Over 120 million years ago, a single mass of granite punched through the Earth’s crust and intruded into the heart of the Namib Desert in what is now northern Namibia. Today the mountain of rock called the Brandberg Massif towers over the arid desert below. A ring of dark, steep-sided rocks forced upward during the mountain’s arrival encircles the granite intruder.
The locals call it Dâures—the burning mountain. Its volcanism has long since stilled, but the granite core left behind apparently glows red in the light of the setting sun. The formation is a remnant of a long period of tumultuous volcanic and geologic activity on Earth during which the southern super-continent of Gondwana was splitting apart.
The mountain influences the local climate, drawing more rain to its flanks than the desert below receives. The rain filters into the mountain’s deep crevices and slowly seeps out through springs. Unique plant and animal communities thrive in its high-altitude environment, and prehistoric cave paintings decorate walls hidden in the steep cliffs that gouge the mountain.
To the southwest of Brandberg Massif, an older and more-eroded granite intrusion blends in subtly with the desert landscape, while along the Ugab River at upper left, cracks line the brown face of an ancient plain of rock transformed into gneiss by heat, pressure, and time.
This image was acquired by Landsat 7’s
Enhanced Thematic Mapper plus (ETM+) sensor.
Image provided by the
USGS EROS Data Center Satellite Systems
Branch as part of the Earth as Art II image series
The Colorado Plateau of Arizona, Colorado, New Mexico, and Utah is made of mostly flat-lying layers of sedimentary rock that record paleoclimate extremes ranging from oceans to widespread deserts over the last 1.8 billion years. Navajo Mountain in southeastern Utah is a dome-shaped chunk of igneous rock that intruded into the sedimentary layers and lifted up the overlying layer. Navajo Mountain is one of several of these rock formations, called laccolith by geologists, in southeastern Utah’s portion of the Plateau. This oblique (from-the-side) astronaut photograph highlights Navajo Mountain in the center of the image, surrounded by light red-brown Navajo Sandstone (also visible in the canyon at bottom of the image). The igneous rock at the core of the mountain is wrapped in sedimentary layers. The peak of Navajo Mountain, at approximately 3,148 meters (10,388 feet) elevation, is comprised of uplifted Dakota Sandstone deposited during the Cretaceous Period (approximately 66-138 million years ago).
This detailed astronaut photograph depicts a portion of the Gila River channel in south-central Arizona. The northernmost boundary of the Sentinel Volcanic Field is visible in the image, recognizable by the irregular flow fronts of thin basalt lava flows. Active agricultural fields along the Gila River are a rich green set against the surrounding desert.