Early Late Maastrichtian Research Articles

Biostratigraphy and paleobiogeography of the Gan’kino horizon (Maastrichtian) of the Western Siberia

Research subject. This paper investigates Maastrichtian (Upper Cretaceous) foraminifera complexes present in various parts of the Western Siberia.Materials and methods. The materials of parametric drilling performed in the last century were reviewed in the context of new data. The characteristics of the main ecological microfauna groups in the Gan’kino horizon (Maastrichtian) were clarified by analysing their taxonomic composition, structure and diversity. Results. It was shown that, in the typical Yamal-Tyumen district, the Gan’kino horizon consists of three zones: Spiroplectammina variabilis, Gaudryina rugosa (with subzones Bolivina decurrens, Bolivinoides senonicus and Stensioeina caucasica transuralica), Spiroplectammina kasanzevi, Bulimina rosenkrantzi (with subzones Bolivina plaita, Bulimina rosenkrantzi and Heterostomella foveolata) and Brotzenella praeacuta. Here, the horizon volume is limited to the Maastrichtian stages. The Stensioeina caucasica transuralica and Brotzenella praeacuta zones were found to belong to the Upper Maastrichtian.Conclusions. It was established that, the Early and early Late Maastrichtian was characterized by a gradual increase in the diversity of foraminifera complexes due to immigrants from the Boreal-Atlantic realm. The widespread distribution of foraminifera complexes from the Northern district across the Western Siberia during the Spiroplectammina kasanzevi and Bulimina rosenkrantzi period was associated with the transgression of Arctic waters. The appearance of the foraminifera associations with Heterostomella foveolata reflects a wide levelling of the foraminifera composition throughout the Western Siberia. At the beginning of the Brotzenella praeacuta time, Boreal-Atlantic taxa were widely dispersed across the Western Siberian basin.

Late Maastrichtian to Danian organic-walled dinoflagellate cysts and calcareous nannofossils from eastern Austral Basin, Patagonia, Argentina

Late Maastrichtian to Danian dinoflagellate cyst and calcareous nannofossil biostratigraphy was analyzed at the Sur Río Chico borehole, Austral Basin, Argentina. Two stratigraphical intervals from the 965 to 1003 m below ground surface of the drilled section were defined. The co-occurrence of Manumiella bertodano, M. seelandica and M. conorata in the 990–1000 to 1000–1003 mbgs interval, associated with the top of the nannofossil Neprolithus frequens miniporus Zone indicated a late (probably latest) Maastrichtian age. The acme of the presumed heterotrophic Manumiella spp. and the acme of the mesotrophic cool-water nannofossil Prediscosphaera stoveri, together with other cool-water taxa Arkhangelskiella cymbiformis, Kamptnerius magnificus and Nephrolithus frequens may indicate cool nutrient–rich waters in this interval. Finally, the co-occurrence of dinoflagellate cyst taxa Carpatella cornuta, Cerodinium diebelii, Danea californica, Senoniasphaera inornata and Palaeoperidinium pyrophorum linked to the nannofossil NP3 Zone, suggest a middle Danian age for the 965–970 to 985–990 mbgs interval. An acme of P. pyrophorum herein related to the Pp2 of New Zealand, might reflect an episode of cool temperature during the Danian in the Austral Basin. The sedimentary succession is represented by the Campo Bola Formation within which two discontinuities were recognized; the older is of early-late Maastrichtian, and the younger is of the latest Maastrichtian to the earliest Danian. A third discontinuity involving the middle to late Paleocene separates the Campo Bola Formation from the overlain Eocene Man Aike Formation.

Planktonic foraminiferal evidence of Late Cretaceous movements in the Gulf of Hammamet area (northeastern offshore Tunisia)

The gulf of Hammamet (GH) area, located in northeastern offshore Tunisia, experienced several tectonic deformations during the Mesozoic and Cenozoic eras. These deformations generated discontinuities, hiatuses, and thickness variations of sedimentary successions during the late Cretaceous, such as the late Campanian-late Thanetian El Haria Fm, which is documented to be partially or totally eroded in the GH area. Several geological works based on geophysic, seismic, and log data in the GH area attribute the existent (thinner) part of the El Haria Fm to the Palaeocene. The present study analyzes the planktonic foraminiferal biostratigraphy of this thinner part of the El Haria Fm in the well A-1 located in the northeastern part of the GH area. The analyzed foraminiferal assemblages highlight the existence of a Danian sequence (6.1 m) unconformably deposited above a Maastrichtian sequence (12.2 m), which rest unconformably on a late Campanian sequence (12.2 m). The foraminiferal record also indicates the occurrence of three hiatuses across the Campanian-Maastrichtian, early-late Maastrichtian, and Maastrichtian-Danian boundaries, respectively. The correlative data and timelines from the surrounding wells helped to decipher the morphology of the substrate underlying the El Haria Fm (i.e., the Abiod Fm) in the GH area and the distribution pattern of the deposited Campanian-Thanetian sequences. This work depicts subsiding areas towards the northeastern and southwestern parts of the GH area. These subsiding areas are correlative with swells in the southeastern part of the study area, which grade to a NW-trending bald zone without record of the Abiod and El Haria formations.

