Laura Guertin

New Tertiary stratigraphy for the Florida Keys and southern peninsula of Florida

Seven lithologic formations, ranging in age from Oligocene to Pleistocene, were recently penetrated by core holes in southernmost Florida. From bottom to top, they are the early Oligocene Suwannee Limestone; late-early Oligocene-to-Miocene Arcadia Formation, basal Hawthorn Group; late Miocene Peace River Formation, upper Hawthorn Group; newly proposed late Miocene-to-Pliocene Long Key and Stock Island Formations; and Pleistocene Key Largo and Miami Limestones. The rocks of the Suwannee Limestone form a third-order sequence. Although the entire thickness was not penetrated, 96 m of Suwannee core from one well contains at least 50 vertically stacked, exposure-capped limestone cycles, presumably related to rapid eustatic fluctuations while experiencing tropical to subtropical conditions. The Arcadia Formation is a composite sequence containing four high-frequency sequences composed of multiple vertically stacked carbonate cycles. Most cycles do not show evidence of subaerial exposure and were deposited under more temperate conditions, relative to the Suwannee Limestone. The Arcadia Formation in southernmost Florida is bounded by regional unconformities representing third-order sequence boundaries. Post-Arcadia transgression produced a major backstepping of sediment accumulation above the upper sequence boundary of the Arcadia Formation. The Peace River Formation, composed of diatomaceous mudstones, has been identified only beneath the Florida peninsula and is not present beneath the Florida Keys. Deposition occurred during marine transgressive to high-stand conditions and a local phosphatization event (recorded in northeast Florida). The transgression is possibly related to a global rise in sea level, which resulted in upwelling of relatively cooler, relatively nutrient-rich water masses onto the Florida Platform. It is proposed that the absence of Peace River sediments beneath the Keys is due to sediment bypass of the upper surface of the Arcadia, a result of sediment sweeping by an ancestral Florida current. During late Miocene to Pliocene time in the Florida Keys, siliciclastics of the Long Key Formation and fine-grained carbonates of the Stock Island Formation prograded toward the southern edge of the Florida Platform and downlapped onto the regional unconformity at the top of the Arcadia. Shallow-marine Pleistocene limestones (Key Largo and Miami Limestones), deposited during tropical to subtropical conditions, drape over accretionary successions of the Long Key and Stock Island Formations.

Interplay of Late Cenozoic Siliciclastic Supply and Carbonate Response on the Southeast Florida Platform

ABSTRACT High-resolution seismic-reflection data collected along the length of the Caloosahatchee River in southwestern Florida have been correlated to nannofossil biostratigraphy and strontium-isotope chemostratigraphy at six continuously cored boreholes. These data are interpreted to show a major Late Miocene(?) to Early Pliocene fluvial-deltaic depositional system that prograded southward across the carbonate Florida Platform, interrupting nearly continuous carbonate deposition since early in the Cretaceous. Connection of the platform top to a continental source of siliciclastics and significant paleotopography combined to focus accumulation of an immense supply of siliciclastics on the southeastern part of the Florida Platform. The remarkably thick (> 100 m), sand-rich depositional system, which is characterized by clinoformal progradation, filled in deep accommodation, while antecedent paleotopography directed deltaic progradation southward within the middle of the present-day Florida Peninsula. The deltaic depositional system may have prograded about 200 km southward to the middle and upper Florida Keys, where Late Miocene to Pliocene siliciclastics form the foundation of the Quaternary carbonate shelf and shelf margin of the Florida Keys. These far-traveled siliciclastic deposits filled accommodation on the southeastern part of the Florida Platform so that paleobathymetry was sufficiently shallow to allow Quaternary recovery of carbonate sedimentation in the area of southern peninsular Florida and the Florida Keys.

Integrating Handheld Technology with Field Investigations in Introductory-level Geoscience Courses

Many geoscience students do not receive the opportunity to use handheld computers and similar tools during field experiences until they enroll in upper-division courses or attend field camp. Although many outdoor exercises in introductory-level courses include demonstrations of pieces of equipment in the field, students in these classes may not have a chance to use these equipment individually. However, handheld technology can be successfully integrated with introductory-level field experiences as a data collection tool and reference guide. Palm Pilot handheld computers offer each student the opportunity to become actively involved in the field experience. Forms can be created and tailored to a specific outdoor investigation and placed on the Palms for students to collect data. Instructors can create instructional videos and eBooks with references on the Palms that correspond to the project objective. For two years Penn State Delaware County has integrated handheld technology with field experiences into introductory-level geoscience courses in physical geology and oceanography. In addition to giving students a valuable introduction to technology that can be used in the field, the experience gives non-science majors a chance to see an application of an everyday technological tool in a nontraditional setting. End-of-semester course evaluations are filled with positive comments and student suggestions of further Palm Pilot integration.

