Paleocene isocrinids (Echinodermata: Crinoidea) from the Kauru Formation, South Island, New Zealand

1994 ◽  
Vol 68 (1) ◽  
pp. 135-141 ◽  
Author(s):  
Jeffrey D. Stilwell ◽  
R. Ewan Fordyce ◽  
Peter J. Rolfe
Keyword(s):  
New Zealand ◽  
Storm Surge ◽  
Late Cretaceous ◽  
Fossil Record ◽  
High Energy ◽  
Coarse Grained ◽  
Local Equivalent ◽  
Energy Environment ◽  
First Time

Crinoids are reported from the New Zealand Paleocene for the first time and include rare articulated columnals and brachia with pinnules. These specimens of Metacrinus sp. (Isocrinidae) are present in basal, fossiliferous, coarse-grained, quartzose sediments of the Kauru Formation, a few centimeters above schist basement, in the Kakanui Valley, North Otago. The crinoid-bearing facies probably represents earliest onlap or a storm surge onto a wave cut platform; sedimentological and paleontological evidence indicates a moderate- to high-energy environment. The crinoids were most probably buried rapidly while alive or shortly after death. The presence of isocrinids in the Kauru Formation and younger Paleogene strata reveals that the supposed shift of some isocrinids from a shallower to a deeper environment actually occurred much later in the Paleogene, and not the Late Cretaceous as previously supposed. Associated molluscs indicate a mid to upper “Wangaloan” Stage (local), equivalent to mid Paleocene. A summary of the New Zealand crinoid fossil record is presented.

Chathamirhynchia kahuitara, a new genus and species of Late Cretaceous rhynchonellide brachiopod from the Chatham Islands, New Zealand: shell structure, palaeoecology and biogeography

2007 ◽  
Vol 98 (3-4) ◽  
pp. 357-367 ◽  
Author(s):  
Daphne E. Lee ◽  
Neda Motchurova-Dekova
Keyword(s):  
New Zealand ◽  
Shallow Water ◽  
Volcanic Rock ◽  
Late Cretaceous ◽  
Shell Structure ◽  
New Genus ◽  
High Energy ◽  
New Genus And Species ◽  
Cardinal Process ◽  
Energy Environment

ABSTRACTA new rhynchonellide brachiopod has been collected from the Kahuitara Tuff (Campanian–Maastrichtian) of Pitt Island, Chatham Islands, New Zealand. Brachiopods are extremely rare in Cretaceous rocks from New Zealand, and this new genus and species is unlike any other rhynchonellide known from Australasia or elsewhere. Chathamirhynchia kahuitara is distinguished by its small size, strong ribbing, and well-developed sulciplicate folding, and internally by a large, robust cardinal process and raduliform crura. The shell structure of C. kahuitara is shown to be of typical fine fibrous ‘rhynchonellidine’ type. This brachiopod was probably strongly attached to volcanic rock or shells in a shallow-water, high-energy environment. Implications for the biogeography of brachiopods during the Late Cretaceous are briefly discussed.

Linuparus korura n. sp. (Decapoda: Palinura) from the Bortonian (Eocene) of New Zealand

1988 ◽  
Vol 62 (2) ◽  
pp. 245-250 ◽  
Author(s):  
Rodney M. Feldmann ◽  
Robert K. Bearlin
Keyword(s):  
New Zealand ◽  
Fossil Record ◽  
Middle Eocene ◽  
Species Comparison ◽  
Morphological Descriptors ◽  
First Occurrence ◽  
First Time ◽  
Pacific Species

Linuparus (Linuparus) korura n. sp. is described from Bortonian (middle Eocene) rocks in Otaio Gorge, South Canterbury, New Zealand. This discovery represents the first occurrence of the genus in New Zealand and the first notice of a fossil occurrence of the subgenus which is represented by three modern Indo-Pacific species. Comparison of key morphological descriptors suggests that L. korura is related to L. scyllariformis and L. trigonis. A stridulatory mechanism, similar to that seen on modern Linuparus, is described for the first time from the fossil record.

