DOCSLIB.ORG

Early Diagenetic Origin of Mudrock Concretions from the Hornbrook Formation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Early Diagenetic Origin of Mudrock Concretions from the Hornbrook Formation Early diagenetic origin of mudrock concretions from the Hornbrook Formation (Upper Cretaceous) in Siskiyou County, California: Implications for preservation of primary sedimentary fabrics Michael J. Stephens, William S. Elliott, Jr., Department of Geology and Physics, University of Southern Indiana, 8600 University Blvd., Evansville, Indiana 47712; [email protected] Jad. A. D’Allura, Department of Chemistry, Southern Oregon University, 1250 Siskiyou Blvd., Ashland, Oregon 97520 Abstract Methods Results and Discussion The Hornbrook Formation (Upper Cretaceous) consists of approximately 1,200 m of mudrock, sandstone, and Concretions were collected from several locations within southern Oregon and northern California. Most concretions Figure 15. Geochemical Data Figure 16. Geochemical Data Figure 17. Geochemical Data 22.00 8.50 3.50 conglomerate exposed along the northeastern flank of the Klamath Mountains in southwestern Oregon and northern were collected from the Blue Gulch Mudstone Member of the Hornbrook Formation. Host mudrock samples adjacent to Mudrock Mudrock Mudrock 7.50 3.00 20.00 California. The Hornbrook Formation is subdivided into five members: Klamath River Conglomerate (oldest), the concretions were also collected for geochemical analyses. Field relationships between the concretions and bedding 6.50 2.50 18.00 Osburger Gulch Sandstone, Ditch Creek Siltstone, Rocky Gulch Sandstone, and Blue Gulch Mudstone (youngest). planes were recorded. 5.50 3 2.00 O 2 16.00 4.50 For this study, 20 mudrock concretions were examined from the Blue Gulch Mudstone Member collected near the FeO Mass and volumes of cubed samples of concretions were measured to calculate densities. MgO Al 1.50 3.50 town of Hilt in Siskiyou County, California. 14.00 Concretions Then, dilute hydrochloric acid digestion was used to remove calcite from the samples 1.00 Concretions 2.50 Concretions (Fig. 3). The samples were then centrifuged, decanted, and dried. The mass of the 12.00 In the field, mudrock concretions are spherical- to disk-shaped, 20- to 180-cm in diameter, and are encased in 1.50 0.50 siliciclastic mudrock. The concretions are oriented with the long axes parallel to bedding, and occur as isolated bodies remaining sediments were measured and then subtracted from the original amount. 10.00 0.50 0.00 63.00 65.00 67.00 69.00 71.00 73.00 75.00 77.00 79.00 62.00 64.00 66.00 68.00 70.00 72.00 74.00 76.00 78.00 80.00 62.00 64.00 66.00 68.00 70.00 72.00 74.00 76.00 78.00 80.00 and/or bands within mudrock intervals. In several instances, thin (2 to 4 cm) sandstone beds in close stratigraphic Calcite weight percentages were then calculated. SiO2 SiO2 SiO2 proximity wrap around and drape mudrock concretions. Several concretions contain vertical fractures filled with The samples were analyzed using X-Ray Fluorescence Spectroscopy and the geochemical Figure 3. Samples digested by dilute hydrochloric acid to Figures 15. 16. and 17. Geochemical data (Al O vs. SiO , FeO vs. SiO , MgO vs. SiO ) for concretions and nearby mudrock calcite that produce a brecciated fabric. In the laboratory, concretions contain 65 to 75 wt. % calcite as determined by data were obtained for mudrock and concretion samples. This allowed for comparison of 2 3 2 2 2 dilute hydrochloric acid digestion; mudrocks encasing the concretions are not calcareous. Preliminary geochemical determine the amount of calcite sediments from the Hornbrook Formation. the geochemistry of the concretions and surrounding mudrocks. in concretions. analyses of the siliciclastic sediment from the concretions by X-ray fluorescence spectroscopy yielded 72.7 to 78.0 wt. % SiO2, 12.8 to 15.8 wt. % Al2O3, 0.6 to 1.0 wt. % MgO, and 1.7 to 3.8 wt. % FeO compared to encasing mudrocks The mudrock concretions in the Hornbrook are