The River Loop Trail at Black Hawk State Historic Site in Rock Island, Illinois, has exposures revealing nearly 130 million years of geologic history. At the base of the hill is Devonian-aged limestone containing brachiopods and bryozoans. Above the limestone is Pennsylvanian-aged shale, with an unconformity between the two. The black shale is rich with fossils of ferns and marsh grasses. Directly on top of the shale is Pennsylvanian-aged sandstone. Using the geologic materials described, determine the environment of deposition for each unit. How has the overall environment changed from the Devonian to the end of the Pennsylvanian?
Answers: 3
Geography, 23.06.2019 14:30
Why slip off slopes are found on the inside of meanders? why river cliffs are found on the outside of meanders?
Answers: 1
Geography, 24.06.2019 12:30
Gains you more knowledge intensify your soft skills strong ethics and grows your network
Answers: 1
Geography, 24.06.2019 13:00
The french to push mexican leader benito juarez out of blank . a) the oil industry b) poverty c)power
Answers: 2
The River Loop Trail at Black Hawk State Historic Site in Rock Island, Illinois, has exposures revea...
History, 14.07.2021 01:00
Mathematics, 14.07.2021 01:00
English, 14.07.2021 01:00
English, 14.07.2021 01:00
Mathematics, 14.07.2021 01:00
Mathematics, 14.07.2021 01:10
Mathematics, 14.07.2021 01:10
Health, 14.07.2021 01:10
Mathematics, 14.07.2021 01:10
Mathematics, 14.07.2021 01:10