EVOLUTION OF THE NASIELSK–DĘBE GRABEN (EASTERN CENTRAL POLAND) DURING CRETACEOUS TIMES

The paper portrays the geological evolution of the Nasielsk–Dębe tectonic graben during Cretaceous times. The analysis is based on data from the Dębe 1, 2, 5, 6, and 7 and Nasielsk 1 and 2 boreholes. Only well logs, archived borehole materials (drill core description) and published data have been used because the drill cores are no longer available. The graben’s Cretaceous evolutionary stages have been identified based on thickness analysis, and correlated to depositional cycles. The analysis shows that greater thickness gradients are observed at the north-eastern graben-bounding fault, which indicates its higher activity compared to the south-western fault throughout nearly the entire Cretaceous. The upper part of the Cretaceous succession reveals the presence of at least two discontinuity surfaces (possibly even hardgrounds): approximately at the Campanian/Maastrichtian boundary, and near the lower Mastrichtian/upper Maastrichtian boundary. It is suggested to distinguish two separate lowest-order cycles within the lower-order cycle K4-IV: cycle K4-IVa correlated approximately with the late early Maastrichtian, and cycle K4-IVb corresponding roughly to the early late Maastrichtian.

Upheavals during the Late Maastrichtian: Volcanism, climate and faunal events preceding the end-Cretaceous mass extinction

The late Maastrichtian was a time of major climate, evolution and extinction extremes. Rapid climate warming of 2–3°C in intermediate waters between 69.5 and 68Ma (top C31r to base C30n) accompanied maximum evolutionary diversification (43% increase, zone CF5 to low CF4) in planktic foraminiferal history, followed immediately by a cluster of extinctions. During the last 250ky of the Maastrichtian (C29r, zones CF2–CF1), rapid warming of 4°C in intermediate waters and 8°C on land resulted in high-stress environments ending in the mass extinction. The end-Cretaceous mass extinction is recorded in sediments between massive Deccan lava flows in India and attributed to SO2 and CO2 outgassing leading to ocean acidification. The early late Maastrichtian climate and faunal upheavals are not well known.Here we document the faunal similarities of both events from the Indian Ocean through the Tethys and Gulf of Mexico. Results show that both extreme warm events are marked by high-stress environments characterized by decreased abundance and diversity of large specialized species and dwarfing, high abundance of low oxygen tolerant species, and disaster opportunist surface dweller Guembelitria blooms. The similarity in faunal response with the Deccan warming of C29r (CF2–CF1) suggests that volcanism was also responsible for the warming and faunal upheaval of the early late Maastrichtian. Major volcanic activity at this time included the onset of Deccan eruptions and Ninetyeast Ridge volcanism. The role of the Chicxulub impact appears to have been a contributing, rather than causal, factor in the mass extinction.

Palynology, Palynostratigraphy and Paleoenvironmental Analysis of Maiganga Coal Mine, Gombe Formation, Nigeria

Palynological analysis provides data for determinations of ages, palynostratigraphy and paleoenvironments of the studied parts of Gombe Formation (around Maiganga coal mine) in the Upper Benue Trough. The studied sections of the formation were sampled from the drilled cores of the strata derived from the coal exploration drilling project carried out at Maiganga. A total of 174 core samples from three boreholes that penetrated the strata have been studied for their palynofloral contents and the results used to date, zone and interprete the paleoclimatic conditions of the paleoclimatic conditions of the studied strata. The aim was to establish their microfloral assemblages, age, paleoclimate and biozonation. The standard maceration method was employed for the palynological analyses employing both acid and hydrogen peroxide as the processing media. The studied boreholes (BA-7, BA-16 and BA-17) were considerably rich in palynomorphs especially the samples processed with H2O2. Majority of the pollen and spores observed from the study included Proteacidites sigalii, Retidiporites magdalensis, Monoporites annulatus, Cingulastisporites ornatus,Rugulatisporites caperatus, Scabratriporites annellus, Proteacidites longispinosis, Distaverrusporites simplex and Foveotrilete margaritae. The recovered marker species have been used to date the studied section Early-Late Maastrichtian. The analyses of the palynomorphs were used to interpret the paleoclimate of the studied sections as well as zoning the sections into two palyzones, Proteacidites sigalii-Echitriporites trianguliformis and Cyathidites spp-Laevigatosporites haardtii zones. The paleoclimatic conditions were inferred to belong to the Late Cretaceous Palmae province.

