Search USGSSearch

SEARCH · Search USGS

Results for “Names”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources

Geologic map of the Sappho Patera Quadrangle (V-20), Venus

The Sappho Patera quadrangle (V–20) of Venus is bounded by 0° and 30° East longitude, 0° and 25° North latitude. It is one of 62 quadrangles covering the entire planet at a scale of 1:5,000,000. The quadrangle derives its name from Sappho Patera, a large rimmed depression (diameter about 225 km) lying on top of a shield-shaped mountain named Irnini Mons. Sappho, a noted Greek poet born about 612 B.C., spent most of her life on the island of Lesbos. All of her works were burned in 1073 by order of ecclesiastical authorities in Rome and Constantinople. What little survives was discovered in 1897 as parts of papier mâché coffins in the Fayum (Durant, 1939). The Sappho Patera quadrangle includes the central portion of Eistla Regio, an elongated, moderately elevated (relief ~1 km) region extending for about 7,500 km west-northwestward from the west end of Aphrodite Terra. It is generally interpreted to be the surface manifestation of one or more mantle plumes (Phillips and Malin, 1983; Stofan and Saunders, 1990; Kiefer and Hager, 1991; Senske and others, 1992; Grimm and Phillips, 1992; Solomon and others, 1992). Eistla Regio is dominated by several large volcanic features. All or parts of four of these occur within the Sappho Patera quadrangle: the eastern flank of Gula Mons, Irnini Mons, Anala Mons, and Kali Mons. The quadrangle also includes eight named coronae: Nehalennia, Sunrta, Libera, Belet-Ili, Gaia, Asomama, Rabzhima, and Changko. A major rift extends from Gula Mons in the northwestern corner of the quadrangle to Libera Corona near the east border. East of Irnini and Anala Montes this rift is named Guor Linea; west of the montes it is named Virtus Linea. In addition to these major features, the Sappho Patera quadrangle includes numerous smaller volcanic flows and constructs, several unnamed coronae and corona-like features, a complex array of faults, fractures, and wrinkle ridges, and extensive plains that are continuous with the regional plains that constitute about 80% of the surface of Venus (Masursky and others, 1980). This area is geologically interesting because it contains examples of most globally important types of features and deposits and is an excellent area to study the temporal and genetic relations among plains, rifts, coronae, and large shield volcanoes. The temporal relations displayed in this quadrangle can provide useful constraints on models for venusian tectonic style (McGill, 1994b).

IMAP

Correlation chart of Pennsylvanian rocks in Alabama, Tennessee, Kentucky, Virginia, West Virginia, Ohio, Maryland, and Pennsylvania showing approximate position of coal beds, coal zones, and key stratigraphic units

The Appalachian basin, one of the largest Pennsylvanian bituminous coal-producing regions in the world, currently contains nearly one-half of the top 15 coal-producing States in the United States (Energy Information Agency, 2006). Anthracite of Pennsylvanian age occurs in synclinal basins in eastern Pennsylvania, but production is minimal. A simplified correlation chart was compiled from published and unpublished sources as a means of visualizing currently accepted stratigraphic relations between the rock formations, coal beds, coal zones, and key stratigraphic units in Alabama, Tennessee, Kentucky, Virginia, West Virginia, Ohio, Maryland, and Pennsylvania. The thickness of each column is based on chronostratigraphic divisions (Lower, Middle, and Upper Pennsylvanian), not the thickness of strata. Researchers of Pennsylvanian strata in the Appalachian basin also use biostratigraphic markers and other relative and absolute geologic age associations between the rocks to better understand the spatial relations of the strata. Thus, the stratigraphic correlation data in this chart should be considered provisional and will be updated as coal-bearing rocks within the Appalachian coal regions continue to be evaluated. Most geologic formations are identified and defined by the distinctive lithologic features they contain. However, formations of Pennsylvanian age in the Appalachian basin and the Pennsylvania Anthracite region have traditionally been described and named to reflect the presence or absence of economic coal beds and coarse-grained sandstone units, most of which have since been proven to be locally or regionally discontinuous (Ruppert and Rice, 2001). Many of the stratigraphic names and boundaries used for the coals and other geologic units in the Pennsylvanian rocks differ between States or regions (fig. 1). Because local and regional stratigraphic complexities occur within some States, a multiplicity of State-specific names is introduced that may be confusing to those conducting regional geologic assessments in the basin. Nonetheless, many of these stratigraphic names and boundaries have some elements that allow for regional stratigraphic correlation. For instance, many coals in the northern Appalachian basin coal region are easier to trace over greater distances than coals in the central and southern Appalachian basin coal regions (fig. 2). The Upper Pennsylvanian Pittsburgh coal bed (fig. 1) of the northern Appalachian basin coal region, for example, occurs as a synchronogenic bed deposited on a laterally continuous surface of sediments (Cross, 1954; Tewalt and others, 2001). The base of the Pittsburgh coal bed is designated as the contact between the Conemaugh Group (Upper Pennsylvanian) and the overlying Monongahela Group in western Pennsylvania, western Maryland, Ohio, and West Virginia (fig. 1). Therefore, in areas where the Pittsburgh coal bed is present, there is little controversy over its position or the placement of the boundary between the Conemaugh and Monongahela Groups. In other regions of the basin, group and formation boundaries are more difficult to identify over extensive areas. One example is the placement of the contact between the New River Formation and the overlying Kanawha Formation—a boundary that is not easily defined beyond the area where these units were first defined in West Virginia. At the type section of the Kanawha Formation, the base of the Lower Douglas coal zone (fig. 1) defines the contact between the Kanawha Formation and the underlying New River Formation (Rice and others, 1994b). However, subsequent mapping has demonstrated that the Lower Douglas coal zone is regionally discontinuous and in many parts of West Virginia is absent (Blake and others, 2002). Where absent, the Nuttall Sandstone Member of the underlying New River Formation sometimes occurs in the stratigraphic position of the Lower Douglas coal zone. Yet, even the Nuttall Sandstone Member has been found to be regionally discontinuous and of varying thickness throughout its extent, features that hinder its use as a regional stratigraphic marker bed in the Appalachian basin. Because of the many names used to identify individual coal beds and coal zones in the historic Appalachian basin coal-mining districts, coal bed designations may differ even more than stratigraphic nomenclature. In eastern Kentucky, northwest of the Pine Mountain thrust fault on the Cumberland overthrust sheet, for example, coal beds or coal zones equivalent to the Lower Elkhorn coal zone (within the Pikeville Formation) are identified also as the Eagle coal zone, Pond Creek coal zone, and Blue Gem coal bed (fig. 1). Southeast of the Pine Mountain thrust fault, yet still in Kentucky, equivalent coals in this same interval are known as the Imboden and Rich Mountain. Moreover, this same interval of coal is identified as the Blue Gem coal in Tennessee, the Imboden coal bed or Campbell Creek or Pond Creek coal zones in Virginia, and the Eagle coal zone in West Virginia.