interpreted to have formed in an early diagenetic environment. Concretions in the Hornbrook are found oriented along bedding with values of 63.5 to 64.9 wt. % SiO2, 18.5 to 19.4 wt. % Al2O3, 2.6 to 3.0 wt. % MgO, and 6.3 to 7.6 wt. % FeO. Hand Samples There were no distinguishable differences for TiO2, MnO, CaO, Na2O, K2O, and P2O5. planes, and in several instances, sandstone beds in close vertical stratigraphic proximity Overall, the mudrock concretions in the Hornbrook are interpreted to have formed in an early diagenetic environment, Figure 4. Hand sample of Figure 5. Concretion are contorted (Fig. 18). Moreover, mudrock concretions contain vertical fractures filled concretion with vertical with lamination and as evidenced by contorted bedding and fractures resulting from differential compaction associated with burial after with calcite creating a brecciated fabric (Fig. 4). These fractures have been interpreted to fractures. Note the fractures discrete bioturbation have formed during compaction. their formation. Additionally, early diagenetic formation of the concretions resulted in differing chemical are concentrated near the along bedding planes. transformations of the encasing mudrock. Finally, the early diagenetic origin of these concretions may preferentially center of the concretion. Also Note the weathering The mudrock concretions found in the Hornbrook contain different geochemistry preserve primary sedimentary fabrics and textures that would otherwise be obliterated by compaction. note the presence of burrows. near the top of the than the surrounding mudrock. Preliminary geochemical analyses of the siliciclastic concretion. 2 cm 2 cm sediment from the concretions by X-Ray Fluorescence Spectroscopy yielded 72.7 to Introduction 78.0 wt. % SiO2, 12.8 to 15.8 wt. % Al2O3, 0.6 to 1.0 wt. % MgO, and 1.7 to 3.8 wt. % FeO compared to encasing mudrocks with values of 63.5 to 64.9 wt. % SiO2, The Hornbrook Formation is a 1,200 m thick deposit of Upper Cretaceous conglomerate, sandstone, and mudrock 18.5 to 19.4 wt. % Al2O3, 2.6 to 3.0 wt. % MgO, and 6.3 to 7.6 wt. % FeO. exposed along the northeastern flank of the Klamath Mountains in southwestern Oregon and northern California (Fig. There were no distinguishable differences for TiO2, MnO, CaO, Na2O, K2O, and P2O5. Chlorite, Figure 18. Mudrock 1). The Hornbrook Formation is interpreted to represent a marine transgression and nonconformably overlies igneous for example, is a mineral associated with diagenesis and is composed of Mg, Fe, Al, and Si. Most concretion with sandstone and metamorphic rocks of the Klamath Mountains. Locally, the Hornbrook is disconformably overlain by the Eocene Figure 6. Mudrock concretion 2 cm of these oxides are enriched within the mudrock further suggesting that the concretions form beds draped around it. Payne Cliffs Formation and the Oligocene Colestin Formation of the Western Cascade Group (Fig. 2). containing fractures and Figure 7. Concretion that is being cut by a early and are not as subjected to geochemical transformations as the surrounding mudrock during 2 cm The Blue Gulch Mudstone Member of the Hornbrook Formation (Upper Cretaceous) is composed of dark gray to burrows. sandstone dike. The formation of the concretion diagenesis. occurs after the intrusion of this sand. greenish gray, silty mudrock. It is interbedded with claystone and sparse thin-to-medium bedded, planar stratified, Concretions provide preferential preservation compared to host rock and contain original fabrics. For example, some of the very fine-grained sandstones with various convoluted bedding and scour features (e.g. flute casts). Within mudrock Thin Sections concretions studied show laminations, intact fossils (e.g. gastropod shells), and bioturbation (see hand sample and thin sections intervals, there are several discrete bands of oblate to spherical concretions that range in size from 20 to 180 cm in images). If not for the preferential preservation of the relatively hard concretions, these features