scholarly journals LATE CRETACEOUS STRATIGRAPHY OF THE SOUTHEASTERN CHACO - PARANÁ BASIN (“NORTE BASIN” - URUGUAY): THE MAASTRICHTIAN AGE OF THE CALCRETIZATION PROCESS

2019 ◽  
Vol 38 (2) ◽  
pp. 427-449 ◽  
Author(s):  
Gerardo VEROSLAVSKY ◽  
Natalie AUBET ◽  
Sergio A. MARTÍNEZ ◽  
Larry M. HEAMAN ◽  
Fernanda CABRERA ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Sedimentary Rocks ◽  
Field Work ◽  
Geological Mapping ◽  
Practical Usefulness ◽  
Evolutionary Scheme ◽  
Calcite Cement ◽  
Absolute Age ◽  
Siliciclastic Rocks ◽  
Epigenetic Processes

In the last 40 years, successive revisions have been introduced to the lithostratigraphy of the Late Cretaceous of the Norte Basin, whose record is formed by predominantly siliciclastic continental fossiliferous sedimentary rocks. A factor that contributed to the terminology proliferation was the misplaced importance attributed to the epigenetic processes and products (calcretes and ferricretes, occasionally fossiliferous) affecting those siliciclastic rocks. Based on field work and lithological logs from a number of key areas, the validity of the original stratigraphic column showing, from base to top, the Guichón, Mercedes, Asencio and Queguay formations is supported. For those particular units, the lithostratigraphic scope given by the original definitions is correct and, with minimum adjustments, they should be restored for their practical usefulness as geological mapping units. An evolutionary scheme for the Late Cretaceous of the Norte Basin is herein presented, with the aim of contributing to a greater understanding of the succession of sedimentary and epigenetic processes. A Maastrichtian age is proposed for the carbonatic cementation and/or substitution that affected the Mercedes and Asencio formations, thus originating the Queguay Formation, based on absolute age of the calcite cement (~ 72 Ma; U-Pb), paleontological data, and the correlation established with similar events recorded in the Marília Formation on the Bauru Basin (Brazil).

scholarly journals Upper Cretaceous lithostratigraphy of the Panagyurishte strip (Central Bulgaria) – part of the Late Cretaceous Apuseni-BanatTimok-Srednogorie magmatic belt

2019 ◽  
Vol 48 (3) ◽  
pp. 11-33
Author(s):  
Dian Vangelov ◽  
Ianko Gerdjikov ◽  
Docho Dochev ◽  
Zornitsa Dotseva ◽  
Stefan Velev ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
Sedimentary Rocks ◽  
Field Work ◽  
Mineral Deposits ◽  
Published Data ◽  
Practical Application ◽  
Layer Cake ◽  
Stratigraphic Model ◽  
Extinction Event

The investigations of the Upper Cretaceous Panagyurishte and Chelopech volcano-sedimentary strips of the Central Srednogorie tectonic subzone date back to the end of 19th and became more intensive during the middle of the 20th century, mainly due to the discovery of important mineral deposits in the area. Our field work during the last 15 years and analysis of previously published data show that the existing lithostratigraphic scheme does not cover the entire spectrum of lithologies, successions and interrelations in both strips. This study deals with four stratigraphic sections, along the valleys of the Topolnitsa, Kamenitsa and Mirkovska rivers, and their correlation on the basis of the Turonian/Coniacian boundary, local extinction event and palaeontological data that demonstrate the unreliability of already existing schemes. The previously used “layer-cake” stratigraphic model does not reflect the diachronism of the studied units or the existence of subaerial volcano craters, together with synchronous deposits. In this paper, we also propose a subdivision of the intervals containing magmatic and sedimentary rocks into individual members, including non-layered magmatic centres, stratified lava flow and volcanoclastic flow deposits and stratified epiclastic deposits of mainly turbiditic origin, instead of the currently used Chelopech Formation. The presented herein new data do not cover entirely the wide palette of problems with the lithostratigraphy of the area, but clearly demonstrate the necessity of its revision, especially for practical application and better understanding of the Late Cretaceous evolution of the area.

