A device for rapid sectioning of soft bottom sediment cores

A new mechanical sectioning device for transverse cutting of cylindrical soft bottom sediment cores is presented. The instrument is rapid and efficient in use, works serially when sectioning a core and permits rinsing of the sample compartment without removal from the coring tube. The device is made of plastic, is lightweight, convenient to operate even in the field and simple and cheap to manufacture.     

Drought is the major limiting factor for tree-ring growth of high-altitude Canary Island pines on Tenerife

This is a detailed study of 50 wood cores sampled from 25 Canary Island pines ( Pinus canariensis ) growing in a subtropical climate close to the tree limit (at Lomo de Retamar, 2000–2100 m a.s.l.) on the southern, leeward side of Tenerife.
The Canary Island pines form tree-rings and, similarly to temperate pines, earlywood is formed during spring. But many pines fail to form tree-rings every year and one purpose for this paper has been to find a way to overcome this problem. Another purpose has been to see what correlations, if any, exist between the ring widths and meteorological data. Meteorological data have been collected since 1916 at the nearby Izaña meteorological observatory. It was also important to find the limiting factor for growth of Canary Island pines close to the tree limit.
Through cross-dating, missing rings were found to be typical for younger parts of older trees; in the same years younger trees instead had low growth. Some trees lacked more than 20 rings in a century. This study shows that it is possible to compensate for missing rings, at least when the number of missing rings is less than 10%.
Correlation studies showed that the growth of the tree rings was mainly due to the precipitation factor, particularly the annual precipitation one year before the ring formation, but also due to temperature. Strangely enough, multiple linear regression gave the highest correlation coefficient (0.50) for a combination of annual precipitation one year earlier and temperature four years earlier.     

Landslide and Tsunami 21 November 2000 in Paatuut,West Greenland

A large landslide occurred November 21, 2000 at Paatuut, facing the Vaigat Strait onthe west coast of Greenland. 90 million m³ (260 million tons) of mainly basalticmaterial slid very rapidly (average velocity 140 km/h) down from 1,000–1,400 maltitude. Approximately 30 million m³ (87 million tons) entered the sea, creatinga tsunami with an run-up height of 50 m close to the landslide and 28 m at Qullissat,an abandoned mining town opposite Paatuut across the 20 km wide Vaigat strait. Theevent was recorded seismically, allowing the duration of the slide to be estimated tocirca 80 s and also allowing an estimate of the surface-wave magnitude of the slideof 2.3. Terrain models based on stereographic photographs before and after the slidemade it possible to determine the amount of material removed, and the manner ofre-deposition. Simple calculations of the tsunami travel times are in good correspondencewith the reports from the closest populated village, Saqqaq, 40 km from Paatuut, whererefracted energy from the tsunami destroyed a number of boats. Landslides are notuncommon in the area, due to the geology with dense basaltic rocks overlying poorlyconsolidated sedimentary rocks, but the size of the Paatuut slide is unusual. Based onthe observations it is likely at least 500 years since an event with a tsunami of similarproportions occurred. The triggering of the Paatuut slide is interpreted to be caused byweather conditions in the days prior to the slide, where re-freezing melt water inpre-existing cracks could have caused failure of the steep mountain side.     

Implications of a new,biostratigraphically well-controlled,radio-isotopic age for the lower Telychian Stage of the Llandovery Series （Lower Silurian,Sweden）

