Seafloor geological impacts associated with drilling disturbance

This study describes the sedimentological composition and morphology of the sea bottom in an area located at 902 m depth in the Campos Basin of Brazil, and compares characteristics before and after drilling activity for oil exploration. The results show no significant sedimentological variation in the area affected by drilling. The most noticeable effects were observed during the second (MD(2)) of three cruises, in terms of change to grain size distribution, total organic carbon and clay mineral composition around the Eagle well. This impact occurred over the seabed in a direction that corresponds to the near-bottom circulation pattern, predominantly northward. In the third cruise (MD3), 12 months after drilling, some recovery was observed. Side-scan sonar imaging was used to explore the extent of the area affected by drilling, and sedimentological samples from it confirmed the effects of drilling. (C) 2008 Elsevier Ltd. All rights reserved.

The phylogeography of trypanosomes from South American alligatorids and African crocodilids is consistent with the geological history of South American river basins and the transoceanic dispersal of Crocodylus at the Miocene

Abstract Background Little is known about the diversity, phylogenetic relationships, and biogeography of trypanosomes infecting non-mammalian hosts. In this study, we investigated the influence of host species and biogeography on shaping the genetic diversity, phylogenetic relationship, and distribution of trypanosomes from South American alligatorids and African crocodilids. Methods Small Subunit rRNA (SSU rRNA) and glycosomal Glyceraldehyde Phosphate Dehydrogenase (gGAPDH) genes were employed for phylogenetic inferences. Trypanosomes from crocodilians were obtained by haemoculturing. Growth behaviour, morphology, and ultrastructural features complement the molecular description of two new species strongly supported by phylogenetic analyses. Results The inferred phylogenies disclosed a strongly supported crocodilian-restricted clade comprising three subclades. The subclade T. grayi comprised the African Trypanosoma grayi from Crocodylus niloticus and tsetse flies. The subclade T. ralphi comprised alligatorid trypanosomes represented by Trypanosoma ralphi n. sp. from Melanosuchus niger, Caiman crocodilus and Caiman yacare from Brazilian river basins. T. grayi and T. ralphi were sister subclades. The basal subclade T. terena comprised alligatorid trypanosomes represented by Trypanosoma terena n. sp. from Ca. yacare sharing hosts and basins with the distantly genetic related T. ralphi. This subclade also included the trypanosome from Ca. crocodilus from the Orinoco basin in Venezuela and, unexpectedly, a trypanosome from the African crocodilian Osteolaemus tetraspis. Conclusion The close relationship between South American and African trypanosomes is consistent with paleontological evidence of recent transoceanic dispersal of Crocodylus at the Miocene/Pliocene boundaries (4–5 mya), and host-switching of trypanosomes throughout the geological configuration of South American hydrographical basins shaping the evolutionary histories of the crocodilians and their trypanosomes.

The phylogeography of trypanosomes from South American alligatorids and African crocodilids is consistent with the geological history of South American river basins and the transoceanic dispersal of Crocodylus at the Miocene

Background: Little is known about the diversity, phylogenetic relationships, and biogeography of trypanosomes infecting non-mammalian hosts. In this study, we investigated the influence of host species and biogeography on shaping the genetic diversity, phylogenetic relationship, and distribution of trypanosomes from South American alligatorids and African crocodilids. Methods: Small Subunit rRNA (SSU rRNA) and glycosomal Glyceraldehyde Phosphate Dehydrogenase (gGAPDH) genes were employed for phylogenetic inferences. Trypanosomes from crocodilians were obtained by haemoculturing. Growth behaviour, morphology, and ultrastructural features complement the molecular description of two new species strongly supported by phylogenetic analyses. Results: The inferred phylogenies disclosed a strongly supported crocodilian-restricted clade comprising three subclades. The subclade T. grayi comprised the African Trypanosoma grayi from Crocodylus niloticus and tsetse flies. The subclade T. ralphi comprised alligatorid trypanosomes represented by Trypanosoma ralphi n. sp. From Melanosuchus niger, Caiman crocodilus and Caiman yacare from Brazilian river basins. T. grayi and T. ralphi were sister subclades. The basal subclade T. terena comprised alligatorid trypanosomes represented by Trypanosoma terena n. sp. from Ca. yacare sharing hosts and basins with the distantly genetic related T. ralphi. This subclade also included the trypanosome from Ca. crocodilus from the Orinoco basin in Venezuela and, unexpectedly, a trypanosome from the African crocodilian Osteolaemus tetraspis. Conclusion: The close relationship between South American and African trypanosomes is consistent with paleontological evidence of recent transoceanic dispersal of Crocodylus at the Miocene/Pliocene boundaries (4–5 mya), and host-switching of trypanosomes throughout the geological configuration of South American hydrographical basins shaping the evolutionary histories of the crocodilians and their trypanosomes.

