Facilities and Instruments

Colgate’s system combines a double-beam Echelle optical system with a solid state detector. Both acetylene and nitrous oxide fuel mixtures can be used to allow for the analysis of a wide range of elements. Cordless LuminaTM lamps provide the element specific light. The system is run by WinLab 32TM operating software with touch-screen controls.

Broadband seismometers measure ground motion across a broad range of frequencies, detecting not only earthquakes, but also storms, footsteps, loud noises, and even passing vehicles!  These instruments measure ground motion (as movement velocity) as small as micrometers per second, and in three dimensions.  Motion is recorded electronically as a suspended weight moves independently from the casing, passing a magnet through coiled wires, inducing an electrical current.  To collect meaningful information on ground motion, these broadband seismometers are buried in locations of geologic interest for periods of time ranging from months to several years.

The Geode seismic acquisition system includes 24 sensitive geophones that measure ground motion at very high frequencies at evenly-spaced distances.  Signals recorded by this system are typically from a man-made source, such as a weight-drop or the impact of a sledgehammer on a metal plate.  Timing of this signal is precisely synchronized with all 24 geophones to create records of how energy is transmitted through the ground, and how it reflects off of subsurface interfaces.

The G-857 is a proton procession magnetometer, which measures magnetic fields to a sensitivity of tenths of a nanoTesla.  The sensor is filled with a fluid containing hydrogen atoms.  A strong magnetic field is created around the fluid, causing the protons of the hydrogen atoms to align within the field.  When the artificial magnetic field is released, the protons realign with the natural ambient magnetic field, creating an electrical current that is recorded by the instrument and converted to magnetic field strength.  By making measurements like this in many locations, we can create a map showing how the magnetic field varies spatially.  This can reveal changes in subsurface geology, buried objects containing small amounts of ferrous material, or even disturbed soils.

Inductively coupled plasma mass spectrometers (ICP-MS) measure the concentrations of trace and major elements in liquid or solid samples. The Varian 820-MS ICP-MS is set up to process data from solutions using the Cetac ASX-520 autosampler or solids using the New Wave UP 213nm laser ablation system. This laser ablation system allows researchers to get pinpoint, in situ data from solid samples like rocks, glass, and crystals. Both the Varian and Argilent instruments housed in this lab are quadrupole ICP-MS systems, so researchers can measure the majority of the periodic table in just seconds.

Instrument statistics

Download the Bruker 820-MS brochure.

View information about the laser ablation system.

How it works

A beam of high-energy electrons is produced in the electron gun at the top of the column by applying high voltage to a tungsten filament and nearby anode. This beam is accelerated past the anode into the column, where it is condensed and aligned by a series of electromagnetic lenses and coils within the column. This focused beam continuously rasters back and forth across the sample. Interactions between the electron beam and the sample result in different types of emissions that are measured by a series of detectors located within the sample chamber. The types of emissions that are measured are: secondary electrons, backscattered electrons, x-rays, and cathode luminescence. X-ray data is sent to the x-ray system, where it is translated into elemental plots. The other three detectors are connected to a monitor where the signal produces a clear image of the sample. Secondary electron imaging provides good three-dimensional topographic views of the sample. Backscattered electron images show less-defined topography but clearly display differences in elemental compositions because higher-atomic-number elements appear brighter. Cathode luminescence imaging highlights chemical variations within individual grains due to trace element variations and zoning.

Instrument statistics

Colgate’s EDS system is run by Inca software. The detector has a beryllium window. Quantitative analyses are performed at 20 kV using a 25 mm working distance, 35 percent dead time, and are collected for 200 seconds of live time.

Select publications from work done at Colgate's SEM lab
* indicates collaborative research with students

Peck, WH, and *Eppich, GR, 2019, The Kilmar magnesite deposits: Evaporitic metasediments in the Grenville supergroup, Morin terrane, Quebec): Minerals, v. 9, 554.

Peck, WH, *Quinan, MP, and Selleck, BW, 2019, Detrital zircon constraints on Grenville sedimentation at the margin of Laurentia: Precambrian Research, v. 331, 105342.

Peck, WH, Selleck, BW, Regan, SP, *Howard, G, and *Kozel, OO, 2018, In-situ dating of metamorphism in Adirondack anorthosite: American Mineralogist, v. 103, p. 1523-1529.

