been found in the Goose Tickle Formation of northernmost Newfoundland.Except for the deep-water environment of the Goose Tickle strata, all other autochthonous formations were deposited under shallow sublittoral conditions with only sparse graptolites preserved. The argillaceous beds of the Cow Head allochthonous complex probably have been brought in from a rapidly subsiding miogeosynclinal shelf margin intermittent between the circumcratonic limestone belt and the mobile belt in the east. A “pre-klippen” reconstruction of the Cow Head sequence and correlations of the graptolite facies suggest the existence of a “pre-Atlantic rift” belt, a Pacific development of graptolite associations along the “Logan's Zone” of the Appalachians to western Ireland and Atlantic Norway, and a contrasting Baltic faunal development having temporarily encroached on northern Newfoundland during Goose Tickle time. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Esquisse geologique de la chaine des Mauritanides entre M'Bout et Moudjeria (Mauritanie occidentale)

Abstract Metamorphic, serpentinite complex, granites, epimetamorphic and pelitic series (Precambrian, Paleozoic, Tertiary and Quaternary), autochthonous formations, Hercynian (lower Paleozoic) folds

Introduction

Abstract Portuguese Timor forms the eastern half of Timor which is the largest of the Lesser Sunda Islands. Timor is that island of the Indonesian Archipelago nearest to Australia, being separated from the Sahul Shelf by only 120 km (75 miles). The geology of Timor is therefore particularly relevant to the problems of the geological relationships between Asia and Australia. This Memoir deals mainly with the stratigraphy and structure of Portuguese Timor, an area of 16000 km 2 (7500 square miles). It is based upon 28 months of field mapping and three years of laboratory studies, mainly petrography and geochemistry. Two-thirds of the area was mapped on a scale of 1:40000 and the remainder on 1:100000. This detailed reconnaissance is supported by the palaeontological reports of several specialists. Twenty-four formations are distinguished, four of which are wholly allochthonous. The autochthonous formations range in age from Lower Permian to Recent, and make up a section of 8000m thickness. Of the wholly allochthonous formations one is pre-Permian, two are Permian, and the other a mid-Miocene gravity slide deposit. Four separate periods of folding are recognized, two of which, the Timorean and the Ramelauean, are of major importance and were accompanied by large-scale overthrusting. Two unconformities in the Lower Tertiary are recognized but no associated folding can be distinguished. Immediately following both the Timorean and Ramelauean orogenies there were periods of uplift. The geological history of Portuguese Timor is described, and in broad terms an attempt is made to correlate events in eastern Timor with those in western Timor, the other islands of the Indonesian Archipelago, New Guinea, and northern Australia. A regional tectonic sequence emerges. The seepages of petroleum and natural gas are described and their origin briefly discussed.

Le "flysch a quartzites" des territoires calabro-lucaniens (Italie meridionale)

Abstract So-called quartzitic Flysch deposits of the southern Apennines in Calabria and Lucania, Italy, have generally been described as transgressive Eocene deposits. Evidence is here presented to show that they are allochthonous deposits, probably older than Eocene, which have been subjected to low-grade metamorphism and that they are in fault contact with a complex basement of autochthonous Mesozoic and Tertiary formations.

Geologie des unites situees entre l'autochtone de l'Argentera et les couches triasiques du Monte Vecchio (province de Cuneo, Italie)

Abstract The autochthonous formations of the Argentera massif form the base of the Col de Tende unit in Cuneo province, Italy. The Cretaceous beds of the unit are well developed to the northwest, but are absent to the southeast as a result of pre-Lutetian erosion. Toward the northwest the Col de Tende unit becomes more plastic and underlies overthrust units. Some of the latter show facies of Triora-type units, while others exhibit a facies hitherto unknown among the Subbrianconnais units. The contact with the Triassic of the Monte Vecchio unit is marked by a crush zone in beds exhibiting facies of the basal complex of the Helminthoid Flysch nappe.

Esquisse geologique de la bordure occidentale de la plaine d'Argos (Peloponese, Grece)

Abstract On the southeastern margin of the Argos plain, Peloponnesus, Greece, a neritic limestone series, the Aspis series, is thrust over the Pindus nappe; along the western border and elsewhere, the plain is bounded by the nappe. Erosion of a window has exposed autochthonous formations and the metamorphic basement. The structural relations between the different series are examined, and the different phases of tectonic activity that have affected the sedimentary formations are outlined.