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Articles 31 - 60 of 112
Full-Text Articles in Physical Sciences and Mathematics
Identifying Key Variables Associated With The Temporal And Spatial Distribution Of Prolific Marine Petroleum Source Rock (Mpsr) Units And Its Application To The Taconic Foreland Basin, Eastern New York, C. Mark Achong
Geology Theses and Dissertations
Correctly identifying key variables associated with the temporal and spatial distribution of prolific marine petroleum source rock (MPSR) units is of critical importance towards the future development of models accurately predicting their existence and effective exploitation. The geographic positioning and prevailing paleoclimatic conditions on paleocontinental reconstructions, in combination with the processes controlling the drowning of continental margins and parameters associated with the establishment of high biologic productivity and long term anoxic conditions within the water column, have been pursued as first-order constraints controlling the development of some prolific marine petroleum source rock (MPSR) deposits. From this, a model has been …
Trace-Element Modelling Of Melting In Spinel Peridotites, Susanne Petra Vogel
Trace-Element Modelling Of Melting In Spinel Peridotites, Susanne Petra Vogel
Geology Theses and Dissertations
This study addresses three independent topics related to trace element modeling of spinel peridotites that are suggested by the pioneering work of Johnson et al. (1990) on abyssal harzburgites.
First, the fractional non-modal melting equation derived by Johnson and coworkers (1990) is algebraically modified to present a "one-element/two-phase" model. This model suggests a simple test for estimating mantle heterogeneity in the source rock of spinel lherzolites. This model is applied to data from the literature for samples from Dreiser Weiher, Germany; San Luis Potosi, Mexico; and Western Victoria, Australia.
Second, trace elements in clinopyroxenes of abyssal peridotites and continental spinel …
A Paleoseismic Investigation Of The Mcgregor Fault, East-Central New York, Steven J. Tice
A Paleoseismic Investigation Of The Mcgregor Fault, East-Central New York, Steven J. Tice
Geology Theses and Dissertations
The structural disposition and movement potential of the McGregor Fault System in Eastern New York State are reviewed from the perspective of a paleoseismic investigation. The McGregor Fault zone has been located beneath deltaic sediments west of West Glens Falls using commercial and residential bore hole data and microgravity surveys. A 34 m long trench was excavated in overburden near the western margin of the McGregor Fault zone to a depth of 3.2 m. Stratified fluvially deposited sediments were exposed which showed no evidence of earthquake induced deformation or offset. However, the overburden present here does not possess optimal qualities …
Correlation Of The Tioga Bentonites Using Rhyolitic Melt Inclusions Found In Quartz Phenocrysts As Geochemical Fingerprints, John W. Waechter
Correlation Of The Tioga Bentonites Using Rhyolitic Melt Inclusions Found In Quartz Phenocrysts As Geochemical Fingerprints, John W. Waechter
Geology Theses and Dissertations
The Tioga bentonites were first noted by Fettke in 1931 from well cuttings in the Tioga gas fields of Tioga County, Pennsylvania. They have been used by many investigators (Oliver, 1954, 1956; Dennison, 1963; Dennison and Textoris, 1967, 1978; Epstein, 1986; Smith and Way, 1983; Way et al., 1986) as a time-plane to correlate stratigraphic units from eastern Pennsylvania to Illinois and from southern Ontario to Virginia. The Tioga bentonites are recognized as seven major volcanic ash layers labeled Tioga-A - Tioga-G as well as several minor layers labeled Tioga-A1 - Tioga-A3 (Way et al., 1986). They occur within the …
Thermal-Mechanical Response To An Intruding Magma Chamber, Christoph Arz
Thermal-Mechanical Response To An Intruding Magma Chamber, Christoph Arz
Geology Theses and Dissertations
The thermal-mechanical response of rock at shallow to medium depth beneath the earth's surface has been modeled as a magma body ascends toward it. The overall stress field is calculated by considering the country rock as a viscous fluid, a thermal-elastic material, or as an elasto-plastic material that fractures when its strength is overcome.