Search for helium in the upper atmosphere of the hot Jupiter WASP-127 b using Phoenix/Gemini

2020 ◽  
Author(s):  
Leonardo A. dos Santos ◽  
David Ehrenreich ◽  
Vincent Bourrier ◽  
Romain Allart ◽  
George King ◽  
...  
Keyword(s):  
Large Scale ◽  
High Energy ◽  
Upper Atmosphere ◽  
Metastable Helium ◽  
Atmospheric Escape ◽  
Short Period ◽  
Energy Environment ◽  
In Transit ◽  
First Time ◽  
Hot Jupiter

<div class="page" title="Page 1"> <div class="layoutArea"> <div class="column"> <p>Large-scale exoplanet search surveys have shown evidence that atmospheric escape is a ubiquitous process that shapes the evolution and demographics of planets. However, we lack a detailed understanding of this process because very few exoplanets discovered to date could be probed for signatures of atmospheric escape. Recently, the metastable helium triplet at 1.083 μm has been shown to be a viable window for the presence of He-rich escaping envelopes around short-period exoplanets. Our objective is to use, for the first time, the Phoenix spectrograph to search for helium in the upper atmosphere of the inflated hot Jupiter WASP-127 b. We observed one transit and reduced the data manually since there is no pipeline available. We did not find a significant in-transit absorption signal indicative of the presence of helium around WASP-127 b, and set a 90% confidence upper limit for excess absorption at 0.87% in a 0.75 Å passband covering the He triplet. Given the large scale height of this planet, the lack of a detectable feature is likely due to unfavorable photoionization conditions to populate the metastable He I triplet. This conclusion is supported by the inferred low coronal and chromospheric activity of the host star and the old age of the system, which result in a relatively mild high-energy environment around the planet.</p> </div> </div> </div>

scholarly journals PRELIMINARY REPORT ON THE LACUSTRINE STRATA OF THE SANFRANCISCANA BASIN IN NORTHERN MINAS GERAIS, BRAZIL

2020 ◽  
pp. 1-10
Author(s):  
Jonathas S. Bittencourt ◽  
Pedro L. C. R. Vieira ◽  
Raphael M. Horta ◽  
André G. Vasconcelos ◽  
Natália C. A. Brandão ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Fossil Record ◽  
Preliminary Report ◽  
Upper Cretaceous ◽  
Minas Gerais ◽  
Fish Scales ◽  
The North ◽  
Younger Age ◽  
First Time ◽  
Pelitic Rocks

We report new data on the geology and the fossil record of the Sanfranciscana Basin in sites to the north of the traditionally explored localities within Minas Gerais. The strata in the new explored area are formed by distinct lithologies, encompassing pelitic rocks with caliche levels and metric bodies of cross-bedded sandstone towards the top, similar to the fluviolacustrine beds of the Areado Group in the southern portions of the basin. Also similar to other regions of the São Francisco Craton, the deposits of the Sanfranciscana Basin studied herein lie discordantly to the rocks of the Bambuí Basin. We preliminarily report neopterygian fish scales, little informative archosaurian bones and an association of the ostracods Ilyocypris- Fossocytheridea. This ostracod association is registered for the first time in the Cretaceous of the Sanfranciscana Basin. The ostracods have been collected from the lacustrine, vertebrate-bearing rocks cropping out in Lagoa dos Patos and Coração de Jesus. The cytherideid Fossocytheridea assigns a minimal Aptian age to its bearing rocks. Its association with Ilyocypris was also reported in Upper Cretaceous oligohaline paleoenvironments in Brazil and Argentina, indicating similar depositional conditions to the strata reported in this paper. The putative affinities of the specimens of the Sanfranciscana Basin with F. ventrotuberculata, and their association with Ilyocypris, raise the hypothesis of a younger age for some levels of that basin in northern Minas Gerais, perhaps ranging into the Late Cretaceous. Keywords: Ostracoda, Archosauria, Areado Group, Cretaceous, Gondwana

Toward a Comprehensive Upper Quaternary Tephra and Ignimbrite Stratigraphy in New Zealand using Electron Microprobe Analysis of Glass Shards

1983 ◽  
Vol 19 (2) ◽  
pp. 188-200 ◽  
Author(s):  
P. C. Froggatt
Keyword(s):  
New Zealand ◽  
Marine Sediments ◽  
Electron Microprobe ◽  
Volcanic Ash ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
High Energy ◽  
Energy Environment ◽  
Tephra Stratigraphy ◽  
Glass Shards

AbstractNew Zealand Quaternary marine and terrestrial sequences contain numerous tephras, or volcanic-ash horizons, that are the distal correlatives of voluminous welded ignimbrite sheets, erupted from central North Island. Electron microprobe analyses of glass shards from the distal tephras demonstrate their homogeneity and are shown to identify each tephra examined. By matching tephras from stratigraphically controlled sequences, the first comprehensive tephra stratigraphy spanning from 50,000 to 700,000 yr ago and covering the New Zealand region is advanced.Analyses on glass shards from the unwelded base of ignimbrite sheets are comparable to the distal tephra analyses and allow correlation between ignimbrites and to the distal tephras. The better exposed tephra record constrains the number of separate eruptive events and the stratigraphy of the ignimbrites, both of which were previously confused by lack of outcrop.Samples from pumiceous marine sediments were found to contain two or more chemically distinct populations of glass. The pumice is in cross-bedded sands or sand lenses within conglomerate, attesting to a shallow high-energy environment where reworking could occur. However, each glass population could be matched to older, known tephras.