Petrography and provenance of the Marambio Group, Vega Island, Antarctica

1994 ◽  
Vol 6 (4) ◽  
pp. 517-527 ◽  
Author(s):  
Duncan Pirrie
Keyword(s):  
Late Cretaceous ◽  
Sedimentary Rocks ◽  
Clay Mineralogy ◽  
Minor Component ◽  
Source Area ◽  
Low Grade ◽  
Western Margin ◽  
Sediment Input ◽  
A Minor ◽  
Sandstone Petrography

Late Cretaceous sedimentary rocks assigned to the Santa Marta (Herbert Sound Member) and López de Bertodano (Cape Lamb and Sandwich Bluff members) formations of the Marambio Group, crop out on Cape Lamb, Vega Island. Although previous studies have recognized that these sedimentary rocks were derived from the northern Antarctic Peninsula region, the work presented here allows the provenance and palaeogeographical evolution of the region to be described in detail. On the basis of both sandstone petrography and clay mineralogy, the Herbert Sound and Cape Lamb members reflect sediment input from a low relief source area, with sand grade sediment sourced from low grade metasediments, and clay grade sediment ultimately derived from the weathering of an andesitic source area. In contrast, the Sandwich Bluff Member reflects a switch to a predominantly andesitic volcaniclastic source. However, this sediment was largely derived from older volcanic suites due to renewed source area uplift, with only a minor component from coeval volcanism. Regional uplift of both the arc terrane and the western margin of the James Ross Basin was likely during the Maastrichtian.

scholarly journals The firstCaipirasuchus(Mesoeucrocodylia, Notosuchia) from the Late Cretaceous of Minas Gerais, Brazil: new insights on sphagesaurid anatomy and taxonomy

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5594 ◽  
Author(s):  
Agustín G. Martinelli ◽  
Thiago S. Marinho ◽  
Fabiano V. Iori ◽  
Luiz Carlos B. Ribeiro
Keyword(s):  
New Species ◽  
Late Cretaceous ◽  
Field Work ◽  
Lower Portion ◽  
Main Subject ◽  
Vertebrate Fauna ◽  
Paulo State ◽  
New Material ◽  
Fish Remains ◽  
A New Species

Field work conducted by the staff of the Centro de Pesquisas Paleontológicas Llewellyn Ivor Price of the Universidade Federal do Triângulo Mineiro since 2009 at Campina Verde municipality (MG) have resulted in the discovery of a diverse vertebrate fauna from the Adamantina Formation (Bauru Basin). The baurusuchidCampinasuchus diniziwas described in 2011 from Fazenda Três Antas site and after that, preliminary descriptions of a partial crocodyliform egg, abelisaurid teeth, and fish remains have been done. Recently, the fossil sample has been considerably increased including the discovery of several, partially articulated fish remains referred to Lepisosteiformes and an almost complete and articulated skeleton referred to a new species ofCaipirasuchus(Notosuchia, Sphagesauridae), which is the main subject of this contribution. At present, this genus was restricted to the Adamantina Formation cropping out in São Paulo state, with the speciesCaipirasuchus montealtensis,Caipirasuchus paulistanus, andCaipirasuchus stenognathus. The new material represents the holotype of a new species,Caipirasuchus mineirusn. sp., diferenciated from the previously ones due to the following traits: last two maxillary teeth located posterior to anterior edge of infraorbital fenestra, elongated lateroventral maxillo-jugal suture—about ½ the anteroposterior maxillar length—and contact between posterior crest of quadrate and posterior end of squamosal forming an almost 90° flaring roof of the squamosal, among others.C. mineiruswas found in the same outcrop thanCampinasuchusbut stratigraphically the former occurs in the lower portion of the section with no unambiguous data supporting the coexistance of both taxa.

scholarly journals Review of the Survey's activities in 1985

1986 ◽  
Vol 130 ◽  
pp. 5-8
Author(s):  
M Ghisler
Keyword(s):  
Mineral Resources ◽  
Basic Research ◽  
Field Work ◽  
Editorial Staff ◽  
Systematic Investigation ◽  
Geological Mapping ◽  
Glacial Geology ◽  
Precambrian Geology ◽  
Field Activity ◽  
June July

The systematic investigation of the geology of Greenland for the State was continued in 1985 by the Geological Survey of Greenland (GGU). The investigations encompassed basic research and geological mapping as well as investigations in applied disciplines. Field work, mainly in the months of June, July and August, was carried out by seventy-five scientists and technicians, half of whom belong to the Survey's staff. In addition to the GGU parties several groups from other institutions worked in close collaboration with GGU. The areas of field activity reported on in 1985 are indicated on fig. 1. During 1985 the Survey was partly reorganised, and it is now built up of six main units: Department of Stratigraphy and Structural Geology, Department of Precambrian Geology, Department of Geochemistry, Department of Mineral Resources, Department of Petroleum Geology and Department of Glaciology and Glacial Geology. The administration, computing facilities and editorial staff are directly responsible to the Director.

scholarly journals Wandel Sea Basin: basin analysis – a summary

1995 ◽  
Vol 165 ◽  
pp. 42-48
Author(s):  
E Håkansson ◽  
L Stemmerik
Keyword(s):  
Financial Support ◽  
Research Council ◽  
Science Research ◽  
Field Work ◽  
Geological Mapping ◽  
Basin Analysis ◽  
Geological Survey ◽  
Natural Science Research Council ◽  
Field Season ◽  
North Greenland