The stress field within and around a spherical magma body surrounded by a homogeneous, Newtonian fluid has been evaluated and can be used at deeper levels in the earth's crust where the viscosity of the country rock is relatively low. With decreasing depth wall rock material …
The Origin Of Metalliferous Argillites In The Shoal Arm Formation Of North-Central Newfoundland, Volker Brüchert
The Origin Of Metalliferous Argillites In The Shoal Arm Formation Of North-Central Newfoundland, Volker Brüchert
Geology Theses and Dissertations
The Middle Ordovician Shoal Arm Formation, which is located in the central volcanic belt of north-central Newfoundland, is a tripartite assemblage of hematitic argillites, grey cherts, and black shales directly underlying a flysch sequence. The hematitic argillites are enriched in Fe, Mn, Ni, Pb, and Co. Factor analysis and principal component analysis indicate the presence of a hydrothermal component, presumably derived from hydrothermal activity in the coeval Lawrence Head volcanics. Unusual, (?) calcareous Mn-Fe-oxide nodules are present in the top parts of turbidites in the hematitic argillites. Electron microprobe analysis of a color transition from a red to a green …
A Kinematic Study Of The Summit Valley Plutonic Complex, Klamath Mountains, California, Nancy E. Griesau
A Kinematic Study Of The Summit Valley Plutonic Complex, Klamath Mountains, California, Nancy E. Griesau
Geology Theses and Dissertations
The Summit Valley plutonic complex (SVPC) is a multi-phase intrusive body of Late Jurassic age. Crystallization age for a zircon of 150±1 Ma and a cooling age for a hornblende of 144±1 Ma indicate a protracted period of high temperature. The SVPC is irregularly shaped, covers <15 km2, and is believed to be in the western limb of a post-Nevadan syncline, with an easterly dip estimated at about 45°. The SVPC penetrated the Orleans Fault and intruded and contact metamorphosed the upper and lower plates of the thrust. The Orleans Fault is a major tectonic boundary separating the Western Paleozoic …
The Geology Of The Vermont Valley And The Western Flank Of The Green Mountains Between Dorset Mountain And Wallingford, Vermont, Rolf Herrmann
The Geology Of The Vermont Valley And The Western Flank Of The Green Mountains Between Dorset Mountain And Wallingford, Vermont, Rolf Herrmann
Geology Theses and Dissertations
The carbonate sequence of the Vermont Valley has been generally believed to lie on the east limb of a major unfaulted syncline ("Middlebury Synclinorium"), and the exposed Precambrian basement and overlying cover rocks of the Green Mountain massif on the west limb of the adjacent major unfaulted anticline ("Green Mountain Anticlinorium"). Except for the Basal Thrust of the Taconic Allochthon, all faults shown on previous maps die out north of Dorset Mountain.
In contrast, detailed mapping for this thesis in the Vermont Valley and the western flank of the Green Mountain massif has revealed several major north/south trending thrust faults, …
Slickenside Petrography: Slip-Sense Indicators And Classification, Young-Joon Lee
Slickenside Petrography: Slip-Sense Indicators And Classification, Young-Joon Lee
Geology Theses and Dissertations
Petrographic study has been carried out on slickenside thin sections, to find out reliable microstructures for determining the slip-sense of faults, and to classify slickensides morphologically. Thin sections are made cut parallel to the striation and perpendicular to the slip plane. Many useful slip-sense indicators are found in thin section even though such indicators may be absent in hand specimens. They are (1) off-set or bending of once-continuous bodies such as veins, layers, grains or twin lamellae, (2) crystal fibers growing nearly parallel to the slip direction, (3) extensional fractures aligned oblique to the slip plane, (4) S-C geometries in …
Mineral Paragenesis Of The Granulite Facies In The Lake George Area, New York, Boknam Ree
Mineral Paragenesis Of The Granulite Facies In The Lake George Area, New York, Boknam Ree
Geology Theses and Dissertations
The Lake George Area belongs to the southeastern part of the Adirondack Highlands. The rocks of this area show variations in mineral assemblages which are caused by differences in bulk chemical composition. This makes it unsuccessful to use a subdivision of the granulite facies which is suggested by de Waard (1965).
The CFM diagram (Abbott, 1982) is used to show the relationship between composition and paragenesis of the Lake George Area. In this study, a different result has been found in the order of partitioning of Fe between coexisting minerals, namely, garnet>hornblende>biotite>orthopyroxene>clinopyroxene. The hornblende granitic gneiss …
Evaluation Of Computational Methods Of Paleostress Analysis Using Fault-Striation Data, Steven Henry Schimmrich
Evaluation Of Computational Methods Of Paleostress Analysis Using Fault-Striation Data, Steven Henry Schimmrich
Geology Theses and Dissertations
Over the past 12 years, many different computational methods or variations of existing methods have been proposed for determining paleostress tensors from fault populations and their slip directions. These methods are all based upon well-known relationships between stress and shear and use iterative, non-linear mathematical algorithms which seek to minimize the angles between the calculated maximum shear stress direction and the observed movement directions on each fault plane in a population. The solution returned is the best-fit paleostress tensor for the population.
