Dr. Jim Miller is an emeritus assistant professor of geology at the University of Minnesota. He received his Bachelor of Science degree in 1977 from the University of Illinois-Urbana and his PhD in 1986 from the University of Minnesota-Twin Cities. Joining the U of MN’s Minnesota Geological Survey in 1983, Jim worked his way up to senior geologist in charge of geological mapping and research in northeastern Minnesota. In 2008, he was appointed assistant professor in the Department of Geological Sciences at the University of Minnesota-Duluth (UMD). There, Jim taught a variety of geological courses, including Earth Science for Teachers, Geologic Maps, and Earth History, and served as advisor to 20 graduate students. He also served as administrative director for UMD’s Precambrian Research Center, which is a field mapping institute created in 2007. He has authored or coauthored over 50 reports, field guides, and geologic maps. In May, 2016, Jim retired from the University and now resides on Lake Superior near Thunder Bay, Ontario, Canada.

Throughout his professional career, Jim has also been extensively involved in public outreach, enthusiastically spreading his knowledge of local and global geology, geological processes, and Earth history to schoolchildren, K-12 educators, and adult learners. He first caught the outreach bug as a graduate student when had to fill in for his advisor to teach an Elderhostel class on Minnesota geology. In his retirement, Jim continues to pursue his passion for telling awe-inspiring and entertaining stories about the 4.5 billion year history of Planet Earth.

Geological Lectures for Cruise Ship Presentations
By Jim Miller, Professor Emeritus, University of Minnesota Duluth

Presented here are annotated outlines of five general geoscience lecture series consisting of 5-6 Powerpoint lectures that focus on the development of modern geologic theories and on geological evolution the Atlantic Ocean, the Pacific Ocean, the Mediterranean Sea, and the Caribbean Sea. The lectures are intended for a lay audience with a minimal understanding of geology and Earth history. Each of these can be modified to suit the geological details of specific locations visited by particular cruises.

---

SERIES 1: Development of Modern Geologic Theories
Lectures: Six 45-minute Powerpoint presentations

---

Lecture 1: The Scientific Revolution and Early Theories of the Earth (1500-1800)
In the centuries leading up to the Enlightenment, theories about the origin of the Earth and the natural world gradually and fitfully transitioned from outright speculations, commonly rooted in the biblical account of genesis, to ideas based on keen observations, balanced interpretations and application the scientific method of hypothesis testing. This lecture will consider some of the more notable theories about the Earth proposed during this transition period, commonly referred to as the Scientific Revolution.

Lecture 2: The Birth of Modern Geologic Thought
In the late 1700, James Hutton (1726-1797), a physician by vocation and gentleman naturalist by avocation, regaled other Edinburgh intellectuals with lectures and field trips which illustrated his interpretations of geological processes that he read in the rocks of Scotland and beyond. He made the bold and, at the time, heretical speculation that Earth “has no vestige of a beginning, no prospect of an end” and has been constantly recycling itself by uplifting mountains due to the internal heat of the earth and then eroding them away. He summarized his ideas just before his death in a rather unreadable (and largely unread) treatise in 1795. However, thanks to a more understandable rendering of his theories by John Playfair in 1802, Hutton’s ideas of a dynamic Earth now stand as the basis of modern geologic thought.

Lecture 3: The Map that Changed the World
William Smith, a self-taught son of a blacksmith from Oxfordshire, trained to be a surveyor of canals and coal mines in southern England during the Industrial Revolution. With a curious mind and a keen eye, Smith came to recognize patterns to the sequence of rock layers (strata) that occurred below the surface and which could be traced across the countryside. He also recognized the progression of fossils in the various strata that could be used to correlate strata of similar age. On his own, he began to compile the first modern geologic map showing the distribution of various rock units across England, Wales and part of Scotland. The map also included a cross section showing how the strata occurred in the subsurface. His map was completed in 1815, but due to financial and personal problems, plagiarism, and classism, his accomplishment was not fully acknowledged by the geologic community until 1831. William Smith is now revered as the Father of English Geology and his map still stands as the model for how geologic maps are created today.

Lecture 4: Uniformitarianism and the Principles of Geology
Building on Hutton’s paradigm of an ancient, dynamic earth and gradually being freed of religious constraints to read the rocks for clues to their origin and antiquity, the science of geology came into its own in the early 1800’s. Charles Lyell (1797-1875), a Scottish geologist, took it upon himself to compile the state of geologic knowledge into a textbook entitled Principles of Geology. First published in 1830, it saw 12 revised editions over the next 45 years. The book was one of several that Darwin brought with him on his 5-year global voyage on the Beagle. One of the most notable concepts put forth by Lyell was the principle of Uniformitarianism, commonly paraphrased as “the present is the key to the past”. He posited that geologic processes that we observe on earth today (e.g., volcanism, mountain building, sediment deposition, etc.) have been active throughout most of geologic time. Although exceptions have since been noted, the basic message of the principle holds for most Earth processes and provides a powerful conceptual tool for reading the rocks and interpreting past geologic events.