would have been obliterated by diameter. Concretions are hard, spherical to ellipsoidal features that form by the precipitation of mineral cement compaction and diagenesis. within the pore space of existing sediment. The concretions are calcite-cemented and encased by mudrock. These features along with field relationships were analyzed to help determine timing of their formation and any differences Mudrock concretions from the Hornbrook were found to be 65 to 75 wt. % calcite. This high percentage of calcite is probably in geochemical variation from their encasing mudrocks. due to the early cementation of the concretions, preserving the original porosity of the sediment. Thus, initial porosity of these muddy sediments may have been 60 to 70 percent. GENERALIZED GEOLOGIC MAP OF THE STUDY AREA GENERALIZED STRATIGRAPHIC COLUMN X X X X X o o o W123 5 W123 45’ W123 30’ Western Cascades (Paleogene) X X X X X e Colestin Fm. n Western e g Conclusions Medford Hornbrook Formation Acknowledgements (Late Cretaceous) X X X X X X X Cascades o e l X X Payne Cliffs Fm. a o X X Diorite & granodiorite plutons N42 15’ X X (Late Jurassic) P Condrey Mountain Terrane • Mudrock concretions in the Hornbrook are interpreted to have We would like to thank Endeavor and the X Ashland (Late Jurassic) X Rattlesnake Creek Terrane X X Figure 8. Sandstone dike Figure 9. Bioturbation Figure 10. Possible algae Figure 11. Bioturbation cross- Provost Programming Grant at USI for funding X X (Late Triassic to Early Jurassic) formed in an early diagenetic environment, as evidenced by X X X X X Hayfork & Applegate Terranes s n through concretion. Mt Ashland (Permian to Early Jurassic) Blue Gulch u patterns in concretion. preserved in concretion. cutting lamination. o X o student travel to GSA, and the Science, X X X i t X Pluton Central Metamorphic Belt Mudstone e contorted bedding and fractures resulting from differential a Hilt Bed c X X (Devonian) a t X X 5 m r e Engineering, and Education Research Award of X X r o OREGON o C N42 X F compaction associated with burial after their formation.
Load more

Recommended publications
  • Lacustrine Massive Mudrock in the Eocene Jiyang Depression, Bohai Bay Basin, China: Nature, Origin and Significance
    Marine and Petroleum Geology 77 (2016) 1042e1055 Contents lists available at ScienceDirect Marine and Petroleum Geology journal homepage: www.elsevier.com/locate/marpetgeo Research paper Lacustrine massive mudrock in the Eocene Jiyang Depression, Bohai Bay Basin, China: Nature, origin and significance * Jianguo Zhang a, b, Zaixing Jiang a, b, , Chao Liang c, Jing Wu d, Benzhong Xian e, f, Qing Li e, f a College of Energy, China University of Geosciences, Beijing 100083, China b Institute of Earth Science, China University of Geosciences, Beijing 100083, China c School of Geosciences, China University of Petroleum (east China), Qingdao 266580, China d Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 100083, China e College of Geosciences, China University of Petroleum, Beijing 102249, China f State Key Laboratory of Petroleum Resources and Prospecting, Beijing 102249, China article info abstract Article history: Massive mudrock refers to mudrock with internally homogeneous characteristics and an absence of Received 13 May 2016 laminae. Previous studies were primarily conducted in the marine environment, while notably few Accepted 6 August 2016 studies have investigated lacustrine massive mudrock. Based on core observation in the lacustrine Available online 8 August 2016 environment of the Jiyang Depression, Bohai Bay Basin, China, massive mudrock is a common deep water fine-grained sedimentary rock. There are two types of massive mudrock. Both types are sharply delin- Keywords: eated at the bottom and top contacts, abundant in angular terrigenous debris, and associated with Massive mudrock oxygen-rich (higher than 2 ml O /L H O) but lower water salinities in comparison to adjacent black Muddy mass transportation deposit 2 2 Turbiditic mudrock shales.
