Mud layers trapped within stalagmites from caves in a variety of environmental settings have been interpreted as flood deposits.  Here we present a combined petrographic and isotopic analysis of one glacial-age stalagmite, AUS-118 from Cape Range, coastal Western Australia.  Stalagmite AUS-118 was thin sectioned and visually inspected and 121 mud layers were identified.  The distance of each layer was measured from the bottom of the stalagmite.  Read More…

Paleoclimate reconstructions for Portugal and the Iberian margin have recently been conducted for the last glacial cycle with the main focus centered on both terrestrial and marine-based data. Portuguese stalagmites provide climatic information through oxygen and carbon isotopes in stalagmite calcite and can be dated using uranium-thorium techniques. One area of particular interest is the climatic response in Iberia to Heinrich-events, the coldest points during glacial stadials having sub-polar climatic conditions and are signaled in the Iberian margin by large influxes of ice-rafted debris. Read More…

Tropical cyclones (a.k.a. hurricanes and typhoons) are among the most devastating forms of extreme weather events in terms of loss of life and destruction of property.  Identifying long-term trends in tropical cyclone activity is crucial to understanding the mechanisms that drive variability in frequency and intensity.  Historical records of cyclone activity are high-resolution, but short-reaching, making them ineffective as tools to identify trends that may only appear over multi-decadal to centennial timescales. Read More…

Our current understanding of trends in tropical cyclone activity in the Indo-Pacific is restricted by a limited historical record.  Mud layers deposited in stalagmites during flooding events in cave KNI-51 from tropical Western Australia appear to be a proxy for tropical cyclone activity in the region. Read More…

An ultrahigh-pressure (UHP) metamorphic zone has been identified in the North Qaidam Mountains of China. Located on the northeastern edge of the Tibetan Plateau, the North Qaidam Mountains contain UHP eclogites, which indicate subduction of continental materials to > 90 km deep. Read More…

The northeastern region of the Tibetan plateau is composed of multiple terranes and tectonically altered zones, including the North Qaidam (ultra)high-pressure metamorphic belt (NQMB).  The NQMB is roughly 15 km wide, extends 350 km NW-SE, and contains well-exposed continental collision-type (ultra)high-pressure metamorphic rocks. Eclogites in the NQMB occur as blocks, boudins or layers within the host orthogneiss. Read More…

Approximately one third of the global population lives in the area affected by the Indo-Australian monsoon. Understanding the variability and dynamics of Australian monsoon rainfall, especially in response to global climate change, is of critical importance. Research in Borneo and Indonesia has demonstrated that the strength of the Indo-Australian monsoon is tied to millennial-scale climate anomalies originating in the North Atlantic.  Read More…

Large body size in movie monsters has inspired a new generation of scientists to explore the fact that real animals, both extinct and extant, have attained almost comparable sizes throughout geologic time. In this study I look at gigantism as preserved in the fossil record and at biologic problems arising from attaining a large size. Read More…

Pyroxenes are among the most common minerals in the inner solar system. The degree of order/ disorder in their crystal structure relates to the cooling history of the mineral. In pyroxenes, Fe2+ prefers the M2 cation site, and Mg prefers the M1 cation site in the crystallographic structure; the slower the pyroxene cools, the more ordered it will be. Previous work revealed that the ordering of Fe2+ and Mg between the M1 and M2 sites affects the relative strengths of absorption bands in the near-infrared. Read More…

We present U-Th and Sr isotopic data on young (Holocene) lavas from Lassen and Mt Shasta volcanic fields and surrounding areas.   Andesitic lavas from Shasta have ²³²Th/²³⁸U ratios of 2.6–2.7 and, similar to those reported previously, have activity ratios  (²³⁰Th/²³⁸U) of 1.01–1.03 close to secular equilibrium. Read More…

Our ability to understand multi-decadal to centennial-scale trends in tropical cyclone activity is limited by the short duration of, and limitations in, historical records. In order to extend these records for tropical Western Australia, we have analyzed mud layers in stalagmite KNI-51-11 from the Kimberley region of north-central Australia that appear to be formed by cyclone-induced flooding.  KNI-51-11 grew over the last 250 years and contains 39 mud layers. Read More…

Few paleoclimate records preserve high-resolution information for the middle Holocene in (near) coastal Portugal, but this region contains many caves within a few kilometers of the coast.  In addition, shells of shallow marine invertebrates record sea surface conditions and some of these were harvested and preserved in archaeological middens. Read More…

