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USGS2002

Mesozoic and Cenozoic tectonics of the eastern and central Alaska Range: Progressive basin development and deformation in a suture zone

Analysis of late Mesozoic and Cenozoic sedimentary basins, metamorphic rocks, and major faults in the eastern and central Alaska Range documents the progressive development of a suture zone that formed as a result of collision of an island-arc assemblage (the Wrangellia composite terrane) with the former North American continental margin. New basin-analysis, structural, and geochronologic data indicate the following stages in the development of the suture zone: (1) Deposition of 3-5 km of Upper Jurassic-Upper Cretaceous marine strata (the Kahiltna assemblage) recorded the initial collision of the island-arc assemblage with the continental margin. The Kahiltna assemblage exposed in the northern Talkeetna Mountains represents a Kimmeridgian-Valanginian backarc basin that was filled by northwestward-flowing submarine-fan systems that were transporting sediment derived from Mesozoic strata of the island-arc assemblage. The Kahiltna assemblage exposed in the southern Alaska Range represents a Valanginian-Cenomanian remnant ocean basin filled by west-southwestward-flowing submarine-fan systems that were transporting sediment derived from Paleozoic continental-margin strata uplifted in the along-strike suture zone. A belt of retrograde metamorphism and a regional anticlinorium developed along the continental margin from 115 to 106 Ma, roughly coeval with the end of widespread deposition in the Kahiltna sedimentary basins. (2) Metamorphism of submarine-fan deposits of the Kahiltna basin, located near the leading edge of the island-arc assemblage, occurred at ca. 74 Ma, as determined from a new U-Pb zircon age for a synkinematic sill. Coeval with metamorphism of deposits of the Kahiltna basin in the southern part of the suture zone was development of a thrust-top basin, the Cantwell basin, in the northern part of the suture zone. Geologic mapping and compositional data suggest that the 4 km of Upper Cretaceous nonmarine and marginal marine sedimentary strata in this basin record regional subaerial uplift of the suture zone. (3) Shortening and exhumation of the suture zone peaked from 65 to 60 Ma on the basis of metamorphic and geochronologic data. In the southern part of the suture zone, submarine-fan deposits of the Kahiltna basin, which had been metamorphosed to kyanite schists at ???25 km depth and ???650 ??C, were exhumed and cooled through the biotite closure temperature (???300 ??C) by ca. 62 Ma. In the northern part of the suture zone, this time period was marked by shortening, uplift, and erosion of sedimentary strata of the Cantwell basin. (4) From 60 to 54 Ma, ???3 km of volcanic strata were deposited over deformed sedimentary strata of the Cantwell basin, and several granitic plutons (the McKinley sequence) were emplaced along the suture zone. (5) Following igneous activity, strikeslip displacement occurred from ca. 54 to 24 Ma along the Denali fault system, which had developed in the existing suture zone. Late Eocene-Oligocene strike-slip displacement resulted in the formation of several small sedimentary basins along the Denali fault system. (6) Regional transpressive shortening characterized the suture zone from ca. 24 Ma to the present. Flexural subsidence, related to regional shortening, is represented by late Eocene to Holocene nonmarine deposits of the Tanana foreland basin. Regional subsidence resulted in Miocene coal seams up to 20 m thick and well-developed lacustrine deposits. Overlying the Miocene deposits are ???1.2 km of Pliocene and Holocene conglomeratic deposits. Compositional and paleocurrent data from these younger deposits record regional Neogene uplift of the suture zone and recycling of detritus from older basins to the south that had become incorporated into the uplifted suture zone. Geologic mapping of major thrust faults along the northern and southern margins of the suture zone documents Paleozoic strata thrust over both Pliocene fluvial deposits and Quaternary glacial deposits of the Tanana basin.

Geological Society of America Bulletin↗

USGS1984

Common-depth-point seismic-reflection survey on the Mississippi River in the vicinity of Alton, Illinois