Appalachian basin

Stratigraphic notes—Volume 1, 2022

This is the first volume in the U.S. Geological Survey (USGS) series of reports on stratigraphy entitled “Stratigraphic Notes,” which consists of short papers that highlight stratigraphic studies, changes in stratigraphic nomenclature, and explanations of stratigraphic names and concepts used on published geologic maps. “Stratigraphic Notes” is a long-term (multiyear), multivolume publication containing articles that address updates or revisions to stratigraphic nomenclature (and whose content ultimately will be incorporated by National Geologic Map Database personnel into Geolex, https://ngmdb.usgs.gov/Geolex/ ). We welcome papers for the “Stratigraphic Notes” series from geoscientists of the USGS, of State Geological Surveys, and from academicians. Papers can be submitted for publication in “Stratigraphic Notes” by contacting the USGS Geologic Names Committee ( gnc@usgs.gov ). As new “Stratigraphic Notes” volumes are published, links to the volumes will be posted at https://doi.org/10.3133/pp1879 . This first volume ("Stratigraphic notes—Volume 1, 2022") includes articles that provide guidance for those who wish to submit papers to “Stratigraphic Notes,” as well as information on how to make your manuscripts compliant for geologic names reviews and how to organize your paper’s content to facilitate inclusion of new or revised names in Geolex. This volume also includes some specific guidance on conducting geologic names reviews of geologic and hydrogeologic reports.

Professional Paper

Dasypodidae Borner, 1919 (Insecta, Hymenoptera): Proposed emendation of spelling to Dasypodaidae, so removing the homonymy with Dasypodidae Gray, 1821 (Mammalia, Xenarthra)

The family-group name DASYPODIDAE Borner, 1919 (Insecta, Hymenoptera) is a junior homonym Of DASYPODIDAE Gray, 1821 (Mammalia, Xenarthra). It is proposed that the homonymy between the two names, which relate to short-tongued bees and armadillos respectively, should be removed by emending the stem of the generic name Dasypoda Latreille, 1802, on which the insect familygroup name is based, to give DASYPODAIDAE, while leaving the mammalian name (based on Dasypus Linnaeus, 1758) unchanged. Dasypus novemcinctus Linnaeus, 1758, the type species of Dasypus, has a wide distribution in the southern United States, Central and South America. The genus Dasypoda ranges throughout most of the Palearctic region.

Bulletin of Zoological Nomenclature

Systematic studies of Oryzomyine rodents (Muridae, Sigmodontinae): diagnoses and distributions of species formerly assigned to Oryzomys 'capito'

