(Supplement Table S2) Results of 230Th/U-dating

We compared the suitability of two skeletal materials of the Atlantic brain coral Diploria strigosa for 230Th/U-dating: the commonly used bulk material comprising all skeletal elements and the denser theca wall material. Eight fossil corals of presumably Last Interglacial age from Bonaire, southern Caribbean Sea, were investigated, and several sub-samples were dated from each coral. For four corals, both the ages and the activity ratios of the bulk material and theca wall agree within uncertainty. Three corals show significantly older ages for their bulk material than for their theca wall material as well as substantially elevated 232Th content and (230Th/238U) ratios. The bulk material samples of another coral show younger ages and lower (230Th/238U) ratios than the corresponding theca wall samples. This coral also contains a considerable amount of 232Th. The application of the available open-system models developed to account for post-depositional diagenetic effects in corals shows that none of the models can successfully be applied to the Bonaire corals. The most likely explanation for this observation is that the assumptions of the models are not fulfilled by our data set. Comparison of the theca wall and bulk material data enables us to obtain information about the open-system processes that affected the corals. The corals showing apparently older ages for their bulk material were probably affected by contamination with a secondary (detrital) phase. The most likely source of the detrital material is carbonate sand. The higher (230Th/232Th) ratio of this material implies that detrital contamination would have a much stronger impact on the ages than a contaminant with a bulk Earth (230Th/232Th) ratio and that the threshold for the commonly applied 232Th reliability criterion would be much lower than the generally used value of 1 ng g^-1. The coral showing apparently younger ages for its bulk material was probably influenced by more than one diagenetic process. A potential scenario is a combination of detrital contamination and U addition by secondary pore infillings. Our results show that the dense theca wall material of D. strigosa is generally less affected by post-depositional open-system behaviour and better suited for 230Th/U-dating than the bulk material. This is also obvious from the fact that all ages of theca wall material reflect a Last Interglacial origin (~125 ka), whereas the bulk material samples are either substantially older or younger. However, for some corals, the 230Th/U-ages and activity ratios of the bulk material and the theca wall samples are similar. This shows that strictly reliable 230Th/U-ages can also be obtained from bulk material samples of exceptionally well-preserved corals. However, the bulk material samples more frequently show elevated activity ratios and ages than the corresponding theca wall samples. Our findings should be generally applicable to brain corals (Mussidae) that are found in tropical oceans worldwide and may enable reliable 230Th/U-dating of fossil corals with similar skeletal architecture, even if their bulk skeleton is altered by diagenesis. The 230Th/U-ages we consider reliable (120-130 ka), along with a recently published age of 118 ka, provide the first comprehensive dating of the elevated lower reef terrace at Bonaire (118-130 ka), which is in agreement in timing and duration with other Last Interglacial records.

Living benthic foraminifera of the western and southern Arabian Sea

Sediments from the western and southern part of the Arabian Sea were collected periodically in the spring intermonsoon between March and May 1997 and additionally at the end of the Northeast Monsoon in February 1998. Assemblages of Rose Bengal stained, living deep-sea benthic foraminifera, their densities, vertical distribution pattern, and diversity were analysed after the Northeast Monsoon and short-time changes were recorded. In the western Arabian Sea, foraminiferal numbers increased steadily between March and the beginning of May, especially in the smaller size classes (30-63 µm, 63-125 µm). At the same time, the deepening of the foraminiferal living horizon, variable diversity and rapid variations between dominant foraminiferal communities were observed. We interpret these observations as the time-dependent response of benthic foraminifera to enhanced organic carbon fluxes during and after the Northeast Monsoon. In the southern Arabian Sea, constant low foraminiferal abundances during time, no distinctive change in the vertical distribution, reduced diversity, and more stable foraminiferal communities were noticed, which indicates no or little influence of the Northeast Monsoon to benthic foraminifera in this region.