A high-resolution seismic-reflection survey was run on the Mississippi River using marine common-depth-point (CDP), digital, and multichannel techniques in an attempt to locate a possible fault that had been interpreted by others from magnetic and land seismic data to be in the vicinity of Lock and Dam No. 26. The geologic feature is commonly known in the literature as the Cap au Ores Fault or Cap au Ores Uplift. A second objective was to demonstrate that the marine seismic system could be used successfully for making relatively deep penetration seismic-reflection surveys on inland waterways with shallow water depths (less than 10 meters) and organic sediments on the waterway bottom. The survey was made by agreement between the U.S. Army Corps of Engineers (COE), St. Louis District, and the U.S. Geological Survey (USGS). The USGS used a specially equipped, trailerable, 38-ft aluminum boat for the work. The quality of the survey records can be classified as from fair to good. Seismic-reflection events could be interpreted in the upper 200 ms of data. Five reflecting horizons with little slope were recorded between Mississippi River Miles 195 and 210 without any evidence of faulting of the magnitude (50 to 100 m) suggested by the Shannon and Wilson report (1980). Minor faulting and buried channeling could be interpreted. This survey demonstrated the value and economy of obtaining deeper penetration seismic data on inland water using an offshore marine, CDP, digital, multichannel seismic-reflection system. On-going modifications in field procedure, equipment configuration, equipment, and data processing will further improve the results obtained with such equipment. Future marine-style surveys conducted with the newly available hydraulic waterguns (80-, 200-, and 400-in 3 ) would probably produce data that are a significant improvement over data obtained with the 15-in 3 pneumatic watergun and 40-in 3 airgun used during the 1980 survey.

Illinois, Missouri↗

USGS1992

Geology and mineral paragenesis of the Pea Ridge iron ore mine, Washington County, Missouri: Origin of the rare-earth-element- and gold-bearing breccia pipes. Some mineralogical and geochemical aspects of middle and upper Pennsylvanian marine black shales in part of the midcontinent region. Mineralogical and geochemical analysis of the metal- and organic-rich Grassy Creek Shale of the New Albany group (Upper Devonian and Lower Mississippian) in Hardin County, southern Illinois

No abstract available.

Illinois, Iowa, Kansas, Missouri, Nebraska, Oklaho↗

USGS2018

Geologic map of the Lower Valley quadrangle, Caribou County, Idaho

The Lower Valley 7.5-minute quadrangle, located in the core of the Southeast Idaho Phosphate Resource Area, includes Mississippian to Triassic marine sedimentary rocks, Pliocene to Pleistocene basalt, and Tertiary to Holocene surficial deposits. The Mississippian to Triassic marine sedimentary sequence was deposited on a shallow shelf between an emergent craton to the east and the Antler orogenic belt to the west. The Meade Peak Phosphatic Shale Member of the Permian Phosphoria Formation hosts high-grade deposits of phosphate that were the subject of geologic studies through much of the 20th century. Open-pit mining of the phosphate has been underway within and near the Lower Valley quadrangle for several decades.

Idaho↗

USGS2002

Geology and geochemistry of Carlin-type gold deposits in China

The Carlin-type gold deposits in China lie mostly near the margins of the Proterozoic Yangtze and Aba cratons. Submicron-sized gold in micron-sized arsenian pyrite is disseminated in fractured Cambrian through Triassic carbonaceous shale and carbonate rocks, and is associated with anomalous Hg, Sb, As, U, and Tl. Alteration typically includes silicification, argilization, and sulfidation. Aqueous fluid inclusions contain CO2, have relatively low temperatures of homogenization (250-150 ??C), and salinities (8-2 wt% equiv. NaCl) that typically decrease from early to later stages. The indicated pressures of 105-330x105 Pa correspond to depths in excess of 1.0 to 3.0 km, assuming hydrostatic conditions. The ??D values of fluid inclusions (-87 to -47%) and the calculated ??18 values for water in ore fluids (-2.1 to 16.2%) reflect interactions between meteoric water and sedimentary rocks. The ??13C values of calcite (-9 to 2%) and ??34S values of sulfides (-24 to 17%) suggest that C and S were derived from marine carbonate (and organic carbon) and diagenetic sulfides (and organic sulfur) in the vicinity of the deposits. Geologic relationships and geochronologic evidence indicate the deposits formed during a late phase of the Yanshanian orogeny (140-75 Ma). These gold deposits share much in common with the Carlin-type gold deposits in Nevada, USA. Both occur in carbonaceous, pyritic, sedimentary rocks deposited on extended margins of Precambrian cratons. The smaller Chinese deposits are generally in more siliceous rocks and the larger Nevada deposits in more calcareous rocks. In both countries, the host rocks prior to mineralization were affected by contractional deformation that produced many of the ore-controlling structures and the deposits do not show consistent spatial or genetic relationships with epizonal plutons. However, the Nevada deposits show broad spatial and temporal relationships with shifting patterns of calc-alkaline magmatism. The ore and alteration mineral assemblages, residence of gold, geochemical signatures, paragenetic sequence, and fluid inclusions are remarkably similar, which indicates that the deposits formed from low salinity, moderately acidic, CO2 and H2S-rich in the crust similar processes at relatively shallow levels in the crust (<5 km). However, the deposits in China are associated with large Hg, Sb, As, U, and Tl deposits, which may reflect higher background abundances of these elements. Stable isotopic data suggest meteoric water evolved to become ore fluids through interactions with sedimentary rocks, although contributions of volatiles or metals from deeper levels are present in some deposits in Nevada. In both countries, the deposits appear to have formed in an area of high paleothermal gradients after a change in stress regime during the later phases of orogenic activity.