We describe the morphological species-boundaries and geographic distributions of ten Neotropical Oryzomys based on analyses of museum specimens (skins and skulls, examples preserved in fluid, chromosomal spreads, and information about collection sites from skin tags, field catalogs, and other sources). These species have been regarded as members of an Oryzomys capito complex and for a long time were consolidated into a single entity identified as O. capito. Our study documents the following: 1. Defining the limits of species within the O. capito complex first requires a comprehensive review and rigorous definition of O. capito itself. We consider Fischer's (1814) Mus megacephalus to be valid and available, designate a neotype to bear the name, and reinstate it as a senior synonym of capito Olfers (1818). We then provide a working definition of O. megacephalus and its close relative, O. laticeps, derived from analyses of morphometric variation, estimates of geographic distributions, and evaluations of synonyms. In our view, O. megacephalus occurs in Amazonia but also extends into eastern Paraguay; its synonyms are capito Olfers (1818), cephalotes Desmarest (1819), velutinus Allen and Chapman (1893), goeldi Thomas (1897), modestus Allen (1899), and perenensis Allen (1901). Oryzomys laticeps Lund (1840) occurs in the Atlantic Forest region of eastern Brazil. We designate a lectotype for laticeps and allocate the names saltator Winge (1887) and oniscus Thomas (1904) as synonyms. 2. We provide the first comprehensive taxonomic revision of Oryzomys yunganus Thomas (1902). Its range covers tropical evergreen rainforest formations in the Guiana region and the Amazon Basin where, as documented by voucher specimens, it has been collected at the same localities as O. megacephalus, O. nitidus, and O. tern of carotid arterial circulation, occlusal patterns of second upper and lower molars, cranial proportions, and chromosomal features. Appreciable intraspecific geographic variation occurs in diploid number of chromosomes and frequency of occurrence of the hypothenar plantar pad, but sampling inadequacies obscure the significance of this variation. Large body size is characteristic of populations in the western Amazon Basin and in the tepui region of eastern Venezuela; smaller size characterizes populations in the Guianas and along the eastern margin of the Amazon Basin. No other scientific name has been correctly associated with the species. Samples from Mirador, Palmera, and Mera in the western Andean foothills of central Ecuador possess a combination of pelage, cranial, and dental traits that distinguish them from all samples of O. yunganus. These specimens are the basis for a new species we describe here, one that is more closely related to O. yunganus than to any other member of the former O. 'capito' complex. 3. We redescribe Oryzomys bolivaris (reviewed by Pine, 1971, under the name O. bombycinus), amplify its geographic range, and contrast it with O. talamancae and O. alfaroi, two sympatric congeners often confused with it. A distinctive set of morphological traits allows unambiguous identification of specimens belonging to O. bolivaris. It is a trans-Andean species recorded from very wet tropical evergreen rainforests extending from eastern Honduras and Nicaragua through Costa Rica and Panama to western Colombia and Ecuador. Allen's (1901) bolivaris is the oldest name for this species; castaneus Allen (1901), rivularis Allen (1901), bombycinus Goldman (1912), alleni Goldman (1915), and orinus Pearson (1939) are synonyms. 4. We revise the definition of Oryzomys talamancae Allen (1891) provided by Musser and Williams (1985), document additional specimens, describe karyotypes from Ecuadoran and Venezuelan samples, and contrast its morphology, chromosomes, and distribution with those of O. alfaroi and O. megacephalus. The geographic distribution of O. talamancae is also trans-Andean, but it inh