Late Maastrichtian foraminiferids and diatoms from the Polish Carpathians (Ropianka Formation, Skole Nappe): a case study from the Chmielnik-Grabówka composite section

ABSTRACT Gasiński, M.A., Olshtynska, A. and Uchman, A. 2013. Late Maastrichtian foraminiferids and diatoms from the Polish Carpathians (Ropianka Formation, Skole Nappe): a case study from the Chmielnik-Grabowka composite section. Acta Geologica Polonica, 63(4), 515-525. Warszawa. Well-preserved foraminiferids have been found in the Chmielnik-Grabowka section (Skole Nappe, Polish Carpathians). The Abathomphalus mayaroensis (late Maastrichtian) and Racemiguembelina fructicosa (earlylate Maastrichtian) standard planktonic foraminiferal biozones have been recognized, based on the occurrence of their respective index species. Sediments of the R. fructicosa Zone contain diatoms, which are a rare component of Cretaceous flysch microfossil assemblages in the Carpathians. The diatom frustules and some foraminiferid tests are pyritized, probably after burial in the sediment, below the redox boundary or in the oxygen- deficient microenvironment inside the frustules or tests of microfossils; the presence of trace fossils and bioturbational structures in the same bed indicate an oxygenated sea floor.

Biostratigraphy of Bluish Marl Succession (Maastrichtian) in Sulaimanyia, Area, Kurdistan Region NE- Iraq

Recently a new lithology is found at the middle part of Tanjero Formation (Maastrichtian) and consists of a bluish marl succession about 100m thick in Sulaimayia area. This succession is lithologically similar to Shiranish Formation and has nearly same color and stacking pattern which didn’t described in the original description in the type section of Tanjero Formation. Geographically it can be seen in Piramagroon and Sharazoor plains, Chaqchaq valley (to the northwest of Sulaimani City) and Dokan area. The biostratigraphy of this succession indicates Early Maastrichtian to Early Late Maastrichtian which includes four interval zones of: Racemiguembelina fructicosa Interval Zone (CF4) (Early late Maastrichtian), Pseudotextularia intermedia Interval Zone (CF5) (Early Maastrichtian) Contusotruncana contusa Interval Zone (CF6) (Early Maastrichtian) Gansserina gansseri Interval Zone (CF7) (Early Maastrichtian) As concerned to the affinity of this succession two possibilities can be assigned: 1-Middle part of Tanjero Formation. 2-lentils of Shiranish Formation inside Tanjero Formation. This study prefers the first assignation as the foraminiferal assemblages show that the marly succession is not belonging to Shiranish which has, in the studied area, the age of Campanian. Another reason for this assignation is that the environment and sequence stratigraphy, tectonics of Tanjero Formation is more understandable than the first assignation (If it is included in the Shiranish Formation). The record of this new lithology and submergence of the type section of the formation under the water of Darbandikhan (dam) impose selection of a new type section or a supplementary type section for the formation either in Dokan or Chwarta areas where there are representatives of the new lithology inside the Tanjero Formation and the sections are well exposed.

Paleofloristic and paleoenvironmental information from a Late Cretaceous (Maastrichtian) flora of the lower Cantwell Formation near Sable Mountain, Denali National Park, Alaska

