Cross what? Sandstone was formed from sand that became washed or blown into place and later cemented together by waterborne minerals to become solid rock. Crossbedding refers to a specific type of layering which is noticeable in many sandstone deposits. In the picture above, notice the flat horizontal line and then the layers dipping downward to the left. This is typical crossbedding. Measuring the angle that the layers dip can give a clue as to what deposited the sand. Studies indicate that wind-deposited sand (think Sahara sand dunes) is frequently 30 to 37 degrees. Water-deposited sand is typically less than 30 degrees. The crossbedding in the photo above of the Entrada sandstone measures about 25 degrees. From that we get a good clue that this sandstone was deposited under water.
Where we have been able to measure the angles in the Wingate and Entrada Sandstones of the Colorado National monument, we have found angles of 25 degrees or less. This is significant. According to the prevailing view, the Wingate and Entrada sandstones were formed over millions of years from huge wind-blown sand dunes. The angle of crossbedding, however, indicates that it was deposited underwater by strong currents. Such deposition would not take long and could have easily been completed during the yearlong Noahic Flood.
Researchers have found the same thing with the huge layers of Navaho Sandstone at Zion National Park and with the Coconino Sandstone found in the Grand Canyon. Both of these deposits cover vast areas of the United States and are usually referred to as cemented Sahara-type sand dunes. Considerations such as individual sand particle size, shape, and features thought to be pitting from abrasion have been advanced as proof of a wind origin of the sandstone. However, recent research1 by Dr. John H. Whitmore focused on the angle of crossbedding, particle size, particle shape, as well as mineral content (particularly mica which is quickly destroyed in a windblown environment). His conclusion was that Coconino sandstones are more consistent with a water dune deposition.
More research on hundreds of samples needs to be undertaken to apply these analysis methods to the sandstones at the Colorado National Monument. Considering the angle of crossbedding observed here, we would predict that when preconceived ideas and blanket assumptions are removed, the research will be consistent with a water dune origin just like the other major sandstones mentioned above. But what kind of event can explain massive water dunes over large sections of North America? (Hint: check out Genesis chapters 6 through 8 in the Bible).
1Dr. John H. Whitmore, “Mica, Mica in the Sand, Tell Us Something Really Grand”, Answers magazine, Vol. 14 No. 5, pp 26-29. https://answersingenesis.org/answers/magazine/
Here are some other examples and info on crossbedding: