Abstract The Neogene Productive Series, the main reservoir unit of the prolific hydrocarbon province in the South Caspian Basin, and the modern Volga delta in the northern Caspian Sea, are deltas deposited by the same river into the same closed sea. Both deltas are low- gradient, mud-dominated, river-dominated, multichannel, ramp deltas without a shelf break, and show the impact of rapid changes in sea level, climate-driven discharge, and sediment input. But there are also prominent differences. The Productive Series forms the lowstand wedge of the most dramatic sea-level fall the Caspian has ever experienced. It consists of a succession, up to 7 km thick, of fluviodeltaic sediments, deposited at extremely high sedimentation rates (2-4 mm/y) by a paleo-Volga River in the narrow, rapidly subsiding South Caspian basin. Simultaneously, the paleo-Volga carved a canyon 2000 km long and up to 600 m deep far upstream into the Russian plain. The smaller Kura and Amu Darya rivers also contributed to the Productive Series. The sedimentary succession in the proximal part of the Productive Series shows the transition from an alternation of sheetflood sandstones and floodplain mudstones with great lateral continuity to finer-grained packages in which coarsening-upwards facies successions are common and there is evidence of repeated emergence and desiccation. A coarser-grained interval reflects increasing uplift in the adjacent Greater Caucasus mountains. The upsection increase in mud-dominated deposition in the Productive Series is thought to reflect a trend towards more humid climates. The modern Volga delta is not more than 20 m thick and has been deposited during the last 6000 years on a wide stable continental platform at a level halfway between a major Last Glacial highstand and a deep Early Holocene lowstand. It shows rapid lateral and vertical facies changes at the delta front, and it is characterized by many small radial sand bodies with low connectivity, coarsening-upwards mouthbar and levee deposits overlying clayey prodelta deposits, and fining-upwards channel fills. There is evidence of frequent emergence and submergence due to rapid sea-level changes. Average sedimentation rates are lower than in the Productive Series (0.7-1 mm/y in uncompacted muds). The reasons for the differences are threefold. Sedimentation in the Productive Series spanned two million years, but in the modern Volga delta less than 6,000 years, so the latter cannot be more than a partial analogue of the former. The outcropping sediments of the Productive Series were deposited in a more proximal position than the studied sediments of the modern Volga delta front, which may partly explain the difference in lateral continuity of the sandy successions. But above all the paleo-Volga shed its load in a narrow, rapidly subsiding basin, whereas the present Volga spreads its sediment across a wide and shallow stable continental platform. The differences in basin geometry and dynamics explain part of the differences in 3-D architecture and sedimentation rates.

Abstract The origin and modes of transportation and deposition of inorganic sedimentary material of the Black Sea were studied in approximately 60 piston, gravity, and Kasten cores. The investigation showed that the sediment derived from the north and northwest (especially from the Danube) has a low calcite-dolomite ratio and a high quartz-feldspar ratio. Rock fragments are generally not abundant; garnet is the principal heavy mineral and illite is the predominant clay mineral. This sedimentary material differs markedly from that carried by Anatolian rivers, which is characterized by a high calcite-dolomite ratio and a low quartz-feldspar ratio. Rock fragments are abundant; pyroxene is the principal heavy mineral and montmorillonite is the predominant clay mineral. In general, the clay fraction is large in all sediments (27.6–86.9 percent), and the lateral distribution indicates an increase in clay content from the coasts toward two centers in the western and eastern Black Sea basin. Hlite is fhe most common clay mineral in the Black Sea sediments. The lateral changes in composition of the clay mineral can easily be traced to the petrologic character of northern (rich in illite) and southern (rich in montmorillonite) source areas. In almost all cores, a rhythmic change of the montmorillonite-illite ratio with depth was observed. These changes may be related to the changing influence of the two provinces during the Holocene and late Pleistocene. Higher montmorillonite content seems to indicate climatic changes, probably stages of glaciation and permafrost in the northern area, at which time the illite supply was diminished to a large extent. The composition of the sand fraction is related to the different petrologic and morphologic characteristics of two major source provinces: (1) a northern province (rich in quartz, feldspars, and garnet) characterized by a low elevation, comprising the Danube basin area and the rivers draining the Russian platform; and (2) a southern province (rich in pyroxene and volcanic and metamorphic rocks) in the mountainous region of Anatolia and the Caucasus, characterized by small but extremely erosive rivers. The textural properties (graded bedding) of the deep-sea sand layers clearly suggest deposition from turbidity currents. The carbonate content of the contemporary sediments ranges from 5 to 65 percent. It increases from the coast to a maximum in two centers in the western and eastern basin. This pattern reflects the distribution of the <2-μ fraction. The contemporary mud sedimentation is governed by two important factors: (1) the deposition of terrigenous allochthonous material of low carbonate content originating from fhe surrounding hinterland (northern and southern source areas), and (2) the autochthonous production of large quantities of biogenic calcite by coccolithophores during the last period of about 3,000–4,000 years.