Pollen profiles from 8 sediment cores from the Degersee, Southern Germany

The discovery of a neolithic pile field in the shallow water near the eastern shore of the Degersee confirmed earlier palynological and sedimentological studies stating that early man was active in the region since more than 6000 years. The already available off-site data were freshly assessed, completed by additional data from old and new cores and the interpretations revised. A common time scale for the off-site data and the on-site data was obtained by AMS dating of terrestrial macro remains of the neolithic section of off-site core De_I+De_H. The ages can thus be parallelled with AMS ages of construction timber on-site. Pollen analyses from all cores provide a further time scale. The continuously and densely sampled pollen profile of the profundal zone embracing the entire Late glacial and Holocene serves as a reference. From the Boreal onwards the relative ages are transformed by AMS ages and varve counts into calibrated and absolute. A transect cored close to the neolithic pile field across the lake marl-platform demonstrates its geological architecture in the shallow water since the Lateglacial. Studies of the microfabric of thin sections of drilled cores and of box cores from the excavations demonstrate that neolithic settlements now at 2-3,5 m water depth had been erected on lake marl freshly fallen dry, thus indicating earlier lake levels dropped by 1.5-2 m. The neolithic section of the highly resolved off-site profile in the lake=s profundal zone has laminated and calcareous zones alternating with massive ones. Assemblages of diatoms and concentrations of trace elements changing simultaneously characterise the calcareous sections as deposits of low lake levels that lasted between some 40 and more than 300 years. The ages of discovered lake shore dwellings fall into calcareous segments with low lake levels. From the end of the Upper Atlantic period (F VII) appear Secondary Forest Cycles in the beech forest, a man-made sequence of repeated vegetational development with an identical pattern: With a decrease of beech pollen appear pollen of grasses, herbs and cultural indicators. These are suppressed by the light demanding hazel and birch, those again by ash, and finally by the shade demanding beech forming a new pollen peak. Seven main Forest Cycles are identified In the upper Neolithic period each comprising some 250, 450 or 800 years. They are subdivided into subcycles that can be broken down by very dense sampling in even shorter cycles of decadal length. Farming settlers have caused minor patchy clearances of the beech-mixed-forest with the use of fire. The phases of clearance coincide with peaks of charcoal and low stands of the lake levels. The Secondary Forest Cycles and the continuous occurrence of charcoal prove a continued occupation of the region. Together with the repeated restoration of the beech climax forest they point to pulsating occupation probably associated with dynamic demography. The synchronism of the many palynological, sedimentological and archaeological data point to an external forcing as the climate that affects comprehensively all these proxies. The fluctuations of the activity of the sun as manifested in the residual d14C go largely along with the proxies. The initial clearances at the begin of the forest cycles are linked to low lake levels and negative values of d14C that point to dry and warm phases of a more continental climate type. The subcycles exist independent from climatic changes, indicating that early man acted largely independent from external forces.

Organic carbon and calcium carbonate concentrations of K/T boundary samples from southern Tethyan margin location (Table 1)

Regional consequences of the biotic extinctions and of the changes in biological productivity that occurred at the time of the Cretaceous/Tertiary (K/T) boundary were investigated by comparison of organic matter in sediments from three southern Tethyan margin locations. Organic matter characterization comprised Rock-Eval pyrolysis and organic carbon measurements. Low concentrations of organic matter precluded additional detailed determinations. At all three locations, the organic matter has been microbially reworked and evidently was deposited in oxygenated marine environments.

Geochemistry of sediment cores of the Southern Ocean

We examine the possibility that glacial increase in the areal extent of reducing sediments might have changed the oceanic Cd inventory, thereby decoupling Cd from PO4. We suggest that the precipitation of Cd-sulfide in suboxic sediments is the single largest sink in the oceanic Cd budget and that the accumulation of authigenic Cd and U is tightly coupled to the organic carbon flux into the seafloor. Sediments from the Subantarctic Ocean and the Cape Basin (South Atlantic), where oxic conditions currently prevail, show high accumulation rates of authigenic Cd and U during glacial intervals associated with increased accumulation of organic carbon. These elemental enrichments attest to more reducing conditions in glacial sediments in response to an increased flux of organic carbon. A third core, overlain by Circumpolar Deep Water (CPDW) as are the other two cores but located south of the Antarctic Polar Front, shows an approximately inverse pattern to the Subantarctic record. The contrasting patterns to the north and south of the Antarctic Polar Front suggest that higher accumulation rates of Cd and U in Subantarctic sediments were driven primarily by increased productivity. This proposal is consistent with the hypothesis of glacial stage northward migration of the Antarctic Polar Front and its associated belt of high siliceous productivity. However, the increase in authigenic Cd and U glacial accumulation rates is higher than expected simply from a northward shift of the polar fronts, suggesting greater partitioning of organic carbon into the sediments during glacial intervals. Lower oxygen content of CPDW and higher organic carbon to biogenic silica rain rate ratio during glacial stages are possible causes. Higher glacial productivity in the Cape Basin record very likely reflects enhanced coastal up-welling in response to increased wind speeds. We suggest that higher productivity might have doubled the areal extent of suboxic sediments during the last glacial maximum. However, our calculations suggest low sensitivity of seawater Cd concentrations to glacial doubling of the extent of reducing sediments. The model suggests that during the last 250 kyr seawater Cd concentrations fluctuated only slightly, between high levels (about 0.66 nmol/kg) on glacial initiations and reaching lowest values (about 0.57 nmol/kg) during glacial maxima. The estimated 5% lower Cd content at the last glacial maximum relative to modern levels (0.60 nmol/kg) cannot explain the discordance between Cd and delta13C, such as observed in the Southern Ocean. This low sensitivity is consistent with foraminiferal data, suggesting minimal change in the glacial Cd mean oceanic content.

Pollen and macrofossils profiles and age determination from three cores in Northeastern Kansas, U.S.A.

Two marshes near Muscotah and Arrington, Atchison County, northeastern Kansas, yielded a pollen sequence covering the last 25,000 yrs of vegetation development. The earliest pollen spectra are comparable with surface pollen spectra from southern Saskatchewan and southeastern Manitoba and might indicate a rather open vegetation but with some pine, spruce, and birch as the most important tree species, with local stands of alder and willow. This type of vegetation changed about 23,000 yrs ago to a spruce forest, which prevailed in the region until at least 15,000 yrs ago. Because of a hiatus, the vegetation changes resulting in the spread of a mixed deciduous forest and prairie, which was present in the region from 11,000 to 9,000 yrs ago, remain unknown. Prairie vegetation, with perhaps a few trees along the valleys, covered the region until about 5,000 yrs ago, when a re-expansion of deciduous trees began in the lowlands.