Lecture 5: Discovery of Radioactivity and the Age of the Earth
During the explosive development of geologic observations and theories about the Earth in the 1800’s, a persistent and seemingly intractable question was – What is the age of the Earth? The preeminent British physicist of the time, Lord Kelvin (1842-1907), made multiple attempts to calculate the Earth’s age based on estimated rates of cooling of the Earth from an originally molten state. Although his calculation were revised many times, he ultimately concluded that the Earth was 20 to 40 million years old. Geologists generally dismissed this estimate as being insufficient to explain the vast history they interpreted in the rocks, but had no reasonable alternative. However, the discovery of radioactivity around the turn of the 20th century by British and French scientists provided an unaccounted for source of heat that put Kelvin’s calculations in doubt. When it was further recognized that radioactive decay occurred at a constant rate, this provided a means of using radioactive isotopes to accurately date the formation age of rocks and minerals. It is now clear that Kelvin was a bit off and that the Earth is actually 4,540(±50) million years old.

Lecture 6: Continental Drift, Seafloor Spreading and the Theory of Plate Tectonics
In 1914, Alfred Wegener, a German meteorologist, published a book that hypothesized that the positions of the continents have “drifted” over the face of the Earth over geologic time. Despite citing multiple lines of evidence, few geologists and geophysicists were convinced and the idea quickly faded. In the 1950’s, British geophysicists revived Wegener’s idea with the discovery of unique magnetic properties recorded in rocks from various continents. At first glance, these properties implied that the magnetic poles of the earth had wandered over time, but when it was shown that each continent had its own unique “polar wander path”, it became evident that it was in fact the continents that had wandered. What drove this wandering was discovered soon thereafter by international exploration of the geologic and geophysical properties of the seafloor. These studies led to the realization that new ocean crust is created and spreads away from ocean ridges and is ultimately recycled back into the Earth’s mantle at oceanic trenches. By the late 1960’s, the processes of continental drift and seafloor spreading were integrated into the Theory of Plate Tectonics. Plate Tectonics is now recognized as the grand unifying theory of the Earth that explains virtually all geological phenomenon and that is the driving force behind Earth’s dynamism recognized by Hutton over 200 years ago

---

SERIES 2: The Opening and Closing and Opening of the Atlantic Ocean
Lectures: Six 45-minute Powerpoint presentations

---

Lecture 1: Continental Drift, Seafloor Spreading and Plate Tectonic Theory
Plate Tectonic theory is the grand paradigm of Earth science that explains various features and phenomenon of the Earth and its inherent dynamism. One important element of Plate Tectonic theory, sea floor spreading, was developed by in the 1950s largely from geophysical studies of the Atlantic Ocean. These and other studies lead to the development and enthusiastic acceptance of the Plate Tectonic theory in the late 1960’s.

Lecture 2: Assembly and Disassembly of the Supercontinent Rodinia
Before the last great supercontinent Pangea broke up about 250 million years ago to create the present-day Atlantic Ocean, there was Rodinia. The assembly of the Rodinian Supercontinent by the merging of many continental masses occurred about a billion years ago and included present-day North America at its core. The break-up of Rodinia by continental rifting began about 750 million years ago and created an early version of the Atlantic Ocean (the proto-Atlantic or Iapetus Ocean).

Lecture 3: The Closing of the Proto-Atlantic and the Creation of Laurasia
As complex lifeforms exploded in the margins of the Iapetus Ocean in the Cambrian Period (~550 million years ago), the ocean basin began to gradually shrink due to the convergence of the North America (Laurentia) and European (Baltica) continents. The merging of these landmasses ultimately resulted in the building of the Himalayan-scale Acadian-Caledonian Mountains and the creation of a new continent called Euramerica about 400 million years ago. Soon thereafter, the Siberia and parts of China were added to grow this northern hemisphere landmass to a mega-continent called Laurasia.

Lecture 4: The Geography of the Supercontinent Pangea
Around 335 million years ago, at the end of the Paleozoic era, the southern hemisphere mega-continent Gondwanaland, composed of what is now South America, Africa, India, Australia and Antarctica, collided with the southwestern margin of Laurasia. This collision created an enormous mountain range, the Appalachians in SE North America and the Atlas Mountains in NW Africa. The merging of Laurasia and Gondwanaland created the mother of all supercontinents, Pangea. During the Mesozoic era, Pangea became the breeding ground for the evolution of dinosaurs and the great seaway between Laurasia and Gondwanaland, the tropical Tethys Sea, became host to a great diversity of marine organisms.