Assessment of a high school geological field course

Fieldwork is supportive of students’ natural inquiry abilities. Educational research findings suggest that instructors can foster the growth of thinking skills and promote science literacy by incorporating active learning strategies (McConnel et al, 2003). Huntoon (2001) states that there is a need to determine optimal learning strategies and to document the procedure of assessing those optimal geoscience curricula. This study seeks to determine if Earth Space II, a high school geological field course, can increase students’ knowledge of selected educational objectives. This research also seeks to measure any impact Earth Space II has on students’ attitude towards science. Assessment of the Earth Space II course objectives provided data on the impact of field courses on high school students’ scientific literacy, scientific inquiry skills, and understanding of selected course objectives. Knowledge assessment was done using a multiple choice format test, the Geoscience Concept Inventory, and an open-ended format essay test. Attitude assessment occurred by utilizing a preexisting science attitude survey. Both knowledge assessments items showed a positive effect size from the pretest to the posttest. The essay exam effect size was 17 and the Geoscience Concept Inventory effect size was 0.18. A positive impact on students’ attitude toward science was observed by an increase in the overall mean Likert value from the pre-survey to the post-survey.

A Geological Report on an Area Five Miles Southeast of Renova, Montana, and on an Area Seven Miles South of Jefferson Island, Montana

This trip was conducted to give those students working for their respective degrees an excellent opportunity to work under actual field conditions. A total of three weeks was taken to complete the required work. Two weeks were spent in the field gathering data, and making maps, and the last week was spent in the drawing room at the college preparing the final map.

A Geological Report on South Boulder Canyon and The Mayflower Mine-Renova Areas

The purpose of this report is to serve as a written explanation of the accompanying geologic maps and columnar sec­tion. Each year the senior students in mining and geological engineering at the Montana School of Mines spend two weeks in the field where they learn the fundamentals of geologic mapping and related field studies. An additional week is spent at the school where maps are assembled, prints made, end other work is done in preparation for the writing of the report.

Geology 63: Geological Report of Senior Field Trip

The field work was conducted in areas adjacent to White­hall, Montana, as has been the custom for the past several years. Instruction in the proper use of the telescopic and open sight alidades, and the Brunton compass for surveying geologic features was given. Advantages of pacing and speed­ometer mapping were pointed out and used.

Geology and Geological Structure of the Alberta and Saskatchewan Plains

Alberta, responsible for ninety per cent of Canada's output, had, by 1947 entered into her fifth year of production decline. Only ten per cent of Canada's oil requirements were secured from home fields. Ninety per cent had to be imported, mainly from the United States. How long could imports be maintained on present levels? During the year, the United States had started rationing; in one sector of its domain. Would this become general? If so, what was the answer for Canada?

A Geological Report on Several Localities in the Northwestern Tobacco Root Mountains

To better acquaint seniors in Geology and mining with actual field practice, the Montana School of Mines offer a course in Geologic Field Mapping, during the three weeks preceding the opening of the fall semester. The first two weeks are spent in actual field mapping of the geologic formations near Whitehall, Montana, while the third week is spent back on the campus compiling data and finishing maps started in the field.

Geological Report of Conrow Wood Creek Area 8 Miles N.E. of Whitehall, Montana

Plane table and pacing methods were used in the mapping of the individual areas, but an automobile traverse was used to tie the independent areas into a composite group that would be useful for the entire zone. All land marks, section corners, roads, fence lines, drainage, and geologic features were plotted in the field and later transferred to a master map.

A community-based geological reconstruction of Antarctic Ice Sheet deglaciation since the Last Glacial Maximum

A robust understanding of Antarctic Ice Sheet deglacial history since the Last Glacial Maximum is important in order to constrain ice sheet and glacial-isostatic adjustment models, and to explore the forcing mechanisms responsible for ice sheet retreat. Such understanding can be derived from a broad range of geological and glaciological datasets and recent decades have seen an upsurge in such data gathering around the continent and Sub-Antarctic islands. Here, we report a new synthesis of those datasets, based on an accompanying series of reviews of the geological data, organised by sector. We present a series of timeslice maps for 20 ka, 15 ka, 10 ka and 5 ka, including grounding line position and ice sheet thickness changes, along with a clear assessment of levels of confidence. The reconstruction shows that the Antarctic Ice sheet did not everywhere reach the continental shelf edge at its maximum, that initial retreat was asynchronous, and that the spatial pattern of deglaciation was highly variable, particularly on the inner shelf. The deglacial reconstruction is consistent with a moderate overall excess ice volume and with a relatively small Antarctic contribution to meltwater pulse 1a. We discuss key areas of uncertainty both around the continent and by time interval, and we highlight potential priorities for future work. The synthesis is intended to be a resource for the modelling and glacial geological community.

Results of hydrological and geological investigations in Benin

Focus of this study is the analysis of a local hydrogeological system in the subhumid outer tropics in the western African country of Benin. The aim was to characterize, qualify and quantify the hydrogeological and hydrological properties of the approx. 30 km2 big study area and to develop a conceptual hydrogeological model. This model should provide the basis for further studies on a regional scale. The main goal was to obtain the process knowledge of the hydrogeological system and to determine the process and the quantity of the groundwater recharge in the working area. According to the objectives, a broad hydrogeological approach was chosen. In a spacious network on the local scale TDR probes, suction cups and groundwater observation bores were installed. Also in a multidisciplinary cooperation with hydrology, geography, soil science, biology, meteorology and plant nutrition sciences, instruments like discharge gauging stations, tensiometers, lysimeter, climate stations, runoff plots and erosion pins were installed in the test site for the investigation of the relevant parameters of the hydrological cycle.