Microflora from Molasse sediments in southern Germany

1. Polleninventar: Erstmals wurde der Sporomorpheninhalt der Süssbrackwassermolasse und der Oberen Süsswassermolasse Südbayerns einer umfassenden Sichtung unterzogen. Von den überprüften 92 Fundstellen erwiesen sich 55 als sporomorphenführend. Nur 15 davon waren so ergiebig, daß ihr Inhalt quantitativ erfaßt und als Grundlage für die Erstellung eines Diagramms herangezogen werden konnte. Dennoch weist der systematische Katalog 272 Formen auf. Dies ist eine im Vergleich mit anderen, in neuerer Zeit bearbeiteten neogenen Pollenfloren Mitteleuropas sehr große Zahl, wie folgende Angaben belegen: Niederrheinische Braunkohle 175 Arten, Braunkohle der Oberpfalz 138 Arten, subalpine Flözmolasse Bayerns 93 Arten und subalpine Molasse der Ostschweiz und der zentralen und westlichen Paratethys 219 Arten. Dieser Reichtum erklärt sich unschwer aus der Größe des Untersuchungsgebietes, das vom Allgäu im Westen bis an die Salzach im Osten reichte. Überwiegend gehören die nachgewiesenen Formen gutbekannten Arten bzw. Formenkreisen an. Deshalb wurde lediglich die Aufstellung von 2 neuen Gattungen, 19 neuen Arten sowie 5 Neukombinationen nötig. Neue Genera: Nr. (165) Ludwigiapollis Nr., (248) Caesalpiniaceaepollenites, 311 Neue Spezies: (039) Polypodiaceoisporltes subtriangularis, (046) P. pityogrammoides, (067) Perinomonoletes imperfectus, (124) Cycadopltes gemmatus, (125) C. concinus, (133) Lillacidites tener, (137) Nupharipollenites microechinatus, (150) Polyporopollenites nanus, (161) Porocolpopollenites subrotundus, (165) Ludwigiapollis labiatus, (169) Sporotrapoidites cucculatus, (190) Tricolpopollenites cribosus, (192) T. variabilis, (204) Tricolporopollenites pulcher, (210) T. operculiferus, (213) T. pseudomarcodurensis, (217) T. magnolaevigatus, (245) Umbelliferaepollenites achldorfensis, (248) Caesalpiniaceaepollenites antiquus Neukombinationen: (081) Pityosporites koraensis, (128) Magnoliaepollenites magnolioides, (130) M. graciliexinus, (168) Sporotrapoidites erdtmannii, (177) Chenopodipollis psilatoides. Für die meisten der vorgefundenen Sporomorphen sind die Lieferpflanzen bereits bekannt. Dennoch gingen parallel zur Bestimmung, d.h. der Zuordnung der Funde zu Gruppen des morphographischen Sporomorphensystems, die Bemühungen auch dahin, solche Lieferpflanzen, v.a. der selteneren oder neu gefundenen Sporomorphen, zu ermitteln; einige der neuen Arten sind in ihrer Verwandtschaft eindeutig, was durch die Benennung zum Ausdruck gebracht wird (s.o). Für die Mehrzahl der neuen Spezies und für viele bisher in ihrer Verwandtschaft unklare Formen ließ sich die botanische Deutung zumindest eingrenzen. Dies gelang für 148 Formen. Es handelt sich dabei teils um subtropisch-tropische Gewächse, teils aber auch um Pflanzen gemäßigter Klimata. Für genaue Zuweisungen sind jedoch umfangreiche Rezentvergleiche nötig, die einer eigenen Bearbeitung vorbehalten bleiben müssen. Auch einige als Sammelgruppen behandelte Formenkreise erfordern für eine Aufgliederung detailliertere Untersuchungen als sie in diesem Rahmen durchführbar waren. (z. B. Tricolpopollenites asper, T. sp. 2 u.a.). Andere Formen und Gattungen wiederum erwiesen sich dagegen als viel zahlreicher und leichter differenzierbar als bisher angenommen (z. B. Pinaceen, Magnoliaceen, Cyperaceen). In diesem Zusamenhang ist auch zu erwähnen, daß von Hemitrapa zwei Arten mit offensichtlich stratigraphischer Aussagekraft unterscheidbar sind; die Interpretation von Tricolporopol1enltes wackersdorfensis sensu MOHR & GREGOR (1984) als Gleditsia muß nach vorliegenden Erkenntnissen dagegen in Frage gestellt werden. Für 36 Formspezies blieb die Lieferpflanze völlig unbekannt oder es lassen sich höchstens vage Vermutungen anstellen. 2. Biostratigraphie: Fragen der Brauchbarkeit von Mikrofloren für die stratgraphische Gliederung der jüngsten Molassesedimente Südbayerns bildeten den zweiten Schwerpunkt vorliegender Bearbeitung. a) Reichweite: Die Fülle des gefundenen Sporomorphenmaterials brachte es mit sich, daß bei etlichen Formen eine weitere stratigraphische Reichweite als bisher angenommen festgestellt wurde. Zum Teil wurde diese Revision durch die Neugliederung des Paratethys-Miozäns nötig. b) Palynologische Gliederung: Im Laufe der Untersuchungen zeigte sich bald, daß allein auf der Basis der mikrofloristischen Bearbeitung kein von anderen Fossilresten unabhängiges stratigraphisches Gliederungsschema zu finden war. Weder die von anderen Autoren favoritisierte Leitformen-Methode, noch die Aufgliederung nach Klimaelementen ergab ein brauchbares Bild. Lediglich die bekannte generelle Abnahme der