Images are central to metamorphic geochemistry, and images must be stored with rock descriptions and chemical analyses.
MetPetDB will store images of every type tagged to samples or subsamples. Doing this in a way that provides the maximum flexibility and also enables spatial relations in a sample are critical to the usefulness of the database.
Information about image object model can be found in the Image Object page.
In many situations, a large number of images may be collected on a single polished thin section (e.g. photomicrographs, BSE images, X-ray maps, etc.). The spatial relationship of these images is an important piece of information. MetPetDB will preserve this information in the following way.
All images collected on a specific subsample of a sample (eg. a thin section) will be spatially located with respect to either a thin section template, or another image (the parent image). The thin section template will be an empty coordinate system the size of the thin section glass. A digital scan of the thin section will fit inside this template. Other images will be located relative to either this template, or to a parent image. Four pieces of information are required to correctly locate one image with respect to another. Two ways to specify this information are:
- (X,Y) position of two corners of the daughter image with respect to the parent image
- (X,Y) position of one corner (or center) of the daughter image, a rotation angle, and a scale factor
Some of the fields in the image data description record are for the purpose of this registration.
Chemical analysis registration
Chemical analyses by electron microprobe are located at a small spot on a sample, and this is often recorded on an image. In the old days, this was done by placing a dot on a photomicrograph with a pen. Modern microprobes do this digitally. See the page on chemical analyses for more information.
Some fields required for certain image types. You may spell out name or use abbreviations. Acceptable image formats are: .jpg , .gif , .tif , and .png.
|Field Notes||FIELDNOTES||Scanned/digital field notes|
|Drawing||DRAWING||hand sketch or drawing|
|Map||MAP||Map (geologic or otherwise) with sample locations|
|Cross Section||XC||Geologic cross section with sample locations|
|Figure||FIG||Miscellaneous figure, may be composite|
|Field Photo||FIELDPHOTO||Field photo of outcrop or sample location|
|Photograph||PHOTO||General sample imagery|
|Thin Section Scan||TSS||Special image of entire thin section|
|Photomicrograph-Transmitted Plane Polarized||TPPL|
|Photomicrograph-Transmitted Crossed Polars||TXPL|
|Photomicrograph-Reflected Plane Polarized||RPPL|
|Photomicrograph-Reflected Crossed Polars||RXPL|
|Secondary Electron Image||SE|
|Back-Scattered Electron Image||BSE|
|X-ray Map||XRM||Element name (or combo) is required for X-ray maps|