    [Show full text]
  • Colorado Plateau Coring Project, Phase I (CPCP-I)
    Science Reports Sci. Dril., 24, 15–40, 2018 https://doi.org/10.5194/sd-24-15-2018 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. Colorado Plateau Coring Project, Phase I (CPCP-I): a continuously cored, globally exportable chronology of Triassic continental environmental change from western North America Paul E. Olsen1, John W. Geissman2, Dennis V. Kent3,1, George E. Gehrels4, Roland Mundil5, Randall B. Irmis6, Christopher Lepre1,3, Cornelia Rasmussen6, Dominique Giesler4, William G. Parker7, Natalia Zakharova8,1, Wolfram M. Kürschner9, Charlotte Miller10, Viktoria Baranyi9, Morgan F. Schaller11, Jessica H. Whiteside12, Douglas Schnurrenberger13, Anders Noren13, Kristina Brady Shannon13, Ryan O’Grady13, Matthew W. Colbert14, Jessie Maisano14, David Edey14, Sean T. Kinney1, Roberto Molina-Garza15, Gerhard H. Bachman16, Jingeng Sha17, and the CPCD team* 1Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA 2Department of Geosciences, University of Texas at Dallas, Richardson, TX 75080, USA 3Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA 4Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA 5Berkeley Geochronology Center, 2455 Ridge Rd., Berkeley CA 94709, USA 6Natural History Museum of Utah and Department of Geology & Geophysics, University of Utah, Salt Lake City, UT 84108, USA 7Petrified Forest National Park, Petrified Forest, AZ 86028, USA 8Department of Earth and Atmospheric Sciences, Central Michigan University, Mount Pleasant, MI 48859, USA 9Department of Geosciences, University of Oslo, P.O. Box 1047, Blindern, Oslo 0316, Norway 10MARUM Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany 11Earth and Environmental Sciences, Rensselaer Polytechnic Institute (RPI), Troy, NY 12180, USA 12National Oceanography Centre, Southampton, University of Southampton, Southampton, SO17 1BJ, UK 13Continental Scientific Drilling Coordination Office and LacCore Facility, N.H.
    [Show full text]
  • Slate Shale/Mudrock Regional 060(240)±20/70±10SE 020(200)±20/20±10NW No 060(240)±20/70±10SE 120(300)±20/20±10SW Yes No Q
    Name: Reg. lab day: M Tu W Th F Geology 1013 Field trip to Black River Valley (Lab #7, Answer Key) Drive south on Gaspereau Avenue and stop at the Highway 101 overpass. Stop 1: HALIFAX GROUP A: Go to the north side of the overpass. slate a) Name the rock exposed in this outcrop. b) What was the original rock before metamorphism? Shale/mudrock c) Was the metamorphism regional or contact? regional d) Use the compass to measure strike & dip of cleavage. 060(240)±20/70±10SE e) Use the compass to measure strike & dip of bedding. 020(200)±20/20±10NW f) Is cleavage parallel to bedding? no g) Plot cleavage and bedding on the attached map using the proper symbols. B: Go to the south side of the overpass. 060(240)±20/70±10SE a) Use the compass to measure strike & dip of cleavage. 120(300)±20/20±10SW b) Use the compass to measure strike & dip of bedding. c) Is the cleavage orientation similar to that in (d) above? yes d) Is the bedding orientation similar to that in (e) above? no Drive on through Gaspereau to White Rock. Go through the intersection in White Rock and stop in the big quarry on the right. Stop 2: WHITE ROCK FORMATION quartzite a) Name the rock. quartz sandstone b) What was the original rock before metamorphism? c) This rock unit is more resistant to weathering than the Halifax Formation. Suggest reasons why. 1. composition (hard, chemically inert mineral) 2. no foliation (no planes of weakness) Black River Lab – Answer Key Page 2 of 4 Drive back through White Rock, turn south, and stop at the parking area at the Gaspereau River bridge.
