No description available.

The geophysical reasons for requiring magnetic measurements in the upper atmosphere are outlined and the scientific, technical and administrative problems involved in using a Skylark rocket for the purpose are described. The principles and advantages of a measuring technique utilising the free precession of protons in a hydrogenous liquid are discussed and this technique is applied to the design and construction of a portable magnetometer, which was used for general magnetic measurements. A series of experiments, designed to investigate the effect of a rocket's rotational motions on the proton magnetometer data, is described and the results presented. The application of the preliminary work to the design, construction and testing of an early valve/transistor magnetometer and of a later, completely transistorized, version is described, together with their associated equipment for pre-flight testing and post-flight data processing. The results of the first, partially successful, instrument-proving flight of a single coil transistorized proton precession magnetometer are presented and discussed. The evaluation of the flight data involved carrying out a ground survey, at the Woomera rocket range, and also an investigation into the effect of magnetic field gradients on the rocket-borne magnetometer. Where possible the various stages of the project are described in chronological order.

Folldal, about 100 miles north of Oslo in Norway, is the centre of a longstanding mining industry based on a large number of broadly stratiform pyritic and pyrrhotitic deposits which yield pyrite, copper and zinc in varying quantities. The region studied straddles the Caledonian geosynclinorium of Lower Paleozoic Trondheim Schists, bordered east and west by Eocambrian Sparagmites. The country rocks consist mainly of a volcanic sequence of basic lavas and pyroclastics interrupted by beds of acidic pyroclastics, mainly tuffs, of which some have been described as Itrondheimitet. Purely sedimentary pelites, many calcareous, scattered small limestone bodies and some gabbro intrusions also occur. The whole area has been regionally metamorphosed in Caledonian times to greenschist facies grade. Thin but widespread sedimentary ore horizons are numerous and are of two facies - the dominant pyrrhotite - graphite schist and the magnetite quartzite. Five ore-types have been recognised in the region but the constituent mineralogy of all are essentially the same - generally subhedral pyrite and magnetite with anhedral pyrrhotite, chalcopyrite, sphalerite, minor galena and gangue of mainly quartz, calcite and chlorite. Chemical studies further indicate the division of ore-types. The generally remobilised textural features and the complexly folded nature of the orebodies show that all the ores have been regionally metamorphosed. Consequently the primary genesis of the ores cannot be conclusively determined and the useful evidence was limited to the structure of the orebodies, their association with volcanic sequences and a few features of their chemistry and mineralogy. The genetic classification of the ores is:- 1) Coarse-grained pyrite ores : volcanic - exhalative sedimentary deposits; 2) Fine-grained pyrite ores : broadly similar to (1); 3) Magnetite - pyrite ores : oxidising facies of (1); 4) 1) Pyrrhotite chalcopyrite ores (in independent orebodies) : epigenetic deposits: 4)ii) Pyrrhotite - chalcopyrite ores (in type (1) orebodies) : sedimentary facies of (1), or metamorphic segregations from (1).

No description available.

Ostracoda from the Palaeocene of the Sor Range and from the Palaeocene and Eocene of the Rakhi Nala, Zao River and Shpalai Khwara sections, Sulaiman Range, West Pakistan, have been examined The family TRACHYLEBERIDIDAE has been studied in detail. It is represented by fourteen genera, 4subgenera and sixty-one species. Four new genera (Alocopocythere, Gyrocythere, Phalcocythere and Stigmatocythere) and two new subgenera (Paracosta and Scelidocythereis) are proposed. Out of the sixty-one species described, fifty-two are new. The Palaeocene and Eocene of the Rakhi Nala section is divided into five ostracod biostratigraphic units. The biostrati graphic units IV and V of the Rakhi Nala are represented in the Zao River section and have almost identical ostracod faunas. The biostratigraphic unit IV of the Rakhi Nala is also represented in the Shpalai Khwara section. The Equations of Correlation between the Rakhi Nala and Zao River sections for biostratigraphic unit V (i.e. Middle - Upper Eocene) have been calculated by means of ranges of ostracod species common to the two sections. The standard errors of estimate for the Equations of Correlation have also been calculated. The boundaries between the Palaeocene - Lower Eocene, Lower - Middle Eocene and Middle - Upper Eocene in the Sulaiman Range are discussed.

Small scattered disseminations of metalliferous minerals, primarily copper bearing sulphides and secondary malachite, are widespread in the Upper Devonian sedimentary rocks of South-West Cork. This mineralization is spatially associated with the development of 'red beds'. Typically the host rocks are the sandstone and comstone fractions of green-grey coloured strata. In the 'red bed' sequence such greon-grey strata are present as thin concordant bands. An upward stratigraphic zoning of the sulphides from those rich in copper to those relatively rich in iron occurs. In addition the sulphides show evidence of having been deformed together with the enclosing host rocks during the Ilercynian orogeny. The copper abundances in unmineralized portions of the succession are apparently abnormally lev. Similar though less richly mineralised cupriferous strata occur in the Devonian succession elsewhere in Southern Ireland and in the Anglo-Welsh area. The disseminated mineralisation is considered to have formed as a result of diagenetic processes active within the coinpacting sedimentary column. The position of the water table, the presence of sulphate-reducing) bacteria, the movement of 'waters of compaction', variations in sediment permeability and the presence both of 'red beds' and of the adjacent Variscan marine eeosynclinal basin are considered to have bean important factors in effecting metal concentration. In South-West Cork the subsequent Hercynian orogeny produced small quartz-sulphide veins by lccal renobilization of cupriferous country rock. Larger vein deposit of quartz, of baryte, and of manganese and iron oxides also occur. Where quarts forms a major constituent, metalliferous (chiefly Cu-Pb) mineralization is common. It is suggested that in the main such metalliferous mineralization vas emplaced during the Hercynian orogeny from remnant connate fluids channelled through fractures after the surrounding strata were rendered impermeable. The baryte and the manganese and iron oxides may have been deposited at a much later stage from ground waters circulating in the pre-existing Eercynian fractures. Various microscopic sulphide textures present in the mineralization of the South-West Cork area are, in addition, described and their modes of formation discussed.

This project is aimed at finding the best methods for geochemical exploration in the fast eroding lofty mountains of northern Pakistan and includes studies of parts of the Khoistan and Karakoram tectonic terranes. In the Chitral area (Karakoram terrane), three interlinked studies were undertaken to determine the primary concentration of elements, their dispersion into drainages and the regional distribution of trace metals within drainages. Panned concentrates are most effective in detecting the mineralization due to the dominance of clastic dispersion and the insolubility of many metallic minerals in the cold alkaline river waters. The regional survey reveals that Chitral has a high potential for mineralization and many valleys contain polymetallic anomalies. The rock geochemistry of the low grade gold prospect in the Shoghor area demonstrates the concentration of As, Sb and Ag along faults and in iron rich siliceous carbonate units and the secondary clastic enrichment of gold in the siliceous carbonates. In the Kohistan terrane, studies consisted of an orientation study in the Bagrot valley, a regional survey of the Gilgit area and an experimental investigation of the stability of the uraninite- pyrite- gold assemblage. The Bagrot study demonstrates that panned concentrates are the best medium for mineral exploration because of the coarse grained nature of the gold and the dominance of clastic dispersion. The regional panned concentrate survey of the Gilgit area demonstrates that this part of Kohistan has a high mineral potential, particularly for precious metals. The gold- pyrite- uraninite assemblage in the rivers around Gilgit, particularly the Indus, is very similar to that from the Archean Witwatersrand basin and has been proposed as a modern analogue. Gold and pyrite are derived from the Chalt volcanics and quartz veins near the Northern Suture while the origin of the uraninite is unknown, presumably from the Karakoram batholith or pegmatites.

The NE-SW trending Gördes basin developed in the early Miocene as indicated by palynological data and K-Ar dating of igneous rocks. In the basin centre rhyolitic and dacitic volcanic domes cut the Neogene sedimentary filling and ophiolitic basement of the Izmir-Ankara suture zone. Geochronological data and field relationships demonstrate that compressional movement on this suture zone had ceased, at least, before the latest Oligocene. The palynological data from the E-W trending Alasehir and Buyuk Menderes graben fillings indicate that these major extensional structures started to develop during middle Burdigalian-middle Serravallian. Consequently, it is concluded that N-S extensional tectonics in west Turkey commenced in the early Miocene. It is evident from the age determinations of the G?rdes basin and the Alasehir and Buyuk Menderes grabens that the E-W and NE-SW trending grabens / basins developed coevally under a N-S extensional regime during the early Miocene in west Turkey. This joint initiation of basins is inconsistent with both the cross graben and the multi-phased extensional models. In west Turkey, the latest Oligocene-early Miocene calcalkaline intermediate and acid volcanism with an inherited subduction-related geochemical signature occurred under the N-S extensional regime. Due to the continuation of extension after the late Miocene the thickness of the lithosphere would be reduced and consequently alkaline volcanism became dominant in this advanced stage of extension (late Miocene and younger). This change in nature of volcanism is not related to a change of regional tectonic regime as previously thought. It is apparent from the above findings that the tectonic escape and back-arc spreading models cannot explain the commencement of extensional regime due to the younger triggering events, the collision of Eurasia/Arabia in Langhian-Serravallian and inception of the roll-back process in late Serravallian-early Tortonian. Alternatively it is proposed that N-S extensional tectonics is related to spreading and thinning of the crust which commenced in the early Miocene. This occurred immediately after the cessation of compressional regime due to the high thermal profile of the crust in west Turkey.

No description available.

No description available.