Radio-isotopic analysis of single zircons from two early Telychian K-bentonites, one of which is among the most widespread Lower Paleozoic volcanic ash falls in north- ern Europe, yields overlapping weighted mean 206pb/238U ages of 438. 7± 1.0 Ma and 437.8 ± 0.5 Ma, respectively. The former age is from zircons of the Osmundsberg K-bentonite from the type locality at Osmundsberget in the Siljan area of central Sweden where it occurs in the lower part of the Spirograptus tur- riculatus Graptolite Zone and in the lower part of the Angochitina longicollis Chitinozoan Zone. Zircons giv- ing the latter age are from a bed previously identified as the Osmundsberg K-bentonite at the Kallholn Quarry in the same area. Based on new biostratigraphic data, the latter bed is now considered to be slightly younger than the Osmundsberg K-bentonite. The dated stratigraphic level of the ash layers is slightly younger than the base of the Telychian Stage and thus represents a minimum age for the Aeronian/Telychian Stage boundary. A U-Pb age of 〉 438 Ma for the base of this stage, however, is older and in conflict with estimates in the most recent compilation of the Silurian time scale. In view of the fact that only three radio-isotopic dates from the entire Llan- dovery have been previously accepted, this new and biostratigraphically exceptionally well-controlled radio-isotopic date fills an important gap in the Lower Silurian geochronology.     

Conodont Biostratigraphy of the Middle Cambrian through Lowermost Ordovician in Hunan, South China

Since 1985, samples with a total weight of more than 14,000 kg, mainly from three key sections in western and northwestern Hunan, South China, have been processed for conodonts. In strata older than the late Late Cambrian paraconodonts have proved useful for stratigraphic subdivision and correlation. Thirteen conodont zones are proposed in the Middle Cambrian through lowermost Ordovician. The correlation between these zones and those of North China, western U. S.A., western Newfoundland, Canada, and Iran is discussed. In ascending order, these 13 zones are as follows: The Gapparodus bisulcatus-Westergaardodina brevidens Zone, Shandongodus priscus-Hunanognathus tricuspidatus Zone, Westergaardodina quadrata Zone, Westergaardodina matsushitai-W. grandidens Zone, Westergaardodina lui-W. am Zone, Westergaardodina cf. calix-Prooneotodus rotundatus Zone, Proconodontus tenuiserratus Zone, Proconodontus Zone, Eoconodontus Zone, Cordylodus proavus Zone, Cordylodus intermedius Zone, Cordylodus lindstromi Zone, and     

Lead in the North Sea and the north east Atlantic Ocean

Lead has been determined in 105 water samples from the north east Atlantic and from the North Sea. Rigorous precautions were applied to avoid contamination during sampling and analysis.Two different analytical methods were used: ASV and AAS. Determinations with ASV were carried out on board, directly after sampling. After two months storage, acidified samples were analysed by AAS after freon dithiocarbamate extraction and nitric acid back extraction. Particulate lead was determined by AAS after an acid digestion.The profiles of lead concentration versus depth show around 160 pM at the surface and around 20 pM at the bottom, both in the Atlantic and in the Norwegian Sea. The shapes of the profiles are different, however, depending on the hydrography of the area sampled. The profiles from the north east Atlantic coincide with a recently published profile from the north west Atlantic. Moreover, these profiles have lead concentrations about a factor of three higher than those in the Pacific.Considering the high lead input to the North Sea, the lead concentrations found there are remarkably low, probably because of scavenging effects in estuaries leading to a short residence time in the water column. The dominant lead input in offshore regions is from the atmosphere. The highest lead levels are found in the northern North Sea, around 300 pM in surface water.In the Atlantic, particulate lead is a minor part of the total lead whereas in the North Sea the particulate fraction is larger, up to 40%.     

The Palaeoproterozoic Kristineberg VMS deposit, Skellefte district, northern Sweden, part I: geology

