This continues the series began last month, providing GMs with descriptions of interesting geological features.

Desert Finds

Deserts can take out a party like no other, but often traversing the desert is preferable to a roundabout route that takes months.

Ergs

The classic endless shifting sea of sand, dunes change shape within the hour, controlled by the prevailing winds. At the edges the dunes are stabilized by vegetation, often the only place a local tribe can manage a crop of life-preserving food.

Example: The Erg of Bilma, Chad/Niger

Example Description: From horizon to horizon, the desert is daunting, a billowing expanse of sand dunes creating patterns of ridges and depressions as far as the eye can see.

Example Description: Unending ridges of deep-red sand corrugate the surface, like waves of a monstrous bloody sea. Far from lifeless, low shrubs and clumps of grass dot the steep slopes before you.

Artesian Spring

Water from a water-bearing rock layer is trapped between two impermeable rock layers. The water escapes through a natural outlet, such as a fault, in the upper rock layer, and boils out as a spring. Such finds are welcome in desert conditions and often the remains of temporary camps can be found nearby.

Example: Ain ez Zarqa, Lebanon

Example Description: Suddenly, in the midst of this parched desolation, a surprisingly green area rich in trees and other plants interrupts the landscape. The blue waters roil violently as they pour through the valley and beyond the next barren hill.

Example Description: Encircled by ochre-colored hills on the edge of a vast desert, a broad roughly triangular basin contains a bubbling spring, nourishing groves of date palms, citrus, and other crops. Scattered amongst the green trees are the tan brick buildings of a town.

Oasis Valley

A river, sustained by plentiful precipitation on the high peaks of nearby mountains, winds through the desert and creates a valley lush with greenery. Often these oasis valleys are dotted with villages, taking advantage of the available water supply. Further downstream the oases are fewer and the river smaller, until only the desert can be seen, the water absorbed by the parched sands.

Example: Abiod Valley, Algeria

Example Description: Stark cliffs and barren plateaus greatly contrast the greenery erupting from the floor of the valley.

Example Description: Flanked by desert, the river winds its way through the sand, leaving behind sufficient water for crops for those who know how to find it.

Dry Canyon

Thousands, or even millions of years ago, waters provided by recurring wet cycles were sufficient to carve out this section of a flat-topped plateau, creating a crack in the earth where water no longer flows. Travelers can find shelter here from the winds that chase across the higher land.

Example: Amojir Pass, Mauritania

Example Description: Incised in the flat terrain, the meandering canyon walls are topped by towering vertical cliffs. A few drought-resistant plants, mostly acacias, dot the valley floor.

Example Description: Reared up like ancient battlements, sandstone cliffs overlook barren valleys where few plants thrive.

Desert Plateau

Once under the sea, the land rose, exposing the floor to the erosion of the surface, leaving behind multihued domes with valleys between. Although not often settled, these are places where travelers must often pass on their way to another part of the region. A rare few use these plateaus as home territory, generally living beneath the soil where the air is cooler.

Example: Petrified Forest, Arizona

Example Description: Surrounded by hills tinted with horizontal bands of color, the remains of a bygone forest turned to stone are strewn across the landscape, gleaming in the sun.

Example Description: A desolate-looking chain of hills provides easily dug caves in the thick-compacted beds of soil, providing a surprisingly comfortable home for industrious societies.

Plateau Erosion Canyon

The edge of the plateau is fractured by erosion and occasional flash floods, splitting off walls and isolated columns of rock. With the debris washed out, passageways are formed in a labyrinth of tall spires of rocks.

Example: Bryce Canyon, Utah

Example Description: A multicolored mass of ravines, pinnacles, and colonnades break up the landscape before you, creating a maze of rock and debris.

Example Description: Towering red sandstone remnants rise from sloping bases of shale, creating massive monoliths that dot the desert flatlands.

