Macrostrat Beta 0.3

As the first publicly accessible version of Macrostrat, functionality is still very limited. But there’s a lot that you can do right now. Here are some tips and caveats that will help you use Macrostrat to explore the rock record of 1534 geographic regions.

Stay tuned! 1491 radioisotopic ages are already included, but more will be added, along with geochemical and measured section data.

What is Macrostrat Beta?

Macrostrat Beta 0.3 is the initial public, graphical interface for a comprehensive relational database currently containing 35154 stratigraphic units and more than 90,000 attributes (radioisotopic ages, lithologies, economic uses, etc.). Macrostrat is intended to become a community-driven platform for macrostratigraphy, which facilitates the rigorous testing of hypotheses related to the spatial and temporal distribution of sedimentary, igneous, and metamorphic rocks and proxy data extracted from them. It is also meant to facilitate teaching in the earth sciences.

Updates in Version 0.3

Designed for quick and easy navigation and exploration.

The fundamental architecture of Macrostrat allows new quantitative analyses of the rock record, particularly those that are based on the principles of macrostratigraphy. Although we are working hard to bring you this capability, the web tools necessary to conduct quantitative analyses aren't yet finished. Instead, for this version, we have emphasized a visual navigation and data exploration experience that is useful for both teaching and research. Stay tuned for more analytical functionality and even more useful search and navigation tools.

As part of Version 0.3, we have integrated the 2005 Geologic Map of North America, which is stored in Macrostrat as fully indexed spatial objects. 39,827 polygons and 12,424 faults and fold axes are included. This makes it possible to calcuate outcrop and subsurface area for stratigraphic units among other things. Stay tuned! We are working hard to bring many greatly enhanced features that will put geologic maps to whole new uses.

Lithostratigraphic units are the basics.

Lithostratigraphic units from individual geographic locations (columns) constitute the fundamental currency of Macrostrat. Units (typically formations, but also members and groups) serve as the hub for linking fossil collections, environments, lithologies, and economic uses together. In the case of Macrostrat, the same named lithostratigraphic unit might occur separately in many columns. This isn’t redudant it's an accurate reflection of spatial coverage.

Naturally, many of the lithostratigraphic units in Macrostrat have little correlation or sequence stratigraphic utility. They do, however, capture some degree of temporal and spatial variability in the rock record. This version of Macrostrat is just the starting point for building a more complete picture of rocks in time and space. More refined data are being compiled and will be available soon. See a complete list of lithostratigraphic names currently in the database by following this link: Stratigraphic Names.

Easy-to-scan geologic time scales.

Geologic time scales are provided on all unit and column pages. These highlight all time intervals that are represented by the currently viewable units, such as those that might be retrieved by a search or by navigation in map view. When a complete stratigraphic column is examined, the information pages provide a summary of the rock record for that column. The graphical renderings of rock units within columns and within gap-bound packages are schematic and do not yet accurately show lateral relationships. We are working to make the rendering of stratigraphic columns more accurate.

Reintegrating the fossil and rock records.

Macrostrat is synced with the Paleobiology Database (PaleoDB) daily through the official PaleoDB mirror site hosted at the University of Wisconsin-Madison. Using a combination of stratigraphic nomenclature and geography we have matched greater than 91% of all North America PaleoDB collections to lithostratigraphic units. For each fossiliferous unit, the number of PaleoDB collections, occurrences and unique taxa (as entered into the PaleoDB, typically genera or species) are tabulated and links to the PaleoDB are plotted on the map. This integration of the rock and fossil records will allow the quantitative analysis of the of covariation, or lack there of, between these two records. Stay tuned for online analytical tools.

Due to performance issues in many browsers, maps do not currently display more than 500 fossil collections. The displayed collections are randomly chosen from the available collections to provide a sense of geographic coverage. We are working on ways to keep Macrostrat forward looking while also maintaining good performance on older browsers and systems.

Explicit stratigraphic hierarchy.

Stratigraphic nomenclatural heirarchies are stored explicitly in Macrostrat. This makes it possible to easily navigate up and down the hierarchy to see where lithostratigraphic names occur in time and in space. Click on a cell in the hierarchy table and instantly see all of the locations where that unit occurs, along with all of their attributes and fossil collections. A list of all stratigraphic names is available.

Visual barcodes for data summaries.

We all spend too much time reading text on our computer screens. To speed up your information retrevial, we have developed a barcode module that displays the proportion of various unit data categories as colored bars. The four caetgories shown are Lithology, Environment, Economic and Paleontology. Note that a unit may have more than one attribute within each category. Currently, every unit in Macrostrat has at least one dominant lithology attribute, but not all units have secondary lithologies. The paleoenvironmental data are also in a state of flux and many sedimentary units do not yet have any environmental data. The paleontology data are updated daily from the Paleobiology Database.

Because not all rock units have been assigned complete or partial environmental, economic, and/or lithological data, your search may return an incomplete subset of data. We are working hard to fill in these gaps, but do be aware of this important limitation.