Show HN: Point your camera at a landscape to learn about its geology

outcrop.rocks via hnrss.org/news 2026-10-29 2 min read original

Point your camera at the landscape around you to learn about its geology: what its rocks are called, when and how each one formed, and where the continents were at the time. Works offline.

Free, for iPhone and Android. Geologic maps worldwide from Macrostrat.

Earth’s history#

Outcrop shows where a rock’s age falls in Earth’s 4.5 billion years.

Cenozoic 66–0 Ma
Mesozoic 252–66 Ma
Paleozoic 539–252 Ma
Precambrian 4540–539 Ma

Hover over or tap the line to read a period or an event.

Geologic maps in augmented reality#

Hold your phone up to a canyon wall, a road cut or a far ridge. Outcrop 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, the rest gone grey.

Live at a riverbank: the camera's view of the river and its far bank with the Platteville and Glenwood Formations drawn over the land in green, the reticle on the bank 480 metres away and the unit named below it, Late Ordovician.

Know what’s under your feet.#

The map opens on the rock where you’re standing: its name, its age, what it’s made of and how it formed. Tap anywhere else to read that spot instead.

The geologic map tilted over Upheaval Dome in Canyonlands, the Navajo Sandstone's ring around it outlined, and the Navajo's page below: Early Jurassic, its rocks, the map's description and its age, 201 to 175 million years, on a timeline of Earth's history.

Read the rock below.#

Where Macrostrat has a column for the spot, see the rock beneath it from the surface down: each unit with its age, each gap with the time it leaves out, and the fossils found in them. Tap a unit to read about it.

The rock column under the Navajo Sandstone in the Paradox Basin: 47 units spanning 1.9 billion years, from the Navajo at the surface down through the Permian and Pennsylvanian to a gneiss complex 2 billion years old, with 893 million years missing below the Cambrian.

See where it formed.#

Turn the map into a globe at the rock’s age, drawn from Christopher Scotese’s PALEOMAP maps: where it lay, how far it has come and how fast. Press play to ride its plate to today.

The globe 450 million years ago, in the Ordovician, with the spot where the Platteville and Glenwood Formations formed at 17 degrees south, in the tropics, 7,620 kilometers from where it is now, having moved 4.5 centimeters a year on average.

Find any rock.#

Search for a unit, an age, a rock or a fault. The map lights the places it’s mapped and tells you how far the nearest is, even when it’s off the screen.

From bedrock to topsoil.#

Read the bedrock and its faults from Macrostrat’s geologic maps, in as much detail as each place has been mapped. Switch to Quaternary geology for the glacial and river deposits on top and the faults that have moved recently, or to the soil and the plants that grow in it. On the map and through the camera.

Bedrock and faults worldwide
Quaternary, active faults and soil in the US

The Layers sheet over the geologic map of the Grand Canyon by the Bright Angel Fault: a satellite or map base, Bedrock from Macrostrat, Quaternary from the USGS and Soils from the USDA NRCS to choose from, and Saved areas below.

Save it before you go.#

Outline an area to save it to your phone. The map and the camera view then work with no signal. Fossil finds and active faults in the camera view still need a connection.

Saving the Grand Canyon for offline use: the save at 75 percent, six of its eight steps along, on Live's labels and then the base map, over the Saved areas sheet with satellite imagery switched on.

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