Brine Lake

They occupy depressions where the earth’s crust is split and adjacent areas have moved with respect to one another. Usually these lakes have no outlet and a high evaporation rate, which leads to an increasing concentration of salt in the water. The mineral salts crystallize on the shore and at the bottom of the lake. Any animal that falls into the salt water is killed almost instantly. Debris such as wood and bone are immediately coated with a layer of preserving salt.

Example: Lake Assal, Djibouti; The Great Salt Lake, Utah, Dead Sea, Israel/Jordan

Example Description: The small waves slap against glistening encrustations of white material. Surrounding the lake is a glittering expanse of this same material.

Example Description: Cupped at the bottom of a long narrow desert valley, the glittering expanse of brilliantly blue water beckons you. Miniature castles made up of salt are reflected in briny moats along the shoreline.

Salt Flats/Domes

Once inundated by water, all that’s left in the basin after evaporation is a few shallow brine lakes and bubbling springs. The deposits are up to three miles (five kilometers) thick. Some salt flats are so old that all groundwater is gone, leaving forbidding mosaics of rock, sand, and salt. Travelers and nearby villagers gather the salt for a number of uses.

Example: Dallol Salt Flats, Ethiopia

Example Description: The surface of this hot, dry place is patched throughout with white deposits. Nearby, a large pale conical mound spits out water like a miniature volcano.

Example Description: Relentless winds have sculpted ridges of salt and clay into a turbulent pattern of jagged crests and troughs.

Coastal Seascapes

The continuous onslaught of the waves molds breathtaking landscapes for those on land, but dangerous landing sites for travelers at sea.

Drowned Coastline

The tremendous weight of the ice cap pushed this land downwards and the later ice melt raised the sea level. Former valleys were flooded and mountain ridges surrounded by encroaching water. The headlands are often scalloped by the tides and long-gone glaciers, providing small bays, coves, sea caves, and tranquil tidal pools. Fishing villages develop among the bays, but are unable to sustain larger craft readily. Further inland are rugged granite hills covered with forests, rolling meadows, and steep valleys, with freshwater lakes and ponds in the numerous basins.

Example: Acadia, Maine; Moskenesoy, Norway

Example Description: Sweeping slopes, rugged headlands, and sheltered beaches create a striking array of scenery, a dramatic meeting place of solid land and surging sea.

Example Description: Jagged mountain peaks, deeply sculpted by glacial erosion, stand guard over the headland’s picturesque harbors, deep waters, and tiny fishing villages.

Large Natural Bay

A broad, deep, indentation on the coast, often partially enclosed by a sheltering peninsula. Perhaps an island or two at the mouth of the deep-water bay further protects it from ocean swells. A mountain barrier rises steeply and nearly encircles the lowlands by the bay. Bays this well protected are usually recognized for their potential early on and become main ports for trade, resulting in cities.

Example: Acapulco, Mexico; Diégo-Suarez Bay, Madagascar

Example Description: Protected by a narrow inlet that shelters the region from strong winds, the bay opens out into a series of arms separated by long ridges and flat-topped plateaus. From the narrow coastal plains surrounded the fine harbor, the terrain rises abruptly along a series of escarpments to a high central plateau.

Example Description: On all sides the steep slops of the domelike emerald-green mountains plunge down nearly to the sea, separated from it by long, crescent-shaped beaches. The city itself spreads out in every direction through narrow valleys between the massifs.

Sea Cliffs

Usually made up of a low range of mountains, the slope facing the ocean is very steep, while the other side inclines gently, allowing for easy cultivation.

Example: Serra da Arrabida, Portugal

Example Description: Covered with dark pines and cypresses, the pink and white cliffs rise serenely above an ocean of matchless blue.

Example Description: The pounding sea has carved this coastline into spectacular headlands, arches, and isolated sea stacks, many of which seem ready to fall at any moment.

