I have to write a brief geological history of a region starting with the oldest events schist being the earlisest and then i have sandstone and gabbro, could you see if what i have wrote is correct

The schist would have probably originally been deposited first as a layer of mudstone, which through metamorphism formed into the layer of schist. An unknown layer of rock above the schist would have been present for the gabbro to then intrude into it (it could have formed by rapid cooling on the surface). Then through erosion/ weathering, the layers of rock above the schist would have eventually exposed the upper part of gabbro intrusion, finally more than one layer of sandstone would have been deposited and lithified (by being compacted and cemented) to form sandstone. I would assume the sandstone wasn’t present when the intrusion took place because it hasn’t gone through the phase of metamorphism

Based on your description, it seems like you have a good understanding of the geological processes that could have led to the formation of schist, gabbro, and sandstone in your region. However, it's important to note that without specific geological observations or data, we can only speculate about the processes that may have occurred.

Here's a breakdown of the events you described:

1. Schist Formation: Your idea that the schist may have initially been deposited as mudstone and later metamorphosed into schist is plausible. Metamorphism typically occurs under high temperatures and pressures, transforming existing rocks into different types.

2. Gabbro Intrusion: It is possible that a layer of rock was present above the schist, and the gabbro intruded into it. Gabbro is an igneous rock that forms from magma cooling slowly beneath the Earth's surface. In this case, the rock above the schist could have been eroded or weathered away, exposing the upper part of the gabbro intrusion.

3. Sandstone Deposition: After the gabbro intrusion, layers of rock above it could have been eroded further over time. The resulting sediments may have been transported and deposited, eventually forming multiple layers of sandstone. These layers could have been lithified through compaction and cementation to become solid sandstone.

It's important to note that the specific sequence and timing of events in geological history can vary greatly depending on the region and geological processes involved. Therefore, it is always best to consult local geological maps, studies, or experts to obtain accurate information regarding the geological history of your region.