Fossil crabs (Crustacea: Decapoda) from the Late Cretaceous cárdenas Formation, east-central Mexico

1995 ◽  
Vol 69 (2) ◽  
pp. 340-350 ◽  
Author(s):  
Francisco J. Vega ◽  
Rodney M. Feldmann ◽  
Francisco Sour-Tovar
Keyword(s):  
Late Cretaceous ◽  
Fossil Record ◽  
New Genus ◽  
Gulf Coast ◽  
Central Mexico ◽  
New Genus And Species ◽  
East Central ◽  
The Family ◽  
Marine Lagoon ◽  
First Time

Twenty-four nearly complete carapace samples were collected at three different localities of the Maastrichtian (Late Cretaceous) Cárdenas Formation in San Luis Potosí, east-central Mexico. The material has been assigned to five families: the Callianassidae, Dakoticancridae, Carcineretidae, ?Majidae, and Retroplumidae. Two genera of callianassid shrimp are described, Cheramus for the first time in the fossil record. Dakoticancer australis Rathbun is reported as the most abundant crustacean element; one new genus and species of carcineretid crab, Branchiocarcinus cornatus, is erected, and a single, fragmentary specimen is questionably referred to the Majidae. The three localities reflect paleoenvironmental differences, exhibited by different lithologies, within marginal marine, lagoon environments. The record of dakoticancrid crabs in the Cardenas Formation extends the paleobiogeographic range of the family and the genus Dakoticancer. Carcineretid crabs, although not abundant, seem to have been a persistent element of crustacean assemblages in clastic environments during the Late Cretaceous of the ancestral Gulf Coast of Mexico.

Parasitic castration of the crab, Tumidocarcinus giganteus Glaessner, from the Miocene of New Zealand: Coevolution within the Crustacea

1998 ◽  
Vol 72 (3) ◽  
pp. 493-498 ◽  
Author(s):  
Rodney M. Feldmann
Keyword(s):  
New Zealand ◽  
South Dakota ◽  
Late Cretaceous ◽  
Adult Male ◽  
Fossil Record ◽  
Adult Males ◽  
Decapod Crustaceans ◽  
Parasitic Castration

Feminization of adult male xanthid crabs, Tumidocarcinus giganteus Glaessner, from the Miocene of New Zealand, represents the first notice of the phenomenon in the fossil record. Marked broadening of the abdomen of adult males, to assume a form much like that of mature females and limitation in the size of the major claw likely result from parasitic castration by rhizocephalan, probably kentrogonid, barnacles. A sexually aberrant dakoticancrid, Dakoticancer overanus Rathbun, from the Late Cretaceous of South Dakota (Bishop, 1983) may extend this coevolutionary relationship between parasitic barnacles and decapod crustaceans into the Mesozoic.

scholarly journals Procesos tafonómicos en una encrinita regional pensilvánica (Atokano), Sonora, México

2017 ◽  
Vol 65 (1-1) ◽  
pp. 147
Author(s):  
Catalina Gómez-Espinosa ◽  
Blanca Estela Buitrón-Sánchez
Keyword(s):  
North America ◽  
Debris Flow ◽  
Fossil Record ◽  
High Energy ◽  
Marine Communities ◽  
Storm Wave ◽  
Energy Environment ◽  
Taphonomic Processes

Taphonomic processes in a Pennsylvanian regional encrinite (Atokano), Sonora, Mexico. Crinoids have an extensive fossil record and were a major component in Paleozoic marine communities; encrinites are common crinoid accumulations where specimens are totally disarticulated from the Ordovician to the Jurassic. In Sonora, Mexico, the crinoid skeleton was altered during diagenesis and replaced by silica. The corrasion was high; the incrustation low and there is evidence of dissolution and compaction. This is a sedimentological type accumulation in a high energy environment of allochthonous organism transported in a debris flow, deposited below the storm wave base in an outer ramp. Our results can be correlated with regional encrinites prevalent in the Pennsylvanian cyclothems of North America. Rev. Biol. Trop. 65(Suppl. 1): S147-S159. Epub 2017 November 01. 

scholarly journals Search for helium in the upper atmosphere of the hot Jupiter WASP-127 b using Gemini/Phoenix