Insights from a Convocation: Integrating Discovery-Based Research into the Undergraduate Curriculum

The National Academies of Sciences, Engineering, and Medicine organized a convocation in 2015 to explore and elucidate opportunities, barriers, and realities of course-based undergraduate research experiences, known as CUREs, as a potentially integral component of undergraduate science, technology, engineering, and mathematics education. This paper summarizes the convocation and resulting report.

An Indoor Shopping Mall Building Stone Investigation with Handheld Technology for Introductory Geoscience Students

Field exercises are a valuable addition to introductory-level geoscience courses but are not always possible in an urban setting. To further develop student skills in rock identification, a project implementing the scientific method has been constructed that allows students to examine the building stones found in the store fronts at a shopping mall. The project is further enhanced with the use of Palm Pilot handheld technology as a tool for reference and data collection. This project allows students to see the use of geologic materials in an everyday setting and experience an innovative use of handheld technology.

Utilizing Google Earth to Teach Students about Global Oil Spill Disasters.

ABSTRACT The United States is currently experiencing its worst man-made environmental disaster, the BP Deepwater Horizon oil leak. The Gulf of Mexico oil spill is severe in its impact, but it is only one of several global oil spill disasters in history. Students can utilize the technology of Google Earth to explore the spatial and temporal distribution of oil spills. In addition to increasing content knowledge of oil spills, Google Earth assists in developing student geographic and technologic literacy. Designed for a middle school science class, this activity may also be used in English, history, math, art, and poster-making.

Using Logic Problems in Introductory-Level Geoscience Courses to Develop Critical Reasoning and Basic Quantitative Skills

Problems that involve quantitative skills require students to reason logically. Strong logical-reasoning and problem-solving skills are necessary for students in proceeding with the application of mathematical methods. introductory geoscience courses offer an excellent opportunity for students, especially nonscience majors, to develop their problem-solving and quantitative skills. A series of logic problems that increase in difficulty level as the course progresses are given to students in my introductory geoscience courses. Because each student works through problems at his/her pace, many exercises are given as homework. To tie the problems to the course material, real geologic data are used. For example, one logic problem uses streamflow discharge data for a local river. Each student must perform unit conversions, solve the problem, plot data, and provide a written interpretation of the graph. At the end of one semester, a majority of students state that their self-reported ability to solve logic problems has increased. It is essential that students have the confidence and ability to solve relatively simple problems before they can go on to complete problems requiring the use of more complex quantitative methods.

Introducing University Students to Authentic, Hands-On Undergraduate Geoscience Research in Entry-Level Coursework

Undergraduate research experiences can be embedded into introductory-level geoscience courses to provide students an early opportunity to apply content knowledge and develop skill sets. These inquiry-based experiences are important to show students the relevance of geoscience to their lives and how even a basic level of content and skills can assist community-based organizations with their outreach mission. Geoscience research experiences can connect to global research efforts and be interdisciplinary in design. Undergraduate research experiences in the first 2 years of university studies are not without challenges, however. The time necessary to prepare students for research and to carry out the projects can take time away from traditional classroom lectures. In addition, sites for authentic, hands-on research may not exist in close proximity to the university. But the benefits of undergraduate research to individual student development on a personal and professional level are significant and will be carried forward by students to future courses and academic opportunities.

Combining a Historical Geology Project with a Campus Student Organization's Fundraising Efforts

Combining a classroom activity with the goals of a campus student organization can promote active learning for the enrolled students, the campus and local community. A service-learning project in a general education geoscience course encourages stronger student enthusiasm and a vested interest towards the success of the project. Undergraduate students enrolled in historical geology are required to present summaries of geologic time periods and fossil samples during the Change Thru Geologic Time project, a service-learning activity at Penn State University Delaware County. Attendees at the event are asked to donate change to a student organizations fundraising efforts for pediatric cancer patients, their families, and innovative pediatric cancer research. The success of this event demonstrates that a common historical geology class assignment requiring students to scale geologic time over a certain distance can be modified to serve as an educational showcase and a fundraiser for a campus student organization.