The Kristineberg volcanic-hosted massive sulphide (VMS) deposit, located in the westernmost part of the Palaeoproterozoic Skellefte district, northern Sweden, has yielded 22.4 Mt of ore, grading 1.0% Cu, 3.64% Zn, 0.24% Pb, 1.24 g/t Au, 36 g/t Ag and 25.9% S, since the mine opened in 1941, and is the largest past and present VMS mine in the district. The deposit is hosted in a thick pile of felsic to intermediate and minor mafic metavolcanic rocks of the Skellefte Group, which forms the lowest stratigraphic unit in the district and hosts more than 85 known massive sulphide deposits. The Kristineberg deposit is situated lower in the Skellefte Group than most other deposits. It comprises three main ore zones: (1) massive sulphide lenses of the A-ore (historically the main ore), having a strike length of about 1,400 m, and extending from surface to about 1,200 m depth, (2) massive sulphide lenses of the B-ore, situated 100–150 m structurally above the A-ore, and extending from surface to about 1,000 m depth, (3) the recently discovered Einarsson zone, which occurs in the vicinity of the B-ore at about 1,000 m depth, and consists mainly of Au–Cu-rich veins and heavily disseminated sulphides, together with massive sulphide lenses. On a regional scale the Kristineberg deposit is flanked by two major felsic rock units: massive rhyolite A to the south and the mine porphyry to the north. The three main ore zones lie within a schistose, deformed and metamorphosed package of hydrothermally altered, dominantly felsic volcanic rocks, which contain varying proportions of quartz, muscovite, chlorite, phlogopite, pyrite, cordierite and andalusite. The strongest alteration occurs within 5–10 m of the ore lenses. Stratigraphic younging within the mine area is uncertain as primary bedding and volcanic textures are absent due to strong alteration, and tectonic folding and shearing. In the vicinity of the ore lenses, hydrothermal alteration has produced both Mg-rich assemblages (Mg-chlorite, cordierite, phlogopite and locally talc) and quartz–muscovite–andalusite assemblages. Both types of assemblages commonly contain disseminated pyrite. The sequence of volcanic and ore-forming events at Kristineberg is poorly constrained, as the ages of the massive rhyolite and mine porphyry are unknown, and younging indicators are absent apart from local metal zoning in the A-ores. Regional structural trends, however, suggest that the sequence youngs to the south. The A- and B-ores are interpreted to have formed as synvolcanic sulphide sheets that were originally separated by some 100–150 m of volcanic rocks. The Einarsson zone, which is developed close to the 1,000 m level, is interpreted to have resulted in part from folding and dislocation of the B-ore sulphide sheet, and in part from remobilisation of sulphides into small Zn-rich massive sulphide lenses and late Au–Cu-rich veins. However, the abundance of strongly altered, andalusite-bearing rocks in the Einarsson zone, coupled with the occurrence of Au–Cu-rich disseminated sulphides in these rocks, suggests that some of the mineralisation was synvolcanic and formed from strongly acidic hydrothermal fluids. Editorial handling: P. Weihed     

New multifunctional hunting landscapes in Denmark

Between 1992 and 2008 subsidization of mandatory set aside land under the EU Common Agricultural Policy (CAP) gave rise to the establishment of a characteristic type of multifunctional hunting landscapes in Denmark, primarily located on fallow land in tilled valley bottoms. A national survey of these landscapes in 2006 has been carried out and 1061 hunting areas have been identified nationwide. Subsidies relating to set aside land acted as a supplementary type of income, which supported the development of multifunctional land use on marginal soils where the income from hunting and subsidies in combination was a viable alternative to monofunctional rotational agriculture. Hunting landscapes developed as the consequence of landscape management strategies designed to comply with the requirements of the CAP while improving habitat conditions for wildlife and increasing income from hunting rental activities. Forty-seven percent of the hunting landscapes in 2006 were in rotational production in 2010 while 19% were used for other agricultural purposes and 34% were taken out of the subsidy regime and removed from the general agricultural register. In 2012, a total of 431 such areas ? 41% of the areas identified in 2006 ? were still used for hunting. The number and geographical distribution of the hunting landscapes seems closely related to the potential average hunting rent, the level of urbanisation and the occurrence of manorial estates with traditions for multifunctional land use as part of their economic strategy. Implications for the ongoing discussion on land use policy concerning land sharing vs. land sparing is discussed.