Paleoecological evaluation of Late Eocene biostratigraphic zonations on the west coast

1979 ◽  
Author(s):  
Kristin A. McDougall
Keyword(s):  
2013 ◽  
Vol 87 (5) ◽  
pp. 826-841 ◽  
Author(s):  
Richard L. Squires

The west coast of North America record of the shallow-marine stromboid gastropod genusRimellaAgassiz, 1841 is restudied for the first time in 90 years. This genus comprises a small group of Paleogene gastropods characterized by having an ornamented fusiform shell, a posterior canal ascending the spire, and simple (non-flared) outer lip.Rimella, whose familial ranking has been inconsistent, is placed here in family Rostellariidae Gabb, 1868, subfamily Rimellinae Stewart, 1927.EctinochilusCossmann, 1889;MacilentosClark and Palmer, 1923;VaderosClark and Palmer, 1923; andCowlitziaClark and Palmer, 1923 are recognized here as junior synonyms ofRimella. Four species are recognized from the west coast of North America: early to middle EoceneRimella macilentaWhite, 1889; early EoceneRimella oregonensisTurner, 1938; middle to late EoceneRimella supraplicata(Gabb, 1864) new combination, of whichRostellaria canaliferGabb, 1864,Cowlitizia washingtonensisClark and Palmer, 1923, andCowlitzia problematicaHanna, 1927 are recognized here as junior synonyms; and late EoceneRimella elongataWeaver, 1912.Rimellawas a warm-water gastropod whose earliest known record is of early Paleocene (Danian) age in Pakistan. Other than the west coast of North America,Rimellais found in Eocene strata in western Europe, Turkey, Egypt, Pakistan, southeastern United States, Panama, Peru, and, to a lesser degree, in Trinidad, Columbia, Java, and New Zealand. Global cooling near the end of the Eocene greatly diminished the genus. Its youngest known occurrences are of early Oligocene age in Germany, Italy, England, and Peru.


1989 ◽  
Vol 63 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Richard L. Squires

A new genus, Calorebama, is proposed for a clade of pseudolivine gastropods (family Buccinidae) that has its earliest species in the lower Paleocene (Danian) of Alabama, its next earliest species in the upper Paleocene (Thanetian) of Alabama, and its subsequent species in the Eocene of California, Oregon, and Washington. Calorebama is characterized by an inflated biconical shape, a biangulate body whorl usually with strong nodes on the shoulder, and fine to medium spiral ribbing that is coarser anterior to the medial pseudolivine groove.Previously, these pseudolivines now being placed in Calorebama were assigned to the genus Pseudoliva. Study of the literature and every available museum specimen showed Calorebama to have five species and two subspecies, all of which have biostratigraphic integrity.Calorebama unicarinata (Aldrich) is the earliest species, and it, along with C. tuberculifera (Conrad), are the only known Gulf Coast species. Calorebama dilleri dilleri (Dickerson) is the earliest representative of the genus on the West Coast of North America, and it arrived during the early Eocene (Ypresian). Probable geographic isolation of C. dilleri dilleri in central and southern California resulted in lineage splitting and the appearance of C. dilleri lineata (Gabb), which phyletically evolved into C. inornata (Dickerson). Calorebama dilleri dilleri persisted in northern California and phyletically evolved into C. dilleri kirbyi (Clark), which similarly evolved into C. volutaeformis (Gabb).Calorebama inornata and C. volutaeformis, the youngest species of the genus, became widely distributed along the West Coast of North America before becoming extinct by the end of the earliest late Eocene.