Peck, WH, *Shramko, MF, and Verbeek, ER, 2016, Carbon and oxygen isotopes of secondary carbonates at Franklin and Sterling Hill: The Picking Table, v. 57, p. 29-38. 

Peck, WH, 2016, Protolith carbon isotope ratios in cordierite from metamorphic and igneous rocks: American Mineralogist, v. 101, p. 2279-2287.

Peck, WH, 2012, Reconnaissance geochronology and geochemistry of the Mont-Tremblant gneiss of the Morin terrane, Grenville Province, Quebec: Geosphere, v. 8, p. 1356-1365.

Brown, L.L., McEnroe, S.A., Peck, W.H., Peterson, L.P. (2011). Anorthosites as Sources of Magnetic Anomalies, in Earth’s Magnetic Interior (E. Petrovský, D. Ivers, T. Harinarayana, and E. Herrero-Bervera, Eds.), Springer-Verlag, p. 321-342.

Wong, M.S., Peck, W.H., Selleck, B.W., *Catalano, J.P., *Hochman, S.D., and *Maurer, J.T. (2011). The Black Lake Shear Zone: A boundary between terranes in the Adirondack Lowlands, Grenville Province. Precambrian Research, v. 188, p. 57-72.

Peck, W.H., McLelland, J.M., Bickford, M.E., *Nagle, A.N., *Swarr, G.J (2010.) Mechanism of zircon overgrowth formation of a granulite-facies quartzite, Adirondack Highlands, Grenville Province, New York. American Mineralogist, v. 95, p. 1796-1806. 

Segall, K., Dioguardi, A.P., Fernandes, N., Mazo, J.J. (2009). Experimental Observation of Fluxon Diffusion in Josephson Rings. Journal of Low Temperature Physics, v. 154, 41-54. 

Cavosie, A.J., Kita, N.T., and Valley, J.W. (2009). Magmatic zircons from the Mid-Atlantic Ridge: Primitive oxygen isotope signature. American Mineralogist, 94(7): 926-934. 

King, E.M., Trzaskus, A.P., and Valley, J.W. (2008). Oxygen isotope evidence for magmatic variability and multiple alteration events in the Proterozoic St. Francois Mountains, Missouri. Precambrian Research, Volume 165, Pages 49-60. 

Bickford, M.E., McLelland, J.M., Selleck, B.W., Hill, Barbara M., and Heumann, M.J. (2008). Timing of anatexis in the eastern Adirondack Highlands: Implications for tectonic evolution during ca. 1050 Ma Ottawan orogenesis. Geol. Soc. America Bulletin, v. 120. 

Carr, P., Selleck, B., Stott, M., Williamson, P. (2008). Native lead at Broken Hill, New South Wales, Australia. Canadian Mineralogist, v. 46. 

Kelly, J.L., Fu, B., Kita, N.T., and Valley, J.W. (2007). Optically continuous silcrete quartz cements of the St. Peter Sandstone: High precision oxygen isotope analysis by ion microprobe. Geochimica et Cosmochimica Acta 71(15): 3812-3832. 

Heumann, M.J., Bickford, M., Hill, B.M., McLelland, J., Selleck, B., and Jercinovic, M.J.  (2006). Timing of anatexis in metapelites from the Adirondack lowlands and southern highlands: A manifestation of the Shawinigan orogeny and subsequent anorthosite-mangerite-charnockite-granite magmatism. Geological Society of America Bulletin, v. 118, no. 8. 

Selleck, B., McLelland, J.M., and Bickford, M.E. (2005). Granite emplacement during tectonic exhumation, The Adirondack example. Geology, v. 33, p. 781-784. 

Peck, W.H., DeAngelis, M.T., Meredith, M.T.*, Morin, E. (2005). Polymetamorphism of marbles in the Morin terrane (Grenville Province, Quebec). Canadian Journal of Earth Sciences, v. 42, 
p. 1949-1965.
 

How it works

Oxygen, carbon, or nitrogen must be separated from samples by some chemical method (such as combustion, dissolution in acids, or fusing with a laser in the presence of an oxidizer). Gases are then purified in a vacuum line (glass trellis-work in picture) or within the elemental analyzer. The purified gases are then introduced into the mass spectrometer, either by using the dual-inlet system or continuous flow mode, where they are bombarded by electrons and ionized. The ions travel down a flight tube and are separated according to mass by an electromagnet. The ions are then detected in Faraday cups at the end of the flight tube. The isotope ratio is calculated from the charge of the ions at the end of the flight tube. See Finnigan's brochure for instrument and analytical statistics.