By taking the Coulomb failure criterion into account, several paleostress analysis programs have been able to use linear, …
The Geology Of Taconic Thrust Sheets And Surrounding Carbonates Of The West Central Vermont Marble Belt, North Of Rutland, Vermont, Kay Bierbrauer
The Geology Of Taconic Thrust Sheets And Surrounding Carbonates Of The West Central Vermont Marble Belt, North Of Rutland, Vermont, Kay Bierbrauer
Geology Theses and Dissertations
The carbonates of the Vermont Valley and the overlying rocks of the Taconic sequence have been generally believed to lie on the east limb of a major unfaulted syncline (Middlebury Synclinorium). In this view a westward dipping, north-south trending basal Taconic overthrust must be exposed somewhere along the eastern margin of the Taconic Range.
In contrast, this study based on detailed mapping at the north end of the Taconic Allochthon suggests that a folded overthrust surface is only locally seen in fensters; more commonly the basal obduction surface of the Taconic Allochthon has been truncated by later cross-cutting thrust faults. …
Geochemistry Of Garnet Xenocrysts And Garnet-Bearing Xenoliths In Ordovician Bentonites, Barbara Bock
Geochemistry Of Garnet Xenocrysts And Garnet-Bearing Xenoliths In Ordovician Bentonites, Barbara Bock
Geology Theses and Dissertations
Within outcrops of the black Utica shales south of the Mohawk Valley narrow re-entrants parallel with stratification are visible, often accompanied -by a marked orange-staining of the underlying strata. These rentrant features indicate the presence of bentonites weathered back faster then the enclosing shales. These bentonites are presumably magmatic ashes related to extensive volcanism when an island arc collided with the North American continent in the late Ordovician about 450 million years ago (Taconic orogeny).
Bentonites are good stratigraphic markers because of the short time-interval they represent and the large area they cover. Therefore they are commonly used as correlation …
Petrology And Major Element Geochemistry Of Basaltic Glasses From The Blanco Trough, Northeast Pacific, Glenn A. Gaetani
Petrology And Major Element Geochemistry Of Basaltic Glasses From The Blanco Trough, Northeast Pacific, Glenn A. Gaetani
Geology Theses and Dissertations
The original electron microprobe analyses of suite of basaltic glasses recovered in 1968 by W.G. Melson and co-workers from the Blanco Trough have extremely unusual characteristics. Their compositions plot in a region of the normative Ol-Di-Pl-SiO2 tetrahedron which suggests that they represent liquids in equilibrium with an upper mantle assemblage of olivine + orthopyroxene at 10-15 kb. Given the present state of controversy surrounding the composition and depth of origin of primary MORB, natural examples of such liquids would be very important. The major element variations observed in the suite imply that the dominant phases are olivine and an iron-aluminum …
Application Of A Trace Element Fractionation Model To Cumulate Gabbroic Xenoliths Of Mauna Kea, Hawaii, Ulrike Eberle
Application Of A Trace Element Fractionation Model To Cumulate Gabbroic Xenoliths Of Mauna Kea, Hawaii, Ulrike Eberle
Geology Theses and Dissertations
A trace element fractionation model originally designed to relate plutonic rocks containing a trapped glass component to a complementary volcanic rock suite was applied to olivine and opaque-oxide gabbroic xenoliths from the summit cone of Mauna Kea, Hawaii.
The mathematical model which is based on the Rayleigh Fractionation Law was extended to include the various phases present in these two groups of gabbros and was generalized to treat multiple trace elements, in this case four. These results were incorporated in a new FORTRAN program using the interval-bisection method to greatly improve the convergence time in the numerical solutions.
Calculated results …
Geology And Structure Of The Rocks Associated With The Basal (Madstone) Thrust Of The Josephine Ophiolite In Southwestern Oregon: Evidence For A Metamorphic Sole, Kristin A. Grady
Geology And Structure Of The Rocks Associated With The Basal (Madstone) Thrust Of The Josephine Ophiolite In Southwestern Oregon: Evidence For A Metamorphic Sole, Kristin A. Grady
Geology Theses and Dissertations
Many ophiolites have amphibolite at their base which contains a sharp inverted grade of metamorphism. These metamorphic soles are thought to have formed during the detachment and emplacement of the ophiolite. In addition to the sharp inverted grade of metamorphism, other characteristics of metamorphic soles include 1). a highly strained peridotite unit of the hanging wall which has concordant structures with underlying amphibolite and 2). an underlying melange sequence and continental rocks.