Mineralium Deposita↗

USGS1951

Preliminary report on the stratigraphy and structure of the Shaviovik and upper Sagavanirktok Rivers area, Alaska

During the 1951 field season, U. S. Geological Survey Navy Oil Unit party 1 conducted stratigraphic and structural studies of the rocks in the area between the westernmost fork of the Shaviovik River and the East Kuparuk River. This area is drained by the Sagavanirktok River and its major tributaries; the Echooka River, the Ivishak River, and Lupine River. Owing to the nature of the investigation, the studies were confined to a relatively narrow geographic strip, rarely exceeding a distance of 20 miles north of the northernmost occurrence of the Lisburne limestone of the Brooks Range province. The work was thus conducted in an area of approximately 2,000 square miles, which lies wholly within the Brooks and Arctic Foothill provinces; within this area approximately 1,000 square miles was mapped geologically. The party consisted of six men: A. S. Keller and R. L. Detterman, geologists; I. W. Marine and D. E. Reed, field assistants; L. G. Barbin, cook-field assistant; and T. F. Derrington, weasel mechanic. The party utilized 3 weasels for transportation of equipment and personnel during the season, during which time 15 camps ware established. Work was initiated on the Shaviovik River on May 24, 1951, and the party concluded its investigations on the Kuparuk River drainage on August 24, 1951. In 1947, G. Gryc and E. H. Lathram conducted reconnaissance studies of the rocks in the vicinity of camps 12-15 (pl. 1); and during the same year, G. Gryn visited outcrops on the Ivishak River in the vicinity of camps 6-7 (pl. 1). These studies were made by the Navy Oil Unit of the U. S. Geological Survey in conjunction with the investigations of NPR-4. No other work of a geologic nature had been done in the area in the past. The primary objective of the 1951 party was the correlation of the Mesozoic and upper Paleozoic strata of the foothills province west of the Itkillik River, with that of the Shaviovik and Canning Rivers region. A secondary objective was to determine the cause of the pronounced northeasterly swing in the trend of the Brooks Range front in the Sagavanirktok drainage and to determine the structural implications of this swing. The area was mapped at a scale of 1:20,000 on vertical photographs and transferred to trimetrogon drainage maps at a scale of 1:48,000 and 1:96, 00. An altimeter traverse was carried concurrently with the geologic mapping.

Alaska↗

USGS1994

Sources of dissolved salts in the central Murray Basin, Australia

Large areas of the Australian continent contain scattered saline lakes underlain by shallow saline groundwaters of regional extent and debated origin. The normative salt composition of subsurface pore fluids extracted by squeezing cores collected during deep drilling at Piangil West 2 in the central Murray Basin in southeastern Australia, and of surface and shallow subsurface brines produced by subaerial evaporation in the nearby Lake Tyrrell systems, helps constrain interpretation of the origin of dissolved solutes in the groundwaters of this part of the continent. Although regional sedimentation in the Murray Basin has been dominantly continental except for a marine transgression in Oligocene-Pliocene time, most of the solutes in saline surface and subsurface waters in the central Murray Basin have a distinctly marine character. Some of the Tyrrell waters, to the southwest of Piangil West 2, show the increase in NaCl and decrease in sulfate salts expected with evaporative concentration and gypsum precipitation in an ephemeral saline lake or playa environment. The salt norms for most of the subsurface saline waters at Piangil West 2 are compatible with the dilution of variably fractionated marine bitterns slightly depleted in sodium salts, similar to the more evolved brines at Lake Tyrrell, which have recharged downward after evaporation at the surface and then dissolved a variable amount of gypsum at depth. Apparently over the last 0.5 Ma significant quantities of marine salt have been blown into the Murray Basin as aerosols which have subsequently been leached into shallow regional groundwater systems basin-wide, and have been transported laterally into areas of large evaporative loss in the central part of the basin. This origin for the solutes helps explain why the isotopic compositions of most of the subsurface saline waters at Piangil West 2 have a strong meteoric signature, whereas the dissolved salts in these waters appear similar to a marine assemblage. ?? 1994.

Chemical Geology↗

USGS2003

Geologic map of the MTM 85080 Quadrangle, Chasma Boreale Region of Mars

The polar deposits on Mars probably record martian climate history over the last 107 to 109 years (for example, Thomas and others, 1992). The area shown on this map includes polar layered deposits and polar ice, as well as some outcrops of older, underlying terrain. This quadrangle was mapped using Viking Orbiter images in order to study the relations among erosional and depositional processes on the north polar layered deposits and to compare them with the results of previous 1:500,000-scale mapping of the south polar layered deposits. Published geologic maps of the north polar region of Mars are based on images acquired by Mariner 9 and the Viking Orbiters. The extent of the layered deposits and other units varies among previous maps, in particular within Chasma Boreale. The present map agrees most closely with the map by Dial and Dohm (1994): the mantle material is exposed farther north than mapped by Tanaka and Scott (1987). The polar ice cap, areas of partial frost cover, the layered deposits, and two nonvolatile surface units-dust mantle and dark material-were mapped in the south polar region by Herkenhoff and Murray (1990a) at 1:2,000,000 scale using a color mosaic of Viking Orbiter images. Viking Orbiter rev 726, 768, and 771 color mosaics (taken during the northern summer of 1978) were constructed and used to identify similar color/albedo units in the north polar region, including the dark, saltating material that appears to have sources within the layered deposits. However, no dark material has been recognized in this map area. No significant difference in color exists between the layered deposits and the mantle material mapped by Dial and Dohm (1994), indicating that they are either composed of the same materials or are both covered by eolian debris. Therefore, in this map area the color mosaics are most useful for identifying areas of partial frost cover. Because the resolution of the color mosaics is not sufficient to map the color/albedo units in detail at 1:500,000-scale, contacts between them were recognized and mapped using higher resolution black-and-white Viking Orbiter images. The Viking Orbiter 2 images used to construct the map base were taken during the northern summer of 1976 (mostly Ls=133?-135?), with resolutions typically around 60 m/pixel. As noted on the published base, errors of up to 5 km exist in the placement of images in the base map; such errors are evident upon comparison of sheet 1 (summer) and sheet 2 (spring). Therefore, a new photomosaic base was created during map production and the linework was edited to match the new base. No craters have been found in the north polar layered deposits or polar ice cap. The observed lack of craters larger than 300 m implies that the surfaces of these units are no more than 100,000 years old or that they have been resurfaced at a rate of at least 2.3 mm/yr. The recent cratering flux on Mars is poorly constrained, so inferred resurfacing rates and ages of surface units are uncertain by at least a factor of 2.

IMAP↗

USGS1976

Geologic map of the Oxia Palus Quadrangle of Mars

The Oxia Palus quadrangle contains three distinct geologic provinces: (1) an elevated cratered plateau that occupies three-fourths of the quadrangle and is similar to much of the southern hemisphere of Mars; (2) the low, relatively featureless Chryse Planitia in the northwest corner; and (3) a complex province of chaotic terrain and immense channels or valleys that divides the plateau and terminates in Chryse Planitia. Generally, the oldest geologic units occur in the plateau province and the youngest in Chryse Planitia. Discovery by Mariner 9 of the channels, the four largest of which are given names meaning “Mars” in Akkadian, Sumerian, Angelo-Saxon, and Greek (west to east), renews the possibility of water and therefore life on Mars. This possibility may be tested in July 196 by a landing of the unmanned Viking spacecraft in Chryse Planitia at the mouths of the channels (lat 19 1/2˚ N., long 34˚).

IMAP↗

USGS2001

Sedimentology of the Pennsylvanian and Permian Strathearn Formation, Northern Carlin Trend, Nevada; with a section on microfossil controls on age of the Strathearn Formation

Two framework-supported, poorly bedded conglomerate units of the middle Upper Pennsylvanian and middle Lower Permian Strathearn Formation belonging to the overlap assemblage of the Antler orogen are prominent in the northern Carlin trend. These horizons stratigraphically and temporally bracket thrust emplacement of a major allochthonous thrust plate of mainly quartzarenite of the Ordovician Vinini Formation. Lithologic and shape-ratio data from approximately 4,200 pebbles and cobbles at 17 sites as well as biostratigraphic data in the Strathearn, and their geologic implications, are included in this report. Conodont biofacies throughout the Strathearn Formation are normal marine and suggest middle shelf or deeper depositional environments. The conglomerate units roughly are similar in that they contain only chert and quartzarenite pebbles, but they differ in compositional proportions of the two lithologies. The relative proportion of quartzarenite pebbles increases sixfold in the middle Lower Permian upper conglomerate unit versus its content in the middle Upper Pennsylvanian lower unit, whereas chert pebbles predominate in both units. Various roundness categories of chert pebbles in both conglomerate units of the Strathearn show that the equant pebble class (B/A) = 1 clearly is represented strongly even in the subangular category, the lowest roundness categories for the pebbles. Thus, development of equant pebbles cannot be ascribed totally to a rounding process during predeposition transport. The equant character of many pebbles might, in part, be an original feature inherited from pre-erosion rock fractures and (or) bedding that control overall form of the fragments prior to their release to the transport environment. The allochthon of the Coyote thrust has been thrust above the lower conglomerate unit of the Strathearn during a regionally extensive contractional event in the late Paleozoic. The middle Lower Permian upper conglomerate unit, highest unit recognized in the Strathearn Formation, as well as similarly-aged dolomitic siltstone, onlap directly onto quartzarenite that comprises the allochthon of the Coyote thrust. The conglomerate units thus represent submarine fanglomerates whose quartz grains and quartzarenite fragments of variable roundness and shape were derived from a sedimentologically restored largely southeastward advancing late Paleozoic allochthonous lobe of mostly quartzarenite of the Ordovician Vinini Formation. Chert fragments in the conglomerates probably were derived mostly from Devonian Slaven Chert, including a widespread thick melange unit of the Slaven in the footwall of the Coyote thrust. Some chert pebbles may have been derived from the Ordovician Vinini Formation.

