Earth Sciences Commons^™

Gge Biplot Analysis Of Forage Yield Performance And Stability Assessment Of Tall Fescue Experimental Populations Selected Under Grazing Pressure In A Stress Environment, Ali Missaoui, J. L. Ford, D. R. Woodfield, A. Stewart, S. Makaju

IGC Proceedings (1977-2023)

Integrating the yield and stability of genotypes selected under grazing pressure is an important objective in breeding forage crops. Genotype × environment (G x E) interaction is a major source of inconsistency in crop performance across locations. As a result, a genotype is considered stable if it has a low contribution to the G x E interaction. This study explores the effects of G x E interaction on yield and stability of 10 tall fescue experimental populations selected for persistence under grazing pressure outside the area of adaptation of the species (stress environment). Six standard checks were included. The populations …

Identification Of Endangered Range Plant Species And Change In Ground Cover In North Kordofan State, Sudan, Mohammed D. Elnazeir, A. A. Khatir, A. M. Morakah

IGC Proceedings (1977-2023)

This study was conducted in North Kordofan State. With the objectives of identifying change in ground cover, other range attributes and the endangered plant species. The primary source of data was mainly from previous studies, while secondary data were obtained from field work using loop and transect method, personal interviews, rapid rural appraisal technique and direct observation, SPSS software was used in statistical analysis. The results indicate that there were notable changes in range composition. Percentage live plants and decreased by 17.5, while litter and rock increased by 17.9% and 0.30%. Some of the species still exist, with higher percentage …

Strategies For Seed Quality Improvement In Eastern Gamagrass, A Tripsacum Species, J. I. Morrison

IGC Proceedings (1977-2023)

In the southeastern United States, perennial warm-season grasses constitute the backbone of many forage production systems, whether for grazing or harvested feed. North American native plants offer unique ecosystem benefits as well as high forage quality when managed properly. Popular native grasses used for grazing in the southeastern US include Andropogon (bluestems), Sorghastrum (indiangrass) and members of the genus Tripsacum including eastern gamagrass (T. dactyloides) in North and Central America; Guatemala grass (T. fasciculatum syn. T. andersonii) in Latin America and the West Indies; and wide-leaf gamagrass (T. latifolium) throughout Mesoamerica. Eastern gamagrass …

Chlorophyll And Mineral Dynamics Of Perennial Grass Species Found In Semi- Arid Rangelands Of South Africa, N. H. Msiza, K. E. Ravhuhali, H. K. Mokoboki, Sydney Mavengahama, L. E. Motsei

IGC Proceedings (1977-2023)

Minerals are essential for ruminants and are mostly provided by grass species. Their growth stage is vital in the supply of these minerals. Perennial grass species have been mostly undervalued, owing to the scarce information concerning their potential feeding value and little documentation about their potential nutritive value in different growth stages. This study was conducted to investigate the chlorophyll and mineral concentration of grass species at different growth stages under greenhouse conditions at the North-West University Experimental farm, North West province, South Africa. The soil, collected from different villages, was mixed and samples were drawn for chemical analysis before …

Farmer Experiences With Alfalfa In The Southern U.S.A., M. K. Mullenix, L. S. Silva, C. G. Prevatt, J. J. Tucker

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is a forage crop of primary importance in the United States (USA); however, adoption and use in the southern USA region has been limited. The combination of adapted alfalfa cultivars and management strategies which demonstrate extended forage growing season length, improved forage nutritive value, and reduced N fertilizer inputs have renewed interest in forage-livestock farmers to consider planting alfalfa. A series of Extension-based educational strategies have been used in the southern USA to 1) create awareness on the use of alfalfa, 2) educate farmers regarding establishment and management practices, and 3) showcase opportunities and challenges …

Opportunities For Promoting The Adoption Of Forages In Kenya, Joseph G. Mureithi, Elkana M. Nyambati

IGC Proceedings (1977-2023)

Livestock production plays an important socio-economic role in many areas across Kenya. They are kept in all the major livestock production systems including smallholder mixed crop- livestock system, crop-livestock-tree production system, and pastoral/extensive livestock production system, which occupy about 70% of land in Kenya. Livestock production is mainly constrained by inadequate feed quantity and quality. Forage forms the major source of feed for ruminant livestock as they provide high-quality forage to alleviate feed shortages. The demand for pasture and fodder production and conservation to meet livestock feed requirements, particularly during the dry seasons, has created the need to re-position the …