The Madstone thrust displaces the Josephine peridotite (Josephine ophiolite-162 Ma) onto amphibolites and underlying deformed gabbros of the Chetco Intrusive Complex. The rocks associated with the Madstone thrust …
Origin, Sedimentary Geochemistry, And Correlation Of Middle And Late Ordovician K-Bentonites: Constraints From Melt Inclusions And Zircon Morphology, Carsten Schirnick
Origin, Sedimentary Geochemistry, And Correlation Of Middle And Late Ordovician K-Bentonites: Constraints From Melt Inclusions And Zircon Morphology, Carsten Schirnick
Geology Theses and Dissertations
The present study of Paleozoic K-bentonites demonstrates that the geochemistry of melt inclusions and the morphology of zircons can be studied by inexpensive and simple-to-use methods, which rely on phenocrysts. Constraints are obtained that lead to (a) the origin of these altered volcanic ashes, (b) the geochemistry of ash-to-K-bentonite-alteration, and (c) the reliable correlation of extensively altered volcanic ashes (i.e. K-bentonites).
Silicic melt inclusions (i.e. non-devitrified) have been found in quartz and zircon phenocrysts contained within Ordovician and Devonian K-bentonites from New York State, the Upper Mississippi Valley, and Pennsylvania. Origin, source, and tectonic setting of the volcanism that produced …
Structural Geology Of The Northern Galice Formation, Western Klamath Mountains, Oregon And California, F. Ross Jones
Structural Geology Of The Northern Galice Formation, Western Klamath Mountains, Oregon And California, F. Ross Jones
Geology Theses and Dissertations
The Galice Formation is a thick, turbiditic flysch sequence that depositionally overlies the Josephine ophiolite in the western Klamath Mountains of northwestern California and southwestern Oregon. The Josephine ophiolite and Galice have been interpreted as the basement and sedimentary cover of a Late Jurassic back-arc basin that opened proximal to the continental margin. During the Nevadan orogeny (ca. 151-147 Ma), the ophiolite and overlying Galice sediments were thrust eastward beneath the continental margin along the regional Orleans fault. Two distinct Nevadan deformational phases are recognized in the Galice – an initial D1 or "main-phase" deformation and a later brittle deformation …
Sedimentology, Structure, And Geochemistry Of The Galice Formation: Sediment Fill Of A Back-Arc Basin And Island Arc In The Western Klamath Mountains, Rosann Park-Jones
Sedimentology, Structure, And Geochemistry Of The Galice Formation: Sediment Fill Of A Back-Arc Basin And Island Arc In The Western Klamath Mountains, Rosann Park-Jones
Geology Theses and Dissertations
The western Jurassic belt of the Klamath Mountains is an ideal locale for the study of ophiolite genesis, island arc development, and study of flysch deposition from a nearby eroding island arc and continental margin. Closure and imbrication of an inferred back-arc basin coincided with the Late Jurassic Nevadan orogeny (ca 150 Ma). The Galice Formation is the youngest formation involved in the Nevadan orogeny (Lanphere et al., 1968). In the type section in southwestern Oregon, the Galice structurally overlies the Rogue Formation volcaniclastics. The Rogue Formation has been previously interpreted as an island arc assemblage (Garcia, 1979). The type …
Petrology Of The Kula Volcanic Field, Western Turkey, Julie M. Dyer
Petrology Of The Kula Volcanic Field, Western Turkey, Julie M. Dyer
Geology Theses and Dissertations
The Kula volcanics are a small Pleistocene to Recent volcanic field located on the north shoulder of the Gediz graben, approximately 120 km east of Izmir. The field consists of a mixture of flows, small cones and pyroclastic deposits erupted during three periods of volcanic activity beginning about one million years ago. The volcanics range in composition from basanites to trachybasalts, commonly porphyritic with abundant clinopyroxene, olivine and amphibole phenocrysts. The lavas also host a wide variety of megacrysts, crustal xenoliths and hydrous mantle-derived nodules. These volcanics unconformably overlie Neogene lacustrine sedimentary rocks and the metamorphic basement rocks of the …
Structural Analysis Across The Northeast Boundary Of The Taconic Allochthon, West-Central Vermont, Thomas E. Hoak
Structural Analysis Across The Northeast Boundary Of The Taconic Allochthon, West-Central Vermont, Thomas E. Hoak
Geology Theses and Dissertations
The Taconic Allochthon is an elongate belt of Cambro-Ordovician, argillaceous sediments with lesser occurrences of calcareous and siliceous lithologies. These lithologically distinctive strata lie tectonically juxtaposed over a coeval medial-Ordovician carbonate shelf sequence. This geometry resulted from an arc-continent collision in which a westward-migrating arc (Ammonoosuc Volcanics) collided with an eastern North America passive margin and the accumulated accretionary prism of the forearc region was thrust onto the passive continental margin.
