A large sink hole formed overnight Thursday in the swamps below La. 70 South in a part of northern Assumption Parish where unexplained gas bubbles have been rising from nearby bayous and tremors have been felt for more than two months, a parish official said Friday.

The formation of the hole was also accompanied Friday morning with a slight diesel smell in the area that has since dissipated, the parish official said.

John Boudreaux, director of the parish Office of Homeland Security and Emergency Preparedness, estimated the sinkhole is about 200 feet by 200 feet.

He said it is on private land near the Texas Brine Co., LLC facility but said he did not know at this point on whose land the hole is actually located.

Two calls to Texas Brine Friday morning went unanswered.

Boudreaux said trees have fallen into the sink hole, which is basically mud inside.

Boudreaux could not yet say how deep the hole is.

Natural gas has been seeping up from Bayou Corne and Grand Bayou, which run below and along the side of the area of the reported sink hole. A suspected water well in the same area has also been venting natural gas.

Residents have also reported contemporaneous tremors in the area, which has a known fault and a salt dome that is mined for brine and used to store natural gas and other hydrocarbons.

Federal, state and parish official have been unable so far to pin down the cause of the earthquakes or the source of the natural gas releases, despite of battery of tests on the oil, gas and brine production infrastructure in the area.

It is not clear at this point whether the smell and sinkhole are related to the natural gas bubbles, the earth tremors or each other.