The North Qaidam Mountains on the northeastern edge of the Tibetan Plateau show evidence of ultrahigh-pressure (UHP) metamorphism, indicating subduction and exhumation of continental materials to > 90 km deep, within the mantle. The area most likely represents a suture zone, as an ophiolite is present, indicating the closing of an ocean. This ocean was located between the North China and South China cratons about 514 million years ago, as dated from zircons in the ophiolite. Read More…

Coral colony orientation data obtained from Late Pleistocene reef coral assemblages preserved on Curaçao, Netherlands Antilles, Great Inagua and San Salvador Islands, Bahamas, indicates that the same gradient in hurricane frequency observed today also was present during Late Pleistocene time. We conduct an independent test of this hypothesis by examining the successional patterns exhibited by epibionts that grew on coral colonies during a distinct reef-building event that is spectacularly preserved in the upper Hato Unit of the Lower Terrace Limestone, exposed on Curaçao, Netherlands Antilles. Read More…

The San Salvador Island, Bahamas, is located within Hurricane Alley, causing the island to be passed by approximately 60 hurricanes in over a 100-year span.  The purpose of this project is to conduct a comparative multiyear study, from 1999 to 2010, of three beaches on San Salvador that experience different wave and wind regimes and examine the effects that time and prevailing trade winds have on the length/anatomy of a beach’s profile, in relation to its location. Read More…

Recent studies from Borneo and Indonesia have increased our understanding of the evolution of the Indonesian-Australian Summer Monsoon (InAuSM) system over the past 10,000 years (the Holocene epoch).  However, little is known about the InAuSM in Australia or at centennial time-scales. Read More…

As global climate change persists, anthropogenic impacts will continue to exacerbate current environmental degradation, particularly to coral reef ecosystems. To mitigate this critical situation, coral reef conservation efforts have focused on the development of effective marine protected areas (MPAs). However, successful ecological conservation and restoration require an understanding of previous community states – unaffected by anthropogenic impacts – to serve as a basis for comparison. Read More…

The Tibetan plateau in Southwestern China is the result of multiple tectonic events. The region is composed of various terranes and tectonically altered zones, including the North Qaidam ultrahigh-pressure (UHP) metamorphic belt. The belt extends roughly 500 km NW–SE before being sinistrally offset by the Altyn Tagh fault and is found between the Qilian terrane and the North Qaidam basin. Read More…

Taxon-specific sampling has been used in many studies of drilling gastropod predation and is particularly useful for rare taxa. Whether predation metrics from such samples are biased compared to bulk samples, the most widely accepted method of collection for studies of predation, requires testing. Read More…

The North Qaidam Ophiolite provides insight into the mechanisms that formed the rocks of the Tibetan Plateau before its uplift through the Cenozoic India-Eurasia collision. The ophiolite, juxtaposed and folded with an ultrahigh-pressure (UHP) terrane across the Luiliangshan Detachment Zone, separates the two major terranes in the region, the Qaidam and Qilian blocks. Read More…

Thin sections, prepared from sherds that were collected during recent excavations at site 13LN323, were analyzed by point counting compositional elements, which included natural inclusions (sand and silt), non-natural inclusions (temper) and matrix (clay). Dominant temper lithologies are granite, gabbro and basalt. Read More…

Fire history recorded in charcoal in lake sediments can be used to determine different climate conditions and vegetation, as well as fire frequency.  The observation of different charcoal morphotypes has been suggested to reflect fuel sources and burn conditions present at the time of the fire. Read More…

Climate change affects sea level causing sea level fluctuations, which are correlated to glacial and interglacial periods. During glacial intervals water is stored as ice on the continents; therefore, sea level drops. Read More…

A 152 cm tall stalagmite (KIM1) was collected from the El Niño-Southern Oscillation (ENSO)-sensitive and monsoon-dominated Kimberly region of northwestern Australia. Read More…

Two morphologies of Millepora, currently classified as separate species, exist off the coast of the Bahamas. Read More…

Melt transport, the movement of molten rock through the Earth’s relatively solid outer shell, is important in many geological processes. Volcanism at subduction zones and hot spots and the formation of oceanic crust at mid-ocean ridges all involve melt transport. To increase our understanding of how melt moves from depth to Earth’s surface, we conducted experiments at high temperature and pressure on fabricated rock samples of modeled mantle rock compositions. Read More…

In 2008, Cornell College’s Geology Club helped sponsor a trip for twelve students to Big Bend National Park in Texas. Read More…

The transition from the Pennsylvanian to the Permian in the tropics of western Pangea was marked by a general trend toward increased temperature and decreased soil moisture, based on geophysical indicators, such as paleosol morphologies and oxygen isotopes. Read More…