Nevada↗

USGS2013

2010 Joint United States-Canadian Program to explore the limits of the Extended Continental Shelf aboard U.S. Coast Guard Cutter Healy--Cruise HLY1002

In August and September 2010, the U.S. Geological Survey, in cooperation with Natural Resources Canada, Geological Survey of Canada, conducted bathymetric and geophysical surveys in the Beaufort Sea and eastern Arctic Ocean aboard the U.S. Coast Guard Cutter Healy. The principal objective of this mission to the high Arctic was to acquire data in support of a delineation of the outer limits of the U.S. and Canadian Extended Continental Shelf in the Arctic Ocean, in accordance with the provisions of Article 76 of the United Nations Convention on the Law of the Sea. The Healy was accompanied by the Canadian Coast Guard icebreaker Louis S. St-Laurent. The scientific parties on board the two vessels consisted principally of staff from the U.S. Geological Survey (Healy), and the Geological Survey of Canada and the Canadian Hydrographic Service (Louis). The crew also included marine-mammal observers, Native-community observers, ice observers, and biologists conducting research of opportunity in the Arctic Ocean. Despite interruptions necessitated by three medical emergencies, the joint survey proved largely successful. The Healy collected 7,201 trackline-kilometers of swath (multibeam) bathymetry (47,663 square kilometers) and CHIRP subbottom data, with accompanying marine gravity measurements, and expendable bathythermograph data. The Louis acquired 3,673 trackline-kilometers of multichannel seismic (airgun) deep-penetration reflection data along 25 continuous profiles, as well as 34 sonobuoy refraction stations and 9,500 trackline-kilometers of single-beam bathymetry. The coordinated efforts of the two vessels resulted in seismic-reflection-profile data that were of much higher quality and continuity than if the data had been acquired with a single vessel alone. The equipment-failure rate of the seismic equipment aboard the Louis was greatly reduced when the Healy led as the ice breaker. When ice conditions proved too severe to deploy the seismic system, the Louis led the Healy, resulting in much improved quality of the swath bathymetric and CHIRP subbottom data in comparison with data collected either by the Healy in the lead or the Healy working alone. During periods when the Healy was operating alone (principally when the Louis was diverted for emergency medical evacuations or ship repairs), the Healy was able to deploy a piston-core-sampler (10 meters maximum potential recovery depending on configuration). The coring operations resulted in recovery of cores at five locations ranging from 2.4 to 5.7 meters in length from water depths ranging from 1,157 to 3,700 meters. One of these cores sited on the Alaskan margin recovered the first reported occurrence of methane hydrate from the Arctic Ocean. Ancillary science objectives, including ice observations and deployment of ice-monitoring buoys and water-column sampling to measure acidification of Arctic waters were successfully conducted. The water-column sampling included using 10 full-ocean-depth, water-sampling casts with accompanying conductivity-temperature-depth measurements. Except for the data deemed proprietary, data from the cruise have been archived and are available for download at the National Geophysical Data Center and at cooperating organizations. Outreach staff and guest teachers aboard the two vessels provided near-real-time connection between the research activities and the public through online blogs, web pages, and other media.