    [Show full text]
  • Clippety Clop), Kwelera, East London, Great Kei Municipality, Eastern Cape
    PALAEONTOLOGICAL ASSESSMENT: COMBINED FIELD ASSESSMENT AND DESKTOP STUDY Proposed development of Portion 3 of Farm 695 (Clippety Clop), Kwelera, East London, Great Kei Municipality, Eastern Cape. JOHN E. ALMOND (PhD, Cantab) Natura Viva cc, PO Box 12410 Mill Street, CAPE TOWN 8010, RSA. [email protected] October 2011 1. SUMMARY The proposed holiday housing development on Portion 3 of Farm 695 (Clippety Clop), Kwelera, East London, is situated on the northern banks of the tidal Kwelera River, some 20 km northeast of East London, Eastern Cape. The development footprint is largely underlain by Late Permian continental sediments of the Adelaide Subgroup (Lower Beaufort Group, c. 253-251 million years old). These rocks are overlain by Early Triassic sandstones of the Katberg Formation (Tarkastad Subgroup) that build the cliffs and higher ground to the northeast. South of the river the Beaufort Group sediments are intruded and baked by Early Jurassic igneous intrusions of the Karoo Dolerite Suite. The Balfour Formation fluvial sediments are potentially fossiliferous, having yielded elsewhere a wide range of terrestrial vertebrates (bones and teeth of pareiasaurs, therapsids, amphibians et al.), bivalves, trace fossils and vascular plants. The overall impact of this project on local palaeontological heritage is likely to be very minor, however, because the potentially fossiliferous Beaufort Group sediments here are (a) deeply weathered, (b) sparsely fossiliferous, (c) have probably been extensively baked by nearby dolerite intrusions, and (d) are mostly covered with a thick (> 3m) mantle of fossil-poor alluvium. No fossils were observed within good exposures of the Balfour Formation rocks at the coast and in excellent roadcuts inland.
    [Show full text]
  • Metamorphic Rocks Specimen Guide
    Metamorphic Rocks Specimen Guide Number Name Information 1 Chlorite schist Chlorite is a green-coloured mica. Schist is a medium grade metamorphic rock which includes 50% mica. It is crumbly due to weathering. The brown patches are iron oxide, probably from weathered-out garnets. 2 Hydrothermally Very hot waters associated with a later phase of altered granite magmatic intrusions has altered some of the feldspars and micas to clay minerals. This specimen also contains cassiterite (tin ore.) From Cornwall. 3 Gneiss A folded and banded rock, evidence of regional metamorphism due to mountain building. Less stretched than a schist. 4 Slate Slate is often formed from mudrock or volcanic ash deposits which have been heated and compressed. This slate clearly shows stripes that are the bedding of the original rock at 90o to the new slaty cleavage (planes along which rock will split) 5 Garnet gneiss This is the oldest rock found in the British Isles, c. 3.8 billion years old, from Scourie in N.W. Scotland. Garnets form only in metamorphic rocks. 6 Marble This rock is highly metamorphosed limestone. The original rock has been completely recrystallised though the composition has remained the same. 7 Metamorphosed This was an igneous rock that originally formed during pillow lava an underwater volcanic eruption during the Devonian. Granite later intruded into the rock and cooked the rock, and introduced some new metamorphic minerals during this process. In Cornwall rocks that have been changed by the intrusions of granite are called “killas”. 8 Contorted gneiss This folded gneiss shows clear bands of stretched minerals, including shiny mica and pale grey quartz.
    [Show full text]
  • International Journal of Coal Geology 165 (2016) 76–89
    International Journal of Coal Geology 165 (2016) 76–89 Contents lists available at ScienceDirect International Journal of Coal Geology journal homepage: www.elsevier.com/locate/ijcoalgeo Microstructures of Early Jurassic (Toarcian) shales of Northern Europe M.E. Houben a,⁎,A.Barnhoornb, L. Wasch c, J. Trabucho-Alexandre a,C.J.Peacha,M.R.Drurya a Faculty of Geosciences, Utrecht University, PO-box 80.021, 3508TA Utrecht, The Netherlands b Faculty of Civil Engineering & Geosciences, Delft University of Technology, PO-box 5048, 2600GA Delft, The Netherlands c TNO, Princetonlaan 6, 3584 CB Utrecht, The Netherlands article info abstract Article history: The Toarcian (Early Jurassic) Posidonia Shale Formation is a possible unconventional gas source in Northern Received 7 January 2016 Europe and occurs within the Cleveland Basin (United Kingdom), the Anglo-Paris Basin (France), the Lower Sax- Received in revised form 4 August 2016 ony Basin and the Southwest Germany Basin (Germany), and the Roer Valley Graben, the West Netherlands Accepted 4 August 2016 Basin, Broad Fourteens Basin, the Central Netherlands Basin and the Dutch Central Graben in The Netherlands. Available online 06 August 2016 Outcrops can be found in the United Kingdom and Germany. Since the Posidonia Shale Formation does not out- crop in the Netherlands, sample material suitable for experimental studies is not easily available. Here we have Keywords: Posidonia Shale investigated lateral equivalent shale samples from six different locations across Northern Europe (Germany, Whitby Mudstone The Netherlands, The North sea and United Kingdom) to compare the microstructure and composition of Clay microstructure Toarcian shales. The objective is to determine how homogeneous or heterogeneous the shale deposits are across Ion-beam polishing the basins, using a combination of Ion Beam polishing, Scanning Electron Microscopy and X-ray diffraction.