In 1991 a three year research project was initiated by the Geological Institute, University of Copenhagen with financial support from the Ministry of Energy, the Danish Natural Science Research Council and the Carlsberg Foundation. The 'Wandel Sea Basin: basin analysis' project was carried out in collaboration with the Geological Survey of Greenland and included field work in North Greenland; in eastern Peary Land in 1991 and Amdrup Land in 1993 (Fig. 1; Hakansson et al., 1994). The project is a continuation of earlier investigations in the Wandel Sea Basin carried out during geological mapping of North Greenland by the Geological Survey of Greenland in 1978–1980 and during later expeditions to the area (e.g. Hakansson, 1979; Hakansson et al., 1981, 1989, 1991, 1994). Hydrocarbon related studies of the Wandel Sea Basin were continued during the 1994 field season (Stemmerik et al., this report).

scholarly journals Review of the Survey's activities in 1986

1987 ◽  
Vol 135 ◽  
pp. 5-7
Author(s):  
M Ghisler
Keyword(s):  
Geophysical Methods ◽  
Basic Research ◽  
Field Work ◽  
Systematic Investigation ◽  
Geological Mapping ◽  
40Th Anniversary ◽  
The Past ◽  
Applied Geology ◽  
Geological Background

The Geological Survey of Greenland (GGU) continued in 1986 the systematic investigation of the geology of Greenland. The work comprises geological mapping and basic research as well as applied geology and geophysics (fig. 1). The long term purpose is to establish the necessary geological background for evaluation of the potential of the non-living resources. The scientific and technical staff of 112 based in Copenhagen and 87 participating in the field work in Greenland carried out programmes of geological mapping and investigation, glaciological investigations, and mineral and oil assessments which included geochemical and geophysical methods. In April 1986 GGU celebrated its 40th anniversary. A special publication dedicated to GGU's former director, K. Ellitsgaard-Rasmussen, was issued which covers different aspects of the Survey's work in the developments in Greenland geology over the past ten years.

Late Cretaceous Kossmaticeratidae (Ammonoidea) from the Magallanes Basin, Chile

1988 ◽  
Vol 62 (6) ◽  
pp. 889-905 ◽  
Author(s):  
Carlos Enrique Macellari
Keyword(s):  
Southern Hemisphere ◽  
Late Cretaceous ◽  
Field Work ◽  
Typical Element ◽  
The Third ◽  
Magallanes Basin ◽  
Assemblage B

Even though ammonites are not very abundant in Patagonia, a large number of specimens were collected by geologists from the Empresa Nacional del Petroleo (ENAP), Chile, during the course of several years of field work in the Magallanes Basin. This study describes the ammonite family Kossmaticeratidae present in that collection, which is a typical element of most southern hemisphere Late Cretaceous assemblages. The species described include: Kossmaticeras (Kossmaticeras?) fasciculatum n. sp., K. (Karapadites) constrictus n. sp., K. (Natalites) cecioni n. sp., K. (Natalites) hauthali (Paulcke), K. (Natalites) sp., Neograhamites kiliani Spath, N. taylori Spath, Gunnarites elegans n. sp., G. bhavaniformis (Kilian and Reboul), Grossouvrites gemmatus (Huppe), and Maorites densicostatus (Kilian and Reboul).The stratigraphic information on this fauna indicates that it is distributed in four assemblages. The oldest (assemblage A), possibly late Santonian to early Campanian in age, includes the species Kossmaticeras (Kossmaticeras?) fasciculatum, Neograhamites taylori, and possibly N. kiliani. This is followed by assemblage B (possibly middle to late Campanian), with K. (Karapadites) constrictus, K. (Karapadites) centinelaense (Blasco, Nullo, and Proserpio), K. (Natalites) hauthali, K. (Natalites) cecioni, Neograhamites morenoi Riccardi, N. taylori, N. kiliani, K. (Natalites) sp., Gunnarites elegans, G. bhavaniformis, and possibly Pseudokossmaticeras paulckei Collignon. The third assemblage (C), possibly late Campanian to early Maastrichtian in age, contains G. elegans, G. bhavaniformis, Grossouvrites gemmatus, and K. (Natalites) hauthali. The youngest assemblage (D) is possibly late Maastrichtian in age and is composed of the species Maorites densicostatus and Grossouvrites gemmatus.

scholarly journals Fault-controlled dolomitization in the Montagna dei Fiori Anticline (Central Apennines, Italy): record of a dominantly pre-orogenic fluid migration