miozänen, paläotropischen und thermophilen Elemente und die Zunahme der pliozänen, arktoteriären und gemäßigten während des Neogens ließ sich deutlich ausmachen. Dagegen ermöglicht die Berücksichtigung des Sporomorpheninhalts eine Ergänzung und Deutung der vertebrat-stratigraphisch ausgeschiedenen Abfolgen. Voraussetzung ist die Möglichkeit einer Zuordnung zu einer natürlichen Art, Gattung oder wenigstens Familie und daraus ableitbar wiederum die Zuordnung zu einer oder mehreren Pflanzengesellschaften. Aufgeteilt nach Diversität, Dominanz und Verhältnis von 'Feuchtpflanzen' bzw. autochthonen Gemeinschaften zu mesophilen Phanerophyten bzw. allochthonen Gemeinschaften lassen sich in Südbayern fünf Pollenbilder erkennen, die mit den MN-Einheiten der Zoostratigraphie in Beziehung gebracht werden können. Die Pollenbilder 1 und 2, ungefähr entsprechend den Säugereinheiten 4b und 5, dokumentieren gattungsreiche, polydominante Mikrofloren, deren Lieferpflanzen vor allem verschiedenen Naß- und Feuchtgesellschaften angehören. Dementprechend sind Pteridaceen, Schizaeaceen, Cyperaceen und Poaceen relativ häufig. Das Pollenbild 1 (Langenau und Rauscheröd) zeichnet sich durch eine gewisse Artenarmut aus, wohingegen im Pollenbild 2 (Hitzhofen und Rittsteig) die Diversität zunimmt und Palmenpollen neben anderen mesophilen Akzessorien eine merkliche Rolle spielt. Bemerkenswert ist in den Entnahmeprofilen das Vorkommen kohliger Sedimente. Bezeichnend für Sporomorphenbild 3 sind oligodominante Mikrofloren, zusammengesetzt aus Elementen artenarmer Au- und Sumpfwälder (Taxodiaceen, Cyperaceen) sowie mesophiler 'Pionierwälder' (Pinaceen, Leguminosen). Fehlende Kohlebildung und das Zurücktreten mesophiler, d. h. allochthoner Lieferpflanzen sind weitere Charakteristika. Dieses Sporomorphenbild mit den Fundpunkten Gallenbach und Unterneul enspricht ungefähr der Säugereinheit MN 6. Die beiden stratigraphisch jüngsten Pollendiagramme 4 und 5 setzen sich deutlich von dem vorhergehenden ab. Belegt sind nun wiederum gattungsreiche, polydominante Pflanzenge seIl schaften feuchter, aber nicht nasser Biotope, in denen es ebenfalls mancherorts zur Kohlebildung kam. Gegenüber den Sporomorphenbildern und 2 ist der Anteil mesophiler Lieferpflanzen deutlich erhöht auf Kosten der Feuchtelemente. Letzteres gilt vor allem für das Sporomorphenbild 5 (Leonberg), in dem Fagaceen Pollen (Quercus, Fagus) vorherrscht. sporomorphenbild 4 entspricht annähernd MN 8 mit den Fundpunkten Hassenhausen und Achldorf, während Leonberg, nahe Marktl gelegen, MN 9 zugehört. Auf dem Umweg über diese an der Säugetierstratigraphie 'geeichten' Mikrofloren gelingt es, stratigraphisch unsichere Fundpunkte, wenn sie nur genügend formen- und individuenreich sind (Burtenbach, Lerchenberg, Wemding), einzuordnen. Auf diese Weise ergibt sich die in Diagramm 10 dargestellte Reihung vom Liegenden zum Hangenden. Dürftige Sporomorphenfloren oder Floren, die ausschließlich autochthone Feuchtelemente zeigen, können pollenstratigraphisch nicht sicher angesprochen werden, weil ihr Pollendiagramm undeutlich bleiben muß. Entsprechend der anerkannten Unterstellung, daß Phytostratigraphie zugleich Klimastratigraphie ist, läßt die dargestellte, im Grunde auf der Ausscheidung verschiedener Ukotypen basierende Gliederung sich auch paläoklimatisch interpretieren: Danach ist das verarmte Sporomorphenbild 3 in Südbayern als Ausdruck des vegetationsgeschichtlichen Pessimums anzusehen. Da die nachgewiesenen Sippen noch höhere Wärmeansprüche besitzen, ist nicht ein Temperaturrückgang, sondern ein Absinken der Niederschlagsmenge als begrenzender Faktor am wahrscheinlichsten und auf diese Weise das Ausbleiben von Pollen mesophiler Phanerophyten des Hinterlandes einleuchtend. 3. Paläogeographie: Bei dem Versuch, mit benachbarten Gebieten stratigraphische Beziehungen herzustellen, ergab sich, daß dies zwar über eine kürzere Entfernung recht gut gelingt, daß aber vor allem zu den Mikrofloren der niederrheinischen Braunkohle ein signifikanter Unterschied besteht: In Süddeutschland lassen die Pollendiagramme auf eine raschere Veränderung in der Zusammensetzung der Wälder schließen. Mit anderen Worten: altersgleiche Mikrofloren in Nordwestdeutschland täuschen ein höheres Alter vor. Erst im Obersarmat ähneln sich die jeweiligen Sporomorphenbilder. Damit erklärt sich auch, daß frühere Bearbeiter Schwierigkeiten hatten, mikrofloristische Befunde aus Süd- und Nordwestdeutschland miteinander zu korrelieren. Als Ursache für dieses überraschende Phänomen einer mittelmiozänen Diagrammverschiebung wird die stärkere, sprich länger andauernde maritime Beeinflussung des Niederrheingebietes angesehen.