Abstract Mineral resources have been important to the Alaskan economy for hundreds of years. The Indians, Eskimos, and Aleuts used gold, copper, and other metals for jewelry, utensils, and weapons and as items of trade. The Russians, who arrived in 1728, showed only minor interest in minerals, focusing instead on furs. Nonetheless, records show that they mined iron ore on the Kenai Peninsula in 1793 and located gold there in 1834. In addition, the Russians were aware of copper-rich occurrences in the Copper River basin. The mining industry grew rapidly in Alaska after the United States purchased the region from Russia in 1867. By 1870, gold was being mined near Windham Bay and near Sitka, in southeastern Alaska. The first major hard-rock gold mining began at the Alaska-Juneau, Perseverance, and Treadwell mines near present-day Juneau following the discovery of placer gold near tidewater in 1880. Significant placer mining operations for gold soon spread northward into districts such as Fairban ks, Nome, Iditarod, and Circle. The exploitation of mineral resources, particularly gold, influenced the settlement and development of much of the state. Major cities such as Nome, Fairbanks, and Juneau, the capital, were originally built around early mining camps. By1996, more than 33 million oz of gold, as well as significant amounts of copper, lead, zinc, silver, and platinum-group elements, had been produced. In addition, there has been minor production of nickel. tin, mercury, and uranium Alaska is presently experiencing a renaissance in mining on federal, state, private, and native lands. From

Abstract Mineral resources have been important to the Alaskan economy for hundreds of years. The Indians, Eskimos, and Aleuts used gold, copper, and other metals for jewelry, utensils, and weapons and as items of trade. The Russians, who arrived in 1728, showed only minor interest in minerals, focusing instead on furs. Nonetheless, records show that they mined iron ore on the Kenai Peninsula in 1793 and located gold there in 1834. In addition, the Russians were aware of copper-rich occurrences in the Copper River basin. The mining industry grew rapidly in Alaska after the United States purchased the region from Russia in 1867. By 1870, gold was being mined near Windham Bay and near Sitka, in southeastern Alaska. The first major hard-rock gold mining began at the Alaska-Juneau, Perseverance, and Treadwell mines near present-day Juneau following the discovery of placer gold near tidewater in 1880. Significant placer mining operations for gold soon spread northward into districts such as Fairban ks, Nome, Iditarod, and Circle. The exploitation of mineral resources, particularly gold, influenced the settlement and development of much of the state. Major cities such as Nome, Fairbanks, and Juneau, the capital, were originally built around early mining camps. By1996, more than 33 million oz of gold, as well as significant amounts of copper, lead, zinc, silver, and platinum-group elements, had been produced. In addition, there has been minor production of nickel. tin, mercury, and uranium Alaska is presently experiencing a renaissance in mining on federal, state, private, and native lands. From 1990 to 1996, the minerals industly had an annual value of approximately $600 million, with a record 1 billion in 1996. Nearly 3,500 year-round jobs were directly attributed to the minerals industq. Looking forward into the twenty-fi rst centu1y, the outlook is even better. Major mines such as Heel Dog are in production. Recently completed exploration at the Red Dog sedimenta1y exhalative deposit has significantly expanded the reserve base and major mine expansion is contemplated. The Nixon Fork gold skarn deposit was put into production in 1995, with the first ore poured in November. The Greens Creek mine resumed production in late 1996, following renewed exploration and development of the volcanogenic massive sulfide deposit. The Fort Knox gold mine, near Fairbanks, is under construction and is scheduled to yield ore by late 1996. In southwest Alaska exploration success has yielded a significant gold resource at Donlin Creek. In addition, the Kensington-Jualin project is