The lower Cantwell Formation in Denali National Park, Alaska, is a Late Cretaceous high-latitude fluvial succession that contains dinosaur and bird footprints, diverse invertebrate traces, and plant fossils. New fossil discoveries and stratigraphic descriptions in the Sable Mountain area allow for refined paleoenvironmental reconstructions and age interpretations. The formation consists of well-indurated conglomerate, sandstone, siltstone, and shale interpreted as gravelly and sandy channel, levee, crevasse splay, sheetflood, lacustrine, and floodplain sediments with interspersed debris flows. The overall depositional environment is interpreted as a braided river floodplain that interfingered with distal alluvial fan sedimentation. Plant fossils include leaves, branches, cones and rare seeds of taxodiaceous and other conifer taxa, fern fronds, rhizomes and stem segments of Equisetites, linear and broad-lanceolate monocot leaf fragments, cf. Kenella, and impressions of diverse angiosperm broad-leaf morphotypes likely belonging to menispermoid, platanoid and several Late Cretaceous hamamelid groups. A sparse palynoflora extracted from the finer-grained facies yielded the pollen taxa Taxodiaceaepollenites, Aquilapollenites and Alnipollenites; monosulcate cycadophyte or ginkgophyte pollen grains; bisaccate and monosaccate conifer pollen grains and a variety of trilete fern and psilate horsetail spores. The Middle to Late Maastrichtian pollen taxon Aquilapollenites conatus provides a maximum age for the Sable Mountain deposits. Floral assemblages occur within distinct lithofacies deposited in a variety of depositional settings in the ancient floodplain. Angiosperm leaf fossils are dominant in channel and levee facies and were part of a mixed forest assemblage growing in floodplain and lake margin environments. A variety of different types of conifers—indicated by saccate pollen types and rare long, thin leaf fragments—probably inhabited distal floodplain realms and uplands. Frequent and abrupt changes in lithology and floral assemblages imply transitory habitats in a rapidly aggrading depositional setting. A Climate Leaf Analysis Multivariate Program (CLAMP) applied to a composite leaf collection yielded a mean annual temperature of 7.42 +/− 1.2 °C, a warmest monthly mean of 17.1 +/− 1.6 °C, and a coldest monthly mean of − 2.3 +/− 1.9 °C. Growing season precipitation is estimated at 229.4 +/− 334.5 mm over 4.8 +/− 0.7 months. Results are suggestive of a cool temperate and highly seasonal paleoclimate with short, warm, dry summers and long, comparatively mild and probably wet winters. Temperature calculations are consistent with previous estimates from Alaska's North Slope and northeastern Russia suggesting a low polar temperature gradient and a slight cooling trend during the Middle to early Late Maastrichtian. Precipitation estimates for the growing season are low compared to overall wet climate predictions for the Maastrichtian. Like other Late Cretaceous Arctic floras the Cantwell flora is classified herein as a Polar Broad-leaved Deciduous Forest flora.

New maastrichtian oxygen and carbon isotope record: Additional evidence for warm low latitudes

The Cretaceous period was generally characterized by greenhouse conditions. Nevertheless, our data on isotopic composition of biogenic carbonates from the Koryak Upland and Sakhalin (Russian Far East) show that during the Maastrichtian, temperatures dropped sharply at high and middle latitudes, with only a slight warming in the early Late Maastrichtian. At the same time, there is contradictory evidence on climatic conditions for low latitude areas during Maastrichtian time. The new and previously published isotopic data on Maastrichtian mollusks in the Western Interior Seaway (North America) (WIS) and some other areas suggest that tropical deep-sea surface temperatures calculated from the oxygen isotopic composition of the majority of investigated Maastrichtian planktic foraminifera are, obviously, underestimated. Unusually low isotopic temperatues were obtained for tropical planktic foraminifera. This probably reflects both local conditions provoked, first of all, by the influence of tropical upwelling zones, and the ability of Maastrichtian planktic foraminifera to migrate within a large vertical interval in the tropical zone in conditions of weakly stratified (well-mixed) ocean. The average tropical deep-sea surface paleotemperature estimates for the Maastrichtian could have been about 26.6–30.2°C, but, apparently, did not reach the level denoted for the Late Albian and Turonian (32±3°C). Negative carbon-isotopic shifts at the end of the early Maastrichtian and the Cretaceous-Tertiary boundary time seem to be connected with the fall of temperature and eventual reduction of oxygen content in the atmosphere and hydrosphere.

Palaeobiological significance of high-latitude Late Cretaceous vertebrate fossils from the James Ross Basin, Antarctica

Abstract A diverse marine assemblage of vertebrate fossils has been collected in recent years under the auspices of the British Antarctic Survey from Seymour, James Ross and Vega islands east of the Antarctic Peninsula. The specimens were derived from the Late Campanian Santa Marta Formation, Early Maastrichtian Snow Hill Island Formation and the Early-Late Maastrichtian López de Bertodano Formation. Sharks, teleosts, plesiosaurs and mosasaurs are represented, but birds and sea turtles are absent from the BAS collections; neornithine birds have been previously reported from the Late Cretaceous deposits of Antarctica. Shark teeth are relatively abundant, but teleosts are seemingly under-represented. Plesiosaurs (Elasmosauridae) are more abundant and complete than mosasaurs, and juveniles of both marine reptile groups are relatively common. The marine lizards, mosasaurs, are taxonomically diverse as elsewhere in the world, but with relatively few individuals compared to the plesiosaurs, which are taxonomically limited. A converse relationship normally occurs at other lower latitude Late Cretaceous localities. Some of these abundances and appearances may be due to collection bias, particularly due to difficult collecting conditions and weathering, but certain distributions may be the result of high latitudes.

