ABSTRACT Although he was legally blind, Charles R. Knight (1874–1953) established himself as the premier paleontological artist in the early 1900s. When the Field Museum, Chicago, commissioned a series of large paintings to document the evolution of life, Knight was the obvious choice. Knight considered himself an artist guided by science; he researched and illustrated living animals and modern landscapes to better understand and represent extinct life forms within their paleoecosystems. Knight began the process by examining fossil skeletons; he then constructed small models to recreate the animals’ life anatomy and investigate lighting. Once details were finalized, Knight supervised assistants to transfer the study painting to the final mural. The Field Museum mural process, a monumental task of translating science into public art, was accompanied by a synergistic tension between Knight, who wanted full control over his artwork, and the museum’s scientific staff; the correct position of an Eocene whale’s tail—whether uplifted or not—documents a critical example. Although modern scientific understanding has rendered some of Knight’s representations obsolete, the majority of his 28 murals remain on display in the Field Museum’s Evolving Planet exhibit. Museum educators contrast these murals with contemporary paleontological knowledge, thereby demonstrating scientific progress for better public understanding of the nature of science.

ABSTRACT The last-glacial megaflood Kankakee Torrent streamlined hills and the remarkably straight backslope of the Kalamazoo moraine (Lake Michigan lobe of the Laurentide ice sheet) in southwestern Michigan. Flooding ensued as proglacial Lake Dowagiac overflowed across remnants of the Lake Michigan lobe at the position of the inner margin of the Kalamazoo moraine as glacial debris and ablating ice were pinned against Portage Prairie. Proglacial Lake Dowagiac developed in the Dowagiac River valley as the lobe retreated to form the Valparaiso moraine. A minimum age of the Kankakee Torrent (18.7 ± 0.6 k.y. B.P) is indicated by the weighted mean value of six optically stimulated luminescence ages determined from quartz sand in glaciofluvial sediment on the Kalamazoo moraine (Lake Michigan and Saginaw lobes). This value is consistent with tighter age control based on radiocarbon ages of tundra plants within silty sediment forming ice-walled lake plains and in a torrent-scoured lake basin (Oswego channel) in Illinois. Crosscutting relationships of well-dated moraines indicate the Kankakee Torrent occurred sometime between 19.7 and 18.9 calibrated (cal.) k.y. B.P. as it skirted the south margin of the Valparaiso Morainic System.

ABSTRACT The Indiana Dunes is a name commonly used for the eastern part of the Calumet Lacustrine Plain, generally referring to the large dunes along the coast from Gary, Indiana, eastward to the Michigan state line. However, the Calumet Lacustrine Plain also contains complex coastal landscapes associated with late Wisconsin to Holocene phases of ancestral Lake Michigan (e.g., mainland-attached beaches, barrier beaches, spits), including those formed during quasi-periodic decadal and shorter-term waterlevel variability that characterize modern Lake Michigan (e.g., beach ridges, dunes, interdunal wetlands). Major industrial development and other human activities have impacted the Calumet Lacustrine Plain, often altering these landscapes beyond recognition. Today, geological and paleoenvironmental data are sought to inform regional environmental restoration and management efforts and to increase the resiliency of the coastal landscape to ongoing disturbances. During this field trip, we will examine the relict shorelines and their associated nearshore and onshore features and deposits across the Indiana portion of the Calumet Lacustrine Plain. These features and deposits record the dynamic interaction between coastal processes of Lake Michigan, lake-level change, and long-term longshore sediment transport during the past 15,000 yr. Participants will examine the modern beach, the extensive beach-ridge record of the Tolleston Beach strandplain, a relict dune field, and the large dunes of the modern shoreline, including Mount Baldy. At Mount Baldy, we will focus on the landscape response to human modification of the shoreline. We will also explore the science behind dune decomposition chimneys—collapse features that caused a 6-yr-old boy to become buried more than 3.5 m below the dune surface in 2013 and highlighted a previously unrecognized geologic hazard.

Abstract A detailed geologic framework model was utilized for groundwater analysis using a fully three-dimensional variably saturated flow model. The geologic framework model, which was developed by a team of glacial geologists from federal and state geological surveys, was fully three-dimensional and did not contain the usual (unrealistic) assumption of widespread aquifer layers separated by leaky aquitard layers of equal extent. The goal of the analysis was to explore the implications of the new generation of geologic framework models for regional groundwater flow, and particularly, groundwater–surface water interactions. A transient numerical simulation, using infiltration at the ground surface as a boundary condition, revealed rich flow complexity, including: (1) widespread, yet patchy, recharge areas with rates that vary through several orders of magnitude, with the recharge rates being statistically correlated to hydraulic conductivity of the vadose zone sediments, elevation, and ground surface slope; (2) the predominance of local flow systems, resulting in an abundance of seepage zones along the sides of the incised (postglacial) stream valleys, and other manifestations of the high water table and strong groundwater–surface water interaction, such as kettle lakes and wetlands; and (3) existence of partially confined aquifers owing to partial burial of deltaic deposits by moraines and lake-bottom deposits having slow vertical permeability. Taken together, these findings support the need for, and value of, high-resolution geologic framework models and the potential fruitful outcome of strong collaboration between glacial geologists and groundwater modelers.

