Libby R.W. Ives

California Institute of Technology | CIT · Jet Propulsion Laboratory

Flutes are flow-parallel till ridges that form subglacially and are conspicuous geomorphic indicators of slip at glacier beds. Flutes commonly have a boulder at their head, lodged in the former till bed of the glacier. In the leading model of flute genesis, weak till of the bed flows into a water-filled cavity where ice separates from the lee surfa...

The currently favored hypothesis for Late Paleozoic Ice Age glaciations is that multiple ice centers were distributed across Gondwana and that these ice centers grew and shank asynchronously. Recent work has suggested that the Transantarctic Basin has glaciogenic deposits and erosional features from two different ice centers, one centered on the An...

We propose that a “local first” approach should be applied to the interpretation of provenance indicators in glacigenic sediments of all depositional ages, especially where the glacier flow path is poorly constrained and the records of potential source lithologies are incomplete. Provenance proxies, specifically U-Pb detrital zircon geochronology,...

Glaciation during the Late Paleozoic Ice Age climatic interval (~ 370–260 Ma) was likely dynamic; consisting of numerous ice centers that grew and shrank asynchronously through time. Improvements in understanding of the spatial and temporal depositional complexity of glaciomarine sedimentary systems have shown that in order to characterize the cond...

In April 2022, the Mars 2020 Perseverance rover arrived at the base of the ancient delta in Jezero crater after completing the first year of its mission exploring and sampling aqueously altered igneous rocks of the present-day crater floor [1]. Perseverance then spent ~200 sols exploring the lower ~25 m of rock exposed within the eastern scarp of t...

The Quaternary geologic map of Jefferson County, Wisconsin, provides details about the surficial sediment and landscapes that were formed largely in the footprint of the Laurentide Ice Sheet's southern Green Bay Lobe during the late Wisconsin Glaciation (ca. 20,000 years before present). These landscapes include lowlands underlain by glacial and po...

The Late Paleozoic Ice Age (LPIA; ~ 374 – 256 Ma) is the longest Phanerozoic icehouse interval. this interval in Earth’s history was largely defined by extensive glaciation of the southern hemisphere at both polar and temperate latitudes. Glaciers are powerful climatic and geologic actors, especially during icehouse periods, and widespread glaciati...

The late Paleozoic Ice Age (LPIA) was one of Earth's most important Phanerozoic climatic events lasting for over 100 Mys. Despite its importance, its history is controversial with two hypotheses that portray glaciation differently (Fig. 1). Traditional views characterize the LPIA as a continuous glacial event that lasted from the Middle Mississippi...

Flutes are low-relief, elongate landforms that form subglacially and parallel to the glacier flow direction. They usually consist of till and have boulders at their heads. Flutes can be pervasive in the forefields of glaciers and contain information about the role of bed deformation in basal slip. There are two leading hypotheses for their formatio...

Macrofabrics have long been used to infer deformational patterns of subglacial till in glacial flutes. Flute macrofabrics, derived from the aggregate orientation of elongate pebbles, are either parallel to glacier flow or form a “herringbone” pattern along the flute’s central axis. Fabrics based on orientation of magnetic particles using anisotropy...