Bulletin of the American Museum of Natural History

Geology and ground-water resources of the island of Kauai, Hawaii

Kauai is one of the oldest, and is structurally the most complicated, of the Hawaiian Islands. Like the others, it consists principally of a huge shield volcano, built up from the sea floor by many thousands of thin flows of basaltic lava. The volume of the Kauai shield was on the order of 1,000 cubic miles. Through much of its growth it must have resembled rather closely the presently active shield volcano Mauna Loa, on the island of Hawaii. When the Kauai volcano started its growth is not known with certainty, but it is believed that activity started late in the Tertiary period, possibly in the early or middle part of the Pliocene epoch. Growth of the shield was rapid and probably was completed before the end of the Pliocene. Toward the end of the growth of the shield, its summit collapsed to form a broad caldera, the largest that has been found in the Hawaiian Islands. Like the calderas of Kilauea and Mauna Loa, that of Kauai volcano had boundaries that were, in part, rather indefinite. The principal depression was bordered by less depressed fault blocks, some of which merged imperceptibly with the outer slopes of the volcano. Elsewhere the caldera rim was low, and flows spilled over it onto the outer slopes. The well-defined central depression of the Kauai caldera was approximately 10 to 12 miles across. At about the same time as the formation of the major caldera, another, smaller caldera was formed by collapse around a minor eruptive center on the southeastern side of the Kauai shield. Lavas accumulated in the calderas, gradually filling them and burying banks of talus that formed along the foot of the boundary cliffs. The caldera-filling lavas differed from those that built the major portion of the shield in being much thicker and more massive as a result of ponding in the depressions. The petrographic types for the most part are the same throughout. Both the flank flows that built most of the shield and the flows that filled the calderas are predominantly olivine basalt. Picrite-basalt (oceanite), containing very abundant large phenocrysts of olivine, and basalt containing little or no olivine are present but together comprise less than 10 percent of the whole. Late in the period of filling of the major caldera a small amount of basaltic andesine andesite was extruded. Near the end of the period of filling of the major caldera further collapse occurred, forming a large graben on the southwestern side of the shield. Lava flows erupting within the caldera poured southwestward over the cliff bounding the graben and spread over the gently sloping graben floor. Near the present Waimea Canyon their advance was obstructed by the fault scarp at the west edge of the graben. The cliff along the northeast edge of the graben eventually was buried by lava flows from within the caldera, but that along the west edge continued to stand above the level of the flows in the graben. The flows that accumulated in the graben are of the same types as those that filled the caldera, and like them are mostly thick and massive because of ponding by the graben walls and of the gentle slopes of the graben floor over which they spread. The rocks of the major Kauai shield volcano are known as the Waimea Canyon volcanic series. The thin flows that accumulated on the flanks of the shield, which compose the major portion of the volcanic edifice, are named the Napali formation of the Waimea Canyon volcanic series. The rocks that accumulated in the big summit caldera are named the Olokele formation, and those that filled the small caldera on the southeast flank of the shield are named the Haupu formation. The volcanic rocks accumulated in the graben on the southwestern side of the shield are named the Makaweli formation of the Waimea Canyon volcanic series, and sedimentary rocks interbedded with them are known as the Mokuone member of the Makaweli formation. Few vents of the Waimea Canyon volcanic series have been recognized, probably because most of them have been destroyed by erosion or are buried by later lavas. Large numbers of dikes cut the lavas of the Napali formation along Waimea Canyon and the Napali Coast and along the east edge of the Waialeale massif. Fewer dikes are found in the other members of the series. Some tendency toward radial arrangement of the dikes is present, but the dominant trend all over the island is east-northeastward. Another great collapse took place on the eastern flank of the volcano at about the time the major shield became extinct, or shortly afterward. A subcircular graben 6 or 7 miles across sank several thousand feet, forming a broad depression between the Waialeale massif on the west and Kalepa and Nonou ridges on the east. This collapsed structure cannot be as clearly demonstrated as the Makaweli graben on the southwest side of the shield, because its walls have been greatly eroded and its floor is deeply buried by lavas of the later Koloa volcanic series. It appears, however, to be the only reasonable explanation of the physiography of the eastern side of the island. After the completion of the great Kauai shield came a long period of erosion during which no volcanic activity occurred. Waves cut high sea cliffs around the island, and streams cut canyons as much as 3,000 feet deep. Thick soil formed over much of the mountain. Then volcanism was renewed. Eruption occurred from a series of minor vents arranged in nearly north-south and northeast-southwest lines across the eastern two-thirds of the island. The lavas, cinder cones, and ash beds of this period of volcanism are known as the Koloa volcanic series. Lavas of the Koloa volcanic series include olivine basalt, picrite-basalt (mimosite) with few phenocrysts of olivine, basanite, nepheline basalt, melilite-nepheline basalt, and ankaratrite (nepheline basalt very rich in pyroxene and olivine). Inclusions of dunite, composed almost entirely of olivine, are common in flows of the Koloa. Just before and during the eruption of the Koloa volcanic series, voluminous landslides and mudflows brought down a large amount of rock debris and soil from the steep slopes of the mountainous central upland and deposited it as breccias at the foot of the steep slopes in valley heads and along the border of the marginal lowland. Streams distributed part of the material across the lowland. The breccias and conglomerates thus formed, and later buried by lavas of the Koloa volcanic series, are named the Palikea formation of the Koloa volcanic series. The structures formed at Koloa vents include cinder cones, one tuff cone, and lava cones. The latter are miniature shields resembling the major shield volcano, formed by repeated outpourings of fluid lava. The tuff cone, at the west side of Kilauea Bay, was formed by phreatomagmatic explosions caused by rising magma coming in contact with water-saturated rocks. Volcanism during Koloa time continued for a long period but was not continuous over the entire area. Locally, long periods of quiet occurred, allowing streams to re-excavate some of the canyons filled by earlier flows of the Koloa volcanic series, and weathering to form soils later buried by new flows. Some of the canyons thus formed during the time when the Koloa was being deposited were several hundred feet deep. Volcanism probably continued throughout most of the Pleistocene epoch. The latest flow of the Koloa volcanic series appears very recent, and rests on lithified calcareous dunes formed during one of the Pleistocene low stands of the sea. During the Pleistocene epoch stream valleys and sea cliffs were eroded to base levels governed by one or more stands of the sea more than 100 feet below present sea level. Beaches of calcareous sand were formed, and the sand blown inland to form calcareous dunes, now lithified. A test boring near Moloaa penetrated calcareous sand 160 feet below sea level, at the foot of a high sea cliff. Coral reef also was built around part or all of the island, and in part buried by lavas of the Koloa volcanic series. The explosions that built the tuff cone at Kilauea Bay threw up fragments of limestone from a buried reef. Much of the apron of lavas of the Kalna series around the northeastern side of the island probably rests on a platform formed below present sea level by wave erosion and the growth of coral reef. As the sea rose around the island, the valley mouths were alluviated. Several levels of the sea higher than the present one probably are represented. Some stream terraces may be graded to a stand of the sea as high as 260 feet above present sea level, but no positive evidence for stands higher than 25 feet have been found. Well-preserved shorelines are recognized approximately 25 and 5 feet above sea level. Much of the present coral reef appears to have been formed when the sea stood about 5 feet higher than now, and reduced to its present level by solutional weathering and wave erosion. The lavas of the Napali formation of the Waimea Canyon volcanic series are highly permeable. They carry basal water over much of the island, and yield it freely to wells. This water is fresh everywhere except very close to the coast on the leeward side of the island. In some areas they may contain water confined at high levels between dikes. The lavas of the Olokele and Haupu formations are moderately to poorly permeable. They probably contain fresh water at sea level, but would not yield it readily to wells. Locally, ash beds perch small bodies of fresh water at high levels in the lavas of the Olokele formation, but these are of no economic importance. The lavas of the Makaweli formation also arc moderately to poorly permeable. They carry fresh or brackish water at sea level. In general, they yield water to wells less readily than the lavas of the Napali formation, but more readily than the lavas of the Olokele. The conglomerates and breccias of the Mokuone member are poorly permeable, but are not known to perch more than a slight amount of water in the overlying lavas, The lava flows of the Koloa volcanic series are poorly to moderately permeable. They carry fresh or brackish water at sea level, but generally yield it slowly to wells. Locally, small bodies of fresh water are perched at high levels in the lavas of the Koloa by beds of ash and soil and by breccia and conglomerate of the Palikea formation. Both the older and the younger alluvium generally are poorly permeable, but contain small amounts of fresh or brackish water. The lithified calcareous dunes are permeable, but they appear to contain only brackish water. Lagoon deposits on the Mana plain are poorly to moderately permeable and yield brackish water to wells.

