Scenery of Beaches & Coast of Kaua'i & Lana'i.
Garden of the Gods, northwestern Lana'i.
The rounded boulders in the photograph are the remnants of basaltic lava that erupted from a rift zone on the north end of the island. As the basalt was eroded by rainfall and stream flow, the more resistant erosional particles formed large rounded cobbles and boulders, while the less resistant material formed a finer-grained red laterite clay soil.
As the erosional process continued, the boulders and cobbles came to rest on the strongly weathered soil. Looking at the base of a boulder you can see concentric "rinds" 2-4 cm thick that mark the transition from the resistant stone to the deeply weathered lateritic soil (see the following photographs). On many of the larger boulders you can see scooped-out cusps and indentations where weathering has penetrated the stone more deeply.
When water permeates the outer 2 or 2 cm of the resistant rock it dissolves the minerals, leaching out the calcium and sodium and forming aluminum- and silica-rich clay. Eventually even the silica is dissolved, leaving only the iron-rich laterite clay. It is the laterite that accounts for the characteristic brownish-red color of the soil.
The rounded boulders in the photograph are the remnants of basaltic lava that erupted from a rift zone on the north end of the island. As the basalt was eroded by rainfall and stream flow, the more resistant erosional particles formed large rounded cobbles and boulders, while the less resistant material formed a finer-grained red laterite clay soil.
As the erosional process continued, the boulders and cobbles came to rest on the strongly weathered soil. Looking at the base of a boulder you can see concentric "rinds" 2-4 cm thick that mark the transition from the resistant stone to the deeply weathered lateritic soil (see the following photographs). On many of the larger boulders you can see scooped-out cusps and indentations where weathering has penetrated the stone more deeply.
When water permeates the outer 2 or 2 cm of the resistant rock it dissolves the minerals, leaching out the calcium and sodium and forming aluminum- and silica-rich clay. Eventually even the silica is dissolved, leaving only the iron-rich laterite clay. It is the laterite that accounts for the characteristic brownish-red color of the soil.
Garden of the Gods, northwestern Lana'i.
The rounded boulders in the photograph are the remnants of basaltic lava that erupted from a rift zone on the north end of the island. As the basalt was eroded by rainfall and stream flow, the more resistant erosional particles formed large rounded cobbles and boulders, while the less resistant material formed a finer-grained red laterite clay soil.
As the erosional process continued, the boulders and cobbles came to rest on the strongly weathered soil. Looking at the base of a boulder you can see concentric "rinds" 2-4 cm thick that mark the transition from the resistant stone to the deeply weathered lateritic soil (see the following photographs). On many of the larger boulders you can see scooped-out cusps and indentations where weathering has penetrated the stone more deeply.
When water permeates the outer 2 or 2 cm of the resistant rock it dissolves the minerals, leaching out the calcium and sodium and forming aluminum- and silica-rich clay. Eventually even the silica is dissolved, leaving only the iron-rich laterite clay. It is the laterite that accounts for the characteristic brownish-red color of the soil.
The rounded boulders in the photograph are the remnants of basaltic lava that erupted from a rift zone on the north end of the island. As the basalt was eroded by rainfall and stream flow, the more resistant erosional particles formed large rounded cobbles and boulders, while the less resistant material formed a finer-grained red laterite clay soil.
As the erosional process continued, the boulders and cobbles came to rest on the strongly weathered soil. Looking at the base of a boulder you can see concentric "rinds" 2-4 cm thick that mark the transition from the resistant stone to the deeply weathered lateritic soil (see the following photographs). On many of the larger boulders you can see scooped-out cusps and indentations where weathering has penetrated the stone more deeply.
When water permeates the outer 2 or 2 cm of the resistant rock it dissolves the minerals, leaching out the calcium and sodium and forming aluminum- and silica-rich clay. Eventually even the silica is dissolved, leaving only the iron-rich laterite clay. It is the laterite that accounts for the characteristic brownish-red color of the soil.