Zircon is a strong mineral capable of withstanding extreme geologic pressures and temperatures. It is able to retain geochemical signatures. which allow the timing of geologic events to be determined. Read More…

Metamorphic rocks, gneisses and pegmatites, from the Western Gneiss Region in southwestern Norway were analyzed to determine when the area was metamorphosed at ultrahigh pressures during the Caleonidonian orogeny. Read More…

Fire coral from the genus Millepora are ubiquitous in tropical western Atlantic reefs. Two distinct morphologies of Millepora, currently classified as separate species, exist off the coast of the Bahamas. M. complanata have broad, smooth blades and prefer shallow waters whereas M. alcicornis have knobby branches and prefer deeper waters. Read More…

The genus Millepora, commonly known as fire coral, is a calcareous hydrozoan common in tropical seas worldwide. Read More…

In moisture-limited environments, meteoric precipitation is the primary control of speleogenesis. We have investigated the growth histories of two stalagmites, 117 & 118, from C -126 Cave, Cape Range, Western Australia (22.1°S, 113.9°E) in order to reconstruct the timing of wet and dry periods during the Holocene and latest Pleistocene. Read More…

Echinoid tests are composed of a series of plates, interlocked with adjacent plates, and reinforced by soft tissue. Read More…

Palisades-Dows State Preserve was excavated by students at Cornell College and has produced sizeable lithic and ceramic assemblages. Read More…

Over an eight year period four beaches on San Salvador Island, Bahamas have been monitored with respect to their dynamic erosion and depositional processes. Read More…

The Pullman Company shaped the traveling experience of generations of people in the US, starting in 1867 and continuing for 102 years. Soon after the Civil War, Pullman was one of the first industrial firms to hire former slaves. Read More…

Stalagmites from two caves, Almonda Cave and Glory Hole Cave, located near Nazare in westcentral Portugal, are being investigated in order to reconstruct the region’ s paleoenvironmental history. Read More…

Taphonomic analyses of reef corals have been conducted in multiple reefal environments present in a great many locations including the Great Barrier Reef, Florida Keys, Bahamas, and Papua New Guinea. Read More…

We present stable isotopic data from CS-04-5, a 54 cm-high, cylindrical calcite stalagmite from Cosmic Cavern, northwest Arkansas, which grew during the penultimate deglaciation (Termination 2). Read More…

Constituent particle analyses have been applied to many different sedimentary environments, especially in the Bahamas and the Caribbean, but have rarely been used in analyzing sediments from Western Australia. Read More…

Isotopic analysis and U-Th dating of New Zealand speleothem MD3 has yielded a 31,000-year record of climate change published by John Hellstrom in 1998 (Hellstrom et al., 1998). This is a particularly important climate record because the Southern Hemisphere is mostly marine, and thus there are very few places to obtain high-resolution climate information. But climatic information is attainable in the oxygen isotopic composition of speleothems. Read More…

Oceans emit small amounts of carbon monoxide (CO) adding to the total CO load in the atmosphere. The hydroxyl radical is the primary sink for CO and other greenhouse gases. Therefore, the amount of CO in the atmosphere indirectly controls the residence time of greenhouse gases. Read More…

Coral are important components of underwater ecosystems and contribute to reef biodiversity. The Millepora genus (fire coral) is a hydrozoan represented predominately by two species prevalent on tropical western Atlantic reefs. Read More…

Archaeological investigations were conducted at three presumed Late Woodland period Native American sites, 13LN315, 13LN316, and 13LN323, located within the Palisades-Dows Nature Area, Linn County , Iowa . This study was conducted as a field school under the joint auspices of the University Of Iowa ‘s Office of the State Archaeologist (OSA), Iowa City , and Cornell College , Mt. Vernon . Read More…

Roughly 15 to 3 million years ago the Central American Isthmus formed between North and South America resulting in a dramatic transformation of Caribbean marine biota. Read More…

Generally, children’s animated programs, features, and films, to name a few, do little to educate today’s youth about their environment. Many movies and shows that promote marine organisms and ecosystems, to some extent, such as Finding Nemo and Spongebob Squarepants, but do not thoroughly educate about the ocean and the major influence it has in sustaining life. Read More…

Oceans emit small amounts of carbon monoxide (CO) adding to the total CO load in the atmosphere. The hydroxyl radical is the primary sink for CO and other greenhouse gases. Read More…

Sedimentary rock strata at Robins Quarry were sampled and examined in an attempt to interpret the history of the geologic processes in the area. Read More…

Sedimentary rock strata at Robins Quarry were sampled and examined in an attempt to interpret the history of the geologic processes in the area. Read More…