Open-File Report↗

USGS1962

Geology of the Powder River Basin, Wyoming and Montana, with reference to subsurface disposal of radioactive wastes

The Powder River Basin is a structural and topographic basin occupying an area of about 20,000 square miles in northeastern Wyoming arid southeastern Montana. The Basin is about 230 miles long in a northwest-southeast direction and is about 100 miles wide. It is bounded on three sides by mountains in which rocks of Precambrian age are exposed. The Basin is asymmetrical with a steep west limb adjacent to the Bighorn Mountains and a gentle east limb adjacent to the Black Hills. Sedimentary rocks within the Basin have a maximum thickness of about 18,000 feet and rocks of every geologic period are represented. Paleozoic rocks are about 2,500 feet thick and consist of marine bonate rocks and sandstone; Mesozoic rocks are about 9,500 feet thick and consist of both marine and nonmarine siltstone and sandstone; and Cenozoic rocks are from 4,000 to 6,000 feet thick and consist of coal-bearing sandstone and shale. Radioactive waste could be stored in the pore space of permeable sandstone or in shale where space could be developed. Many such rock units that could be used for storing radioactive wastes are present within the Powder River Basin. Permeable sandstone beds that may be possible reservoirs for storage of radioactive waste are present throughout the Powder River Basin. These include sandstone beds in the Flathead Sandstone and equivalent strata in the Deadwood Formation, the Tensleep Sandstone and equivalent strata in the Minnelusa Formation and the Sundance Formation in rocks of pre-Cretaceous age. However, most of the possible sandstone reservoirs are in rocks of Cretaceous age and include sandstone beds in the Fall River, Lakota, Newcastle, Frontier, Cody, and Mesaverde Formations. Problems of containment of waste such as clogging of pore space and chemical incompatibility would have to be solved before a particular sandstone unit could be selected for waste disposal. Several thick sequences of impermeable shale such as those in the Skull Creek, Mowry, Frontier, Belle Fourche, Cody, Lewis, and Pierre Formations, occur in rocks of Cretaceous age in the Basin. Limited storage space for liquid waste might be developed in impermeable shale by fracturing the shale and space for calcined or fused waste could be developed by mining cavities.

Open-File Report↗

USGS1983

Multichannel seismic measurements on the northern edge of the Bahaman-Cuban collision zone

This paper presents geophysical data obtained, in the western reaches of the Old Bahama Channel separating Cuba and the Bahamas (Figure 1). These data were collected as part of an ongoing investigation of Caribbean and Bahaman geology primarily conducted by University of Miami and the U.S. Geological Survey (USGS). The work was done on the R/V Gilliss of Rosenstiel School of Marine and Atmospheric Sciences, (RSMAS), University of Miami. The scientific party included members of the Woods Hole Oceanographic Institute (WHOI) and RSMAS.

Open-File Report↗

USGS2023

Decision science as a framework for combining geomorphological and ecological modeling for the management of coastal systems

The loss of ecosystem services due to climate change and coastal development is projected to have significant impacts on local economies and conservation of natural resources. Consequently, there has been an increase in coastal management activities such as living shorelines, oyster reef restoration, marsh restoration, beach and dune nourishment, and revegetation projects. Coastal management decisions are complex and include challenging trade-offs. Decision science offers a useful framework to address such complex problems. Here, we provide a synthesis about how decision science can help to integrate research from multiple disciplines (physical and life sciences) with management of coastal and marine systems. Specifically, we discuss the importance of considering concepts and techniques from ecology, coastal geology, geomorphology, climate science, oceanography, and decision analysis when developing conservation plans for coastal restoration. We illustrate the process with several coastal restoration studies. Our capstone example is based on a recent barrier island restoration assessment project at Dauphin Island, Alabama, which included the development of geomorphological and ecological models. We show how decision science can be used as a framework to combine geomorphological and ecological modeling to help inform management decisions while considering uncertainty about system changes and risk tolerance. We also build on our examples through a review of recently developed techniques for spatial conservation planning for land acquisition decisions and the application of adaptive management for sequential decisions.