Single-grain, laser-ablation inductively coupled plasma–mass spectrometry analyses of detrital apatites from Pliocene sandstones in the South Caspian Basin (Azerbaijan) and Devonian-Carboniferous sandstones from Clair oil field, west of Shetland (UK), demonstrate that apatite geochemistry has significant potential in provenance analysis. Apatites in Pliocene sandstones deposited by the paleo-Kura River system, which drained the Lesser Caucasus region, were derived largely from mafic to intermediate and alkaline rocks. Apatite populations in Pliocene sediments transported by the paleo-Volga River system, which drained the Russian Platform, show greater compositional diversity and indicate supply from granitoids or other acidic rocks together with subordinate mafic to intermediate and alkaline rocks. Apatites in the Devonian-Carboniferous succession west of Britain were derived predominantly from acidic rocks, either directly from Archean gneisses or indirectly from metasedimentary rocks. In the two case studies, the most useful discriminators of apatite provenance proved to be La/Nd and La + Ce/ΣREE. Since apatite is stable during burial in sedimentary basins, apatite geochemistry can be used to determine provenance of sandstones from the full range of diagenetic environments, although the instability of apatite during weathering means that the method will be difficult to apply to sandstones with prolonged weathering history. At present, identification of provenance using apatite geochemistry is limited by the lack of a comprehensive database on apatite compositions in some of the potential source rocks, particularly those of metamorphic origin. The role played by sediment recycling is another factor that requires consideration when reconstructing source areas on the basis of apatite compositions.

Abstract This paper uses an extensive dataset from more than 200 samples to provide a comprehensive source-to-sink analysis of the Amur River and its delta in the Russian Far East. The majority of sand-sized sediment in the Amur River and its former delta comes from upstream of the Lesser Khingan Ridge, shown by uniformity of sediment composition in the lower 1700 km of the river. Stable mineral ratios, U–Pb age spectra and garnet geochemistry show little stratigraphic provenance-specific variation in the Neogene delta. This renders Miocene–Pliocene drainage capture models unlikely. The onset of uplift in the delta is marked by a decrease in the apatite–tourmaline index (ATi) in Upper Pliocene offshore well samples, caused by dissolution of apatite as sediments were uplifted and eroded onshore Sakhalin. These wells also show variable ATi and garnet–zircon index (GZi) values in Lower Miocene samples, which could potentially be used for stratigraphic correlation. A positive correlation between GZi values and distance from the river mouth is attributed to hydrodynamic sorting across the delta system. This has negative implications for the use of this stable mineral index and others of a similar hydraulic equivalence as regional correlation tools on a basin scale (>100 km). Supplementary material: Heavy mineral data, petrographic data, geochronometric data, sample locations available at www.geolsoc.org.uk/SUP18643 .

Abstract The Pliocene Productive Series of the South Caspian Basin records a major lowstand relative to pre-existing Miocene and subsequent Pleistocene and Holocene shelf margins. The Productive Series records approximate 2.6 m.y. of relatively continuous deposition of lacustrine sediments and reaches more than 6 km (0.62 mi) in thickness. Regional-scale seismic mapping has allowed an interpretation of the basin evolution during the deposition of the Productive Series. The Productive Series is subdivided into four phases of deposition. Differences between these phases are interpreted to reflect changes in the balance between sediment and water input and the evolving basin morphology. Basin morphology inherited from a previous depositional phase strongly influence successive phases of deposition. Phase 1. Messinian: Base-level fall, roughly coincident with the Messinian Salinity Crisis, resulted in isolation of the Caspian Sea from the global oceans. Reconstruction of the basin profile immediately after this event indicates that the South Caspian Basins base-level fell by approximately 1.5 km (0.93 mi). Phase 2. Integration of drainage systems to this dramatically lowered base level resulted in the delivery of large volumes of sediment and water from the Russian Platform, Caucasus mountains, and Kopet-Dagh mountains to the South Caspian Basin through the Paleo Volga, Kura, and Amu darya/Uzboy rivers. Within the South Caspian Basin, fluvial and fluvio-lacustrine facies were deposited in preexisting structural depressions, forming the Lower Productive Series. Phase 3. Infill of paleotopographic depressions by the Lower Productive Series resulted in the formation of a low gradient ramp over much of the South Caspian Basin. Middle Productive Series strata were deposited on this low-gradient ramp as aerially extensive fluvial, deltaic, and lacustrine facies. Reconstructed basin profiles show a reduction of the depositional gradient as the result of sediment infill. Phase 4. During deposition of the Upper Productive Series, the ratio of sediment supply to water supply decreased as much of the coarse-grained sediment supplied from the Paleo-Volga was deposited updip. Thus, the updip depositional profile became increasingly low relief. This change led to the creation of a relatively deep-water lake in the center of the South Caspian Basin surrounded by lacustrine shelf margins. Evaporites were deposited in the center of this lake, suggesting that it was subject to episodic phases of desiccation. Overlying the Productive Series is a regionally extensive marine condensed section, the Akchagyl Suite. The Akchagyl Suite records a major regional transgression and a return to marine conditions as the South Caspian Basin was reconnected to the global oceans. Pleis-tocene shelf margin complexes downlap onto the Akchagyl Suite and record progradation of shorelines into a deep-water brackish lake (~1000 m [3280 ft]). This Pleistocene depositional system was similar to the present-day depositional setting of the Caspian Sea.

