generate questions: Underpinning Houston's land surface are unconsolidated clays, clay shales, and poorly cemented sands up to several miles deep. The region's geology developed from river deposits formed from the erosion of the Rocky Mountains. These sediments consist of a series of sands and clays deposited on decaying organic marine matter, that over time, transformed into oil and natural gas. Beneath the layers of sediment is a water-deposited layer of halite, a rock salt. The porous layers were compressed over time and forced upward. As it pushed upward, the salt dragged surrounding sediments into salt dome formations, often trapping oil and gas that seeped from the surrounding porous sands. The thick, rich, sometimes black, surface soil is suitable for rice farming in suburban outskirts where the city continues to grow.
What materials are underpinning the land surface of Houston? {sep_token} Houston's geology was formed from river deposits from the erosion of what mountains? {sep_token} The sand and clay deposited onto decaying marine matter transformed into what? {sep_token} What is halite? {sep_token} What type of farming is Houston's surface soil good for? {sep_token} Besides sands, what are the foundations of Houston's land? {sep_token} How deep are the clay and sands foundations of Houston? {sep_token} What geological event caused the foundations of the land beneath Houston? {sep_token} What agricultural crop was farmed in the rich soils on the outlying areas of Houston? {sep_token} What did the decaying organics under the clay and sand deposits later form?