Evaluation Of Apomictic Megathyrsus Maximus Accessions And Ecotypes To Improve Feed Availability In Western Kenya, David Miano Mwangi, S. W. Mwendia, Joseph G. Mureithi, P. Karimi, Maurice Mudeheri, An Notenbaert, Andres Juan, Tarus David

IGC Proceedings (1977-2023)

In Kenya, the dairy sub-sector is dominated by smallholder farmers, who keep between 1-10 dairy cows, and produce over 80% of the marketed milk in the country. The sub-sector is characterized by low milk production, long calving intervals and high calf mortality. The main constraint is the lack of year- round quality feeds hence the low lactation yield of 1,400 litres from animals capable of 3,500 - 4,000 litres. The main feed is Napier grass (Cenchrus purpureus) formerly Pennisetum purpureum. However, in the last decade the productivity and reliability of Napier grass has been constrained by the emergence Napier …

Annual Clovers Around The World: Current Status And Future Prospects, P. G. H. Nichols, G. R. Smith, D. J. Moot, Serkan Ates, Claudio Porqueddu, Esteban F. Rios, Mounir Louhaichi, Alejandro Del Pozo, N. Kotze, Alan W. Humphries, K. Ghamkhar, M. H. Ryan

IGC Proceedings (1977-2023)

This paper reviews the distribution and importance of annual clover (Trifolium) species for pasture and fodder production systems globally. Of the 158 recorded annual Trifolium species, 65.2% are endemic to the Mediterranean basin and surrounding areas, 14.6% to sub-Saharan Africa, 17.7% to the United States of America and 2.5% to Chile. Fourteen species have been commercialised, while other endemic and naturalised annual clovers are also utilised. Key species for self-regenerating pastures include T. subterraneum, T. michelianum and T. respinatum var. resupinatum, while major dual-purpose grazing and fodder species include T. incarnatum, T. vesiculosum, T. alexandrinum and T. …

Domestication Of The Annual Legume Trigonella Balansae For Mixed Farming Systems In Southern Australia, M. G. Wilmot, H. C. Norman, J. K. Hendry, P. Young, Elizabeth L. Hulm, A. Toovey, R. J. Harrison

IGC Proceedings (1977-2023)

An accession of the annual legume Trigonella balansae Boiss. and Reuter. has been selected for commercial release in Australia. The annual legume has significant potential as a self-regenerating pasture within mixed farming systems. As part of a duty-of-care assessment, we tested the hypothesis that sheep grazing the trigonella cultivar will have similar liveweight, condition scores, health and wool production to sheep grazing two widely adopted annual legumes, subterranean clover (Trifolium subterraneum L. cv Dalkeith) and French serradella (Ornithopus sativus Brot. cv. Erica). Forage dry matter digestibility (DMD), crude protein (CP), fibre, mineral content and isoflavones were measured across …

Pasture Production And Grazing System In Assist Project: Outcome And Replication Viability In Nigeria For Sustainable Ruminant Production, Okanlade A. Lawal-Adebowale, M. Jordana Rivero, John Hunt, Sarah Morgan, Hannah Fleming, R. Pywell, Jonathan Storkey

IGC Proceedings (1977-2023)

As important as pasture is to productive management of cattle, sheep and goats, intensive development of grassland for ruminant animals is rare in Nigeria largely due to no conscious effort at pasture cultivation in the country. Consequently, nomadic and free grazing systems remain a practice in the country, with resultant poor animal productivity and agro-related conflicts between ruminant keepers and crop farmers and/or agro-processors. The need to revert this situation underscored the exploration of the potential value of the innovative pasture production and grazing management system tested under the Achieving Sustainable Agricultural Systems (ASSIST) programmme in Rothamsted Research, United Kingdom, …

Tillering Of ‘Marandu’ Brachiaria Under Different Nitrogen Rates In The Brazilian Savannah, A. B. O. Assis, A. L. Bocchi, T. C. Pedrosa, A. O. Matos, A. P. B. Soares

IGC Proceedings (1977-2023)