The present thesis examined the structural sequence at the north end of the Allochthon and the continuity of this sequence into the adjacent Parautochthonous Shelf strata. Structurally, the study …
Granitic Pegmatites In The Southeastern Adirondacks: Their Use As Indicators Of Temperature, Pressure, And Fluid Conditions During A Late Stage Of The Grenville Orogeny, John P. Mihalich
Geology Theses and Dissertations
Granitic pegmatites associated with the Grenville orogeny intrude a mid-Proterozoic, upper amphibolite to near granulite facies terrane in the southeastern Adirondack Mountains of New York State. The inferred anatectic, fluid-saturated, and minimum melt characteristics of the pegmatites suggest that they can be used as analogs of the "granite" or "haplogranite" system, and as indicators of crustal temperature, pressure, and fluid conditions during a late stage of the Grenville orogeny. Bulk chemical compositions of seven simple, undeformed pegmatites in the southeastern Adirondacks indicate that they are generally depleted in silica and sodium, and enriched in potassium, relative to experimental data on …
Geology, Geochemistry, And Geochronology Of The Lems Ridge Olistostrome, Klamath Mountains, California, Matthias Ohr
Geology, Geochemistry, And Geochronology Of The Lems Ridge Olistostrome, Klamath Mountains, California, Matthias Ohr
Geology Theses and Dissertations
The Lems Ridge olistostrome (LRO), located within the western Jurassic belt of the Klamath Mountains geologic province, is a melange unit showing a distinct block-in-matrix fabric. The conformable relationship to both an igneous basement and the overlying flysch of the Late Jurassic Galice Formation points to a sedimentary origin. The lack of pervasive deformation and the internal stratification also support a predominantly olistostromal origin of the LRO. The matrix of the LRO consists of pebbly mudstone which interfingers with tuffaceous greenstone and tuff-breccias. Subordinate beds of chert, argillite, and sandstone are also present. The matrix contains abundant ophiolitic clasts, fragments …
The Providence Island Formation In The Northern Appalachian Region - A Lower-Lower Middle Ordovician Analogue To Recent Arid-Semiarid Tidal-Flat Carbonates Of The Persian Gulf Trucial Coast, Mauricio Roma Hernandez
The Providence Island Formation In The Northern Appalachian Region - A Lower-Lower Middle Ordovician Analogue To Recent Arid-Semiarid Tidal-Flat Carbonates Of The Persian Gulf Trucial Coast, Mauricio Roma Hernandez
Geology Theses and Dissertations
The Providence Island Formation of Early-early Middle Ordovician age occurs in the Champlain Valley and adjacent areas in eastern New York, western Vermont, and southern Quebec. The unit forms part of a carbonate shelf sequence which occupied the eastern margin of the North American continent from Newfoundland to Alabama, and its lithology is representative of the dolostone lithofacies that characterizes the uppermost Beekmantown Group in this region.
This is the first study documenting depositional environments, diagenesis, and stratigraphic correlations of the Providence Island Formation. This formation consists, in decreasing abundance, of dolostones, limestones, shales, and dedolostones. The dominantly fine grain …
Geology Of The Northern Baie Verte Peninsula, Newfoundland, Canada, Pamela J. Stella
Geology Of The Northern Baie Verte Peninsula, Newfoundland, Canada, Pamela J. Stella
Geology Theses and Dissertations
On the eastern portion of the Burlington Peninsula of northwest central Newfoundland, Canada, there are two different age groups of volcanic and volcaniclastic rocks. There have been arguments in the past as to whether or not these two groups are actually only one group (Cape St. John Group) but with progressive intensity of deformation and metamorphism from south to north. Other workers have divided the rocks into two distinct groups, the Grand Cove Group and the Cape St. John Group based on their differences in deformation style and metamorphic grade. This study ignored previous divisions of the rocks into one …
Structural Investigations On Experimentally And Naturally Produced Slickensides, Thomas Michael Will
Structural Investigations On Experimentally And Naturally Produced Slickensides, Thomas Michael Will
Geology Theses and Dissertations
This work has involved an experimental approach and a study of naturally produced slickensides.