2020 ◽  
Vol 640 ◽  
pp. A29 ◽  
Author(s):  
Leonardo A. dos Santos ◽  
David Ehrenreich ◽  
Vincent Bourrier ◽  
Romain Allart ◽  
George King ◽  
...  
Keyword(s):  
Large Scale ◽  
High Energy ◽  
Upper Atmosphere ◽  
Metastable Helium ◽  
Atmospheric Escape ◽  
Short Period ◽  
Energy Environment ◽  
In Transit ◽  
First Time ◽  
Hot Jupiter

Large-scale exoplanet search surveys have shown evidence that atmospheric escape is a ubiquitous process that shapes the evolution and demographics of planets. However, we lack a detailed understanding of this process because very few exoplanets that have been discovered to date could be probed for signatures of atmospheric escape. Recently, the metastable helium triplet at 1.083 μm has been shown to be a viable window for the presence of He-rich escaping envelopes around short-period exoplanets. Our objective is to use, for the first time, the Phoenix spectrograph to search for helium in the upper atmosphere of the inflated hot Jupiter WASP-127 b. We observed one transit and reduced the data manually since no pipeline is available. We did not find a significant in-transit absorption signal indicative of the presence of helium around WASP-127 b, and we set a 90% confidence upper limit for excess absorption at 0.87% in a 0.75 Å passband covering the He triplet. Given the large scale height of this planet, the lack of a detectable feature is likely due to unfavorable photoionization conditions for populating the metastable He I triplet. This conclusion is supported by the inferred low coronal and chromospheric activity of the host star and the old age of the system, which result in a relatively mild high-energy environment around the planet.

Uncharted archives – imprints of tsunami backwash deposits on the Algarve shelf (Portugal)

2020 ◽  
Author(s):  
Piero Bellanova ◽  
Klaus Reicherter ◽  
Pedro J.M. Costa ◽  
Mike Frenken ◽  
Lisa Feist ◽  
...  
Keyword(s):  
Organic Geochemistry ◽  
High Energy ◽  
Coarse Grained ◽  
Tsunami Deposits ◽  
Depositional Processes ◽  
Polycyclic Aromatic ◽  
Energy Environment ◽  
Shelf Sediments ◽  
Offshore Tsunami Deposits ◽  
Inorganic And Organic

<p>Research on offshore tsunami deposits is scarce and their depositional processes and preservation potential are virtually unexplored. Therefore, the RV Meteor cruise M152 mapped and sampled one coast-parallel and two coast-perpendicular transects at water depths from 65 to 114 m off the Algarve coast (Portugal). This coast was strongly affected by the well-known Lisbon earthquake and tsunami of November 1<sup>st</sup>, 1755 AD. Numerous onshore locations have been well documented and studied with historic damage reports and modern scientific investigations of the onshore tsunami deposits. However, very scarce information about the backwash, the water masses flowing back into the sea, exists and their imprint on the shelf is unexplored.</p><p>In order to fill this gap, a total of 19 vibracores were recovered during the RV Meteor cruise M152. For tracing the sedimentary imprint of the AD 1755 tsunami and potential predecessors, a multi-proxy analysis was carried out (sedimentology, micropaleontology, inorganic and organic geochemistry, radiocarbon and OSL dating). Within the offshore Holocene stratigraphic record, at least two event layers of likely tsunami backwash origin were identified based on their significantly different properties compared to the background shelf sediments. The uppermost tsunami layer (at a depth of 16-25 cm in most cores) displays an erosional contact at the base with heterogeneous compositional changes; its bounding radiocarbon ages allow a correlation with the AD 1755 Lisbon tsunami. Organic-geochemical markers, such as n-alkanes, polycyclic aromatic hydrocarbons, steroids and fatty acids, show an increased input of terrestrial matter in this offshore AD 1755 event layer.</p><p>A surprising discovery was another distinct high-energy deposit, i.e. a potential predecessor to the AD 1755 Lisbon tsunami, at a core depth of about 122-155 cm, which was <sup>14</sup>C-dated to approx. 3700 yrs cal BP. Due to its erosional base and coarse-grained composition (well-sorted medium sand), as well as the increased terrestrial influence (displayed by biomarkers), it can be assumed that this deposit originates from the backwash of a paleo-tsunami.</p><p>This multi-proxy approach with sedimentological, micropaleontological, inorganic and organic-geochemical criteria, enabled us to (1) identify of backwash tsunami deposits; (2) establish a recurrence interval; and (3) estimate the hazard potential for the related coastal areas. Results of the M152 cruise demonstrate for the first time that the depositional basins on the Algarve shelf have the potential to reliably archive Holocene tsunami backwash deposits. The low-energy environment of the outer Algarve shelf sets prime conditions for the preservation of tsunami backwash deposits. Thus, these geoarchives offer the possibility to study the mechanisms and hydrodynamics of backwash currents, and to investigate tsunami strata that are not preserved elsewhere.</p>

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