The tiller is the basic unit of grass growth and tiller density determines the horizontal ground cover, leaves production and pastures perennially. The objective in this study was to quantify the number of aerial and basal tillers and basal:aerial tillers ratio in Urochloa brizantha cv. Marandu, established in Brazilian savannah, submitted to nitrogen doses (0, 50, 100 and 150 kg N/ha). The experiment was carried out in the Forage and Pasture Sector of Jataí Federal University (UFJ) and after soil correction and fertilization, plots were established with Marandu palisade grass in a randomized block design, with four replications and four …

Could Formononetin Of Red Clover (Trifolium Pratense L.) Be Enhanced By Phosphorus And Arbuscular Mycorrhizal Fungi Management?, Fernando Ortega-Klose, Andrés Quiroz, L. Bardehle, P. Aguilera

IGC Proceedings (1977-2023)

Red clover is a forage legume of importance in the world with limited persistency; in Chile this is due mainly to the root borer (Hylastinus obscurus Marsham) infestation. Our previous studies have shown that there is a strong relationship between the root borer and the formononetin content in roots of the plants; therefore, studying factors that enhance the concentration of formononetin in the plant could help to decrease the negative effect of the root borer. The purpose of this research was to assess the relationship between phosphorus availability (P) in the soil interacting with arbuscular mycorrhizal fungi (AMF) over …

The Influence Of High Density Grazing And Conventional, Rotational Grazing On Soil And Vegetation Parameters In The Semi-Arid And Mesic Grasslands Of South Africa, Jamie Paulse, C. Visser, P. J. Malan, G. N. Smit, F. H. De Witt

IGC Proceedings (1977-2023)

In South Africa, multi-camp rotational grazing using ‘conservative stocking rates’ have been the conventional approach to livestock grazing management systems. However, as of late, the high-desnity approach (used interchangeably – depending on the situation – with regenerative grazing, mob grazing, short duration, high pressure grazing, rapid rotation, time controlled, ultra-high density, holistic grazing and holistic resource management) has been adopted by numerous farmers. This approach is considered to be an adaptable one, incorporating the ‘herd effect’ concept, whereby large numbers of animals occupy an area for short periods of time, and allowed an extended rest period. It claims to improve …

Thermal History Of Rocks Along The Totschunda And Denali Faults With Implications For Exhumation, Fault Reactivation, And Fault System Evolution., Jacob Leo Rosenthal

Dissertations - ALL

The main body of this research has focused on the tectonic evolution of the Totschunda fault and its relationship with the Denali fault in central Alaska. This dissertation is divided into three chapters that investigate questions surrounding the evolution of intersecting faults, reactivation of lithospheric structures, and the exhumation of crust surrounding these structures with an initial overview chapter that sets the context for the studied problems followed by a conclusions chapter that provides a summary of conclusions from this work. In the second chapter I document fault rejuvenation through thermal history modelling of multiple bedrock and detrital cobble samples …

Spatial Analyses On Pre-Earthquake Ionospheric Anomalies And Magnetic Storms Observed By China Seismo-Electromagnetic Satellite In August 2018, Jann-Yeng Tiger Liu, Xuhui Shen, Fu-Yuan Chang, Yuh-Ing Chen, Yang-Yi Sun, Chieh‑Hung Chen, Sergey Pulinets, Katsumi Hattori, Dimitar Ouzounov, Valerio Tramutoli, Michel Parrot, Wei-Sheng Chen, Cheng-Yan Liu, Fei Zhang, Dapeng Liu, Xue-Min Zhang, Rui Yan, Qiao Wang

Mathematics, Physics, and Computer Science Faculty Articles and Research

The China Seismo-Electromagnetic Satellite (CSES), with a sun-synchronous orbit at 507 km altitude, was launched on 2 February 2018 to investigate pre-earthquake ionospheric anomalies (PEIAs) and ionospheric space weather. The CSES probes manifest longitudinal features of four-peak plasma density and three plasma depletions in the equatorial/low-latitudes as well as mid-latitude troughs. CSES plasma and the total electron content (TEC) of the global ionosphere map (GIM) are used to study PEIAs associated with a destructive M7.0 earthquake and its followed M6.5 and M6.3/M6.9 earthquakes in Lombok, Indonesia, on 5, 17, and 19 August 2018, respectively, as well as to examine ionospheric …

Implications And Hydrographs For Two Pre-Bonneville Pluvial Lakes And Double Geosols From 14 Osl-Irsl Ages In Cache Valley, Ne Bonneville Basin, Robert Q. Oaks Jr., Susanne Jänecke, Tammy Rittenour, Thad Erickson, Michelle Nelson