Hawaii

Synthesis and revision of the lithostratigraphic groups and formations in the Upper Permian?–Lower Jurassic Newark Supergroup of eastern North America

The Upper Permian? - Lower Jurassic Newark Supergroup of eastern North America has a strikingly uniform succession of lithologic units. This uniformity is seen regardless of whether these units are characterized on the basis of their lithostratigraphy, allostratigraphy, biostratigraphy, or chemostratigraphy. After deposition, these units were broken up tectonically and attacked erosionally; parts of them survive today only within localized, down-faulted areas. Many lines of evidence compellingly demonstrate that most or all of these remnant units once were physically continuous between remaining outcrops. It is needlessly confusing to give every remnant of each unit a different name in each area where it persists simply because it is now physically isolated by erosion from other portions of the same unit. Instead, these units should be defined within a regional lithostratigraphic framework that emphasizes their common origins and original stratigraphic continuity. To this end, the formation-level stratigraphy of the Newark Supergroup is reduced from 58 locally applied and locally defined formations to a succession of only 16 uniformly defined and regionally recognizable formations. In all cases the oldest name validly applied to each formation is given priority over more recently erected synonymous names, which are either abandoned or, in a few cases, changed in rank to a member of one of the formations recognized here. The Newark Supergroup is here organized into four regionally recognizable groups, each subdivided into regionally recognizable formations. In ascending order, the Upper Permian?-Middle Triassic Acadia Group (new name) includes the Honeycomb Point Formation, Chedabucto Formation, Economy Formation, and Evangeline Formation. This group is preserved only in the Canadian Fundy and Chedabucto basins. The Upper Triassic (Carnian-Norian) Chatham Group includes the Doswell Formation, Stockton Formation, Lockatong Formation, and Passaic Formation. The Upper Triassic-Lower Jurassic (upper Rhaetian-lower Hettangian) Meriden Group includes the Talcott Formation, Shuttle Meadow Formation, Holyoke Formation, East Berlin Formation, and Hampden Formation. The term "Agawam Group," previously proposed to encompass all Newark Supergroup strata above the highest basalt of the Meriden Group, is here abandoned and replaced with the name "Portland Group" for the same suite of strata. The Lower Jurassic (upper Hettangian-lower Sinemurian) Portland Group includes a lower Boonton Formation, an overlying Longmeadow Sandstone (here reinstated), and the Mount Toby Conglomerate, which laterally intertongues with both the Boonton Formation and the Longmeadow Sandstone.

Stratigraphy

Lunar highland meteorite Dhofar 026 and Apollo sample 15418: Two strongly shocked, partially melted, granulitic breccias

Studies of lunar meteorite Dhofar 026, and comparison to Apollo sample 15418, indicate that Dhofar 026 is a strongly shocked granulitic breccia (or a fragmental breccia consisting almost entirely of granulitic breccia clasts) that experienced considerable post-shock heating, probably as a result of diffusion of heat into the rock from an external, hotter source. The shock converted plagioclase to maskelynite, indicating that the shock pressure was between 30 and 45 GPa. The post-shock heating raised the rock's temperature to about 1200 °C; as a result, the maskelynite devitrified, and extensive partial melting took place. The melting was concentrated in pyroxene-rich areas; all pyroxene melted. As the rock cooled, the partial melts crystallized with fine-grained, subophitic-poikilitic textures. Sample 15418 is a strongly shocked granulitic breccia that had a similar history, but evidence for this history is better preserved than in Dhofar 026. The fact that Dhofar 026 was previously interpreted as an impact melt breccia underscores the importance of detailed petrographic study in interpretation of lunar rocks that have complex textures. The name “impact melt” has, in past studies, been applied only to rocks in which the melt fraction formed by shock-induced total fusion. Recently, however, this name has also been applied to rocks containing melt formed by heating of the rocks by conductive heat transfer, assuming that impact is the ultimate source of the heat. We urge that the name “impact melt” be restricted to rocks in which the bulk of the melt formed by shock-induced fusion to avoid confusion engendered by applying the same name to rocks melted by different processes.

Meteoritics and Planetary Science

Solving a nomenclatural conundrum: Cernosvitovia crainensis (Mršić, 1989) and Aporrectodea macvensis Šapkarev in Mršić, 1991 (Lumbricidae)

This contribution deals with the names and authorship of two lumbricid taxa endemic to the Balkans (see Stojanović et al., this volume). Although their validity has never been questioned, it has been unclear up to now which publication has made these two species-group names available according to the rules of the International Code of Zoological Nomenclature (Articles in "the Code," ICZN 1999). In the following, we review the somewhat intricate history of these names and explain why the correct citation and spelling of these names are "Cernosvitovia crainensis (Mršić, 1989)" and "Aporrectodea macvensis Šapkarev in Mršić, 1991," respectively.

Zootaxa

Reassessment of the volkonskoite-chromian smectite nomenclature problem.