    [Show full text]
  • Rehabilitation of National Route R61 (Section 3, Km 24.2 to Km 75) Between Cradock and Tarkastad, Eastern Cape
    PALAEONTOLOGICAL HERITAGE STUDY: COMBINED DESKTOP AND FIELD-BASED ASSESSMENT Rehabilitation of National Route R61 (Section 3, km 24.2 to km 75) between Cradock and Tarkastad, Eastern Cape John E. Almond PhD (Cantab.) Natura Viva cc, PO Box 12410 Mill Street, Cape Town 8010, RSA [email protected] February 2013 1. SUMMARY The South African National Roads Agency Limited (SANRAL) is proposing to rehabilitate Section 3 of the National Route R61 (km 24.2 to km 75) between Cradock and Tarkastad, Eastern Cape. The project involves widening of the roadway and of all stormwater structures along the route. Road material is to be sourced from five new or existing borrow pits and one hard rock quarry. A Phase 1 palaeontological heritage assessment for the road project has been commissioned by Arcus GIBB (Pty) Ltd in accordance with the requirements of the National Heritage Resources Act (Act 25 of 1999). Section 3 of the R61 traverses the outcrop area of continental sedimentary rocks of the Upper Beaufort Group (Tarkastad Subgroup, Karoo Supergroup) of Early to Middle Triassic age. These are cut and baked by numerous dolerite intrusions of the Karoo Dolerite Suite of Early Jurassic age. Towards Cradock (Graaff-Reinet and Middelburg 1: 250 000 sheet areas) the sedimentary bedrocks belong to the sandstone-dominated Katberg Formation that was deposited in arid braided fluvial settings following the catastrophic end-Permian mass extinction event. Further east towards Tarkastad (Queenstown and King William’s Town 1: 250 000 sheet areas) the sedimentary bedrocks are assigned to the slightly younger Burgersdorp Formation comprising recessive-weathering reddish mudrocks and braided river channel sandstones.
    [Show full text]
  • Aluminosilicate Diagenesis in a Tertiary Sandstone-Mudrock Sequence from the Central North Sea, Uk
    Clay Minerals (1996) 31, 523–536 ALUMINOSILICATE DIAGENESIS IN A TERTIARY SANDSTONE-MUDROCK SEQUENCE FROM THE CENTRAL NORTH SEA, UK J. M. HUGGETT Department of Geology, Imperial College of Science, Technology and Medicine, London, SW7 2BP, UK (Received 24 November 1995; revised 20 March 1996) ABSTRACT: Mudrocks and sandstones from the Palaeocene of the central North Sea have been studied to assess the petrology, diagenesis and extent of any chemical interaction between the two lithologies. Authigenicand detrital minerals have been distinguished using a variety of electron microscope techniques. Small but significant quantities of authigenic minerals, which would not be detected by conventional petrographic tools, have been detected through the use of high-resolution electron beam techniques. Sandstone mineralogy has been quantified by point counting, and mudrock mineralogy semi-quantified by XRD. The detrital and authigenicmineralogy in the sandstone is almost identical to that found in the mudrock. The principal difference is in the relative proportions. Qualitative mass balance suggests that cross-formational flow has not been significant in either clay or quartz diagenesis. Researchers attempting to quantify the diagenetic SAMPLE MATERIAL relationship between mudrocks and sandstones have concluded that mudrocks act as closed The sampled interval is a cored Palaeocene systems (e.g. Hower et al., 1976; Pearson & sandstone dominated sequence from a well in the Small, 1988; Totten & Blatt, 1993) or that UK sector of the central North Sea. The overall reactants move freely between the two lithologies ratio of sandstone to mudrock is high, *84%, and (e.g. Curtis, 1978; Boles & Franks, 1979; individual mudrock beds average *0.3 m thick.