Geosciences Faculty Publications

In the northeastern Great Basin, USA, thirteen new optically stimulated luminescence (OSL) ages and one infrared stimulated luminescence (IRSL) age show that two deep pluvial lakes preceded the Bonneville lake cycle in Cache Valley during marine oxygen-isotope stages (MIS) 6 (213-191 ka) and 4 (56-71 ka), respectively. Our new data define quantitative hydrographs of the Little Valley and Cutler Dam lake cycles in both Cache Valley and the main Bonneville basin. In western Cache Valley, excavation of a faulted, east-plunging spit has sequentially exposed these deposits and overlying MIS 3 Fielding humid-over-arid double geosols that end westward at a strand …

Estimation Of Sugarcane Yield Using Multi-Temporal Sentinel 2 Satellite Imagery And Random Forest Regression, Alireza Taravat, Gebeyehu Abebe, Berhan Gessesse, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

Advancements in remote sensing techniques have greatly enhanced crop monitoring and yield estimation, with spectral vegetation indices (VIs) serving as a key component. Our study investigates the use of Sentinel-2 data, notable for its red-edge bands, in estimating sugarcane yield in Ethiopia's Awash Basin. Utilizing 22 VIs from S2 imagery, our approach combines Random Forest (RF) regression with the Recursive Feature Elimination (RFE) algorithm to improve the accuracy of sugarcane yield predictions. The results demonstrate the superior performance of the RF-RFE method over traditional RF with full datasets and Stepwise Multiple Regression (SMR). Particularly, VIs focusing on the red-edge spectral …

Cambrian Trilobites From The Nounan Dolomite And Lower St. Charles Formation (Upper Marjuman To Lower Sunwaptan; Miaolingian To Furongian Series), Smithfield Canyon, Northern Utah, Frederick A. Sundberg, Hannah R. Cothren, Carol M. Dehler

Geosciences Faculty Publications

The trilobite faunas that occur with the Steptoean Positive Isotope Carbon Excursion (SPICE) at Smithfield Canyon, Utah, have been reported, but not illustrated. Given the importance of the SPICE at this section for international correlations, the trilobites from new collections from the upper Nounan Dolomite to lower St. Charles Formation at Smithfield Canyon are reported herein and integrated with the previously reported taxa. Trilobite assemblages indicate that the upper Cedaria to the Ellipsocephaloides biozones (Miaolingian Series, Guzhangian Stage to Furongian Series, Jiangshanian Stage) are present stratigraphically below or above the SPICE.

Some of the taxa reported herein may represent new …

2023’S Billion-Dollar Disasters List Shattered The Us Record With 28 Big Weather And Climate Disasters Amid Earth’S Hottest Year On Record, Shuang-Ye Wu

Department of Earth, Environment and Sustainability Faculty Publications

The U.S. set an unwelcome record for weather and climate disasters in 2023, with 28 disasters that exceeded more than US$1 billion in damage each.

While it wasn’t the most expensive year overall – the costliest years included multiple hurricane strikes – it had the highest number of billion-dollar storms, floods, droughts and fires of any year since counting began in 1980, with six more than any other year, accounting for inflation.

Investigation Of Earthquake Sequence And Stress Transfer In The Eastern Anatolia Fault Zone By Coulomb Stress Analysis, Hamdi̇ Alkan, Aydin Büyüksaraç, Özcan Bektaş

Turkish Journal of Earth Sciences

A devastating earthquake with a magnitude of (Mw = 7.7) occurred on February 06, 2023, in the Pazarcık segment of the Eastern Anatolian Fault Zone, which has not shown major earthquake activity for a long time. On the same day, another earthquake with a magnitude of (Mw = 7.6) occurred in Ekinözü-Elbistan (Kahramanmaraş) in the northwest. Three more earthquakes with magnitudes of Mw = 6.6, Mw = 5.9, and ML = 5.7 occurred on the same day, and significant damage, loss of life, and property occurred in 11 provinces and districts. A sixth earthquake occurred with Mw = 6.4 magnitude …

Preliminary Results Of The Great Kahramanmaraş 6 February 2023 Earthquakes (Mw 7.7 And 7.6) And 20 February 2023 Antakya Earthquake (Mw 6.4), Eastern Türkiye, Şule Gürboğa, Önder Kayadi̇bi̇, Hafi̇ze Akilli, Serap Arikan, Sevi̇lay Tan