Composition and age of volcanic rocks from the Sinii Utes Depression, Southern Primoye

New data are reported on structure of sections, chemical composition, and age of volcano-sedimentary and volcanic rocks from the Sinii Utes Depression in the Southern Primorye region. The Sinii Utes Depression is filled with two sequences: the lower sequence composed of sedimentary-volcanogenic coaliferous rocks (the stratotype of the Sinii Utes Formation) and the upper sequence consisting of tephroid with overlying basalts. This work considers chemical composition and problems of K-Ar dating of basalts. The uppermost basaltic flow has K-Ar age 22.0±1.0 Ma. The dates obtained for the middle and upper parts of lava flows are underestimated. It is explained by their heating due to combustion of brown coals of the Sinii Utes Formation underlying the lava flow. Calculations show that argon could only partly have been removed from the basalts owing to conductive heat transfer and was lost largely due to infiltration of hot gases in heterogeneous fissured medium. Basaltic volcanism on continental margins of the southern Primorye region and the adjacent Korean and Chinese areas at the Oligocene-Miocene boundary preceded Early-Middle Miocene spreading and formation of the Sea of Japan basin. Undifferentiated moderately alkaline basalts of intraplate affinity developed in the Amba Depression and some other structures of the southern Primorye region and intraplate alkali basalts of the Phohang Graben in the Korean Peninsula serve as indicators of incipient spreading regime in the Sea of Japan. Potassic basalt-trachybasalt eruptions occurred locally in riftogenic depressions and shield volcanoes. In some structures this volcanism was terminated by eruptions of intermediate and acid lavas. Such evolution of volcanism is explained by selective contamination of basaltic melts during their interaction with crustal acid material and generation of acid anatectic melts.