    [Show full text]
  • The Impact of Coastal Geodynamic Processes on the Distribution of Trace Metal Content in Sandy Beach Sediments, South-Eastern Baltic Sea Coast (Lithuania)
    applied sciences Article The Impact of Coastal Geodynamic Processes on the Distribution of Trace Metal Content in Sandy Beach Sediments, South-Eastern Baltic Sea Coast (Lithuania) Dovile˙ Karloniene˙ 1,*, Donatas Pupienis 1,2 , Darius Jarmalaviˇcius 2, Aira Dubikaltiniene˙ 1 and Gintautas Žilinskas 2 1 Faculty of Chemistry and Geosciences, Naugarduko st. 24, LT 03225 Vilnius, Lithuania; [email protected] (D.P.); [email protected] (A.D.) 2 Nature Research Centre, Akademijos st. 2, LT 08412 Vilnius, Lithuania; [email protected] (D.J.); [email protected] (G.Ž.) * Correspondence: [email protected] Featured Application: Geochemical analysis can provide valuable information about the local and regional patterns of sediment transport, distribution, provenance, and coasts’ conditions. Abstract: Sandy coasts are one of the most dynamic spheres; continuously changing due to natural processes (severe weather and rising water levels) and human activities (coastal protection or port construction). Coastal geodynamic processes lead to beach sediment erosion or accumulation. The coast’s dynamic tendencies determine the changes in the volume of beach sediments; grain size; mineralogical; and geochemical composition of sediments. In addition to lithological and mineralogical analysis of sediments, geochemical analysis can provide valuable information about Citation: Karloniene,˙ D.; Pupienis, the local and regional patterns of sediment transport, distribution, provenance, and coasts’ conditions. D.; Jarmalaviˇcius,D.; Dubikaltiniene,˙ The study aims to assess trace metals’ temporal and spatial distribution determined in the sandy beach A.; Žilinskas, G. The Impact of sediments along the south-eastern Baltic Sea coast (Lithuania) during 2011–2018. The Lithuanian Coastal Geodynamic Processes on the seacoast is divided into two parts: mainland and spit coast.
    [Show full text]
  • Stratigraphic Completeness and Resolution in an Ancient Mudrock Succession
    Sedimentology (2018) 65, 1875–1890 doi: 10.1111/sed.12450 Stratigraphic completeness and resolution in an ancient mudrock succession DAVID B. KEMP*, WESLEY T. FRASER† and KENTARO IZUMI‡ *School of Geosciences, University of Aberdeen, Old Aberdeen, Aberdeen AB24 3UE, UK (E-mail: [email protected]) †Geography, Department of Social Sciences, Oxford Brookes University, Oxford OX3 0BP, UK ‡Faculty and Graduate School of Education, Chiba University, 1-33 Yoyoi-cho, Image-ku, Chiba-shi, Chiba 263-8522, Japan Associate Editor – Vern Manville ABSTRACT Mudrocks are the most common rock type at the Earth’s surface, and they play a major role in informing current understanding of the palaeoenviron- mental history of the planet. Their suitability for this purpose is at least partly underpinned by the assumed stratigraphic completeness of mudrock successions, and the ostensible fidelity with which they record temporal changes in palaeoenvironment. Mud does not necessarily accumulate, how- ever, as a steady, near-continuous ‘rain’ under low energy conditions. Advective modes of mud transport and episodic, ephemeral accumulation have been shown to dominate in many ancient successions. This has impli- cations for the completeness of these records and their suitability for high- resolution sampling and analysis. In this study, a numerical model of mud accumulation, parameterized with data from the Lower Jurassic of Yorkshire (UK) is presented to explore completeness and resolution constraints on ancient epicontinental mudrock successions. Using this model, stratigraphic completeness of the analysed Yorkshire succession is estimated to be ca 13% and ca 98% at centennial and millennial timescales, respectively. The findings indicate that sub-millennial scale processes and events are unlikely to be accurately resolved, despite the largely unbioturbated and well- laminated nature of the succession.