Lecture 5: Growing the Atlantic Ocean
Beginning in the mid- to late Jurassic Period, ~175 million years ago, Pangea began to break apart by continental rifting. Separation began between SE North America and NW Africa and then, like a zipper, progressed to the north and the south to create the Atlantic Ocean. As North and South America drift west away from Europe and Africa, the Atlantic continues to widen at about the rate that your fingernail grows.

Lecture 6: The Atlantic Ocean in the Ice Age
Over the past 2 million years, mile-thick glaciers have repeatedly spread out over the northern continents. Their erosive powers sculpted the landscapes of northern North America (creating the Great Lakes) and northern Europe and Asia. The more significant effects of Ice Age glaciation resulted from the transfer of water from the oceans to continental glaciers. This caused a dramatic lowering of global sea level (>400’), which significantly changed the location and shapes of the coastlines of all the world’s oceans. Glaciation also had a profound effects on ocean currents, global climate, and the evolution of humans.

---

SERIES 3: The Pacific Ring of Fire
Lectures: Six 45-minute Powerpoint presentations

---

Lecture 1: Plate Tectonics around the Pacific Ocean
This introductory lecture describes the basic tenets of the Plate Tectonic theory with particular emphasis on the role of ocean crust subduction in explaining geographic (mountains), geologic (volcanoes), and geophysical (earthquakes) phenomenon around the Pacific Ocean basin. Subsequent lectures will focus on the configuration of tectonic plates around the Pacific Rim which give rise to its dramatic and hazardous qualities.

Lecture 2: Volcanic Island Arcs – Aleutians, Japan, Philippines, and Indonesia
Volcanic island arcs occur along the northern and western margins of the Pacific Ocean due to the subduction of the Pacific Plate beneath oceanic crust belonging to the Eurasian and North American plates. These types of plate margins create island chains beaded with active explosive volcanoes and frequent mild to strong earthquake activity.

Lecture 3: Volcanic Continental Arcs – Pacific Northwest, South America
Subduction of the oceanic plates beneath the margins of thick continents creates mountainous terrains, explosive volcanics and weak to moderate earthquakes. The Cascades of the Pacific Northwest and the Andes of South American are formed in this type of tectonic environment.

Lecture 4: Transform Faults – San Andreas, Denali
Perhaps the most dangerous type of plate boundary occurs where plates slide past each other along vertical fault planes rather than at tilted planes such as occurs at subduction zones. Such plate boundaries are called Transform Faults. Earthquakes associated transform faults that cut through continents can be particularly devastating because the fault movements that trigger strong earthquakes can be located near the Earth’s surface. This type of boundary is best exemplified by the San Andreas Fault system of California.

Lecture 5: Hot Spots – Hawaii, Galapagos, Yellowstone
Volcanic activity within tectonic plates (rather than at their margins) is related to cylindrical plumes of hot mantle impacting beneath oceanic and continental crust. Because tectonic plates move but plumes do not, a string of volcanoes are commonly created as the plate passes over the plume. Over 60 million years of volcanic activity linked to the Hawaiian plume can be traced almost 6,000 kilometers to the northwest of Hawaii along the Emperor Seamount Chain.

Lecture 6: What’s Next – A New Supercontinent?
Given the present drift of continental plates, many scientists have speculated that a new supercontinent will form in another 100-150 million years. One model speculates that North America will merge with Siberia and drift closer to the North Pole. Another model suggests that the current separation of North and South America from Eurasia and Africa will reverse itself to create a new supercontinent in about 250 million years that looks similar to the last great supercontinent – Pangea.

---

SERIES 4: The Geologic History of the Mediterranean
Lectures: Five 45-minute Powerpoint presentations

---

Lecture 1: Plate Tectonic Theory: Continental Drift, Seafloor Spreading, and Crustal Subduction
The basic elements of and evidence for the Plate Tectonic theory will be introduced to provide background necessary to understand the geological evolution of the Mediterranean basin.

Lecture 2: Leonardo’s Fossils – Marine Creatures of the Tethys Sea
Among the most prescient ideas put forth by Leonardo da Vinci (1454-1519) was that shells and fossilized lifeforms observed rocks of the high Alps were not deposited there during the Great Flood or by growing in the rocks as others had speculated , but rather were buried in sediments formed in the sea and later uplifted by powerful Earth forces. Indeed, the rich assemblage of marine fossils found in Alpine rocks are now interpreted to have been deposited in the tropical Tethys Sea, a large precursor ocean to the Mediterranean, which existed between Europe and Africa between 250 and 65 million years ago.

Lecture 3: The Rise of the Alps – Collision of Africa and Europe
We now understand that the great uplift of the Tethys seabed, which Leonardo da Vinci hypothesized over 600 years ago had formed the Alps, was caused by the northward convergence of the African continent with the southern margin of Europe starting about 65 million years ago. This complex collision uplifted the mountain ranges that line southern Europe (Pyrenees, Alps, Carpathian, and Caucus)

Lecture 4: The Catastrophic Filling of the Mediterranean Sea
In the late Miocene epoch (10-5.3 million years ago), the Mediterranean basin was a low arid depression isolated from the waters of the Atlantic Ocean by a mountain range stretching between Morocco and the Iberian Peninsula. The global rise of ocean levels at the end of the Miocene caused a breach of this land barrier (the Straits of Gibraltar) and the rapid filling of the Mediterranean basin – the Zanclean Deluge. Some estimates speculate that the rise in water levels may have reached 30 feet per day – indeed catastrophic.

Lecture 5: The Alps and the Mediterranean Basin in the Ice Age
Over the past 2 million years, the Earth has been cycling between glacial and interglacial periods about every 100,000 years. During glacial periods, climate zones in the Mediterranean region migrated south, global sea levels lowered, and glaciers worked at carving the rugged topography of the Alps. The last glacial maximum occurred about 20,000 years ago. We are presently in an interglacial period. As we enter the human-influenced Anthropocene epoch, it is unclear if Earth will cycle back to another glacial period.

---

SERIES 5: The Geologic History of the Caribbean
Lectures: Five 45-minute Powerpoint presentations

---

Lecture 1: Plate Tectonic Theory: Continental Drift, Seafloor Spreading, and Crustal Subduction
The basic elements of and evidence for the Plate Tectonic theory will be introduced to provide background necessary to understand the geological evolution of the Caribbean ocean.

Lecture 2: Tectonics of the Caribbean Plate
The Caribbean Plate is a relative small, eastward-drifting tectonic plate that is sandwiched between the large, westward-drifting North American and South American plates. The present-day geologic setting of the Caribbean Plate is a complex mixture of many tectonic elements –volcanic arcs, transform faults, subduction zones, and spreading ridges.

Lecture 3: Geological History of the Caribbean Basin
The Caribbean Sea began to form in the Jurassic Period (~160 million years ago) during breakup of the Pangean supercontinent and the westward drift of North and South America. As these two large plates diverged, the Caribbean Plate formed in the breach and by 80 million years ago created a semi-continuous volcanic arc stretching from northwestern South America to the Yucatán Peninsula. This created the first land bridge between North and South America. The Central American land bridge began to form about 57 million years ago.

Lecture 4: Geological Hazards in the Caribbean Sea: Earthquakes, Tsunamis, and Volcanoes
With the Caribbean Plate being surrounded by subduction zones and transform faults (similar to the San Andreas), it is an area ripe with earthquake activity. The 2010 earthquake that devastated Haiti was is just the most recent example of geological hazards that plague this region of the globe. Other hazards of historical consequence include earthquake-triggered tsunamis (over 30 verified events, most recently in 1946) and deadly volcanic eruptions (1902, Mt. Pele, Martinique).

Lecture 5: Climate Change and the Ecology of the Caribbean Sea
The Caribbean is home to almost 10% of the world's coral reefs covering about 50,000 km2 (19,000 sq mi), most of which are located off the Caribbean Islands and the Central American coast. Coral reefs support some of the most diverse marine habitats in the world, but they are fragile ecosystems. In recent decades, unusually warm Caribbean waters have been increasingly threatening Caribbean coral reefs as evidenced by extensive bleaching. This and other effects of climate change on the ecology of the Caribbean will be discussed.

In February 2023, I was chosen for my first enrichment speaking experience with a Princess cruise in the western Caribbean. The three lectures I gave on the geologic history of the Caribbean were well received. In May 2023, I served as a guest lecturer for a Viking Octantis cruise from Toronto to Milwaukee. I gave 3 lectures on the geological history of the lower Great Lakes. I greatly enjoyed both experiences and look forward to giving future enrichment lectures on a variety of geological topics.

During my professional career, I have logged 100's of hours of public speaking experience with adult learners on various Earth Science topics. I can offer multiple lecture series on the geology and geological history of the North Atlantic region (North America, Iceland, UK, Scandinavia), the Pacific rim and islands, the Caribbean Sea (Cuba, Hispaniola, Jamaica, Puerto Rico, Lesser Antilles, northern South America, Central America), and the Mediterranean Sea (Spain, Italy, Greece, Cyprus, Turkey, northern Africa).

The following recent Cruise History has been recorded for this candidate.