Early - Late Miocene palaeoclimate data and palaefloras of 48 samples from Southern China

Southern China, especially Yunnan, has undergone high tectonic activity caused by the uplift of Himalayan Mountains during the Neogene, which led to a fast changing palaeogeography. Previous study shows that Southern China has been influenced by the Asian Monsoon since at least the Early Miocene. However, it is yet not well understood how intense the Miocene monsoon system was. In the present study, 63 fossil floras of 16 localities from Southern China are compiled and evaluated for obtaining available information concerning floristic composition, stratigraphic age, sedimentology, etc. Based on such reliable information, selected mega- and micro-floras have been analysed with the coexistence approach to obtain quantitative palaeoclimate data. Visualization of climate results in maps shows a distinct spatial differentiation in Southern China during the Miocene. Higher seasonalities of temperature and precipitation occur in the north and south parts of Southern China, respectively. During the Miocene, most regions of Southern China and Europe were both warm and humid. Central Eurasia was likely to be an arid center, which gradually spread westward and eastward. Our data provide information about Miocene climate patterns in Southern China and about the evolution of these patterns throughout the Miocene, and is also crucial to unravel and understand the climatic signals of global cooling and tectonic uplift.

Major and trace element composition of melts from the Gorely volcanic center, southern Kamchatka

Melt inclusions in olivine and plagioclase phenocrysts from rocks (magnesian basalt, basaltic andesite, andesite, ignimbrite, and dacite) of various age from the Gorely volcanic center, southern Kamchatka, were studied by means of their homogenization and by analyzing the glasses in 100 melt inclusions on an electron microprobe and 24 inclusions on an ion probe. The SiO2 concentrations of the melts vary within a broad range of 45-74 wt%, as also are the concentrations of other major components. According to their SiO2, Na2O, K2O, TiO2, and P2O5 concentrations, the melts are classified into seven groups. The mafic melts (45-53 wt% SiO2) comprise the following varieties: potassic (on average 4.2 wt% K2O, 1.7 wt% Na2O, 1.0 wt% TiO2, and 0.20 wt% P2O5), sodic (3.2% Na2O, 1.1% K2O, 1.1% TiO2, and 0.40% P2O5), and titaniferous with high P2O5 concentrations (2.2% TiO2, 1.1% P2O5, 3.8% Na2O, and 3.0% K2O). The melts of intermediate composition (53-64% SiO2) also include potassic (5.6% K2O, 3.4% Na2O, 1.0% TiO2, and 0.4% P2O5) and sodic (4.3% Na2O, 2.8% K2O, 1.3% TiO2, and 0.4% P2O5) varieties. The acid melts (64-74% SiO2) are either potassic (4.5% K2O, 3.6% Na2O, 0.7% TiO2, and 0.15% P2O5) or sodic (4.5% Na2O, 3.1% K2O, 0.7% TiO2, and 0.13% P2O5). A distinctive feature of the Gorely volcanic center is the pervasive occurrence of K-rich compositions throughout the whole compositional range (silicity) of the melts. Melt inclusions of various types were sometimes found not only in a single sample but also in the same phenocrysts. The sodic and potassic types of the melts contain different Cl and F concentrations: the sodic melts are richer in Cl, whereas the potassic melts are enriched in F. We are the first to discover potassic melts with very high F concentrations (up to 2.7 wt%, 1.19 wt% on average, 17 analyses) in the Kuriles and Kamchatka. The average F concentration in the sodic melts is 0.16 wt% (37 analyses). The melts are distinguished for their richness in various groups of trace elements: LILE, REE (particularly HREE), and HFSE (except Nb). All of the melts share certain geochemical features. The concentrations of elements systematically increase from the mafic to acid melts (except only for the Sr and Eu concentrations, because of active plagioclase fractionation, and Ti, an element contained in ore minerals). The paper presents a review of literature data on volcanic rocks in the Kurile-Kamchatka area in which melt inclusions with high K2O concentrations (K2O/Na2O > 1) were found. K-rich melts are proved to be extremely widespread in the area and were found on such volcanoes as Avachinskii, Bezymyannyi, Bol'shoi Semyachek, Dikii Greben', Karymskii, Kekuknaiskii, Kudryavyi, and Shiveluch and in the Valaginskii and Tumrok Ranges.

