The Lamont-Doherty Core Repository occupies about 12,000 square feet on the first floor of the Core Laboratory and on the basement level of the Geoscience Building. The space includes a main office and core library of 418.5 sq ft., an exhibit room of 292 sq ft., a cutting/sampling room of 223 sq ft., a walk-in refrigerator of 3,279 sq ft., and a dredge storage area of 1,750 sq ft.
We have four large lockers that are used for storage of cores. There are 77 racks in the main dry core storage areas containing a total of 53,880 eight foot long trays. The refrigerated locker in the Core Repository, kept at 40°F, contains 24 racks holding 2,307 wide diameter, 5 foot long D-tubes, 1,108 small diameter D-tubes, and 3 rolling racks for small sub-samples.
A small section of the core archive.
Typically cores entering the repository are prepared by cutting them into 1.5 m (approximately five feet) lengths and then splitting them longitudinally. Intervals are permanently marked with non-corrosive, non-reactive markers every 10 cm in both working and archive halves of the core. The split cores are photographed and described. Lithologic properties of the sediment are logged by interval, including mass properties such as: texture and color; structure such as bedding, burrows; composition including carbonate content; paleontology and mineralogy; and nature of basal contact to next interval. Storage of the majority of the collection is dry, in 8-foot galvanized steel trays, the archive half sealed in plastic. Cores added to the repository after 1985 have been refrigerated, moist, in 5-foot D-tubes. Dredges, many of them described by the project's Principal Investigator, are stored in 1 x 1 x 2 foot wooden crates, and more recently, 8" x 14" x 24" fiber-glass reinforced plastic bins.
The Repository operates a number of labs and instruments dedicated to making fundamental measurements on material entering the repository including several non-destructive methods. Instruments for conducting and/or assisting with analyses of deep-sea sediments include a GeoTek Multi-Sensor Core Logger, an Itrax XRF core scanner, a UIC coulometer, a Micromeritics sedigraph, Vane Shear, Sonic Sifter, core splitter, freeze dryer, as well as a variety of microscopes, sieves, and sampling tools. We also make these instruments available to the scientific community for conducting analyses of deep-sea sediments (see Samples & Services ).
For actual sampling of core material, standard tools for sampling wet cores are available. We also have a hand-held high-speed drill fitted with a dental bit for high-resolution sampling of dry cores. The sampling can be done without removing the sediment from the tray that in the past has been a problem for maintaining the integrity of dried sediment. For larger samples we use a scroll saw fitted with a diamond coated musical wire that produces clean cuts with almost no loss of material.
MST/XRF Lab: Our GeoTek multisensor track (#46) includes a gamma-ray attenuation porosity evaluater (GRAPE) and compressional wave (P-wave) logger devices that measure bulk density, porosity and sonic velocity. It also has two Bartington magnetic susceptibility loops for different sized cores as well as a Bartington point sensor for running on split cores.
The Itrax Corescanner at LDEO offers rapid, non-destructive analysis of split sediment cores, coral slabs, u-channels... virtually any flat sample. It is capable of sample resolution as high as 20 microns.
The Itrax provides high-resolution digital photography, x-radiography and XRF elemental analysis. The XRF analysis provides data for Aluminum through Uranium, at resolutions of 0.2-20cm and at speeds as low as 2s/2mm. In other words, it is possible to run a 1.5m core section through the instrument and get a hi-res digital photograph, x-radiograph and XRF analysis in less than one hour.
The Itrax data can be used for inter-core correlations, event stratigraphy (ash layers, turbidites, ice-rafted debris, atomic bomb testing), pollution histories (leaded gasoline, localized contaminants), proxies for paleoclimate research, and help in determining relative grain size (turbidites) and water and organic matter content.
We can run samples for you or train you to run them yourself. Our knowledgeable staff can also assist with data reduction and interpretation if you are not familiar with XRF data and the Itrax software.
What can be run on the Itrax Corescanner:
Split sediment cores
...Any sample up to 180cm long by 12cm wide by 6cm high/thick
An image of a carbonate rich core with x-ray and graph of Fe overlayed.
Sediment Lab: We do grain size analysis using a Micromeritics Sedigraph 5100 paired with the MasterTech 51 sampling carousel that allows for grain size measurement below 63 microns (down to 0.8 microns). We also have an ATM L3P Sonic Sifter for separating the coarse fraction of sediments into multiple size fractions. When used together, we can generate a grain size profile for any sediment sample. We also have a UIC CM5012 CO2 Coulometer paired with an AutomateFX sampling carousel that allows us to process almost 100 samples for total inorganic carbon per day.
We recently added several automated sample washing stations that each allow for up to eight disaggregated sediment samples to be wet sieved at one time!
If you are interested in borrowing any field equipment, please contact the Repository Curator .
MST: A second, older GeoTek mutlisensor track (#12) is available to go to sea. It includes a gamma-ray attenuation porosity evaluator (GRAPE) and compressional wave (P-wave) logger devices that measure bulk density, porosity, sonic velocity, and magnetic susceptibility.
Orange-peel Grab: This hollow metal ball, one foot in diameter, can be lowered to the ocean floor and closes when it hits the ground, capturing any soft sediments (and small rocks) below it.
Dredge Net: A 3 foot by 4 foot heavy chain-link 'bag' for dragging along the ocean bottom to collect rock samples.
A dredge net and its recently collected samples