2016 ◽  
Vol 546 ◽  
pp. 31-45 ◽  
Author(s):  
E Infantes ◽  
L Eriander ◽  
PO Moksnes
Keyword(s):  

Author(s):  
S.M. Thomas ◽  
M.H.Beare C.D. Ford ◽  
V. Rietveld

Humping/hollowing and flipping are land development practices widely used on the West Coast to overcome waterlogging constraints to pasture production. However, there is very limited information about how the resulting "new" soils function and how their properties change over time following these extreme modifications. We hypothesised that soil quality will improve in response to organic matter inputs from plants and excreta, which will in turn increase nutrient availability. We tested this hypothesis by quantifying the soil organic matter and nutrient content of soils at different stages of development after modification. We observed improvements in soil quality with increasing time following soil modification under both land development practices. Total soil C and N values were very low following flipping, but over 8 years these values had increased nearly five-fold. Other indicators of organic matter quality such as hot water extractable C (HWC) and anaerobically mineralisable N (AMN) showed similar increases. With large capital applications of superphosphate fertiliser to flipped soils in the first year and regular applications of maintenance fertiliser, Olsen P levels also increased from values


2016 ◽  
Vol 93 (1) ◽  
pp. 26-44
Author(s):  
Larry Schweikart ◽  
Lynne Pierson Doti

In Gold Rush–era California, banking and the financial sector evolved in often distinctive ways because of the Gold Rush economy. More importantly, the abundance of gold on the West Coast provided an interesting test case for some of the critical economic arguments of the day, especially for those deriving from the descending—but still powerful—positions of the “hard money” Jacksonians.


2019 ◽  
Vol 21 (2) ◽  
pp. 1006-1018
Author(s):  
Ana Alexandre Santos Rodrigues ◽  
Francisco Asis Aquino Bezerra Filho ◽  
Jáder Onofre de Morais ◽  
Lidrana De Souza Pinheiro

As práticas de campo proporcionam aos discentes uma proximidade com o cotidiano. A metodologia proposta no estudo sugere uma divulgação simplificada do conhecimento cientifico da Planície Litorânea de Almofala, propondo rotas de acesso didáticas para práticas de campo que auxiliem os professores das escolas de Itarema. Para a complementação teórica foram considerados como base os inventários da Geodiversidade cientifica do litoral oeste do estado do Ceará, realizados no âmbito do projeto PRONEX. Isso foi feito por pesquisadores de várias Instituições de Ensino Superior do Ceará, e a literatura clássica local. Enquanto resultados discutidos, considerou-se que estes roteiros de práticas de campo podem ser estabelecidos e decididos em conjunto, entre professores e alunos. Tendo como base o mapa interpretativo dos roteiros, com intuito de realizar o reconhecimento e entendimento da dinâmica costeira.Palavras-chave: Educação; Geodiversidade; Planície Litorânea. ABSTRACTField practices provide students with a closeness to daily life. The methodology proposed in the study suggests a simplified dissemination of scientific knowledge of the Almofala Coastal Plain, proposing didactic access routes for field practices that help teachers of Itarema schools. For theoretical complementation, the inventories of the scientific geodiversity of the west coast of the state of Ceará, carried out under the PRONEX project were considered. It was done by researchers from various Higher Education Institutions in Ceará, and its local classical literature. As results discussed, it was considered that these field practice roadmaps can be jointly established and decided between teachers and students. Based on the interpretative map of the roadmaps, in order to recognize and understand the coastal dynamics.Keywords: Education; Geodiversity; Coastal plain. RESUMENLas prácticas de campo ofrecen a los estudiantes una cercanía a la vida diaria. La metodología propuesta en el estudio sugiere una divulgación simplificada del conocimiento científico sobre la llanura costera de Almofala, proponiendo rutas de acceso didáctico para prácticas de campo que ayudan a los docentes de las escuelas de Itarema. Para la complementación teórica fueron considerados como información base los inventarios de la geodiversidad científica de la costa oeste del estado de Ceará, realizados en el ámbito del proyecto PRONEX. Fue realizado por investigadores de varias instituciones de educación superior en Ceará, y la literatura clásica local. En cuanto a los resultados discutidos, se consideró que estas hojas de ruta de prácticas de campo pueden ser establecidas y escogidas conjuntamente entre docentes y estudiantes, con base en el mapa interpretativo de ruta, con el fin de reconocer y comprender la dinámica costera de esta región.Palabras clave: Educación; Geodiversidad; Llanura costera.


Sign in / Sign up

Export Citation Format

Share Document