Palaeotemperature curve for the Late Cretaceous of the northwestern circum-Pacific

In the northwestern circum-Pacific, two main trends in Late Cretaceous temperatures can be recognized. (1) In general, a recurrent warming trend is thought to have begun in the Turonian–Campanian, reaching temperature maxima in the early Late Santonian and early Late Campanian, and temperature minima in the earliest Santonian and perhaps early Campanian. (2) During the Maastrichtian, temperatures dropped sharply, with only a slight warming in the early Late Maastrichtian. The existence of a thermal maximum at the Coniacian–Santonian transition has previously been expected, but is not confirmed by new isotopic results.

Biostratigraphic and isotopic data on the Çöreklik Member of the Hekimhan Formation (Campanian-Maastrichtian) of SE Turkey and their palaeoenvironmental significance

The Çöreklik Member of the Hekimhan Formation crops out in the Hekimhan (Malatya) region of SE Turkey. It includes beds that are rich in planktic and benthic foraminifera, and in calcareous nannoplankton. Eighty-eight rock samples, considered to be representative of the stratigraphic section, were examined. Seventeen species of planktic foraminifera and theGlobotruncana ventricosa,Globotruncanita calcarata(Campanian),Globotruncanella havanensis,Globotruncana aegyptiaca, andGansserina gansseri(Maastrichtian) planktic foraminiferal zones were recognised. Thirty-two calcareous nannoplankton species and theCeratolithoides aculeus(CC-20),Quadrum sissinghii(CC-21),Quadrum trifidum(CC-22) (Campanian),Tranolithus phacelosus(CC-23) (Late Campanian-Early Maastrichtian),Reinhardites levis(CC-24),Arkhangelskiella cymbiformis(CC-25), andLithraphidites quadratus(Early-Late Maastrichtian) zones were identified. Analyses of the sediments, the distribution of planktic and benthic foraminifera and calcareous nannoplankton, the sea-surface palaeotemperature values and palaeosalinity levels respectively calculated from δ18O‰ (PDB) andδ13C‰ (PDB) isotope values obtained from globotruncanid tests, and the abundance and diversity of temperature-sensitive calcareous nannoplankton groups allowed the following conclusions to be drawn. (1) Maximum phytoplankton abundances and highest sea level were reached during the Early Campanian; (2) both the numbers of phytoplankton and the sea level began to fall from the Late Campanian onwards, reaching their lowest levels during the Late Maastrichtian; and (3) sea-surface temperature values were stable through the Campanian-Early Maastrichtian but began to fall slowly and intermittently from the end of Early Maastrichtian, reaching minimum values during the Late Maastrichtian.

SOBRE ALGUNS NÍVEIS DE CORRELAÇÃO BIOESTRATIGRÁFICA REGIONAL (FORAMINÍFEROS PLANCTÔNICOS) NO CRETÁCEO BRASILEIRO

Six Cretaceous planktonic foraminiferal extinction levels allow good interbasinal correlation along the Brazilian continenta l margin. From base to top they are as follows: extinction of Favusella and Ticinella at the base and top of the Vraconian, respectively; extinction at Late Turonian of Gtobotruncana inomata and G. wilsoni in equatorial marginal basins and of Dicarinella hagni and D. imbricata in the Santos and Campos basins on eastern margin; the extinction of Dicarinella concavata at the Santonian-Campanian boundary: the extinction of Globotruncana fornicata at the Early-Late Maastrichtian. Three significant regional unconformities have been identified during Cretaceous marine sedimentation. The Jack of Late Campanian and Latest Maastrichtian-Earliest Paleocene sediments indicates a hiatus during these time intervals, caused, probably, by sea-level oscillations as suggested by erosional truncation of Santonian-lower Campanian and lower-upper Maastri htian sediments. The third unconformity, probably controled by tectonic and sedim entary factors related to the post-rift stage of the opening of the South/Equatorial Atlantic ocean, is represented by lack of Cenomanian sediments.