Turkish Journal of Earth Sciences

The first MW 7.7 and second MW 7.6 Kahramanmaraş earthquakes were the strongest tectonic events in Eastern Türkiye since the MW 7.9 Erzincan earthquake in 1939. The first and second events occurred on the Pazarcık and Çardak segments of the East Anatolian Fault System, respectively. A subsequent significant earthquake of MW 6.4 occurred in the Antakya fault zone. We summarize preliminary earthquake data and share our previous field observations to better understand the mechanism and provide scientific consequences for future investigations and layout planning. After combining the field observations, kinematic analysis of fault surfaces, investigations of orthophotos, characteristics of mainshocks, …

Surface Rupture During The 6th Of February 2023 Mw 7.6 Elbistan-Ekinözü (Kahramanmaraş) Earthquake: Implications For Fault Rupture Dynamics Along The Northern Branch Of East Anatolian Fault Zone, Mustafa Softa, Fi̇kret Koçbulut, Eli̇f Akgün, Ercan Aksoy, Hasan Sözbi̇li̇r, Orhan Tatar, Volkan Karabacak, Çağlar Özkaymak, Mehmet Utku, Özkan Cevdet Özdağ, Recep Çakir, Ahmet Demi̇r, Gökhan Arslan

Turkish Journal of Earth Sciences

On the 6th of February 2023, Mw 7.7 Pazarcık (Kahramanmaraş) and Mw 7.6 Ekinözü (Kahramanmaraş) earthquakes that occurred in Türkiye are devastating earthquake series that filled the existing seismic gaps on East Anatolian Fault Zone on the same day. The first Mw 7.7 earthquake caught most people in their sleep and 9 h later, a second one was triggered, ending up with more than 50k death toll, widespread damage to buildings, and massive landslides. This study presents the surface rupture geometry and coseismic displacement characteristics determined with field observations immediately after February 6, 2023, Ekinözü (Kahramanmaraş, Türkiye) earthquake (Mw 7.6). …

Tepehan Rockslide: A Large-Scale Earthquake-Induced Geological Structure Formed By Mw:7.8 Kahramanmaraş (Pazarcık) Earthquake, Türkiye, Ökmen Sümer

Turkish Journal of Earth Sciences

Three devastating and powerful earthquakes hit the southeastern and eastern parts of Turkey and the northestern part of Syria in February of 2023, causing many earthquake-induced slope movements. One of these major mass movements is called the “Tepehan Rockslide”, which was formed by the first Mw: 7.8 earthquake on February 6th, 2023 at Pazarcık (Kahramanmaraş) located in the Altınözü district of Hatay province. The rockslide involved the movement of Middle Miocene basement rocks that consist of clayey limestone, marl, and fine-grained clastic sedimentary rocks. The morphogenetic evaluation of the structure reveals that the Tepehan Rockslide is a very rapidly developed …

Response Of Water Resources To The Kahramanmaraş Earthquakes (Mw 7.7 And Mw 7.6) That Occurred On February 6, 2023, On The East Anatolian Fault Zone (Türkiye), Celaletti̇n Şi̇mşek, Görkem Akinci, Okan Fistikoğlu, Kerem Canli, Hasan Sözbi̇li̇r, Azi̇ze Ayol, Efem Bi̇lgi̇ç

Turkish Journal of Earth Sciences

On February 6, 2023, two destructive earthquakes of 7.7 MW and 7.6 MW occurred in Pazarcık (Kahramanmaraş) and Elbistan (Kahramanmaraş) at 04:17 and 13:24 hours, respectively. These earthquakes caused a surface rupture with a total length of 450 km in the region with an average displacement of 3 m between the Arabian and Anatolian plates. This study was conducted to investigate the physical deformation of the aquifer system and the current water quality characteristics in the affected region utilizing field observations and on-site analysis of water sources and tap water. The study revealed significant physical changes in the karstic springs …

Soil Liquefaction And Subsidence Disaster In İskenderun Related To The 6 February 2023 Pazarcık (Mw: 7.7) And 20 February Defne (Mw: 6.4) Earthquakes, Türkiye, Hüseyi̇n Öztürk, Craig A. Davis, İbrahi̇m Kuşku, Süleyman Dalğiç, Cem Kasapçi, Muharrem Alper Şengül