Benthic foraminiferal faunas of Miocene to Holocene sediments of ODP Site 184-1143 from the southern South China Sea

Deep-sea benthic foraminiferal assemblages from Ocean Drilling Program (ODP) Site 1143 located in the southern South China Sea (SCS) were investigated to evaluate the relationship between faunal composition patterns and paleoceanographic changes during the last 6 million years (late Miocene to Holocene). We used multivariate statistics (correspondence analysis) to analyze carbon-flux-related changes in assemblage composition of benthic foraminifers. Additional proxies for carbon flux and deep-water ventilation include delta13C records of epifaunal Cibicidoides wuellerstorfi and infaunal Uvigerina peregrina var. dirupta and Melonis pompilioides, benthic foraminiferal accumulation rates (BFARs), diversity indices, and relative abundances of indicator species. We observe three significant benthic faunal changes in the southern South China Sea during the last 6 million years. Strong fluctuations in BFAR and relative abundance of productivity indicator species between glacial and interglacial stages after the mid-Pleistocene revolution (MPR) at approximately 0.9 Ma, indicating stronger seasonal carbon flux fluctuations, are accompanied by the extinction of such species as Stilostomella spp. Increases in carbon flux indicator species are coupled with an overall decrease in benthic foraminifer diversity around 3.0 Ma in the late Pliocene. This may indicate increasing carbon flux in a period of productivity maximum caused by enhanced offshore upwelling from intensified winter monsoon wind strength.

U-Pb, trace element, and Hf isotope analysis for Macquarie Island detrital zircon

Oceanic zircon trace element and Hf-isotope geochemistry offers a means to assess the magmatic evolution of a dying spreading ridge and provides an independent evaluation of the reliability of oceanic zircon as an indicator of mantle melting conditions. The Macquarie Island ophiolite in the Southern Ocean provides a unique testing ground for this approach due to its formation within a mid-ocean ridge that gradually changed into a transform plate boundary. Detrital zircon recovered from the island records this change through a progressive enrichment in incompatible trace elements. Oligocene age (33-27 Ma) paleo-detrital zircon in ophiolitic sandstones and breccias interbedded with pillow basalt have trace element compositions akin to a MORB crustal source, whereas Late Miocene age (8.5 Ma) modern-detrital zircon collected from gabbroic colluvium on the island have highly enriched compositions unlike typical oceanic zircon. This compositional disparity between age populations is not complimented by analytically equivalent eHf data that primarily ranges from 14 to 13 for sandstone and modern-detrital populations. A wider compositional range for the sandstone population reflects a multiple pluton source provenance and is augmented by a single cobble clast with eHf equivalent to the maximum observed composition in the sandstone (~17). Similar sandstone and colluvium Hf-isotope signatures indicate inheritance from a similar mantle reservoir that was enriched from the depleted MORB mantle average. The continuity in Hf-isotope signature relative to trace element enrichment in Macquarie Island zircon populations, suggests the latter formed by reduced partial melting linked to spreading-segment shortening and transform lengthening along the dying spreading ridge.