The name volkonskoite was first used in 1830 to describe a bright blue-green, chromium-bearing clay material from the Okhansk region, west of the Ural Mountains, U.S.S.R. Since that time, the name has been applied to numerous members of the smectite group of clay minerals, although the reported chromium content has ranged from 1% to about 30% Cr 2 O 3 . The name has also been applied to some chromian chlorites. Because volkonskoite has been used for materials that differ not only in their chromium content but also in their basic structure, the species status of the mineral has been unclear. To resolve this uncertainty, two specimens of volkonskoite from (1) Mount Efimiatsk, the type locality in the Soviet Union (USNM 16308) and (2) the Okhansk region in the Perm Basin, U.S.S.R. (USNM R4820), were examined by several mineralogical techniques. Neotype sample 16308 has the following structural formula: (Ca 0.11 Mg 0.11 Fe 2+ 0.03 K 0.02 )(Cr 1.18 Mg 0.78 Fe 3+ 0.29 Ca 0.02 )(Si 3.50 Al 0.51 )O 10 (OH) 2 ⋅3.64H 2 O. Sample R4820 has the following structural formula: (Ca 0.25 Mg 0.05 Fe 2+ 0.01 K 0.03 Mn 0.01 )(Cr 1.07 Mg 0.75 Fe 3+ 0.35 (Si 3.59 Al 0.43 )O 10 (OH) 2 ⋅4.22H 2 O. Mössbauer spectroscopy indicates that 91% and 98% of the iron is present as Fe 3+ in samples 16308 and R4820, respectively. X-ray powder diffraction patterns of both samples have broad lines corresponding to minerals of the smectite group. On the basis of these data, volkonskoite appears to be a dioctahedral member of the smectite group that contains chromium as the dominant cation in the octahedral layer. Smectites containing less than this amount of octahedral chromium should not be called volkonskoite, but should be named by chemical element adjectives, e.g., chromian montmorillonite, chromian nontronite.

Clays and Clay Minerals

Amphibians and reptiles of Guyana, South America: illustrated keys, annotated species accounts, and a biogeographic synopsis

Guyana has a very distinctive herpetofauna. In this first ever detailed modern accounting, based on voucher specimens, we document the presence of 324 species of amphibians and reptiles in the country; 148 amphibians, 176 reptiles. Of these, we present species accounts for 317 species and color photographs of about 62% (Plates 1–40). At the rate that new species are being described and distributional records are being found for the first time, we suspect that at least 350 species will be documented in a few decades. The diverse herpetofauna includes 137 species of frogs and toads, 11 caecilians, 4 crocodylians, 4 amphisbaenians, 56 lizards, 97 snakes, and 15 turtles. Endemic species, which occur nowhere else in the world, comprise 15% of the herpetofauna. Most of the endemics are amphibians, comprising 27% of the amphibian fauna. Type localities (where the type specimens or scientific name-bearers of species were found) are located within Guyana for 24% of the herpetofauna, or 36% of the amphibians. This diverse fauna results from the geographic position of Guyana on the Guiana Shield and the isolated highlands or tepuis of the eastern part of the Pantepui Region, which are surrounded by lowland rainforest and savannas. Consequently, there is a mixture of local endemic species and widespread species characteristic of Amazonia and the Guianan Region. Although the size of this volume may mislead some people into thinking that a lot is known about the fauna of Guyana, the work has just begun. Many of the species are known from fewer than five individuals in scientific collections; for many the life history, distribution, ecology, and behavior remain poorly known; few resources in the country are devoted to developing such knowledge; and as far as we are aware, no other group of animals in the fauna of Guyana has been summarized in a volume such as this to document the biological resources. We briefly discuss aspects of biogeography, as reflected in samples collected at seven lowland sites (in rainforest, savanna, and mixed habitats below 500 m elevation) and three isolated highland sites (in montane forest and evergreen high-tepui forest above 1400 m elevation). Comparisons of these sites are preliminary because sampling of the local faunas remains incomplete. Nevertheless, it is certain that areas of about 2.5 km2 of lowland rainforest can support more than 130 species of amphibians and reptiles (perhaps actually more than 150), while many fewer species (fewer than 30 documented so far) occur in a comparable area of isolated highlands, where low temperatures, frequent cloudiness, and poor soils are relatively unfavorable for amphibians and reptiles. Furthermore, insufficient study has been done in upland sites of intermediate elevations, where lowland and highland faunas overlap significantly, although considerable work is being accomplished in Kaieteur National Park by other investigators. Comparisons of the faunas of the lowland and isolated highland sites showed that very few species occur in common in both the lowlands and isolated highlands; that those few are widespread lowland species that tolerate highland environments; that many endemic species (mostly amphibians) occur in the isolated highlands of the Pakaraima Mountains; and that each of the isolated highlands, lowland savannas, and lowland rainforests at these 10 sites have distinctive faunal elements. No two sites were identical in species composition. Much more work is needed to compare a variety of sites, and especially to incorporate upland sites of intermediate elevations in such comparisons. Five species of sea turtles utilize the limited areas of Atlantic coastal beaches to the northwest of Georgetown. All of these are listed by the International Union for the Conservation of Nature as being of global concern for long-term survival, mostly owing to human predation. The categories of Critically Endangered or Endangered are applied to four of the local sea turtles (80%). It is important to protect the few good nesting beaches for the sea turtles of Guyana. We have documented each of the species now known to comprise the herpetofauna of Guyana by citing specimens that exist in scientific collections, many of which were collected and identified by us and colleagues, including students of the University of Guyana (UG). We also re-identified many old museum specimens collected by others in the past (e.g., collections of William Beebe) and we used documented publications and collection records of colleagues, most of whom have been working more recently. We present dichotomous keys for identifying representatives of the species known to occur in Guyana, and we present brief annotated species accounts. The accounts provide the current scientific name, original name (with citation of the original description, which we personally examined in the literature), some outdated names used in the recent past, type specimens, type localities, general geographic distribution, examples of voucher specimens from Guyana, coloration in life (and often a color photograph), and comments pointing out interesting subjects for future research.