The experiments, carried out on a pyrophyllitic rock, have been performed in order to define some extrinsic parameters that control surface and microstructural features. Normal stress, speed (i.e. strain rate), and amount of slip and total displacement were related to measureable surface features, such as length, and spacing between the developing ridges and grooves. Special attention was paid to a newly recognized type of slickenside lineation (Means, 1986). This lineation produced experimentally cannot be explained in terms of the traditional asperity ploughing or dissolution/precipitation models. It …
Identification Of Endmembers For Magma Mixing In Little Sitkin Volcano, Alaska, Douglas A. Wolf
Identification Of Endmembers For Magma Mixing In Little Sitkin Volcano, Alaska, Douglas A. Wolf
Geology Theses and Dissertations
Little Sitkin island is an Aleutian calc-alkalic volcanic center that has erupted a suite of lavas ranging from andesite through rhyodacite. Whole-rock chemistry of these lavas indicates contrasting evolutionary processes; major-oxide silica variation diagrams exhibit linear trends that are suggestive of magma-mixing while trace-element trends are largely controlled by accessory-phase fractionation.
Plagioclase, the dominant phenocryst phase in all lavas, commonly occurs in two distinct populations with markedly different compositions and textures. Both normal and reverse zonation is noted in the plagioclase and clinopyroxene of several samples. In addition, clinopyroxene is found as rims on orthopyroxene grains and as cores with …
Dolomitization Of The Hatch Hill Arenites And The Burden Iron Ore, Peter Michael Hofmann
Dolomitization Of The Hatch Hill Arenites And The Burden Iron Ore, Peter Michael Hofmann
Geology Theses and Dissertations
The Taconic allochthon is a sequence of Cambrian or Precambrian to Ordovician rocks. It is composed of predominantly deep water argillaceous and subordinate arenaceous and calcareous rocks that were deposited on the continental rise and slope. During the Ordovician, sediments which were earlier deposited in the slope-rise environment were incorporated into the accretionary prism of an island arc that approached from the east, and subsequently overthrust the carbonate platform.
The Hatch Hill Formation is part of the Taconic sequence. It consists of dominantly black-gray slates, minor amounts of sandstones and carbonates. Previous workers have recognized the presence of dolomite and …
Stratigraphy And Structure Of The Ganson Hill Area: Northern Taconic Allochthon, Michelle Aparisi
Stratigraphy And Structure Of The Ganson Hill Area: Northern Taconic Allochthon, Michelle Aparisi
Geology Theses and Dissertations
The Ganson Hill study area is located in the Giddings Brook Slice of the Taconic Allochthon. It contains rocks of Cambrian(?), Cambrian and Ordovician age. The predominant rock type is slate with subordinate lithologies including quartzite, limestone, micrite, arenite and graywacke. The lithostratigraphy identified in the Ganson Hill area extends from the basal Bomoseen wacke to the Poultney slate. A more precisely defined lithostratigraphy is derived from the study area by the occurrence and recognition of the Middle Granville Slate Formation and the documentation of a second Cambrian black/green boundary. Previous workers have included this formation in different places, in …
Sedimentology And Tectonic Significance Of The Nutzotin Mountains Sequence, Alaska, Jane Kozinski
Sedimentology And Tectonic Significance Of The Nutzotin Mountains Sequence, Alaska, Jane Kozinski
Geology Theses and Dissertations
The Nutzotin Mountains Sequence, a Mesozoic flysch sequence in the eastern Alaska Range, was studied along the southern border and in the central portions of the outcrop belt. Three lithologic associations are recognized in the Bonanza Creek section (southern margin) that together indicate a coarsening-upward trend, suggestive of a prograding fan system. These associations are (from bottom to top): 1) debris flow conglomerates overlain by 500 m of intercalated mudstone and base-missing turbiditic siltstone, and mass movement features such as slump folds and slump horizons, 2) 195 m of thicker, coarser turbidites intercalated with mudstones; turbidites are graded but lack …