Solid Earth ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 1355-1383 ◽  
Author(s):  
Mahtab Mozafari ◽  
Rudy Swennen ◽  
Fabrizio Balsamo ◽  
Hamdy El Desouky ◽  
Fabrizio Storti ◽  
...  
Keyword(s):  
Field Work ◽  
High Amplitude ◽  
Lower Jurassic ◽  
Upper Triassic ◽  
Fluid Migration ◽  
Central Apennines ◽  
Elevated Salinity ◽  
Siliciclastic Rocks

Abstract. The Lower Jurassic platform and basinal deposits exposed in the Montagna dei Fiori Anticline (Central Apennines, Italy) are pervasively affected by dolomitization. Based on the integration of field work, petrography, and geochemistry, two fault-related dolomitization events were recognized and interpreted as having occurred before and during the Apenninic orogeny. Fluid inclusion analysis indicates moderate to elevated salinity values of 3.5 to 20.5 and 12.8 to 18.6 eq. wt % NaCl in the first and the second event, respectively. The estimated salinities, in combination with δ18O values and 87Sr∕86Sr ratios, suggest significant involvement of evaporitic fluids in both events, most likely derived from the underlying Upper Triassic Burano Formation. In addition, the 87Sr∕86Sr ratios up to 0.70963 suggest the circulation of deep-sourced fluids that interacted with siliciclastic rocks and/or the crystalline basement during the dolomitization events. Two major dolomite types (D1 and D2) were recognized as pertaining to the first event, both postdated by high-amplitude bed-parallel stylolites, supporting a syn-burial pre-layer-parallel shortening dolomitization. A possible geodynamic framework for this dolomitization event is Early Jurassic to Late Jurassic rift-related extensional tectonism. The second dolomitization event (D3, D4, and D5) is characterized by a temperature upturn (up to 105 ∘C) and interpreted as associated with the inflow of hydrothermal fluids, possibly related to major changes in the permeability architecture of faults during early- to syn-thrusting and folding activity. Based on the timing of deformation in the Montagna dei Fiori Anticline, the second dolomitization event likely occurred in Late Miocene to Pliocene times. The findings regarding characteristics and timing of dolomitization here illustrates the long-term controlling role of the evaporitic detachments in the dolomitization process. This study shows that the Mg-rich fluids that were most likely derived from evaporites may prime the tectonically involved successions for repeated dolomitization, and hence the formation of potential reservoirs during sequential tectonic modifications (extensional vs. compressional).

The Desert Sandstone of Australia A Late Nineteenth-Century Enigma of Deposition, Fossils, and Weathering

2004 ◽  
Vol 23 (2) ◽  
pp. 208-256 ◽  
Author(s):  
David Branagan
Keyword(s):  
Late Cretaceous ◽  
Sedimentary Rocks ◽  
Late Nineteenth Century ◽  
Late Mesozoic ◽  
Weathering Processes ◽  
Geological Maps ◽  
Different Ages ◽  
Lateral Extent ◽  
Similar Appearance ◽  
Late Nineteenth

The term "Desert Sandstone" was featured on geological maps and in the literature of Australian geology for more than eighty years from 1872. The name was suggested by Richard Daintree (1832-1878) (1868) for what were later described as "a promiscuous lot of sediments that form a dissected tableland in some of the drier portions of the continent" (Howchin, 1918). The name became current, particularly in Queensland, but there were many problems in mapping the unit, which was at first thought to be of Tertiary age, but then became largely accepted as Late Cretaceous.While some geologists thought the unit was of marine origin, others believed it was aeolian, even partly made of volcanic dust, but most geologists thought it was largely lacustrine. In many areas the rock appeared to be highly silicified, and opinions differed as to the source of silicification—a former covering of basalt, or siliceous hot waters from below?Complications arose when Glossopteris, regarded as a Late Palaeozoic fossil, was found in the "Desert Sandstone," and arguments arose about the possibility of this plant having persisted in Australia until the late Mesozoic.The stratigraphic/palaeontological problems were eventually sorted out by detailed mapping, which showed that there were in fact a number of sandstones of similar appearance but quite different ages. It took longer to realise that the apparent uniformity of sedimentary rocks of different ages was largely the result of weathering, which produced the silicified "duricrust" in many parts of inland Australia.The "Desert Sandstone" played an important part in the unravelling of three important lines of earth history in Australia (and there were even repercussions abroad). These were: (a) sedimentation during the Mesozoic and Cainozoic; (b) the clarification of the temporal range (and lateral extent) of the Glossopteris flora; and (c) the weathering processes that produced some of the characteristic scenery of inland Australia.

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