Outcrop app overlays geologic maps on your phone camera view
Outcrop is a free geology app for iPhone and Android that uses the phone camera to show geologic maps over the landscape. A Show HN post points to its page, which describes the idea in one line: hold the phone up to a canyon wall, a road cut or a far ridge, and the app lays the geologic map over the land, names the rock at the center of the screen and labels the peaks and lakes in view. Pick a rock and the land keeps it in color while the rest goes grey.
Beyond the live camera view, the page lists several features. For the spot where you stand, the map identifies the rock, with its name, age, composition and how it formed, and you can tap other spots to read about them. Where data exists, a rock column shows the layers below a spot, with their ages, gaps in the record and fossils. An "ancient locations" feature shows where a rock formed, using paleogeographic maps by Christopher Scotese (PALEOMAP), along with an animation of the rock's plate movement to the present day.
You can also search for units, ages, rock types or faults and see the nearest mapped location, and switch among bedrock, Quaternary geology and soils layers, over satellite or map backgrounds. An area can be saved for offline use, and the app works offline once it is saved. Fossil finds and active faults in the camera view require a connection.
On availability, the page lists Google Play and an iPhone beta through TestFlight. The data sources named are Macrostrat, USGS, USDA NRCS, Paleobiology Database, Mapterhorn, OpenStreetMap and USGS GNIS, with imagery from USDA NAIP. The developer, Flyover Country LLC, also makes Flyover Country, a geology guide for flights. The page invites users to check in at outcrops through Rockd, Macrostrat's field app, and lists a contact address for questions or corrections.
Key facts
- Outcrop is a free geology app for iPhone and Android that overlays geologic maps on the live camera view.
- It names the rock at the center of the screen, labels peaks and lakes, and can keep a selected rock in color while the rest of the land turns grey.
- Extra features: rock column with layers, ages and fossils; paleogeographic maps by Christopher Scotese (PALEOMAP) showing where a rock formed; search; bedrock, Quaternary and soil layers.
- It works offline once an area is saved, but fossil finds and active faults in the camera view require a connection.
- Android is on Google Play; iPhone is a beta through TestFlight. The developer is Flyover Country LLC.
Why it matters
Geologic maps are usually read on a flat screen or on paper, away from the rock they describe. Outcrop puts that information over the view of the real landscape, so a hiker or traveler can point at a canyon wall or ridge and see what the rock is. The page lists name, age, composition and formation for the rock at your location, and the rock column adds the layers below a spot, with ages, gaps in the record and fossils. The data comes from established sources including Macrostrat, USGS and the Paleobiology Database.
Who it affects
The page frames the app around people looking at terrain: canyon walls, road cuts and distant ridges. That points to hikers, travelers and anyone curious about the rock under their feet. The developer also makes Flyover Country, a geology guide for flights, and points users to Rockd, Macrostrat's field app, for checking in at outcrops.
How to use it
Outcrop is described as free for iPhone and Android. Android users get it from Google Play; iPhone users can join a beta through TestFlight. Hold the phone toward a landscape to see the rock at the center of the screen and labeled peaks and lakes, and tap a rock to highlight it in color. Save an area ahead of time to use the app offline. Search covers units, ages, rock types and faults, and layers switch among bedrock, Quaternary geology and soils over satellite or map backgrounds.
How solid is it
The only source is the product's own page, so the feature list is the developer's description rather than an independent review. The data sources it names are established ones: Macrostrat, USGS, USDA NRCS, Paleobiology Database, Mapterhorn, OpenStreetMap and USGS GNIS, with imagery from USDA NAIP. No accuracy figures for rock identification are given, and no release date, version number or download count is stated.
Risks and caveats
The iPhone version is a beta, not a full release. Offline use needs an area saved in advance, and fossil finds and active faults in the camera view require a connection. No coverage area is stated on the page text, and no accuracy figures for rock identification are given, so how well the overlay matches what you see on the ground is not documented there. The page lists a contact address for questions or corrections.
“Hold your phone up to a canyon wall, a road cut or a far ridge.”
— Outcrop page