Proceedings of the Biological Society of Washingto

Index of surface-water records, part 4, St. Lawrence River Basin, to September 30, 1950

The index lists the stream-flow and reservoir stations in the St. Lawrence River Basin for which records have been or are to be published for periods prior to September 30, 1950. The stations are listed in downstream order. Tributary streams are indicated by indention. Station names are given in their most recently published forms. Parentheses around part of a station name indicate that the inclosed word or words were used in an earlier published name or the station or in a name under which records were published by same agency other than the Geological Survey. The drainage areas, in square miles, are the latest figures published or otherwise available at this time. Drainage areas that were obviously inconsistent with other drainage areas on the same stream have been omitted. Some drainage areas not published by the Geological Survey are listed with an appropriate footnote stating the published source or the figure or drainage area. Under "period of record" breaks of less than a 12-month period are not shown. A dash not followed immediately by a closing date shows that the station was in operation on September 30, 1950. The years given are calendar years. Periods of records published by agencies other than the Geological Survey are listed in parentheses only when they contain more detailed information or are for periods not reported in publications to the Geological Survey. Records both of gage height and of discharge are listed for stream-flow stations, and records of gage height and of contents (or of change in contents) are listed for stations on reservoirs. Records of gage heights only and records consisting only of monthly figures either of stream flow or reservoir contents are designated by symbols and footnotes. For early years when daily discharges were not generally published by the Geological Survey, published daily gage heights and a published rating table are considered to be equivalent to daily discharges. An alphabetical index of streams. canals. and reservoirs is given on pages 12 to 14.

St. Lawrence River Basin

Index of surface-water records, part 7, Lower Mississippi River basin, to September 30, 1950

The index lists the steam-flow and reservoir stations in the Lower Mississippi River Basin for which records have been or are to be published for periods prior to September 30, 1950. The stations are listed in downstream order. Tributary streams are indicated by indention. Station names are given in their most recently published forms. Parentheses around part of a station name indicate that the inclosed word or words were used in an earlier published name of the station or in a name under which records were published by some agency other than the Geological Survey. The drainage areas, in square miles, are the latest figures published or otherwise available at this time. Drainage areas that were obviously inconsistent with other drainage areas on the same stream have been omitted. Some drainage areas not published by the Geological Survey are listed with an appropriate footnote stating the published source of the figure of drainage area. Under "period of record" breaks of less than a 12-month period are not shown. A dash not followed immediately by a closing date shows that the station was in operation on September 30, 1950. The years given are calendar years. Periods of records published by agencies other than the Geological Survey are listed in parentheses only when they contain more detailed information or are for period.s not reported in publications of the Geological Survey. Records both of gage height and of discharge are listed for stream-flow stations, and records of gage height and of contents (or of change in contents) are listed for stations on reservoirs. Records of gage heights only and records consisting only of monthly figures either of stream flow or reservoir contents are designated by symbols and footnotes. For early years when daily discharges were not generally published by the Geological Survey, published daily gage heights and a published rating table were considered to be equivalent to daily discharges. An alphabetical index of streams, canals, and reservoirs is given on pages 14-16.

Circular

Index of surface-water records, part 11, Pacific slope basins in California, to September 30, 1950

The index lists the stream-flow and reservoir stations in the Pacific Slope Basins in California for which records have been or are to be published for periods prior to September 30, 1950. The stations are listed in downstream order. Tributary streams are indicated by indention. Station names are given in their most recently published forms. Paren- theses around part of a station name indicate that the enclosed ward or words were used in an earlier published name of the station or in a name under which records were published by some agency other than the Geological Survey. The drainage areas, in square miles, are the latest figures published otherwise available at this time. Drainage areas that were obviously inconsistent with other drainage areas on the same stream have been omitted. Some drainage areas not published by the Geological Survey are listed with an appropriate footnote stating the published source of the figure of drainage area.

Circular

Niobium and tantalum: indispensable twins

Niobium and tantalum are transition metals almost always paired together in nature. These “twins” are difficult to separate because of their shared physical and chemical properties. In 1801, English chemist Charles Hatchett uncovered an unknown element in a mineral sample of columbite; John Winthrop found the sample in a Massachusetts mine and sent it to the British Museum in London in 1734. The name columbium, which Hatchet named the new element, came from the poetic name for North America—Columbia—and was used interchangeably for niobium until 1949, when the name niobium became official. Swedish scientist Anders Ekberg discovered tantalum in 1802, but it was confused with niobium, because of their twinned properties, until 1864, when it was recognized as a separate element. Niobium is a lustrous, gray, ductile metal with a high melting point, relatively low density, and superconductor properties. Tantalum is a dark blue-gray, dense, ductile, very hard, and easily fabricated metal. It is highly conductive to heat and electricity and renowned for its resistance to acidic corrosion. These special properties determine their primary uses and make niobium and tantalum indispensable.