Island Labyrinths

As masses of ice ground by, they stripped away most of the soil and the surface rock, bending the earth’s crust. Later, the ice melt covered the region by sea and the release of the weight off the earth’s crust has allowed it to spring back a bit, creating thousands of islands in the mouth of a gulf. Small boats travel easily between the shoreline and provide food and shelter for all types of animals and the villagers that hunt them.

Example: Aland Islands, Finland

Example Description: Capped with fragrant groves of evergreens near the waterline, the gently rounded rocky islands seem to drift in a labyrinth of picturesque channels.

Example Description: Land and water intermingle in the island-studded bay, like an abandoned fleet of ships scattered across the surface of the water.

Extinct Volcanic Islands

Often tropical paradises, these islands were once volcanoes that have long eroded, leaving a deep depression or small sections of exposed crater in the center, surrounded by a nearly circular coral reef. As sea levels changed portions of the coral reef emerged from the water as long narrow islands, now covered with greenery. The lagoon within the coral barrier is usually calm and makes excellent shelter for passing ships, so long as they can find an entrance past the coral reef. As these ancient volcanoes age and face constant erosion, the protective reef vanishes, leaving only a long curled spur in the waters.

Example: Bora-Bora, French Polynesia

Example Description: Jagged crests and ridges, lush with vegetation, rise dramatically from the deeply indented shoreline. Surrounding the larger island are long narrow islets enclosing one of the most beautiful lagoons you have ever seen.

Example Description: From a distance this rocky islet appears devoid of vegetation, but closer inspection reveals vines and small prostrate shrubbery on the low hills. The hook of the island curls around what appears to be a bay, but the water is too rough to provide a landing. On the high side of the tallest spur of the island, however, appears to be a small lee where landing is possible.

Saltwater Gulf

Usually only seen at low tide, the sand flats are interlaced with channels of water. Water bird flock to the region, sometimes in flocks of thousands, providing human inhabitants with an almost limitless supply of food.

Example: Waddenzee, Netherlands; Las Marismas, Spain

Example Description: The distinction between land and sea is hard to determine at this site of struggle between earth and water. Natural drainage channels snake across soft silt, leaving the footing precarious.

Example Description: Behind a belt of coastal dunes lies a vast mosaic of land and water—low-lying islands, ponds, and silt-choked waterways teaming with wildlife.

Geothermal Devices

Geothermal areas are usually fun to use in adventures, and often attract attention.

Hotsprings

Signs of current volcanic activity, these regions have hotsprings, geysers, and fumaroles (vents emitting gases and steam). Although they attract tourists, they are also often sued to provide treatement for illnesses and to supply heat and hot water to local communities.

Example: Beppu Thermal Area, Japan; Whakarewarewa, New Zealand

Example Description (fumarole): The boiling pond of mud emits grotesque bubbles of mud, while nearby, amidst the gray stones, a puff of steam and hot water tops an bubbling spout.

Example Description (geyser): The water in the nearby pool begins to boil over, then steam and spray shoot from a nearby cone, the reservoir emptying itself from somewhere below the surface.

Example Description (travertine): Like a frozen waterfall, multicolored draperies of hardened minerals spill from the edge of a steaming hotspring.

Volcanoes

These broad, often snow-capped cones tower above the landscape, often emitting jets of steam or toxic gases into the atmosphere. Often the region surrounding the volcano is subject to tremors and shakes, sometimes on a daily basis. This does not stop civilizations from cropping up around these giants, in fact many early civilizations see them as monuments to the gods.

Example: Mount Etna, Italy;

Example Description: Looming over the small city, the majestic peak of this restless mountain is wreathed in vapor, said to be the breath of the gods that reside there.

Example Description: Hidden inside the crater walls is a desolate tormented place, the floor pockmarked with numeroud domelike hillocks painted in garish combinations of ochre, yellow and red. A multitude of hotsprings hiss and bubble with boiling water and churning mud. Violent bursts of steam surround a central toxic pool of sulfurous water.