Abstract Alaska’s first commercial oil and gas province, the Cook Inlet Basin, of south-central Alaska, was identified by the presence of numerous oil and gas seeps in the southern part of the basin and the Alaska Peninsula. These were first recognized by Russian explorers in the 1850s. Early exploratory drilling was centered in the vicinity of these seeps, which emanate from rocks of Jurassic and Cretaceous ages. Eighteen wells were drilled in this southern area prior to 1950. After 1950, exploration shifted northward, and the fourth well drilled in the northern portion of the basin discovered the Swanson River field in 1957. This generated an exploration boom, and by 1970, seven of the inlet’s ten oil fields and 17 of the 34 gas fields had been discovered. These discoveries represent more than 98% of both the oil and gas produced to date. After the Prudhoe Bay discovery, in early 1968, activity in the Cook Inlet area declined sharply, and over the next 30 years, only three small oil fields and nine small gas fields were discovered. As of year-end 2011, the cumulative production from these discoveries was less than 20 MMBO and 65 BCFG. A declining reserve base and concerns regarding the ability to meet local gas demands led to an increase in gas exploration in the late 1990s and early 2000s. From 2000 to year-end 2011, eight additional gas fields were discovered, with the most important discoveries occurring in 2011. Cumulative production from the five pre-2011 discoveries totals approximately 25 BCFG. The three fields discovered in 2011 have yet to be developed; however, the cumulative, preliminary reserve estimates from these three discoveries are thought to be in excess of 1.0 TCFG. The total cumulative production in the Cook Inlet Basin, from 1958 through 2011, is 1.3 BBO from eight fields and just under 7.5 TCFG from 28 producing fields. Given the relatively short, punctuated exploration history of this prolific hydrocarbon basin, renewed exploration activity using modern technology will very likely produce significantly positive results. Recent evaluations by the United States Department of Energy/National Energy Technology Laboratory and the United States Geological Survey place the mean for conventional undiscovered technically recoverable resources in the range of 13 to 17 TCFG and approximately 600 MMBO.

ABSTRACT Zone-diagnostic Middle to Upper Devonian ammonoids and conodonts occur in a sequence of thin carbonate beds in siliciclastic sections along the Allegheny front and northern fold belt of central Pennsylvania. The lowest, in the upper Tully Formation, and the succeeding four in the Harrell Shale, are southward continuations of marker beds long known in the Tully Limestone and overlying basin, slope, and shelf facies of the Genesee Group of New York State. These pelagic beds are Appalachian Basin signals of transgressive condensed intervals within global high-sea-level episodes and are associated with a worldwide biotic overturn in the tropical marine realm. The Upper Givetian Tully Pharciceras amplexum bed has close lithic and faunal equivalents in the Taghanic biocrisis interval in Morocco and southern Europe. The Lower Frasnian styliolinid upper Genundewa Limestone, with the entry of Manticoceras , and, in the succeeding dark West River Shale, the Bluff Point Bed, with the entry of late Koenenites and early palmatolepid conodonts, are Appalachian highstand signals of the worldwide Timan bioevent transgression recognized in Western Australia, the Russian Platform, southern Europe, Morocco, western Canada, and now Pennsylvania. The widespread occurrences of discrete ammonoid beds, even in the more proximal or shoreward sedimentary settings of the Catskill Delta, reinforce the view that they accumulated under conditions of sequestered sediment supply when transgressions flooded the newly vegetated and deep-root-forested delta flats. As such, they overprinted or interrupted the westward progradation of siliciclastic sediments generated by mountain-building tectophases of the Acadian orogeny. The Lower Frasnian ammonoid Epitornoceras dennisoni n. sp., described herein, from the Crosby Beds in the Harrell Shale at Milesburg, Pennsylvania, is named in honor of John Dennison.