Turkish Journal of Earth Sciences

The Mw 7.7 Pazarcık earthquake on February 06, 2023, struck southern Türkiye, causing typical liquefaction along the shores of İskenderun Bay. This liquefaction was characterized by lateral spreading, subsidence, and flooding. Subsidence-triggered sand ejecta, water flows, and opening cracks were identified in areas spanning approximately 2 km in length and 300 m in width. Based on coastal references such as lighthouses or harbor platforms, settlements of 0.8 m and lateral spreading of 0.4% were recorded along the coastal zone following the Pazarcık earthquake. According to camera recordings, liquefaction-related water and silty sand outflows occurred 29 min after the earthquake. The …

Assessing Sediment Migration And Salmonid Habitat Recovery Following A Small Dam Removal And A Flood, Mill Creek, California, Usa, Madeline C. Doyle

Master's Theses

In 2021, the lower Mill Creek Dam (~4 m tall, ~8 m wide) was removed from the Mill Creek-San Vicente Creek watershed (18 km2), located in the Santa Cruz Mountains. Topographic surveys and pebble counts were performed at 27 transects four times between 2021 and 2023 to compare changes in channel characteristics and grain size to document the response to a small dam removal and the transition between drought and flood conditions. The goals of this study were to: (1) describe the movement of impounded sediment; (2) assess the success of habitat restoration for two endangered anadromous fish species: coho …

Fauna, Flora, And Land Cover Changes Over The Last Two Decades In The Mobile-Tensaw River Delta, Gabriel De Oliveria, Steven R. Schultze, Guilherme Mataveli

Technical Reports

A technical report documenting ecosystem changes to the Mobile-Tensaw River Delta region due to urban expansion over approximately two decades (2001-2019).

Soil And Fertiliser Management For Orchards In The Manjimup District, Neil Lantzke, Simon Yeap, Lukasz Kotula, B Goldspink, Valeria Almeida Lima, John Kammann

Horticulture research reports

This publication aims to give orchardists a broad understanding of the soils in the Manjimup district. It provides information on soil and fertiliser management that will assist in the sustainable production of fruit crops. This document was prepared for a Soils Course for horticulturalists, that was held in September 2023 at Manjimup Horticultural Research Centre.

The Manjimup local government area (LGA) is the most important horticultural district in Western Australia, particularly for fruit and in 2020 the total value of horticultural production was valued at $236 million (Figure 1). Avocados and apples were the most valuable horticultural crops, valued at …

Cold-Season Precipitation Sensitivity To Microphysical Parameterizations: Hydrologic Evaluations Leveraging Snow Lidar Datasets, W. J. Rudisill, A. N. Flores, H. P. Marshall, E. Siirila-Woodburn, D. R. Feldman, A. M. Rhoades, Z. Xu, A. Morales

Geosciences Faculty Publications and Presentations

Cloud microphysical processes are an important facet of atmospheric modeling, as they can control the initiation and rates of snowfall. Thus, parameterizations of these processes have important implications for modeling seasonal snow accumulation. We conduct experiments with the Weather Research and Forecasting (WRF V4.3.3) Model using three different microphysics parameterizations, including a sophisticated new scheme (ISHMAEL). Simulations are conducted for two cold seasons (2018 and 2019) centered on the Colorado Rockies’ ∼750-km² East River watershed. Precipitation efficiencies are quantified using a drying-ratio mass budget approach and point evaluations are performed against three NRCS SNOTEL stations. Precipitation and meteorological outputs …

Geologists As Colonial Scouts: The Rogers Expedition To Otavi And Tsumeb, Namibia, 1892–1895, Selby Hearth

Geology Faculty Research and Scholarship

From 1892 to 1895, the South West Africa Company (SWACO) expedition led by geologist Matthew Rogers conducted the first geologic mapping in Namibia’s Otavi Mountains, including the now world-famous Tsumeb Mine. This paper uses archival documents from the Rogers expedition to trace his geologic contributions and to illustrate important themes in the relationships between 19th century colonial geologists, Western colonizing governments, Indigenous communities, resource extraction, and corporations. To carry out his mapping, Rogers performed a continuous balancing act between British and German colonial powers and local African leaders. The local leaders and communities he interacted with variously resisted his incursions, …