Alabama↗

USGS2012

User’s guide and metada for the PICES Nonindigenous Species Information System

Introduction Welcome to the PICES Nonindigenous Species Information System, a Microsoft Access database that displays the biogeographic distributions, invasion status, vectors, and key life history attributes of the approximately 740 reported nonindigenous species (NIS) in the estuarine and near-coastal habitats of the North Pacific and Hawaii. This database was developed by the U.S. Environmental Protection Agency and the U.S. Geological Survey under the auspices of Working Group 21 (Invasive Species) of the North Pacific Marine Science Organization (PCIES). The PICES database contains the data used to generate the “Atlas of Nonindigenous Marine and Estuarine Species in the North Pacific” (Lee and Reusser, 2012; herein referred to as the “Atlas”). The User’s Guide provides instructions on how to use the PICES database as well as metadata for the database and the Atlas. We note that for most users, the Atlas provides a simpler approach to accessing key information on NIS in the PICES countries than the database, though the database does provide additional information on species and sources as well as allowing users to extract information on specific taxa and/or locations (see Section 4). The PICES database also includes species reported from the PICES Rapid Assessment Surveys (RAS). PICES sponsored four rapid assessment surveys with the objective of quickly characterizing the native, non-native, and cryptogenic species present in different locations. Surveys were sponsored in Dalian, China in 2008, Jeju, Korea in 2009, Newport, Oregon, USA in 2010, and Peter the Great Bay, near Vladivostok and Nakhodka, Russia in 2011 ( http://www.pices.int/publications/pices_press/volume19/v19_n1/pp_30-31_Kobe-WS_f.pdf , http://www.pices.int/publications/pices_press/volume20/v20_n1/pp_26-29_RAS-2011.pdf ). The PICES database contains the RAS species that were made available in time for inclusion. Thus, the database does not capture all the species found in these surveys. In addition, much of the information on the RAS species was provided by the experts conducting the survey, and their distributions, environmental requirements, and life history attributes were not evaluated to the same level of detail by the PICES authors as the North Pacific NIS. In lieu of the more extensive review as conduced with the Atlas species, the information on the RAS species needs to be considered preliminary. Additionally, it is important to use the “Map All Distributions” option (see Section 3.6.6) when mapping their distribution or conducting a query. The general reference for the RAS surveys in the PICES database is “PICES Working Group 21, YEAR SURVEY”. The overall goal of both the database and Atlas was to simplify and standardize the dissemination of distributional, habitat, and life history characteristics of near-coastal and estuarine nonindigenous species. This database provides a means of querying these data and displaying the information in a consistent format. The specific classes of information the database captures include: Regional and global ranges of native and nonindigenous near-coastal and estuarine species at different hierarchical spatial scales. Habitat and physiological requirements of near-coastal and estuarine species. Life history characteristics of near-coastal and estuarine species. Invasion history and vectors for nonindigenous species. This standardized and synthesized data in the database and the Atlas provide the basic information needed to address a number of managerial and scientific needs. Thus, users will be able to: Create a baseline on the extent of invasion by region in order to assess new invasions. Use existing geographical patterns of invasion to gain some insights into potential new invaders. Use existing geographical patters of invasion to gain some insights into mechanisms affecting relative invasibility of different areas. Use life history attributes and environmental requirements of the reported nonindigenous species to evaluate traits of invaders. Understand the potential spread of invaders based on their habitat and environmental requirements. Understand importance of different vectors of introduction of nonindigenous species by region. The data in the Atlas of Nonindigenous Marine and Estuarine Species in the North Pacific (Lee and Reusser, 2012) are up-to-date as of June 2012. Updates to the PICES database were made in September 2012.

Report↗

USGS1982

Physiographic divisions and differential uplift in the Piedmont and Blue Ridge

The Piedmont and Blue Ridge are dynamic landscapes that have undergone substantial change since the orogenies that ended in late Paleozoic or, as some believe, early Mesozoic time. The southern Blue Ridge region south of Roanoke, Va., lies on the crest of a topographic uplift that corresponds to the eastern continental drainage divide. To the north, this uplift and divide cross the Appalachian Valley and form the crest of the Appalachian Plateaus as far north as central Pennsylvania. The northern Blue Ridge Mountains as well as parts of the Piedmont are on the eastern part of the uplift area. The southeastern margin of the uplift corresponds to a line within the Piedmont physiographic province that extends northeastward from the Tallapoosa River at the Fall Zone and crosses the Rappahannock River at the Fall Zone. The differential elevation on either side of this line is sharp in some places, as, for example, northeast of Atlanta, Ga. In other places, the difference in elevation is difficult to detect, and, in effect, the line becomes a broad monoclinal slope. The region as a whole can be divided into at least six broad subregions that have somewhat different histories in late geologic time. The Piedmont Lowlands subprovince, southeast of the uplifted area, is dominated by a monotonous topography of low rounded ridges and ravines largely underlain by saprolite on crystalline rocks. Isolated ranges of hills of greater relief are scattered across the region; those investigated are directly related to the presence of erosionally resistant rocks. Stream patterns as well as broad topographic forms indicate that although the southern part of the Piedmont Lowlands was probably once covered by younger sediments, this area has been exposed to erosion for a long time. In North Carolina, the inner part of the Piedmont Lowlands has strongly trellised stream patterns, which suggest that subaerial erosion was active for an even longer time period, perhaps since the latest orogeny. North of the Cape Fear River, the outer part of the Piedmont Lowlands was covered by either fluvial or marine sediments or both, probably during Miocene time. Tectonic activity has affected the Piedmont Lowlands in late geologic time. The Fall Zone that forms the southeast border is, at least in places, controlled by faults active in Tertiary time. Late faults have also been found in the Pine Mountain area of Georgia. Minor differences in relief affecting large regions within the Piedmont Lowlands may be related to different rates of uplift in addition to rock resistance, either past or present. The Piedmont northeast of the Potomac River (Northeastern Highlands) rises to more than 300 m in altitude. The major streams have convex profiles that steepen as they near the Coastal Plain. Unusually narrow valleys and broad upland surfaces indicate an increased rate of erosion and show that the relief is now or recently has been increasing because of uplift or tilting. West of the southern end of the Piedmont Lowlands is an area herein called the Southwestern Highlands that in some respects is similar. The area is crossed by two large streams that have convex profiles. The highest mountain ranges in the area rise to altitudes greater than 600 m. Northwest of the Piedmont Lowlands, the topography and relief are higher, and in some places, the rise is gradual, forming a Foothill zone between the Piedmont Lowlands and the high Blue Ridge. This zone is morphologically more complex than the Piedmont Lowlands. North of the Roanoke River, the foothills are commonly chains of isolated hills and ridges generally underlain by resistant rocks. The hills increase in height near the Blue Ridge, an indication that they owe their height to tectonism of late geologic age. South of the Yadkin River, the hills are believed to be residual, the remnants of a larger highland that has been only partially reduced to the lower relief of the general Piedmont surface. The