Colgate’s system uses Cu Kα radiation that has a wavelength of 1.54Å. Analyses are commonly run using a 40kV 45mA x-ray tube voltage, a 0.04° soller slit, 1° divergence and antiscatter slits, and a 1/2° (for powder) or 1/4° (for clays) receiving slit.

How it works

During x-ray diffraction analysis, x-ray beams are reflected off the parallel atomic layers within a mineral over a range of diffraction angles. Because the x-ray beam has a specific wavelength, for any given 'd-spacing' (distance between adjacent atomic planes) there are only specific angles at which the exiting rays will be 'in phase' and therefore rays will be picked up by the detector producing a peak on the 'diffractogram.' Like a human fingerprint, every mineral has its own distinct set of diffraction peaks that can be used to identify it.

Related research

This system has been used extensively to collect data for a wide variety of research. Some of the major projects include:
CZEN — Critical Zone research on soil development and chemical weathering
NSF/CRUI — Study on acid deposition and calcium depletion in Adirondack soils
ILWAS — Integrated Lake Watershed Acidification Study — study of the effects of acid deposition on three Adirondack lakes
RILWAS — Regional Integrated Lake Watershed Acidification Study: a study of the effects of acid deposition on lakes in the Adirondacks and various other locations across the United States, Canada, and Europe
ALBIOS — Aluminum Biogeochemistry Study: a study of the effects of aluminum on forested ecosystems
IFS — Integrated Forest Study, an international effort to study the effects of acid deposition on forest ecosystems throughout the United States, Canada, and Europe
DOE — study of the distribution of Cesium-137 in lake-bottom sediments

Using the same principle of Colgate’s laboratory x-ray fluorescence spectrometer, this hand-held unit uses high-energy x-ray photons to analyze geologic samples. The energy of secondary x-rays emitted by the sample during analysis is specific to each particular element, which can be used to determine its chemical composition.

This lab has been used extensively to collect data for a wide variety of research projects including:

CZEN — Critical Zone research on soil development and chemical weathering 
NSF/CRUI — Study on Acid Deposition and Calcium Depletion in Adirondack Soils
DOE study of the distribution of Cesium-137 in lake bottom sediments
IFS — Integrated Forest Study: an international effort to study the effects of acid deposition on forest ecosystems throughout the United States, Canada, and Europe
ALBIOS — Aluminum Biogeochemistry Study - a study of the effects of aluminum on forested ecosystems
RILWAS — Regional Integrated Lake Watershed Acidification Study - a study of the effects of acid deposition on lakes in the Adirondacks and various other locations across the United States, Canada, and Europe
ILWAS — Integrated Lake Watershed Acidification Study - a study of the effects of acid deposition on three Adirondack lakes

• AACSE – Alaska Amphibious Community Seismic Experiment
• TZVOLCANO
• Seismicity of Upstate New York
• Lamont-Doherty Cooperative Seismic Network

Middle Devonian rocks in New York State are largely marine and represent shallow coastal environments to the east and deeper basinal environments to the west. Most of the fossils at Colgate are from within a 30 km radius of Hamilton, NY, and represent a shallow midshelf fauna rich in brachiopods and bivalves. High sediment influx and variable salinity produced conditions that were distinctly different from the normal marine to anoxic environments in the western part of the state. 

Colgate has about 5000 lots (185 drawers) of identified Hamilton Group fossils. These are from the upper Marcellus, Skaneateles, Ludlowville, and Moscow formations. In addition, there are 750 lots of western New York Hamilton Group fossils, which include many corals, 500 lots of Lower and Upper Devonian fossils, and 200 lots of eurypterids from the Bertie Waterlime. 

The Robert M. Linsley Collections at Colgate comprise an impressive set of identified Tertiary and modern molluscs with around 4000 lots of gastropods and 1300 lots of bivalves. Part of the modern collections are from Albert Bickmore, who collected in the Netherlands East Indies and southwest Pacific in 1865. 

In addition to the teaching collection, there are 250 drawers of non-Devonian invertebrate and plant fossils. 160 drawers are an identified and diverse invertebrate collection spanning the Phanerozoic, 60 drawers are Cenozoic marine molluscs from Florida, and 30 drawers contain Upper Paleozoic and Cenozoic plant fossils.