    [Show full text]
  • Mesa Verde National Park Paleontological Resource Inventory (Non-Sensitive Version)
    National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science Mesa Verde National Park Paleontological Resource Inventory (Non-Sensitive Version) Natural Resource Report NPS/MEVE/NRR—2017/1550 ON THE COVER An undescribed chimaera (ratfish) egg capsule of the ichnogenus Chimaerotheca found in the Cliff House Sandstone of Mesa Verde National Park during the work that led to the production of this report. Photograph by: G. William M. Harrison/NPS Photo (Geoscientists-in-the-Parks Intern) Mesa Verde National Park Paleontological Resources Inventory (Non-Sensitive Version) Natural Resource Report NPS/MEVE/NRR—2017/1550 G. William M. Harrison,1 Justin S. Tweet,2 Vincent L. Santucci,3 and George L. San Miguel4 1National Park Service Geoscientists-in-the-Park Program 2788 Ault Park Avenue Cincinnati, Ohio 45208 2National Park Service 9149 79th St. S. Cottage Grove, Minnesota 55016 3National Park Service Geologic Resources Division 1849 “C” Street, NW Washington, D.C. 20240 4National Park Service Mesa Verde National Park PO Box 8 Mesa Verde CO 81330 November 2017 U.S. Department of the Interior National Park Service Natural Resource Stewardship and Science Fort Collins, Colorado The National Park Service, Natural Resource Stewardship and Science office in Fort Collins, Colorado, publishes a range of reports that address natural resource topics. These reports are of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate comprehensive information and analysis about natural resources and related topics concerning lands managed by the National Park Service.
    [Show full text]
  • Structural Styles of the Niobrara Formation: a Study of Kansas and Colorado Outcrops Using an Unmanned Aerial Vehicle (Uav)
    STRUCTURAL STYLES OF THE NIOBRARA FORMATION: A STUDY OF KANSAS AND COLORADO OUTCROPS USING AN UNMANNED AERIAL VEHICLE (UAV) by Caleb H. Garbus A thesis submitted to the Faculty and the Board of Trustees of the Colorado School of Mines in partial fulfillment of the requirements for the degree of Master of Science (Geology). Golden, Colorado Date Signed: Caleb H. Garbus Signed: Dr. Stephen A. Sonnenberg Thesis Advisor Golden, Colorado Date Signed: Dr. M. Stephen Enders Interim Department Head Department of Geology and Geological Engineering ii ABSTRACT The Late Cretaceous Niobrara Formation is a productive unconventional hydrocarbon system throughout the Denver Basin. Alternating chalk and marl units of the Smoky Hill Member act as a source, reservoir, and seal for the Niobrara petroleum system. The Niobrara has attracted attention from operators after advances in drilling and production technologies have made Niobrara oil and gas economic. The focus of this study aims at achieving a complete understanding of fracture types, fault characteristics, and fault systems in Niobrara outcrop using modern technology. Outcrop analysis across western Kansas indicates the presence of a polygonal fault system (PFS) within the Niobrara. Unmanned aerial vehicle (UAV) data was collected, developed into 3D models, and interpreted to identify fault and joint orientations, geometries, and re- lations across the study area. Polygonal and structurally-reactivated faults were observed in outcrop. Non-tectonic polygonal faults display random orientations, dip-slip normal faults, are characteristically layer-bound, and are unaffected by geomechanical variation. Limited outcrop and exposure bias result in a general SE-NW trend for polygonal strike orienta- tions; however, increased data and hangingwall slip directions confirms the presence of a non-tectonic fault system at Castle Rock, Kansas.
    [Show full text]