Professional Paper↗

USGS2021

Foreward: The paleoclimatic and paleobiogeographic significance of the Tjörnes Basin, Northern Iceland

Since the mid-19th century, geologists and paleontologists have recognized the scientific importance and unique nature of the richly fossiliferous sediments exposed along the Tjörnes Peninsula in Northern Iceland. In the following century and a half, Tjörnes has attracted the attention of an international “who’s who” in Cenozoic paleontology, as well as many paleoclimatologists unraveling the complex climatic history of the North Atlantic and Arctic Oceans. In a seminal meeting, sponsored by the Royal Society of London in 1984, and published in Philosophical Transactions of the Royal Society of London, Series B, volume 318 (“The past three million years: evolution of climatic variability in the North Atlantic region”), an international group of experts addressed climatic history of the last 3 million years. Notably, one of the main invited participants was Iceland’s Dr. Thorleifur Einarsson, who literally wrote the book “Geology of Iceland” (1994, 1999), and was also known for his expertise in Tjörnes paleoclimatology. Einarsson’s key contribution was linking the marine history of Tjörnes to the rapidly growiing paleoclimate records from deep-sea marine sediment cores and improving chronology of climate evolution. This work was closely linked to the dating of Pliocene-Pleistocene glacial sediments and volcanics in Iceland and on Tjörnes in particular, based on paleomagnetic data and biostratigraphic work which was presented jointly with a group from the U.S. Geological Survey at the 1965 INQUA meeting in Boulder, Colorado.

Tjornes Basin↗

USGS2017

Coastal eolian sand-ramp development related to paleo-sea-level changes during the Latest Pleistocene and Holocene (21–0 ka) in San Miguel Island, California, U.S.A.

Coastal eolian sand ramps (5–130 m elevation) on the northern slope (windward) side of the small San Miguel Island (13 km in W-E length) range in age from late Pleistocene to modern time, though a major hiatus in sand-ramp growth occurred during the early Holocene marine transgression (16–9 ka). The Holocene sand ramps (1–5 m measured thicknesses) currently lack large dune forms, thereby representing deflated erosional remnants, locally covering thicker late Pleistocene sand-ramp deposits. The ramp sand was initially supplied from the adjacent island-shelf platform, extending about 20 km north of the present coastline. The sand-ramp deposits and interbedded loess soils were 14 C dated using 112 samples from 32 archaeological sites and other geologic sections. Latest Pleistocene sand ramps (66–18 ka) were derived from across-shelf eolian sand transport during marine low stands. Shoreward wave transport supplied remobilized late Pleistocene sand from the inner shelf to Holocene beaches, where dominant NW winds supplied sand to the sand ramps. The onset dates of the sand-ramp deposition in San Miguel are 7.2 ± 1.5 ka (sample n = 14). The internal strata dates in the vertically accreting sand ramps are 3.4 ± 1.7 ka ( n = 34). The sand ramps in San Miguel show wide-scale termination of sand supply in the latest Holocene time. The sand-ramp top dates or burial dates are 1.7 ± 0.9 ka ( n = 28). The latest Holocene sand ramps are truncated along most of the island's northern coastline, indicating recent losses of nearshore sand reserves to onshore, alongshore, and, possibly, offshore sand sinks. The truncated sand ramps in San Miguel Island and in other sand-depleted marine coastlines provide warnings about future beach erosion and/or shoreline retreat from accelerated sea-level rise accompanying predicted global warming.

California↗