Extract from beginning of chapter: Anyone who is studying dissected volcanoes and ancient lavas and breccia should have some acquaintance with active volcanoes and regions of modern volcanism. So I decided to visit Vesuvius and the Sicilian region, incidentally make the acquaintance of some of the British petrographers, and pay my respects to Rosenbusch in Heidelberg. By the end of February 1890, I was able to leave Washington for a two-month trip, going directly from New York to London via Southampton. Although I had never met Judd or Teall, they were hospitable enough, when they learned of my intention to stop in London on my way to the Continent, to invite me to come directly to their homes upon my arrival. Judd's note reached me before I left Washington, and Teall's caught me before I left the steamer at Southampton. It resulted in my spending a few days with Judd on my way out and in visiting Teall on the way back—a most memorable experience, quite as enlightening as the study of active volcanoes. IMPRESSIONS OF JOHN JUDD After a night at Charing Cross Hotel, I found Judd in his rooms in the “science schools,” 1 South Kensington, and received a most cordial welcome. Probably no British geologist equaled Judd in genial temperament and the ability to be entertaining. His manner was frank and outspoken; his attitude toward his colleagues was generous and not critical. He took an enthusiastic interest in petrography and expressed his opinions with such positiveness that one was led to believe

Eolian sand deposited in lakes downwind of coastal sand dunes can record a history of paleoclimatic fluctuations. The eolian sand signals from sediment within the Grand Mere Lakes, Michigan, which are downwind of sand dunes along southeastern coastal Lake Michigan, record the same sunspot, climate history, and lake-level fluctuations observed elsewhere along the east-central Lake Michigan coastline. Sediment cores were extracted from the Grand Mere Lakes in Berrien County, Michigan, and analyzed for variations in weight percentage of sand with depth, the sand signal, at 1 cm sampling intervals. Radiocarbon dates obtained from terrestrial macrofossils within the cores were used to develop age-depth models, from which sedimentation rates were derived, both for the varying sedimentary facies and the entire core. Spectral analyses of the sand signal data using both multi-taper and REDFIT methods indicate multiple periodicities that correspond to those from other regional and global studies, including Lake Michigan lake-level fluctuations, Lake Michigan coastal dune formation, and solar cycles. The common periodicities between the Grand Mere Lakes sand data and other studies suggest the sand-signal data set is not random, and is best explained as a record of paleo dune mobility. The appearance of the 80–110 year Gleissberg solar cycle in the data suggests that the storminess recorded by the eolian sand was influenced by periodic variability in extratropical cyclones across the Lake Michigan basin which, in turn, reflects variability in circulation patterns driven by the North Atlantic Oscillation, the variability of which has been associated with solar cycles.

Abstract The late Wisconsinan and Holocene coastal evolution of southern Lake Michigan contrasts with the coeval history of ocean-coast settings. Multiple transgressive and regressive events occurred, and rates of lake-level change were often greater than the most rapid eustatic sea-level changes. A succession of lower high-lake maxima is recorded in mainland beaches, spits, and beach-ridge/dune complexes across the Chicago/Calumet lacustrine plain. The plain, which extends approximately 120 km from north of Chicago to the Indiana-Michigan border, was the sink for net-southerly littoral transport. During the high-lake phases between 14.5 ka and about 3.5 ka, littoral transport from the eastern and western lake shores terminated in separate spits on opposite ends of the lacustrine plain. Since about 3.5 ka, littoral transport converged along the southern shore. Gradual changes in coastal geomorphology, brought about by littoral processes acting within an overall trend of lake-level decline over the past 2,500 years, formed the modern coastal geography. The Chicago River was transformed from a westward- to an eastward-flowing drainage; littoral-sediment accretion resulted in an extensive beach-ridge/dune complex and a 35-km stream-mouth deflection forming the Grand Calumet River. A model for the coastal sedimentary evolution during the transgressive phases indicates minimal-sediment supply until rate of lake-level change declined and a peak lake level was reached. Wave erosion along the glacial-bluff lake margins could then supply the littoral-transport system. The overall depositional history of the south Lake Michigan coast is that of a regressive and progradational system.