Fact Sheet

Silver in the United States, exclusive of Alaska and Hawaii

The productive silver districts in the United States (exclusive of Alaska and Hawaii) are shown on the accompanying map. Only those districts known or believed to have contained 100,000 troy ounces or more silver are shown. Three size categories, based on production and estimated reserves, are distinguished and indicated by size of symbols: districts containing 100,000 to 5 million ounces, those containing 5 million to 50 million ounces, and those containing more than 50 million ounces. Symbols show the approximate centers of the districts. Some of the more prominent districts are identified by name on the map, and all are numbered to correspond to the index. Because a name established through common usage may not be the legal name of the mining district, several names are given in the index for some localities. The index, arranged alphabetically by States, includes a brief description of major geologic features for most districts. Both published and unpublished data were used, and at least one reference is given for each locality if reports on it have been published.

Mineral Investigations Resource Map

Ecosystem history of southern and central Biscayne Bay: Summary report on sediment core analyses

During the last century, the environs of Biscayne Bay have been greatly affected by anthropogenic alteration through urbanization of the Miami/Dade County area. The sources, timing, delivery, and quality of freshwater flow into the Bay have been changed by construction of a complex canal system that controls movement of water throughout south Florida. Changes in shoreline and sub-aquatic vegetation and marine organisms have been observed and changes in water delivery are believed to be the cause. Current restoration goals are attempting to restore natural flow of fresh water into Biscayne and Florida Bays and to restore the natural fauna and flora, but first we need to determine pre-alteration baseline conditions in order to establish targets and performance measures for restoration. This research is part of an ongoing study designed to address the needs of the Biscayne Bay Coastal Wetlands Project (BBCW) of the Comprehensive Everglades Restoration Plan (CERP). By establishing the natural patterns of temporal change in salinity, water quality, vegetation, and benthic fauna in Biscayne Bay and the nearby wetlands over the last 100- 500 years the USGS, in collaboration with our partners, will provide the data necessary to set realistic targets to achieve the BBCW Project goals. Six cores from three sites in Biscayne Bay were collected in April 2002 for multidisciplinary multi-proxy analyses. This report details the results of these analyses and compares the 2002 cores to cores collected in 1997. The following are our significant findings to date: The salinity of central Biscayne Bay has become increasingly marine and increasingly stable over the last 100 years. At No Name Bank, prior to approximately 1915, the inter-decadal and decadal salinity fluctuations appear to have been greater than after 1915 when salinities stabilized at that site. Continental shelf/open marine influence on the sites has increased during the 20th century. There is no indication of inter-decadal salinity extremes or periods of hypersalinity. Freshwater and mesohaline salinities have had a minor influence on No Name bank throughout the time of deposition. At Featherbed Bank, the influence is reduced to mesohaline salinities. Card Bank has experienced relatively large swings in salinity over multi-decadal and centennial timescales, compared to central Biscayne Bay, but marine influence at the site has increased over the last century. Indications of regional scale patterns have been found, especially in the shell chemistry data and the pollen assemblages. These regional patterns indicate that the changes are not site specific and may not be limited to Biscayne Bay. Sub-aquatic vegetation has undergone bay-wide patterns of change over the last 200-500 years, which includes expansion prior to 1900 and declines during the last century in central Biscayne Bay. Thalassia appears to have increased at all three core sites sometime between 1550 and 1750 AD. A decline in Thalassia appears to have occurred after 1950 at No Name Bank and slightly earlier in the 20th century at Featherbed Bank. Card Bank does not appear to have experienced any declines in vegetation on an inter-decadal scale during the 20th century. Molluscan faunal abundance and diversity have undergone significant changes in central Biscayne Bay. Indicators of increased organic-rich sediments at No Name occur between 1869 to 1888 and between the 1930’s to 1975. These changes may correlate to human activities (settlement, population growth). These findings represent a first step towards the project’s goal to reconstruct the history of Biscayne Bay and they provide us with a working model to be tested at other sites. It is clear from our findings that Biscayne Bay has been a dynamic environment over the last 500 years, with natural changes occurring in salinity and benthic habitats. However, several significant changes have occurred in the 20th century: 1) increased stabilization of marine salinities; 2) declines in seagrass in central Biscayne Bay; 3) dramatic changes in molluscan abundance and diversity in central Biscayne Bay. The question remains - how do we better differentiate natural cycles of change from anthropogenic change within these observed trends? The preliminary implications from our research are that changes in salinity and benthic habitats have occurred naturally in Biscayne Bay on inter-decadal to centennial scales, perhaps due to climatic changes, changes in sea level, bank migrations, or a combination of factors. However, further work needs to be done to determine which components of change in the 20th century are human-induced and which are natural. By examining the historical records preserved in the sediments of Biscayne Bay, we can provide restoration trust agencies with the information necessary to set realistic targets and performance measures for Biscayne Bay.

Florida

Preliminary integrated geologic map databases for the United States: Digital data for the reconnaissance geologic map for Prince William Sound and the Kenai Peninsula, Alaska

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. The files named __geol contain geologic polygons and line (contact) attributes; files named __fold contain fold axes; files named __lin contain lineaments; and files named __dike contain dikes as lines. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Alaska