Facilities & Equipment

The PAST Laboratory is the newest facility in the Geography and Anthropology Department with 2600 square feet of laboratory and office space containing all the necessary equipment to prepare carbonate samples for geochemical analysis and to collabrate on paleoclimate research.

ICP-OES

ICP-OES

Perkin Elmer 8300 ICP-OES in intrument room

The PAST lab houses a Perkin Elmer 8300 Inductive Coupled Plasma Optical Emission Spectrophotometer (ICP-OES) for trace elemental analysis of Sr/Ca, Mg/Ca, and Ba/Ca in carbonates (corals, shells, foraminfera, and spelothems). The 8300 has radial and axial views of the plasma and simultaneous readings of a wide range of elemental wavelengths. We can analyze up to 200 samples in 24 hours including references. Samples are dissolved in 2% nitric acid and weighed on the microbalance to achieve a 20 ppm Ca concentration for ICP-OES analysis following the method of Schrag 1999. Our in-house gravmetric standard (IGS) has an analytical precision for Sr/Ca is 0.15% and for external coral references 0.16% for Porites lutea (Pl) and 0.18% for JCp-1. Accuracies for Sr/Ca are 0.09% for Pl and -0.15% for JCp-1. Barium in carbonates is a relatively new analyte for ICP-OES analysis and we are achieving accuracies and precisions similar to ICP-MS in coral and shell samples (IGS = 1.49%, Pl =4.67%, and 1.25% accuracy for JCp-1). If you are interested in using the ICP-OES for your project, please contact Kristine DeLong at kdelong@lsu.edu.

Wet lab in PAST lab

Wet lab in PAST lab for preparing aqueous samples.

Wet Lab

The PAST Lab has facilities for aqueous sample preparation including a Milli-Q water filtration system for deionized (Type 3) and ultrapure water (Type 1), and a fume hood rated for acids used in geochemical labs and all the required safety equipment. For cleaning specimens (shells, corals, bone, etc.), there is a large volume (19.5" x 11.5" x 6") Branson® ultrasonic cleaner (corals and their slabs) , a Branson 400 sonifier digital ultrasonic cell disruptor for removing organics without chemicals (corals, shells, bone), a small ultrasonic cleaner (slides and small shells), and a large drying oven. The wet lab also has votex mixers, hot plates, pipets (50 ml, 1000 ul, 500 ul, 10 ul), agate mortar and pestle, glass and plastic ware (LDPE and teflon) for chemical analyses (beakers, test tubes, bottles, carboys).

Micro-Sampling System

Micromill system

Taig micromill with SuperCAM controllers and software.

The PAST Lab has a Taig 3000 Micromill driven by a SuperTech motors, controller, and computer system capable of precision movements in three directions (minimal step = 0.8 μm). The computer system interface is capable of importing drill paths drawn on X-rays for precise and reproducible paths for sampling corals, bivalves, speleothems, and other samples. The micromill allows users to regulate the speed and sampling depth in small increments, which helps reduce chipping and breaking during sampling and greatly improves the extraction of samples from fragile substrates. The micromill uses dental drill bits (1.4, 1.2, 1, 0.7, 0.5 mm) and diamond bits (0.5 mm for small samples).  See our system in action, and check out a close up view of our system shaving coral powder. The lab also has a Dremel tool with flexi-shaft for cutting samples by hand for radiocarbon dating, uranium-thorium dating, and cutting larger pieces for other types of analyses (e.g., laser-ablation, annual bands in corals).

saws for cutting shells

Buehler IsoMet low speed saw (>±5 µm)

Sectioning

The PAST lab has two low speed 5 inch diamond wheel saws for sectioning mollusk shells, fish otoliths, speleothems, and bone for microscopic and microsampling analysis. We also have two tile saws for larger samples and applications such as slabbing corals and speleothems for the micromill. We have different epoxies and molds for small or fragile samples. Cut samples can be mounted on glass slides for polishing to view banding patterns or for micromilling. We also have Mutvei solution for staining cross-sections.

Tree Rings

increment borer

Increment borer on the LSU oak tree cross-section.

The PAST lab has two Haglof increment borers (20 inch and 16 inch), core mounts, and sanding equipment for tree-ring studies.

Imaging

Microscopes with digital cameras including a Zeiss microscope for shell cross-sections, tree-ring, microfossil, and sedimentological analyses, as well as a DinoXcope® digital microscope for capturing magnified images for analysis of variations in incremental banded hard body parts. The DinoXcope® is used with the micromill for detailed sampling work and documentation of sampling.

An EPSON Expression 10000 XL scanner large format color scanner (1200 dpi) for scanning samples and transparent originals, as well as scanning tree cores for length analysis in WinDendro. A HP color laser printer is also available.

Several Macintosh computers with Adobe Software for image analysis and figure creation as well as MatLab licenses for data processing and analysis. All computers have Microsoft Suite software (Word, Excel, PowerPoint).

Weighing

A Mettler–Toledo XS3DU Microbalance (1 microgram) for weighing samples for geochemical analysis as well as three other lower precision balances (Ohaus 0.001 g ) for weighing shells and other samples.

coring a coral boulder

Coring a coral boulder in Little Cayman.

Field Work

The PAST lab has a 4.445-cm pneumatic coring system with 40-cm core barrel with diamond drill bit that is operated by scuba tanks for coring corals on land or in water. The system has 100 feet of tubing and water pump system for clearing cutting while drilling. We also have HOBO data loggers (temperature and salinity). Additionally, the Coastal Studies Insitute and the Department of Geography and Anthropology have boats, dive gear, and vibra coring systems for field work, see https://www.lsu.edu/csi/fieldsupport1.php.